Upload
others
View
13
Download
0
Embed Size (px)
Citation preview
Preparation and characterization of electrodeposited
Cu4SnS4 thin films
By
ASSOCIATE PROFESSOR DR HO SOONMIN
2017
Ideal International E-Publication Pvt. Ltd. www.isca.co.in
427, Palhar Nagar, RAPTC, VIP-Road, Indore-452005 (MP) INDIA
Phone: +91-731-2616100, Mobile: +91-80570-83382
E-mail: contact@ isca.co. in , Website: www.isca.co. in
Title: Preparation and characterization of electrodeposited Cu4SnS4 thin films
Author : DR HO SOONMIN
Edition: First
Volume: I
© Copyright Reserved 2017
All rights reserved. No part of this publication may be reproduced, stored, in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, reordering or otherwise, without the prior permission of the publisher.
ISBN: 978-81-934005-0-0
Preparation and characterization of electrodeposited Cu4SnS4 thin films iii
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Table of content
Pages
Chapter 1: Introduction 1-7
Chapter 2: Literature review 8-17
Chapter 3: Materials and Methods 18-25
Chapter 4: Cyclic voltammetry studies 27-33
Chapter 5: Electro deposition method 34-68
Preparation and characterization of electrodeposited Cu4SnS4 thin films 1
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
CHAPTER 1: INTRODUCTION
Is this solar energy will appear to be one of the most promising ways to meet the
energy demands of the future? Is this the thin films solar cells can replace the silicon solar
cells in one day? The answer absolutely is yes. The availability of cheap sources of primary
energy is a reliable indicator of the standard of living in any country of the world. Worldwide
energy demand is predicted to keep growing with the world population and with the standard
of living that can be afforded. In today’s world, fossil and nuclear fuels are the world’s
primary energy sources. The global resources of fossil fuels are limited and their
consumption implies emission of the greenhouse gases like carbon dioxide, which is of major
concern since global warming seems to be emerging as a reality.
The solar cells are considered a major candidate for obtaining energy from the sun,
since it can convert sunlight directly to electricity. Recently, the use of photoelectrochemical
solar cells leads to a large amount of research on the search for metal chalcogenide thin films
[1-20] with acceptable efficiency. The binary, ternary and quaternary chalcogenides have
potential application in solar energy conversion. These materials to be potential candidates in
solar cells due to the band gap energy between 0.9 to 2.5 eV [21-36]. Thin films have been
prepared by various techniques such as chemical bath deposition, electrodeposition,
molecular beam epitaxy, close spaced sublimation, sputter deposition and metal organic
chemical vapor deposition. Among these techniques, electrodeposition and chemical bath
deposition method are more attractive since these methods offer the advantages of simple,
low-cost and convenient for large area deposition.
Up-to-date, the solar cells include both crystalline silicon solar cells and new thin-film
technologies such as cadmium telluride and copper indium gallium diselenide. The high
growth rate of thin film production and increase of the total production share indicate that the
thin film technology is gaining more and more acceptance. Currently, there are more than 130
companies which are involved in the thin film solar cells production process ranging from
research and development activities to major manufacturing plants. At present, the most
common material used in photovoltaic technology is silicon. The ongoing shortage in silicon
feedstock and the market entry of companies offering turn-key production lines for thin film
solar cells led to a massive expansion of investments into thin film capacities.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 2
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
1.1 Solar cells technology
The conversion of sunlight directly into electricity using the photovoltaic properties of
suitable materials is the most elegant energy conversion process. A laboratory curiosity for
more than a hundred years, solar cell technology has seen enormous development during the
last three decades, initially in providing electrical power for space craft, and satellite.
Furthermore, more recently for terrestrial systems such as aero plane, housing area, charger,
flash light, security camera, hand phone, watch, golf car, street light, calculator, radio and
boat.
1.2 History of solar cells
The photovoltaic effect was discovered by Alexandre-Edmond Becquerel in 1839.
This was the starting of the solar cell technology. Two electrodes were illuminated with
various types of light in his experiment. The electrodes were coated by light sensitive
materials such as AgCl and carried out in a black box surrounded by acid solution. He found
that the electricity increased when the light intensity was increased.
1.3 Crystalline silicon solar cells
In 1954, Gerald Pearson, Daryl Chapin and Calvin Fuller discovered a crystalline
silicon solar cell in Bell laboratories. This was the first material to directly convert sunlight
into electricity to run electrical devices. Initially, the efficiency of their material was 4%
which later successfully increased to 11%.
On the other hand, the scientists from RCA laboratories produced the first amorphous
silicon solar cells in 1976. This material was less expensive as compared with crystalline
silicon devices. However, the efficiency was only about 1 %. In 1985, the researchers from
University of South Wales successfully increased the efficiency of solar cells to 20%.
Currently, this type of solar cell has laboratory energy conversion efficiencies over 25 %.
1.4 Metal chalcogenide thin films
Thin film materials usually have high absorption coefficients so that most of the light
can be absorbed in a layer of about 1 m or less. The main advantage of thin films based
solar cell is their promise of lower costs, since less energy for processing and relatively lower
Preparation and characterization of electrodeposited Cu4SnS4 thin films 3
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
costs for the materials are required and large scale production is feasible. Also, the metal
chalcogenide thin films should be low cost, non-toxic, robust and stable. The metal
chalogenides can produce either n-type or p-type semiconductor. Generally, p-type material
is preferred because electrons in many cases have a higher mobility and the materials
therefore exhibit a higher minority carrier length.
The CdTe thin films have been used in solar cells application since 1980. The
efficiency of solar cell made from CdTe is 15 % due to its direct bandgap at 1.5 eV at room
temperature. These films could be deposited on a substrate using electrodeposition, chemical
surface deposition and vapor transport deposition method. Currently, First Solar crushed the
conversion efficiency mark for CdTe with a world record 21.5%.
In 1980, the first cadmium sulphide thin film solar cells exceeds 10% efficiency was
produced in University of Delaware. But, cadmium is a highly toxic substance which can
accumulate in food chains. Therefore, many researchers are currently investigating cadmium-
free thin film solar cells such as copper indium gallium diselenide (CIGS). The best
efficiecny achieved 21.7 % as reported by Flisom in 2014.
1.5 Dye-sensitized solar cells
The dye-sensitized solar cell is a relatively new class of low cost photovoltaic cells as
reported by many researchers [37-40]. It is based on semiconductor produced between a
photo-sensitized anode and an electrolyte. The dye-sensitized solar cell is attractive due to it
is made of low-cost materials and does not require elaborate apparatus to manufacture. Its
manufacture could be significantly less expensive than older solid-state cell designs.
Nowadays, the efficiency of these type solar cells can be achieved more than 10%.
Basically, the titanium dioxide became the semiconductor of choice. The material has
many benefits such as low cost, widely available and non-toxic. The titanium dioxide covered
with a molecular dye that absorbs sunlight. In the photoelectrochemical system, the titanium
dioxide (anode) and platinum (cathode) were immersed under an electrolyte solution.
The sunlight passes via the transparent electrode into the dye layer then excite
electrons that flow into the titanium dioxide. The electrons flow toward the transparent
electrode where they are collected for powering a load. After flowing through the external
circuit, they are re-introduced into the cell on a metal electrode on the back, flowing into the
electrolyte. The electrolyte then transports the electrons back to the dye molecules. The dye
Preparation and characterization of electrodeposited Cu4SnS4 thin films 4
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
molecules are quite small, in order to capture sunlight, the layer of dye molecules needs to be
made fairly thick, normally, much thicker than the molecules themselves.
References:
1. Bhaskar, P.U., Babu, G.S., Vanjari, S.R., & Kumar, Y.B.K. (2013). Growth and
characterization of Cu2ZnSnSe4 thin films by a two-stage process. Solar Energy
Materials and Solar Cells, 115, 181-188.
2. Kunihiko, T., Noriko, M., & Hisao, U. (2007). Preparation of Cu2ZnSnS4 thin films
by sulfurizing sol gel deposited precursors. Solar Energy Materials and Solar Cells,
91, 1199-1201.
3. Lugo, S., Sanchez, Y., Espindola, M., Oliva, F., Roca, V., Pena, Y., & Saucedo, E.
(2017). Cationic compositional optimization of CuIn(S1-ySey)2 ultra-thin layers
obtained by chemical bath deposition. Applied Surface Science, 404, 57-62.
4. Anuar, K., Ho, S.M., Atan, S., & Saravanan, N. (2010). X-ray diffraction and atomic
force microscopy studies of chemical bath deposited FeS thin films. Studia
Universitatis Babes-Bolyai Chemia, 55, 5-11.
5. Hossain, M.S., Kabir, H., Rahman, M.M., Hasan, K., & Bashar, M.S. (2017).
Understanding the shrinkage of optical absorption edges of nanostructured Cd-Zn
sulphide films for photothermal applications. Applied Surface Science, 392, 854-862.
6. Ho, S.M., Anuar, K., Tan, W.T., Abdul, H.A., & Saravanan, N. (2010). Deposition
and characterization of Cu4SnS4 thin films by chemical bath deposition method.
Macedonian Journal of Chemistry and Chemical Engineering, 29, 97-103.
7. Olgar, M.A., Basol, B.M., Atasoy, Y., Tomakin, M., Aygun, G., Ozyuzer, L., &
Bacaksiz, E. (2017). Effect of heat treating metallic constituents on the properties of
Cu2ZnSnSe4 thin films formed by a two-stage process. Thin Solid Films, 624, 167-
174.
8. Saravanan, N., Anuar, K., Ho, S.M., Tan, W.T., & Dzulkefly, K. (2007). Cyclic
voltammetry study of copper tin sulfide compounds. Pacific Journal of Science and
Technology, 8, 252-260.
9. Sabah, F.A., Ahmed, N.M., & Hassan, Z. (2017). Effects of concentration and
substrate type on structure and conductivity of p-type CuS thin films grown by spray
pyrolysis deposition. Journal of Electronic Materials, 46, 218-225.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 5
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
10. Saravanan, N., Anuar, K., Ho, S.M., Abdul, H.A., & Noraini, K. (2010). Influence of
the deposition time on the structure and morphology of the ZnS thin films
electrodeposited on indium tin oxide substrates. Digest Journal of Nanomaterials and
Biostructures, 5, 975-980.
11. Fatas, E., Herrasti, P., Medina, J.A., & Arjona, F. (1987). Electrodeposition and
characterization of CdS thin films on stainless steel and tin oxide substrates.
Electrochimica Acta, 32, 139-148.
12. Haron, M.J., Anuar, K., Ho, S.M., & Atan, S. (2011). The effect of the pH value on
the growth and properties of chemical bath deposited SnS thin films. Research
Journal of Chemistry and Environment, 15, 45-48.
13. Cuevas, A., Romero, R., Dalchiele, E.A., Ramos, J.R., Martin, F., & Leinen, D.
(2016). Spectrally selective CuS solar absorber coatings on stainless steel and
aluminium. Surface and Interface Analysis, 48, 649-653.
14. Anuar, K., Ho, S.M., Tan, W.T., Atan, S., and Saravanan, N. (2011). Chemical bath
deposition of ZnSe thin films: SEM and XRD characterization. European Journal of
Applied Sciences, 3, 113-116.
15. Sun, K., Liu, F., Yan, C., Zhou, F., Huang, J., Shen, Y., Liu, R., & Hao, X. (2016).
Influence of sodium incorporation on kesterite Cu2ZnSnS4 solar cells fabricated on
stainless steel substrates. Solar Energy Materials and Solar Cells, 157, 565-571.
16. Pujari, R.B., Lokhande, A.C., Kim, J.H., & Lokhande, C.D. (2016). Bath temperature
controlled phase stability of hierarchical nanoflakes CoS2 thin films for
supercapacitor application. RSC Advances, 6, 40593-40601.
17. Anuar, K., Tan, W.T., & Ho, S.M. (2013). Thickness dependent characteristics of
chemically deposited tin sulfide films. Universal Journal of Chemistry, 1, 170-174.
18. Dhaygude, H.D., Chikode, P.P., Shinde, S.K., Shinde, N.S., & Fulari, V.J. (2017).
Evaluation of the holographic parameters by electrosynthesized CdxZn1-xS(X=0.3)
thin films using double exposure digital holographic interferometry technique. Optics
& Laser Technology, 88, 194-197.
19. Ho, S.M., Anuar, K., Loh, Y.Y., & Saravanan, N. (2010). Structural and
morphological characterization of chemical bath deposition of FeS thin films in the
presence of sodium tartrate as a complexing agent. Silpakorn University Science and
Technology Journal, 4, 36-42.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 6
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
20. Shaji, S., Garcia, L.V., Loredo, S.L., Krishnan, B., Martinez, J.A., Roy, T.K., &
Avellaneda, D.A. (2017). Antimony sulfide thin films prepared by laser assisted
chemical bath deposition. Applied Surface Science, 393, 369-376.
21. Ho, S.M., Saravanan, N., Anuar, K., & Tan, W.T. (2012). Temperature dependent
surface topography analysis of SnSe thin films using atomic force microscopy. Asian
Journal of Research in Chemistry, 5, 291-294.
22. Ho, S.M. (2014). Atomic force microscopy investigation of the surface morphology
of Ni3Pb2S2 thin films. European Journal of Scientific Research, 125, 475-480.
23. Mobarak, M., & Shaban, H.T. (2014). Characterization of CuInTe2 crystals. Materials
Chemistry and Physics, 147, 439-442.
24. Roy, S., Bhattacharjee, B., Kundu, S.N., Chaudhuri, S., & Pal, A.K. (2003).
Characterization of CuInTe2 thin film synthesized by three source co-evaporation
technique. Materials Chemistry and Physics, 77, 365-376.
25. Ananthan, M.R., & Kasiviswanathan, S. (2009). Growth and characterization of
stepwise flash evaporated CuInTe2 thin films. Solar Energy Materials and Solar
Cells, 93, 188-192.
26. Kazmerski, L.L., & Juang, Y.J. (1998). Vacuum deposited CuInTe2 thin films:
Growth, structural and electrical properties. Journal of Vacuum Science and
Technology, DOI: http://dx.doi.org/10.1116/1.569265.
27. Boustani, M., Assali, K.E., Bekkay, T., & Khiara, A. (1997). Structural and optical
properties of CuInTe2 films prepared by thermal vacuum evaporation from a single
source. Solar Energy Materials and Solar Cells, 45, 369-376.
28. Manorama, L., Mahapatra, S.K., & Chaure, N.B. (2016). Development of CuInTe2
thin film solar cells by electrochemical route with low temperature (80 °C) heat
treatment procedure. Materials Science and Engineering B, 204, 20-26.
29. Lakhe, M., & Chaure, N.B. (2014). Characterization of electrochemically deposited
CuInTe2 thin films for solar cell applications. Solar Energy Materials & Solar Cells,
123, 122-129.
30. Dixit, P., Kavita, D., Ashok, K.S., Vikas, T., & Poolla, R. (2013). Electrochemical
growth and studies of indium rich CuInTe2 thin films. International Journal of
Materials Science and Applications, 3, 1-5.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 7
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
31. Cham, K., Dong, H.K., Young, S.S., Kim, H., Jea, Y.B., & Yoon, S.H. (2012).
Solvothermal synthesis and characterization of a CuInTe2 absorber for thin film
photovoltaics. Materials Research Bulletin, 47, 4054-4058.
32. Tembhurkar, Y.D. (2016). Annealing effect on structural and electrical properties of
CuInTe2 thin films. International Journal of Scientific Research, 5, 504-506.
33. Prabukanthan, P., Asokan, K., Avasthi, D.K., & Dhanasekaran, R. (2007). Effect of
80 MeV Au8+ ions irradiation on CuInTe2 single crystals grown by CVT technique.
Materials Science in Semiconductor Processing, 10, 252-257.
34. Galindo, H., Hanus, F., Joliet, M.C., Vincent, A.B., & Laude, L.D. (1989). Laser
induced synthesis of CuInTe2. Proc. SPIE 1022, Laser Assisted Processing, 77 (April
10, 1989); doi:10.1117/12.950104.
35. Zedan, I.T., & El-Menyawy, E.M. (2016). Illumination induced changes on the
optical functions and valence band splitting parameters of flash evaporated CuInTe2
films. Optik, 127, 1301-1306.
36. Neelima, A.P., Manorama, L., & Chaure, N.B. (2012). Characterization of CuInTe2
thin films deposited by electrochemical technique. AIP Conference Proceedings, doi:
10.1063/1.4710378.
37. Bayram, K., Sunay, T., Oguz, C.O., Mansur, A., Ozge, B., Gokhan, S., Aykut, A., &
Duygu, E. (2016). Produce of graphene/iron pyrite (FeS2) thin films counter electrode
for dye-sensitized solar cell. Materials Letters, 185, 584-587.
38. Supriya, A.P., Naveed, M., Anam, A.M., Sung, H.J., & Kim, H. (2017). CuS thin film
grown using the one pot, solution process method for dye sensitized solar cell
applications. Journal of Alloys and Compounds, 708, 568-574.
39. Haider, A., Basil, A.Mahdi, M.A., Hassan, J.J., & Jennings, P. (2017). Fabrication
and characterization of nanowalls CdS/dye sensitized solar cells. Physica E: Low
Dimensional Systems and Nanostructures, 90, 104-108.
40. Yao, Y., Chao, H., Chang, J., Chou, T., Chang, S., Wu, C., & Ling, Y. (2016). In situ
fabrication of Co0.85Se and Ni0.85Se hierarchical thin films as high performance
counter electrode for dye sensitized solar cells. Solar Energy, 137, 401-408.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 8
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
CHAPTER 2: LITERATURE REVIEW
There are many review articles [1-26] and research articles related to preparation of
thin films. Generally, deposition techniques could be categorized into two groups, namely
physical method and chemical deposition technique. These deposition methods have been
employed by many researchers from around the world to synthesize binary, ternary and
quaternary thin films.
2.1 Thin film deposition methods
Thin film deposition is any method for depositing a thin film of material onto
substrates. There are two categories of thin film processes, namely chemical and physical
process. The example of chemical process such as chemical vapor deposition, chemical bath
deposition and electrodeposition while physical process like sputter deposition, vacuum
evaporation and pulsed laser deposition. The advantages and disadvantages of techniques
have been briefly summarized in Table 1. From such a table, it is not possible to point out the
best way of preparing a thin film. The method used must depend on the type of film required
and the limitation present on choice of substrates. The costs of deposition technique also play
an important role in determining the mass output of thin film products in market.
Table 1 The advantages and disadvantages of different deposition techniques
Chemical vapor deposition [27-29]
Advantages High growth rates possible
Can deposit materials which are hard to evaporate
Can grow epitaxial films
Disadvantages High temperature
Complex processes
Toxic and corrosive gasses
Chemical bath deposition [30-58]
Advantages Low cost
Unnecessary conductive substrate
Low elaboration temperature
Simple instrumentation
Easy coating of large surface
Preparation and characterization of electrodeposited Cu4SnS4 thin films 9
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Disadvantages Deposition lasts for very long time
Electrodeposition [59-63]
Advantages Simple and economical method
Large area deposition
Low temperature growth
Easy to monitor
Control film thickness, morphology by adjusting electrical parameters
Disadvantages The films must be prepared on conducting substrates
Sputtering [64-66]
Advantages Adhesion can be very strong due to high energy particles forcing into substrates
The source and substrates can be spaced close together
There is very little radiant heat in the deposition process
The sputtering target provides a stable, long-lived
vaporization source
Disadvantages Suitable target required
Vacuum required
Use a plasma
High capital expenses are required
Most of the energy incident on the target becomes heat.
Vacuum evaporation [67-69]
Advantages Deposition rate monitoring and control are relatively easy
High purity films, thicker layers with better crystallinity and
stoichiometry are produced
Disadvantages Vacuum apparatus required
Some materials decompose on heating
Poor surface coverage
Pulsed laser deposition [70-73]
Advantages High quality samples can be grown reliably in 10 minutes
One laser can serve many vacuum systems
The laser beam vaporizes a target surface, producing a film
with the same composition as the target
Disadvantages Debris generation and coating flux falling off rapidly with
distance from the source
Difficulty to controlling thickness uniformly across the samples
Preparation and characterization of electrodeposited Cu4SnS4 thin films 10
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
2.2 Electrodeposition method
Electrodeposition is a cost effective method of depositing thin films. It is also usually
a convenient method since all the elements deposited in a single step. There is no need for a
vacuum system and the process can be scaled very easily to any substrate size. Often, the
composition of the deposited material can be controlled through one or more of the
deposition parameters. However, the electrodeposition of ternary compounds is more
complex as they involve several deposition parameters which control the film properties such
as film structure and morphology. This is due to the possibility of the formation of
intermediate phases during electrodeposition.
2.3 Chemical bath deposition method
The chemical bath deposition is a low cost technique for the large area deposition of
thin film. The other advantages of this technique are simple and deposition at low
temperature. In most of the experimental approaches, substrates are immersed in an aqueous
solution (alkaline or acidic solution) containing the chalcogenide source, metal ion and
complexing agents. In chemical bath deposition, a complexing agent is used to bind the
metallic ions to avoid the homogeneous precipitation of the corresponding compound. The
formation of a complex ion is essential to control the rate of the reaction and to avoid the
immediate precipitation of compound in the solution. When the solution is saturated, the
ionic product is equal to solubility product. As the ionic product slowly exceeds the solubility
product the solution becomes supersaturated and precipitation occurs. The deposition begins
with nucleation phase followed by growth phase in which the thickness of film increases with
time.
References:
1. Major, J.D. (2016). Grain boundaries in CdTe thin film solar cells: a review.
Semiconductor Science and Technology, 31, doi:10.1088/0268-1242/31/9/093001.
2. Ho, S.M. (2015). Review on metal telluride thin films. Der Pharma Chemica, 7, 56-
60.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 11
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
3. Lee, TD., & Ebong, A. (2016). Thin film solar technologies: a review. 12th
International Conference on high capacity optical networks and Enabling/Emerging
Technologies.
4. Ho, S.M., & Anand, T.J.S. (2015). A review of chalcogenide thin films for solar cell
applications. Indian Journal of Science and Technology, 8, DOI:
10.17485/ijst/2015/v8i12/67499.
5. Karyn, L.J., & Peter, J. E. (2017). Growth of thin barrier films on flexible polymer
substrates by atomic layer deposition. Thin Solid Films, 624, 111-135.
6. Ho, S.M. (2015). Quaternary thin films: A review. Research Journal of chemistry and
Environment, 19, 48-52.
7. Chassaing, E., Guillemoles, J.F., & Lincot, D. (2009). From metals to
semiconductors: Challenges in electrodeposition for photovoltaic applications. ECS
Transaction, 19, 1-10.
8. Ho, S.M. (2015). Electro deposition of thin films in the presence of complexing agent:
A review. International Journal of Applied Chemistry, 11, 539-544.
9. Daniel, L., Taunier, S., Kerrec, O., & Guillemoles, J. (2004). Chalcopyrite thin film
solar cells by electrodeposition. Solar Energy, 77, 725-737.
10. Ho, S.M. (2016). A Brief review of the growth of pulsed laser deposited thin films.
British Journal of Applied Sciences and Technology, 14, 1-6.
11. Song, X., Ji, X., Li, M., Lin, W., Luo, X., & Zhang, H. (2014). A review on
development prospect of CZTS based thin film solar cells. International Journal of
Photoenergy, http://dx.doi.org/10.1155/2014/613173.
12. Ho, S.M. (2016). Transmission electron microscopy studies on chalcogenide thin
films: A review. Journal of Chemical and Pharmaceutical Research, 8, 71-74.
13. Mugle, D., & Jadhav, G. (2016). Short review on chemical bath deposition of thin
film and characterization. AIP Conference Proceedings, 1728,
DOI:10.1063/1.4946648.
14. Ho, S.M. (2015). Thermal evaporation of thin films: Review. Middle-East Journal of
Scientific Research, 23, 2695-2699.
15. Ezekoye, B.A., Offor, P.O., Ezekoye, V.A., & Ezema, F.I. (2013). Chemical bath
deposition technique of thin films: a review. International Journal of Scientific
Research, 2, 452-456.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 12
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
16. Ho, S.M. (2016). Metal selenide semiconductor thin films: A review. International
Journal of ChemTech Research, 9, 390-395.
17. Hodes, G. (2007). Semiconductor and ceramic nanoparticle films deposited by
chemical bath deposition. Physical Chemistry Chemical Physics, 9, 2181-2196.
18. Ho, S.M. (2016). Power conversion efficiency in thin film solar cell: Review.
International Journal of Chemical Sciences, 14, 143-151.
19. Pawar, S.M., Pawar, B.S., Kim, J.H., Jo, O., & Lokhande, C.D. (2011). Recent status
of chemical bath deposited metal chalcogenide and metal oxide thin films. Current
Applied Physics, 11, 117-161.
20. Ho, S.M. (2016). A review on the sputtering deposition film growth. Journal of
Applied Sciences Research, 12, 44-48.
21. Nair, P.K., Nair, M.T.S., Garcia, V.M., & Arenas, O.L. (1998). Semiconductor thin
films by chemical bath deposition for solar energy related applications. Solar Energy
Materials and Solar Cells, 52, 313-344.
22. Ho, S.M. (2015). Synthesis of binary metal chalcogenides using SILAR method:
Review. Chemical Science Review and Letters, 4, 1305-1310.
23. Mane, R.S., & Lokhande, C.D. (2000). Chemical deposition method for metal
chalcogenide thin films. Materials Chemistry and physics, 65, 1-31.
24. Ho, S.M. (2015). Spray pyrolysis deposition of thin films: Review. European Journal
of Scientific Research, 136, 446-450.
25. Lokhande, C.D. (1991). Chemical deposition of metal chalcogenide thin films.
Materials Chemistry and Physics, 27, 1-43.
26. Ho, S.M. (2016). A review on thin films on indium tin oxide coated glass substrate.
Asian Journal of Chemistry, 28,469-472.
27. Liesbeth, R., Ben, M., Frits, D.L., Joop, S., & Albert, G. (2005). Comparison of CuxS
films grown by atomic layer deposition and chemical vapor deposition. Chemistry of
Materials, 17, 2724-2728.
28. Sixberth, M., Linda, D.N., Peter, T.N., Azad, M., James, R., Paul, O., & Neerish, R.
(2015). Aerosol assisted chemical vapor deposition (AACVD) of CdS thin films from
heterocyclic cadmium (II) complexes. Inorganic Chimica Acta, 434, 181-187.
29. Punarja, K., David, J.L., James, R., Azad, M., & Paul, O. (2015). Thin films of tin (II)
sulphide (SnS) by aerosol assisted chemical vapour deposition (AACVD) using tin
Preparation and characterization of electrodeposited Cu4SnS4 thin films 13
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(II) dithiocarbamates as single source precursors. Journal of Crystal Growth, 415, 93-
99.
30. Hankare, P.P., Delekar, S. D., Bhuse, V.M., Garadkar, K.M., Sabane S.D., & Gavali,
L.V. (2003). Synthesis and characterization of chemically deposited lead selenide thin
films. Materials Chemistry and Physics, 82, 505-508.
31. Anuar, K., Tan, W.T., Ho, S.M., & Saravanan, N. (2011). Deposition and
characterization of ZnS thin films using chemical bath deposition method in the
presence of sodium tartrate as complexing agent. Pakistan Journal of Scientific and
Industrial Research, 54, 1-5.
32. Al-Mamun, & Islam, A.B.M.O. (2004). Characterization of copper selenide thin films
deposited by chemical bath deposition technique. Applied Surface Science, 238, 184-
188.
33. Anuar, K., Abdullah, A.H., Ho, S.M., Saravanan, N. (2010). Influence of deposition
time on the properties of chemical bath deposited manganese sulfide thin films,
Avances en Quimica, 5, 141-145.
34. Bari, R.H., Patil, L.A., Sonawane, P.S., Mahanubhav, M.D., Patil, V.R., & Khanna,
P.K. (2007). Studies on chemically deposited CuInSe2 thin films. Materials Letters,
61, 2058-2061.
35. Bhardwaj, A., Varadarajan, E., Srivastava, P., & Sehgal, H.K. (2008). Structural,
optical and electrical properties of chemically grown Pb1-xFexSe nanoparticle thin
films. Solid State Communications, 146, 53-56.
36. Anuar, K., Saravanan, N., Tan, T.W., Koon, K.L., & Ho, S.M. (2010). Effect of pH
value and electrolyte concentration on the copper sulphide thin films prepared by
chemical bath deposition method. Gazi University Journal of Science, 23, 435-443.
37. Cortes, A., Gomez, H., Marotti, R.E., Riveros, G., & Dalchiele, E.A. (2004). Grain
size dependence of the band gap in chemical bath deposited CdS thin films. Solar
Energy Materials & Solar Cells, 82, 21-34.
38. Anuar, K., Saravanan, N., Tan, W.T., Ho, S.M., & Teo, D. (2010). Chemical bath
deposition of nickel sulphide (Ni4S3) thin films. Leonardo Journal of Sciences, 16, 1-
12.
39. Ezema, F.I., & Osuji, R.U. (2007). Band gap shift and optical characterization of
chemical bath deposited CdSSe thin films on annealing. Chalcogenide Letters, 4, 69-
75.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 14
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
40. Anuar, K., Tan, W.T., Ho, S.M., Shanthi, M., & Saravanan, N. (2010). Effect of bath
temperature on the chemical bath deposition of PbSe thin films. Kathmandu
University Journal of Science, Engineering and Technology, 6, 126-132.
41. Ezema, F.I., & Osuji, R.U. (2007). Preparation and optical properties of chemical bath
deposited MnCdS2 thin films. FIZIKA A (Zagreb), 16, 107-116.
42. Gaewdang, N., & Gaewdang, T. (2005). Investigations on chemically deposited Cd1-
xZnxS thin films with low Zn content. Materials Letters, 59, 3577-3584.
43. Anuar, K., Ho, S.M., Loh, Y.Y., & Saravanan, N. (2010). Structural and
morphological characterization of chemical bath deposition of FeS thin films in the
presence of sodium tartrate as a complexing agent. Silpakorn University Science and
Technology Journal, 4, 36-42.
44. Khefacha, Z., Benzarti, Z., Mnari, M., & Dachraoui, M. (2004). Electrical and optical
properties of Cd1-xZnxS (0x0.18) grown by chemical bath deposition. Journal of
Crystal Growth, 260, 400-409.
45. Gumus, C., Ulutas, C., & Ufuktepe, Y. (2007). Optical and structural properties of
manganese sulfide thin films. Optical Materials, 29, 1183-1187.
46. Anuar, K., Tan, W.T., Jelas, M., Ho, S.M., & Gwee, S.Y. (2010). Effects of
deposition period on the properties of FeS2 thin films by chemical bath deposition
method. Thammasat International Journal of Science and Technology, 15, 62-69.
47. Hankare, P.P., Chate, P.A., Asabe, M.R., Delekar, S.D., Mulla, I.S., & Garagkar,
K.M. (2006). Characterization of Cd1-xZnxSe thin films deposited at low temperature
by chemical route. Journal of Materials Science: Materials in Electronics, 17, 1055-
1063.
48. Anuar, K., Ho, S.M., Tan, W.T., & Ngai, C.F. (2011). Influence of triethanolamine on
the chemical bath deposited NiS thin films. American Journal of Applied Sciences, 8,
359-361.
49. Mane, R.S., & Lokhande, C.D. (2002). Photoelectrochemical cells based on
nanocrystalline Sb2S3 thin films. Materials Chemistry and Physics, 78, 385-392.
50. Mane, R.S., Sankapal, B.R., Gadave, K.M., & Lokhande, C.D. (1999). Preparation of
CdCr2S4 and HgCr2S4 thin films by chemical bath deposition. Materials Research
Bulletin, 34, 2035-2042.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 15
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
51. Anuar, K., Abdul, H.A., Ho, S.M., & Saravanan, N. (2010). Effect of deposition time
on surface topography of chemical bath deposited PbSe thin films observed by atomic
force microscopy. Pacific Journal of Science and Technology, 11, 399-403.
52. Mane, R.S., Todkar, V.V., & Lokhande, C.D. (2004). Low temperature synthesis of
nanocrystalline As2S3 thin films using novel chemical bath deposition route. Applied
Surface Science, 227, 48-55.
53. Anuar, K., Tan, W.T., Ho, S.M., Abdul, H.A., Ahmad, H.J., & Saravanan, N. (2010).
Effect of solution concentration on MnS2 thin films deposited in a chemical bath.
Kasetsart Journal: Natural Science, 44, 446-453.
54. Prabahar, S., & Dhanam, M. (2005). CdS thin films from two different chemical
baths-structural and optical analysis. Journal of Crystal Growth, 285, 41-48.
55. Seghaier, S., Kamoun, N., Brini, R., & Amara, A.B. (2006). Structural and optical
properties of PbS thin films deposited by chemical bath deposition. Materials
Chemistry and Physics, 97, 71-80.
56. Sonawane, P.S., Wani, P.A., Patil, L.A., & Seth, T. (2004). Growth of CuBiS2 thin
films by chemical bath deposition technique from and acidic bath. Materials
Chemistry and Physics, 84, 221-227.
57. Ubale, A.U., Sangawar, V.S., & Kulkarni, D.K. (2007). Size dependent optical
characteristics of chemically deposited nanostructured ZnS thin films. Bulletin
Material Science, 30, 147-151.
58. Soundeswaran, S., Kumar, O.S., & Dhanasekaran, R. (2004). Effects of ammonium
sulphate on chemical bath deposition of CdS thin films. Materials Letters, 58, 2381-
2385.
59. Salim, H.I., Olusola, O.I., Ojo, A.A., Urasov, K.A., Dergacheva, M.B., &
Dharmadasa, I. (2016). Electrodeposition and characterization of CdS thin films using
thiourea precursors for application in solar cells, Journal of Materials Science:
Materials in Electronics, 1-14.
60. Anuar, K., Ho, S.M., Abdul, H.A., Noraini, K., & Saravanan, (2010). Influence of the
deposition time on the structure and morphology of the ZnS thin films
electrodeposited on indium tin oxide substrates. Digest Journal of Nanomaterials and
Biostructures, 5, 975-980.
61. Henriquez, R., Vasquez, C., Briones, N., Munoz, E., Leyton, P., & Dalchiele, E.A.
(2016). Single phase FeS2 (pyrite) thin films prepared by combined electrodeposition
Preparation and characterization of electrodeposited Cu4SnS4 thin films 16
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
and hydrothermal low temperature techniques. International Journal of
Electrochemical Science, 11, 4966-4978.
62. Anuar, K., Saravanan, N., Ho, S.M., & Noraini, K. (2010). XRD and AFM studies of
ZnS thin films produced by electrodeposition method. Arabian Journal of Chemistry,
3, 243-249.
63. Echendu, O.K., Okeoma, K.B., Oriaku, C.I., & Dharmadasa, I.M. (2016).
Electrochemical deposition of CdTe semiconductor thin films for solar cell
application using two electrode and three electrode configurations: a comparative
study. Advances in Materials Science and Engineering,
http://dx.doi.org/10.1155/2016/3581725.
64. Koshy, J. (1991). Electrical contact properties of CdSe thin films prepared by RF
sputtering from powder targets. Physica Status Solidi A, 126,
DOI: 10.1002/pssa.2211260236.
65. Dahi, A., Colson, P., Jamin, C., Cloots, R., Lismont, M., & Dreesen, L. (2016). Radio
frequency magnetron sputtering: a versatile tool for CdSe quantum dots depositions
with controlled properties. Journal of Materials and Environmental Science, 7, 2277-
2787.
66. Montes, J.I., Morales, A., Bernal, R., & Pulzara, A. (2016). Characterization of
CuInSe2 thin films obtained by RF magnetron Co-sputtering from CuSe and In
targets. Chalcogenide Letters, 13, 381-388.
67. Kazmerski, L.L., & Juang, Y.J. (1998). Vacuum deposited CuInTe2 thin films:
growth, structural and electrical properties. Journal of Vacuum Science and
Technology, 14, DOI: http://dx.doi.org/10.1116/1.569265.
68. Pawan, K., Aravind, K., Dixit, P.N., & Sharma, T.P. (2006). Optical, structural and
electrical properties of zinc sulphide vacuum evaporated thin film. Indian Journal of
Pure & Applied Physics, 44, 690-693.
69. Kathirvel, D., & Jeyachitra, R. (2016). Structural properties of vacuum evaporated
ZnS thin films. International Journal of Macro, and Nano Physics, 1, 57-69.
70. Zhang, W., Zeng, X., Lu, J., & Chen, H. (2013). Phase controlled synthesis and
optical properties of ZnS thin films by pulsed laser deposition. Materials Research
Bulletin, 48, 3843-3846.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 17
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
71. Sun, L., He, J., Kong, H., Yue, F., Yang, P., & Chu, J. (2011). Structure, composition
and optical properties of Cu2ZnSnS4 thin films deposited by pulsed laser deposition
method. Solar Energy Materials & Solar Cells, 95, 2907-2913.
72. Xin, Z.J., Peaty, R.J., Rutt, H.N., & Eason, R.W. (1999). Epitaxial growth of high
quality ZnS films on sapphire and silicon by pulsed laser deposition. Semiconductor
Science and Technology, 14, 695-698.
73. Yano, S., Schroeder, R., Ullrich, B., & Sakai, H. (2003). Absorption and photocurrent
properties of thin ZnS films formed by pulsed laser deposition on quartz. Thin Solid
Films, 423, 273-276.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 18
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
CHAPTER 3: MATERIALS AND METHODS
3.1 Chemicals used
All the chemicals used for the deposition were analytical grade without further
purification. The chemicals include copper sulfate (CuSO4, Ajax Chemical), tin chloride
(SnCl2, Merck), sodium thiosulfate (Na2S2O3.5H2O, Hamburg Chemical GmbH), potassium
hexacyanidoferrate (II) (K4[Fe(CN)6], BDH), Potassium hexacyanoferrate (III) (K3[Fe(CN)6],
BDH), sodium hydroxide (NaOH, Merck), ethanol (C2H5OH) and hydrochloric acid (HCl).
All the solutions were prepared using deionised water from Millipore Alpha-Q System.
3.2 Electrodeposition method
3.2.1 Electrochemical cells
Electrodeposition was carried out in a 100 mL electrochemical cell consisting of a three-
electrode system (Figure 3.1). The working electrode was indium tin oxide (ITO) coated
glass substrate while counter electrode was a platinum wire. A silver-silver chloride electrode
(Ag/AgCl) was used as a reference electrode and all potentials are given versus Ag/AgCl.
The reference electrode was placed as close as possible to the working electrode and counter
electrode as well. This is due to minimize cell resistance and maximize current flow between
counter electrode and working electrode. The cell is five-hole PVC covered attached directly
to a retort stand to accommodate a pH electrode, nitrogen gas tube, working electrode,
counter electrode and reference electrode.
Figure 3.1 The electrodeposition method set-up
Preparation and characterization of electrodeposited Cu4SnS4 thin films 19
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
3.2.2 Working electrode
The indium tin oxide coated glass substrates were used as a working electrode. The
ITO glass substrates were first cleaned in ethanol solution for 10 minutes to remove dirty and
oily substance from the surface. Then, it was cleaned with distilled water for 15 minutes in an
ultrasonic cleaner. Finally, it dried in desiccator prior to deposition. In this study, the ITO
glass obtained from the manufacturer (Samsung Corporation). The ITO glass was cut into
desired dimension (1cm x 2 cm) using a glass cutter.
3.2.3 Reference electrode
The silver-silver chloride electrode (Ag/AgCl) was chosen as the reference electrode
due to easily and cheaply prepared. It is also stable and quite robust. Its potential is 0.222 V
against standard hydrogen electrode. The Ag/AgCl reference electrodes are easily ruined by
drying. Keep the tips wetted at all times and store in 3 M NaCl when not in use.
3.2.4 Counter electrode
The platinum wire was used as the counter electrode during deposition. The surface
was polished with alumina slurry.
3.3 Cyclic voltammetry
Prior to the deposition process, cyclic voltammetry was used to monitor the
electrochemical reactions in solutions of CuSO4, SnCl2, Na2S2O3 and mixtures, in order to
find the suitable deposition potential range. All voltammetry curves were scanned first in the
cathodic direction and the positive current density indicates a cathodic current. Cyclic
voltammograms were carried out at a sweep rate of 10 mV/s using Bioanalytical System.
3.4 Electrodeposition process
Copper tin sulfide electrodeposition was carried out in an electrochemical cell
consisting of a three-electrode system under a potentiostatic mode. Aqueous solutions of
CuSO4, SnCl2 and Na2S2O3 were used as Cu2+, Sn2+ and S2- source, respectively. The nitrogen
gas was flowed into the solutions prior to mixing to remove any dissolved oxygen. The
deposition was carried out in an unstirred bath by varying deposition parameters such as
Preparation and characterization of electrodeposited Cu4SnS4 thin films 20
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
deposition potential, deposition time, deposition temperature, solutions concentration and
solution pH. After completed deposition, the films were rinsed with distilled water and were
used for further characterizations.
3.4.1 Investigation of different deposition potentials
The thin films were deposited from the solutions consisted of 20 mL of 0.01 M
CuSO4, 0.01 M SnCl2 and 0.01 M Na2S2O3. The pH was adjusted to pH 1.5 with hydrochloric
acid using pH meter. The deposition process was carried out for 45 min at 25 C. Based on
the cyclic voltammetry studies, the deposition process was done under various potentials
from -400 mV to -1000 mV versus Ag/AgCl.
3.4.2 Investigation of different deposition temperatures
In this experiment, the deposition process was done at a deposition potential of -600
mV versus Ag/AgCl under various bath temperatures from 25 to 50 C while other deposition
conditions were unchanged.
3.4.3 Investigation of different solutions concentration
In order to investigate the effect of electrolytes concentration on the thin film
properties, deposition at various concentrations was carried out. The first set of experiment
was carried out using constant concentration of 0.01 M of CuSO4, SnCl2 and varying
concentrations of Na2S2O3 (0.01 M – 0.02 M) solutions. The second set of experiment was
carried out using fixed concentration of 0.01 M of CuSO4, Na2S2O3 and varying
concentrations of SnCl2 (0.01 M – 0.02 M) solutions. The third set of experiment was carried
out using constant concentration of 0.01 M of SnCl2, Na2S2O3 and varying concentrations of
CuSO4 (0.01 M – 0.02 M) solutions.
3.4.4 Investigation of different deposition periods
In this experiment, the deposition process was done under various deposition periods
from 15 to 60 minutes while other conditions were unchanged.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 21
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
3.4.5 Investigation of different pH values
In this experiment, the deposition process was done under various pH values from 1.1
to 2.0. The pH was adjusted to desired value with hydrochloric acid using pH meter.
3.5 Characterization methods
There are several characterization tools were used in order to investigate the general
properties of thin films [1-32]. Material characterization on a nano or mirco scale is often an
essential part for understanding material behavior. Obviously, no one technique can ever
solve each surface problem. Therefore, two or more techniques were used by material
scientists in their investigation.
3.5.1 X-ray Diffraction (XRD)
The crystalline structure of thin films was examined using X-ray diffraction. The
position and the intensities of the peaks are used for identifying the underlying structure of
the materials. The patterns obtained from experimental samples were compared to Joint
Committee on Powder Data Standards (JCPDS) data to identify crystalline phases. A
SCINTAG XRD 2000 X-ray diffractometers using CuKα (λ=1.5418 Å) was used for this
study. The scanning rate was set to 2/min with a 0.02 step size and the range from 20 to
60. The relationship describing the angle at which a beam of X-rays of a particular
wavelength diffracts from a crystalline surface is known as Bragg’s Law.
..........(1)
= wavelength of the X-ray
= diffraction angle
n= integer representing the order of diffraction peak
d = interplanar spacing generating the diffraction
3.5.2 Atomic Force Microscopy (AFM)
The atomic force microscopy (AFM) was performed on the sample to analyze the
surface morphology of thin films from angstroms (Å) to 100 m. In this study, AFM was
carried out using a Q–Scope 250 (Quesant Instrument Corporation) which operating in
Preparation and characterization of electrodeposited Cu4SnS4 thin films 22
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
contact mode with a commercial Si3N4 cantilever. It is the most popular Quesant model,
primarily used in stand-alone applications. It is equipped with PC-based video subsystem
using a CCD camera for 90° tip and sample viewing and a manual X-Y translation stage for
sample positioning. It also provides a three-dimensional surface profiles.
3.5.3 UV-Visible Spectrophotometer
Ultraviolet Visible spectroscopy involves the spectroscopy of the photons and
spectrophotometry. It uses light in the visible and ultraviolet region. In this region of energy
space molecules undergo electronic transitions. In this study, Perkin Elmer UV-Vis
Spectrophotometer Lambda 20 has been used for investigation of the absorption spectra of
the samples. The indium tin oxide coated glass substrate was placed in the reference path
while the deposited films in the sample radiation path. The optical properties of films
deposited on ITO glass substrates were investigated from the absorption measurements in the
range of 300-800 nm. The band gap energy and transition type were derived from
mathematical treatment with the following relationship for near-edge absorption
..........(2)
Where A is absorbance, Eg is band gap energy, h is Plank’s constant (6.63x10-34), v is
frequency in Hertz, k equals a constant value, n carries the value of either 1 or 4. The
arrangement of the equation (1) gives the following equation:
..........(3)
For a direct transition when n=1, the equation (2) becomes
..........(4)
For an indirect transition when n=4, the equation (2) becomes
..........(5)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 23
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
The data were used to plot a graph of (Ahv)2/n versus hv. Extrapolation of the line to the base
line, where the value of (Ahv)2/n is zero, will give band gap energy.
3.5.4 Photoelectrochemical test (PEC)
The photoactivity of the samples were test in 0.01 M [Fe(CN)6]3-/[Fe(CN)6]4- redox
system by running linear sweep voltammetry technique (LSV) between two potentials limits
(-1000 mV to 1000 mV versus Ag/AgCl). The BAS Potentiostat was used to control the
process and to monitor the current and voltage profiles. The system consists of deposited film
as a working electrode, platinum wire as counter electrode and Ag/AgCl as reference
electrode. The photocurrent (Ip) and darkcurrent (Id) of the PEC cells were recorded under
light illumination and dark condition. The halogen lamp (300W) was used for illuminating
the electrode. The light path towards the PEC cells was chopped manually to study the effect
on photoactivity behavior.
References:
1. Craig, S., Dennis, N., Dimosthenis, S., Miguel, C., Weng, T., Lorelle, M., &
Katherine, E.H. (2017). Soft X-ray absorption spectroscopy investigation of the
surface chemistry and treatments of copper indium gallium diselenide (GIGS). Solar
Energy Materials and Solar Cells, 160, 390-397.
2. Nicole, J., Angus, R., Sefik, S., & Pinar, A. (2016). Electrical properties from
photoinduced charging on Cd-doped (100) surfaces of CuInSe2 epitaxial thin films.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces and Films,
doi: http://dx.doi.org/10.1116/1.4945105.
3. Jiang, F., Ozaki, C., Harada, T., Tang, Z., Minemoto, T., Nose, Y., & Ikeda, S.
(2016). Effect of indium doping on surface optoelectrical properties of Cu2ZnSnS4
photoabsorber and interfacial/photovoltaic performance of cadmium free
In2S3/Cu2ZnSnS4 heterojunction thin film solar cell. Chemistry of Materials, 28,
3283-3291.
4. Deshpande, M.P., Garg, N., Bhatt, S.V., Sakariya, P., & Chaki, S.H. (2013).
Characterization of CdSe thin films deposited by chemical bath solutions containing
triethanolamine. Materials Science in Semiconductor Processing, 16, 915-922.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 24
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
5. Ho, S.M., Saravanan, N., Anuar, K., & Tan, W.T. (2012). Temperature dependent
surface topography analysis of SnSe thin films using atomic force microscopy. Asian
Journal of Research in Chemistry, 5, 291-294.
6. Daniel, T., Henry, J., Mohanraj, K., & Sivakumar, G. (2016). Fabrication of
ITO/Ag3SbS3/CdX(X=S,Se) thin film heterojunctions for photosensing applications.
Materials Research Express, 3, doi.org/10.1088/2053-1591/3/11/116401.
7. Ho, S.M., Anuar, K., Atan, S., & Saravanan, N. (2010). X-ray diffraction and atomic
force microscopy studies of chemical bath deposited FeS thin films. Studies
Universitatis Babes-Bolyai Chemia, 55, 5-11.
8. Mukherjee, A., Ghosh, P., Fu, M., Aboud, A., & Mitra, P. (2016). Microstructural
characterization of chemical bath deposition synthesized CdS thin films: Application
as H2S sensor. Advanced Science Letters, 22, 179-183.
9. Ho, S.M., Anuar, K., & Nani, R. (2011). Atomic force microscopy studies of zinc
sulfide thin films. International journal of Advanced Engineering Sciences and
Technologies, 7, 169-172.
10. Soumya, R.D., Ajaya, K.S., Lata, D., Paliwal, L.J., Singh, R.S., & Adhikari, R.
(2014). Structural, morphological and optical studies on chemically deposited
nanocrystalline CdZnSe thin films. Journal of Saudi Chemical Society, 18, 327-339.
11. Ho, S.M. (2014). Atomic force microscopy investigation of the surface morphology
of Ni3Pb2S2 thin films. European Journal of Scientific Research, 125, 475-480.
12. Sathishkumar, R., Devakirubai, E., David, A., Tamilselvan, S., & Nithiyanantham, S.
(2017). Structural and optical studies of cadmium sulfide (CdS) thin film by chemical
bath deposition (CBD). Materials Focus, 6, 41-46.
13. Salh, A., Moon, K., Park, H., & Kim, W. (2017). Effect of different cadmium salts on
the properties of chemical bath deposited CdS thin films and Cu(InGa)Se2 solar cells.
Thin Solid Films, 625, 56-61.
14. Amira, H., & Hager, M. (2017). Growth of different phases and morphological
features of MnS thin films by chemical bath deposition: Effect of deposition
parameters and annealing. Journal of Solid State Chemistry, 247, 120-130.
15. Chen, H., Fu, S., Wu, S., Wu, H., & Shih, C. (2016). Comparative study of self-
constituent buffer layers (CuS, SnS, ZnS) for synthesis Cu2ZnSnS4 thin films.
Materials Letters, 169, 126-130.
16. Umair, S., Raja, A.H., & Amin, B. (2016). Fabrication and applications of copper
Preparation and characterization of electrodeposited Cu4SnS4 thin films 25
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
sulfide (CuS) nanostructures. Journal of Solid State Chemistry, 238, 25-40.
17. Anuar, K., Ho, S.M., Tan, W.T., Atan, S., & Saravanan, N. (2011). Chemical bath
deposition of ZnSe thin films: SEM and XRD. European Journal of Applied Sciences,
3, 113-116.
18. Vanita, S.R., Chandrakant, D.L., & Vilas, V.K. (2017). Photoelectrochemical studies
on electrodeposited indium doped CdSe thin films using aqueous bath. Journal of
Electroanalytical Chemistry, 788, 137-143.
19. Saravanan, N., Anuar, K., Ho, S.M., Tan, W.T., Dzulkefly, K., & Haron, M.J. (2010).
Preparation and characterization of PbSe thin films by chemical bath deposition.
Jurnal Kimia, 4, 1-6.
20. Ersin, Y., & Yasin, Y. (2017). Fabrication and characterization of Sr-doped PbS thin
films. Ceramics International, 43, 407-413.
21. Anuar, K., Tan, W.T., & Ho, S.M. (2013). Thickness dependent characteristics of
chemically deposited tin sulfide films. Universal Journal of Chemistry, 1, 170-174.
22. Baligh, T., Abdelaziz, G., Illia, D., Marta, M.N., Alberto, V., & Najoua, K.T. (2016).
engineering of electronic and optical properties of PbS thin films via Cu doping.
Superlattices and Microstructures, 97, 519-528.
23. Anuar, K., Tan, W.T., Ho, S.M., Jelas, H.M., Saravanan, N., & Dzulkefly, K. (2007).
Cyclic voltammetry study of copper tin sulfide compounds. Pacific Journal of
Science and Technology, 8, 252-260.
24. Babu, P., Reddy, M.V., Revathi, N., & Reddy, K.T.R. (2011). Effect of pH on the
physical properties of ZnIn2Se4 thin films grown by chemical bath deposition. Journal
of Nano and Electronic Physics, 3, 85-91.
25. Bari, R.H., Patil, L.A., Sonawane, P.S., Mahanubhav, M.D., Patil, V.R., & Khanna,
P.K. (2007). Studies on chemically deposited CuInSe2 thin films. Materials Letters,
61, 2058-2061.
26. Ekuma, C., Nnabuchi, M., Nwabueze, A., & Owate, I. (2010). Optical
characterization of chemically deposited SbCuS thin films. Ceramic Transactions,
222, 243-249.
27. Ho, S.M. (2014). Influence of complexing agent on the growth of chemically
deposited Ni3Pb2S2 thin films. Oriental Journal of Chemistry, 30, 1009-1012.
28. Joshi, R.K., Subbaraju, G.V., & Sharma, R. (2004). Pb1-xFexS nanoparticle films
grown from acidic chemical bath. Applied Surface Science, 239, 1-4.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 26
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
29. Subramanian, B., Sanjeeviraja, C., & Jayachandran, M. (2001). Cathodic
electrodeposition and analysis of SnS films for photoelectrochemical cells. Materials
Chemistry and Physics, 71, 40-46.
30. Mustafa, B., & Ilkay, S. (2011). Electrodeposition and growth mechanism of SnSe
thin films. Applied Surface Science, 257, 2944-2949.
31. Rashwan, S.M., El-Wahab, S.M., & Mohamed, M.M. (2007). Electrodeposition and
characterization of CdSe semiconductor thin films. Journal of Materials Science:
materials in Electronics, 18, 575-585.
32. Mahalingam, T., Kathalingam, A., Lee, S., Moon, S., & Kim, Y.D. (2007). Studies of
electro synthesized zinc selenide thin films. Journal of New Materials for
Electrochemical System, 10, 15-19.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 27
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
CHAPTER 4: CYCLIC VOLTAMMETRY STUDIES
4.1 Cyclic voltammetry process
Cyclic voltammetry (CV) is a versatile electroanalytical technique for the study of
electroactive species in a standard electrochemical bath as reported by many researchers [1-
17]. The common characteristic of voltammetric technique is that they involve the application
of a potential (E) to an electrode and the monitoring of the resulting current (i) flowing
through the electrochemical cell.
Cyclic voltammetry is widely used for the study of redox processes, for understanding
reaction mechanisms and for obtaining stability of reaction products. This technique is based
on varying the applied potential at a working electrode in both forward and reverse directions
while monitoring the current. For example, the initial scan could be in the negative direction
to the switching potential. At that point the scan would be reversed and run in the positive
direction. Depending on the analysis, one full cycle, a partial cycle or a series of cycles can
be performed.
The important parameters in a cyclic voltammogram are the peak potentials (Epc, Ep
a)
and peak currents (ipc, ip
a) of the cathodic and anodic peaks, respectively (Figure 4.1). If the
electron transfer process is fast compared with other processes, the reaction is said to be
electrochemically reversible and the peak separation is
[Equation 1] Reversible couples will display a ratio of the peak currents passed at reduction (ipc)
and oxidation (ipa) that is near unity.
Figure 4.1 The typical cyclic voltammogram recorded for reversible single
electrode transfer reaction
Preparation and characterization of electrodeposited Cu4SnS4 thin films 28
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
For slow electron transfers at the electrode surface, i.e. irreversible processes, the
difference of peak potentials widen. The peak current in reversible systems for the forward
scan is given by Randles-Sevcik equation,
[Equation 2]
where, ip = peak current, n = number of electrons involved, A = electrode area, cm2; D
= diffusion coefficient, cm2/s; C = concentration, mol/cm3 and v = scan rate, V/s. Thus ip
increases with square root of v and is directly proportional to concentration of the species.
The basic components of a modern electroanalytical system for voltammetry are a
potentiostat, computer and the electrochemical cell. The task of applying a known potential
and monitoring the current falls to the potentiostat. Accurate and flexible control of the
applied potential is a critical function of the potentiostat.
4.2 Electrodeposition of copper tin sulphide thin films
The cyclic voltammogram was scanned in the potential range 1000 mV to –1000 mV
versus Ag/AgCl at a sweep rate 10 mVs-1. All voltammetry curves were scanned first in the
cathodic direction and positive current indicated a cathodic current.
In copper sulfate solution (Figure 4.2a), the current rise started at –50 mV, followed
by large reduction wave at –500 mV. This response was associated with Cu (II) reduction on
ITO substrate. The two stripping peaks at positive potential limits, 200-600 mV indicated the
oxidation of the copper compound.
Figure 4.2b shows the voltammogram recorded for tin chloride on ITO glass
substrate. The forward scan showed a reduction potential starting at about –500 mV.
Reduction peak increased towards the more-negative region where hydrogen evolution also
occurred. During the reverse scan, the oxidation wave of tin could be seen starting at about –
450 mV. This peak reached a maximum value of about –200 mV. The forward scan of
sodium thiosulfate solution (Figure 4.2c) shows the cathodic current to start flowing at about
–500mV. The shoulder at –700 mV might be associated with the reduction of thiosulphate
ions.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 29
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(a)
(b)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 30
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 4.2 Cyclic voltammogram of (a) 0.01 M copper sulfate (b) 0.01M tin chloride (c) 0.01
M sodium thiosulfate (d) mixture of (a), (b) and (c) solutions at
(c)
(d)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 31
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
room temperature, scan rate: 10 mV/s and pH 1.5
Figure 4.2d shows the cyclic voltammogram of the ITO working electrode in the
mixture of copper sulfate, tin chloride and sodium thiosulfate. The wave around –475 mV
corresponded to the formation of Cu4SnS4 layers and the cathodic current increased gradually
up to –1000 mV, indicating the growth of layers. The anodic peak start from -500 mV
corresponded to the stripping of deposited layers in the reverse scan.
Figure 4.3 The cyclic voltammograms of electrodeposited Cu4SnS4 thin films on ITO substrate. The deposition bath contains CuSO4, SnCl2 and Na2S2O3 at
same concentration 0.01 M respectively at 25°C. Scan rate = 1, 10, 20, 60,100 mV/s in pH=1.5
Irreversibility reaction is when the rate of electron transfer is sufficiently slow, so that
the potential no longer reflects the equilibrium activity of redox couple at the electrode
surface. In such a case, the potential peak values will change as a function of the scan rate.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 32
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
The reduction peak at low scan rates (1 mV/s) is well marked. At high scan rates (which more
than 10mV/s), it widened and increased both in terms of peak currents and peak potentials.
When the scan rate increased, the peak separation also increased (Figure 4.3) due to the
heterogeneous kinetics and IR drop effects. The ohmic polarization effect is a
characterization of bulk solution. This effect can be minimized by proper cell design during
the experiment.
References
1. Jana, S., Mondal, P., TRipathi, S., Mondal, A., & Chakraborty, B. (2015).
Electrochemical synthesis of FeS2 thin film: An effective material for peroxide
sensing and terephthalic acid degradation. Journal of Alloys and Compounds, 646,
893-899.
2. Thanikaikarasan, S., Mahalingam, T., Sundaram, K., Kathalingam, A., Kim, Y., &
Kim, T. (2009). Growth and characterization of electro synthesized iron selenide thin
films. Vacuum, 83, 1066-1072.
3. Xue, M., & Fu, Z. (2007) Electrochemical properties of FeSe thin film electrode
fabricated by pulsed laser deposition. Acta Chimca Sinica, 65, 2715-2719.
4. Lai, Y., Liu, F., Zhang, Z., Liu, J., Li, Y., Kuang, S., Li, J., & Liu, Y. (2009). Cyclic
voltammetry study of electrodeposition of Cu(In, Ga)Se2 thin films. Electrochimica
Acta, 54, 3004-3010.
5. Lee, H., Lee, J., Hang, Y., & Kim, Y. (2014). Cyclic voltammetry study of
electrodeposition of CuGaSe2 thin films on ITO glass substrates. Current Applied
Physics, 14, 18-22.
6. Liu, J., Liu, F., Lai, Y., Zhang, Z., Li, J., & Liu, Y. (2011) Effects of sodium
sulfamate on electrodeposition of Cu(In,Ga)Se2 thin film. Journal of Electroanalytical
Chemistry, 651, 191-196.
7. Hsieh, M., Chen, C., & Whang, T. (2016). Triethanolamine facilitated one step electro
deposition of CuAlSe2 thin films and the mechanistic studies utilizing cyclic
voltammetry. Journal of Electroanalytical Chemistry, 762, 73-79.
8. Shin, S., Park, C., Kim, C., Kim, Y., Park, S., & Lee, J. (2016). Cyclic voltammetry
studies of copper, tin and zinc electro deposition in a citrate complex system for
CZTS solar cell application. Current Applied Physics, 16, 207-210.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 33
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
9. Kwinten, C., Koen, B., Edward, M., & Jan, F. (2016). Electrochemical studies of the
electrodeposition of copper zinc tin alloys from pyrophosphate electrolytes followed
by selenization for CZTSe photovoltaic cells. Electrochimica Acta, 188, 344-345.
10. Murilo, F.C., Dyovani, C., & Sergio, A.S. (2013). Analyzing Cd under potential
deposition behavior on Se thin films: Atomic force microscopy, cyclic voltammetry
and electrochemical quartz crystal nanobalance studies. Electrochimica Acta, 91, 361-
366.
11. Patil, S.J., Lokhande, V.C., Chodankar, N.R., & Lokhande, C.D. (2016). Chemically
prepared La2Se3 nanocubes thin film for super capacitor application. Journal of
Colloid and Interface Science, 469, 318-324.
12. Riahi, M., Martinez, C., Agouram, S., Boukhachem, A., & Maghraoui, H. (2017). The
effects of thermal treatment on structural, morphological and optical properties of
electrochemically deposited Bi2S3 thin films. Thin Solid Films, 626, 9-16.
13. Rohom, A.B., Londhe, P.U., & Chaure, N.B. (2016). Agitation dependent properties
of copper indium diselenide thin films prepared by electrochemical route. Thin Solid
Films, 615, 366-373.
14. Patil, A.M., Kumbhar, V.S., Chodankar, N.R., Lokhande, A.C., & Lokhande, C.D.
(2016). Electrochemical behavior of chemically synthesized selenium thin film.
Journal of Colloid and Interface Science, 469, 257-262.
15. Fernandez, A.M., Turner, J.A., Lara., B., & Deutsch, T.G. (2017). Influence of
support electrolytic in the electro deposition of Cu-Ga-Se thin films. Superlattices and
Microstructures, 101, 373-383.
16. Pujari, R.B., Lokhande, A.C., Shelke, A.R., Kim, J.H., & Lokhande, C. D. (2017).
Chemically deposited nano grain composed MoS2 thin films for super capacitor
application. Journal of Colloid and Interface Science, 496, 1-7.
17. Aghassi, A., Jafarian, M., Danaee, I., Gobal, F., & Mahjani, M.G. (2011). AC
impedance and cyclic voltammetry studies on PbS semiconducting film prepared by
electro deposition. Journal of Electroanalytical Chemistry, 661, 265-269.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 34
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
CHAPTER 5: ELECTRO DEPOSITION METHOD
5.1 Effect of deposition potential on the properties of films
Based on the cyclic voltammetry studies, the voltammogram suggested that a
deposition on the working electrode can be expected when the potential is -400 mV and
above (more negative values). Thus, the deposition process was carried out at various
deposition potentials from -400 mV to -1000 mV versus Ag/AgCl. The deposition was
carried out for 45 min at 25 C under acidic medium (pH 1.5) using 0.01 M of solutions
concentration.
Figure 5.1 X-ray diffraction pattern of samples prepared at different deposition potentials ( Cu4SnS4)
Figure 5.1 shows the XRD patterns for the films deposited at various deposition
potentials ranging from –400 mV to –1000 mV versus Ag/AgCl. Four main peaks at 2
=30.3, 35.5, 45.2 and 50.6, corresponding to d-spacing values 2.95, 2.55, 2.00 and 1.80 Å
Preparation and characterization of electrodeposited Cu4SnS4 thin films 35
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
which attributed to the (221), (420), (512) and (711) planes, respectively were detected from
all the samples. All these peaks are related to the orthorhombic structure of Cu4SnS4 (a
=13.5580 Å, b = 7.6810 Å, c = 6.4120Å, α = β = γ =90°). The prominent peak corresponds to
(221) plane with the d-spacing value of 2.95Å can be seen. The XRD data shows that the
disappearance of the plane (312) as deposition potential was increased to –600mV and more
negative of values.
Atomic force microscopy (AFM) was used to study the topography of films. The
surface images in an area of 10 μm X 10 μm of the thin films deposited at various deposition
potential values are shown in Figure 5.2. It can be observed that the surface of the films was
not very compact (Figure 5.2a). The films were constituted by nano particles with an irregular
size distribution. A lot of empty spaces could be seen between these particles. AFM images
of samples clearly show the conversion of nano particles into spherical grains that were quite
uniform over the entire glass substrate (Figure 5.2c). However, it is seen from the intensity
distribution that the film consisted of smaller and larger nano particles in deposition potential
above –700 mV (Figure 5.2d to 5.2g). This might be due to the difference of rate of
nucleation and growth.
(a)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 36
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(b)
(c)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 37
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(d)
(e)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 38
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.2 Atomic force microscopy images of Cu4SnS4 thin films at different deposition potentials (versus Ag/AgCl). (a) –400 mV (b) –500 mV (c) –600 mV (d) –700 mV
(e) –800 mV (f) –900 mv (g) –1000 mV
(f)
(g)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 39
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Deposition was carried out on an ITO glass substrate to study the optical behavior of
the Cu4SnS4 films in the range of 300 to 800 nm. Figure 5.3 shows the spectra gradually
increasing absorbance throughout the visible region for all samples, which makes it possible
for this material to be used in a photoelectrochemical cells. The absorbance of thin films
deposited at –600 mV produced higher absorbance value. However, it is seen from figure that
as the deposition potential increased (above –700 mV), the absorbance value decreased.
Figure 5.3 Absorbance versus wavelength spectra for Cu4SnS4 films deposited at different deposition potentials (versus Ag/AgCl)
5.2 Effect of deposition temperature on the properties of films
In order to study the effect of temperature on the properties of thin films, the films
prepared under various bath temperatures (25 C to 50 C). Other deposition parameters were
maintained as stated earlier.
Figure 5.4 shows the X-ray diffraction patterns for the films deposited at various bath
temperatures. The XRD patterns are found to be polycrystalline with orthorhombic structure.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 40
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
There are six peaks at 2=30.2°, 35.4.°, 42.9°, 47.4°, 50.7° and 57.5 °C were detected for
films deposited from 25 °C to 35 °C. The corresponding interplanar distances are well in
agreement with JCPDS data (Reference code: 010710129) of 0.296, 0.255, 0.210, 0.192,
0.180 and 0.161 nm which attributed to the (221), (420), (331), (040), (711) and (532) planes,
respectively. However, raising the bath temperature further to 40 °C and above, resulted in
the disappearance of (532) plane could be observed in XRD patterns. The most prominent
peak obtained at 2 =30.2° corresponding to interplanar distance of 0.296 nm. As the bath
temperature increased, the intensity of the peak (221) increased. This indicates that the grain
size increases when the bath temperature is increased.
Figure 5.4 X-ray diffraction patterns of Cu4SnS4 thin films deposited at various bath
temperatures (a) 25 C (b) 30 C (c) 35 C (d) 40 C (e) 45 C (f) 50 C [Cu4SnS4 (▲)]
Preparation and characterization of electrodeposited Cu4SnS4 thin films 41
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
The Cu4SnS4 thin films were morphologically characterized using atomic force
microscopy (AFM). Figure 5.5 shows the three-dimensional representation of a 20 mm X 20
mm area of the Cu4SnS4 thin films deposited at different bath temperatures. It is observed
that the films deposited at 25 °C have a homogeneous, uniform surface and well cover the
substrate (Figure 5.5a). As the bath temperature was increased to 50 °C (Figure 5.5b),
decreasing in the number of grains could be observed. The grain size of Cu4SnS4 material is
much bigger with diameter around 1 mm.
a
Preparation and characterization of electrodeposited Cu4SnS4 thin films 42
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
b
c
Preparation and characterization of electrodeposited Cu4SnS4 thin films 43
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
d
e
Preparation and characterization of electrodeposited Cu4SnS4 thin films 44
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.5 Atomic force microscopy images of Cu4SnS4 thin films deposited at various bath
temperatures (a) 25 C (b) 30 C (c) 35 C (d) 40 C (e) 45 C (f) 50 C
Figure 5.6 shows the absorption spectra of Cu4SnS4 films at various bath
temperatures. The films show a gradually increasing absorbance throughout the visible
region, which makes it possible for this material to be used in a photoelectrochemical cell.
The film deposited at 25°C showed gradual increasing of absorption starting from 650 nm
downward. This film showed higher absorption characteristics when compared to the films
prepared at other bath temperatures. Thus, this bath temperature is more preferable in the
preparation of Cu4SnS4 films of better quality on ITO substrate.
f
Preparation and characterization of electrodeposited Cu4SnS4 thin films 45
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.6 Optical absorbance versus wavelength of the Cu4SnS4 films deposited at various
bath temperatures (a) 25 C (b) 30 C (c) 35 C (d) 40 C (e) 45 C (f) 50 C
5.3 Effect of solution concentration on the properties of films
The first set of experiment was carried out using constant concentration of 0.01 M of
SnCl2, Na2S2O3 and varying concentrations of CuSO4 (0.01 M – 0.02 M) solutions. The
second set of experiment was carried out using fixed concentration of 0.01 M of CuSO4,
Na2S2O3 and varying concentrations of SnCl2 (0.01 M – 0.02 M) solutions. The third set of
experiment was carried out using constant concentration of 0.01 M of CuSO4, SnCl2 and
varying concentrations of Na2S2O3 (0.01 M – 0.02 M) solutions. (deposition time=45 min, pH
1.5, deposition potential= -600 mV, deposition temperature=25 C).
Figure 5.7 shows the XRD patterns of the films deposited at various CuSO4
concentrations (0.01 M – 0.02 M) and constant Na2S2O3, SnCl2 at 0.01 M. There are six
Cu4SnS4 peaks at 2θ = 28.6°, 30.1°, 35.2°, 42.9°, 45.2° and 50.6° for the samples prepared at
0.01 M, 0.015 M and 0.02 M of CuSO4. The corresponding interplanar distances are 12, 2.96,
Preparation and characterization of electrodeposited Cu4SnS4 thin films 46
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
2.54, 2.10, 2.00 and 1.80 Å, which attributed to the (102), (221), (420), (331), (512) and
(711) planes, respectively. However, as the concentration of CuSO4 was higher than 0.015 M
and 0.02 M, the copper sulfide peaks (Reference code: 000653556) which corresponding to
2.82 Å and 2.32 Å at 2θ = 31.8° and 38.8°, respectively were obtained.
Figure 5.7 XRD patterns of samples prepared at various CuSO4
concentrations: a – 0.01 M; b
– 0.015 M; c – 0.02 M. Concentration of SnCl2
and Na2S
2O
3 are fixed at 0.01 M.
(Cu4SnS
4 – ▲; CuS – ■)
Figure 5.8 shows the XRD patterns of the films deposited at various SnCl2
concentrations (0.01 M – 0.02 M) and fixed Na2S2O3, CuSO4 at 0.01 M. XRD indicates the
presence of six peaks at 2θ = 28.5°, 30.1°, 35.1°, 42.8, 45.2° and 50.5° belonging to Cu4SnS4
for samples prepared using lower concentrations (0.01 M and 0.015 M). There are no copper
sulfide peaks were observed from the samples deposited with 0.01 M of tin chloride. Six
peaks corresponding to interplanar distance of 3.12, 2.96, 2.55, 2.11, 2.01 and 1.80 Å were
observed for the film prepared from 0.02 M SnCl2.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 47
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.8 XRD patterns of samples prepared at various SnCl
2 concentrations: a – 0.01 M; b –
0.015 M; c – 0.02 M. Concentration of CuSO4
and Na2S
2O
3 are fixed at 0.01 M.
(Cu4SnS
4 – ▲; CuS – ■)
Figure 5.9 shows the XRD patterns of the films deposited at various Na2S2O3
concentrations (0.01 M – 0.02 M) with constant CuSO4, SnCl2 at 0.01 M. The thin films
prepared in different concentrations of Na2S2O3 showed six peaks at 2θ = 28.9°, 30.1°, 35.1°,
42.8°, 45.2° and 50.7°, corresponding to d-spacing values 3.08, 2.96, 2.55, 2.11, 2.01 and
1.79 Å, which attributed to the (102), (221), (420), (331), (512) and (711) planes, respectively
were detected. The appearances of copper sulfide peaks were detected when the
concentration of Na2S2O3 was higher at 0.015 M and 0.02 M.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 48
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.9 XRD patterns of samples prepared at various Na2S
2O
3 concentrations: a – 0.01 M;
b – 0.015 M; c – 0.02 M. Concentration of CuSO4
and SnCl2
are fixed at 0.01 M.
(Cu4SnS
4 – ▲; CuS – ■)
Figure 5.10 shows AFM images of films prepared at different CuSO4 concentrations
and constant SnCl2, Na2S2O3 at 0.01 M. The grain size for the film prepared at 0.015 M and
0.02 M are almost similar and do not much different from each other (Figure 5.10b and
Figure 5.10c). The crystal size decreases with the decrease of CuSO4 concentration (Figure
5.10a).
Preparation and characterization of electrodeposited Cu4SnS4 thin films 49
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(a)
(b
Preparation and characterization of electrodeposited Cu4SnS4 thin films 50
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.10 Atomic force microscopy images of Cu4SnS
4 films deposited at various CuSO
4
concentrations: a – 0.01 M; b – 0.015 M; c – 0.02 M. Concentration of Na2S
2O
3
and SnCl2
are fixed at 0.01 M
(c)
(a)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 51
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.11 Atomic force microscopy images of Cu4SnS
4 films deposited at various SnCl
2
concentrations: a – 0.01 M; b – 0.015 M; c – 0.02 M. Concentration of Na2S2O3 and
CuSO4 are fixed at 0.01M.
(b)
(c)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 52
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(a)
(b)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 53
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.12 Atomic force microscopy images of Cu4SnS
4 films deposited at various Na
2S
2O
3
concentrations: a – 0.01 M; b – 0.015 M; c – 0.02 M. Concentration of SnCl2
and CuSO4
are fixed at 0.01 M
Figure 5.11 shows the AFM images of films prepared at different SnCl2
concentrations and constant Na2S2O3, CuSO4 at 0.01 M. The images indicated that higher
concentration of SnCl2 leads to larger crystal size (Figure 5.11b and Figure 5.11c) while
lower SnCl2 exhibits smaller crystal size (Figure 5.11a). Meanwhile, the morphology of thin
films prepared under different concentrations of sodium thiosulfate was shown in Figure
5.12.
Figure 5.13 – 5.15 show the absorption spectra of Cu4SnS4 films at different
concentrations of CuSO4, SnCl2 and Na2S2O3, respectively. The films show a gradually
increasing absorbance throughout the visible region, which makes it possible for this material
to be used in a photoelectrochemical cell. From the graph, it is indicated that the samples
prepared at lower CuSO4, SnCl2 and Na2S2O3 concentration (0.01 M) have higher absorption
values respectively.
(c)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 54
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.13 Optical absorbance versus wavelength of the Cu
4SnS
4 films deposited at various
CuSO4
concentrations (0.01 M – 0.02 M). Concentration of SnCl2
and Na2S
2O
3
are fixed at 0.01 M
Figure 5.14 Optical absorbance versus wavelength of the Cu4SnS
4 films deposited at various
SnCl2
concentrations (0.01 M – 0.02 M). Concentration of CuSO4
and Na2S
2O
3
are fixed at 0.01 M
Preparation and characterization of electrodeposited Cu4SnS4 thin films 55
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.15 Optical absorbance versus wavelength of the Cu4SnS
4 films deposited at various
Na2S
2O
3 concentrations (0.01 M – 0.02 M). Concentration of CuSO
4 and SnCl
2
are fixed at 0.01 M
5.4 Effect of deposition time on the properties of films
Based on the results obtained, we can conclude that the good quality of thin films was
deposited using 0.01 M of solutions concentration. Further experiments were carried out to
determine the effects of deposition time (15 to 60 min) towards the properties of thin films.
Other experimental conditions were not altered to maintain a constant approach towards
uniform set-up. (pH 1.5, deposition potential= -600 mV, solutions concentration=0.01 M,
temperature=25 C).
Figure 5.16 shows the X-ray diffraction patterns of films deposited at –600 mV versus
Ag/AgCl under room temperature for various deposition periods. There are two peaks,
observed at the diffraction angles of 27.6and 38.8 for the films deposited for 15 min of
deposition period. These two peaks were assigned to (002) and (222) plane, respectively.
Meanwhile, the films prepared at 30 min showed five peaks at 2 = 30.3, 35.1, 38.7, 45.3
and 50.5 corresponding to interplanar distances of 2.96, 2.54, 2.33, 2.00 and 1.80 Å
respectively. However, the films prepared at longer deposition period (45 min) showed only
four peaks at 2 = 30.3, 35.1, 43.3 and 50.4 corresponding to interplanar distances of
Preparation and characterization of electrodeposited Cu4SnS4 thin films 56
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
2.96, 2.54, 2.07 and 1.80 Å, respectively. Further increases deposition time to 60 min reduced
in the number of Cu4SnS4 peak as shown in Figure 5.16d. All these peaks are related to the
compound of Cu4SnS4 (Reference code: 010710129) of orthorhombic structure. On the other
hand, the strongest peak occurred at 2 =30.1 with d=2.96 Å. It indicates that the preferred
orientation lies along the (221) plane for electrodeposited Cu4SnS4 thin films. The appearance
of copper sulfide (Reference code: 000653556) was detected at 2 = 31.5 for the films
deposited at 30 min, probably due to the Cu4SnS4 formation reaction is not complete during
electrodeposition process.
Figure 5.16 X-ray diffraction patterns of Cu4SnS4 thin films deposited at various deposition
periods (a) 15 min (b) 30 min (c) 45 min (d) 60 min [Cu4SnS4 (▼), CuS (■)]
Preparation and characterization of electrodeposited Cu4SnS4 thin films 57
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(a)
(b)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 58
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(c)
(d)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 59
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.17 Atomic force microscopy images of Cu4SnS4 thin films deposited at various
deposition periods (a) 15 min (b) 30 min (c) 45 min (d) 60 min
The Cu4SnS4 thin films were morphologically characterized by using atomic force
microscopy. Figure 5.17 shows the three-dimensional representation of a 20 m X 20 m
area of the Cu4SnS4 thin film deposited at various deposition periods. It is indicated that the
deposited thin films are crystalline and their grain size varies with the different deposition
periods. The grain size decreases as the deposition period was increased from 15 min to 60
min. The average grain size of around 2.5 m and 0.8 m were observed on the film prepared
at 15 min (Figure 5.17a) and 60 min (Figure 5.17d) , respectively.
Figure 5.18 Difference between photocurrent and darkcurrent (Ip-Id) of Cu4SnS4 thin film
deposited at 25 C under various deposition periods. (a) 45 min
(b) 30 min (c) 15 min (d) 60 min
Figure 5.18 shows the difference between the photocurrent (Ip) and darkcurrent (Id)
versus potential for the deposited films in contact with Fe2+/Fe3+ solution. The current change
with illumination confirms that the films possess semiconducting properties. The films
prepared at 45 min showed the highest photoresponse activity as compared with other
Preparation and characterization of electrodeposited Cu4SnS4 thin films 60
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
deposition periods. This could be due to sufficient material deposited onto surface of
substrate. The photocurrent occurs on the negative potential indicates that the films prepared
are of p-type semiconductor.
5.5 Effect of pH value on the properties of films
The best optimum deposition time was 45 minutes according to overall results.
Further experiments were carried out to determine the effects of pH (pH 1.1 to pH 2.0)
towards properties of thin films. Basically, the sodium thiosulfate is stable under neutral or
alkaline medium but unstable in acidic solution. Other experimental set-up was maintained as
before. (deposition time=45 min, deposition potential= -600 mV, solutions
concentration=0.01M, deposition temperature=25 C)
Figure 5.19 X-ray diffraction patterns of films prepared at different pH values
(a) pH 1.1 (b) pH 1.3 (c) pH 1.5 (d) pH 2.0 [Cu4SnS4 ]
Preparation and characterization of electrodeposited Cu4SnS4 thin films 61
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.19 shows the XRD patterns of Cu4SnS4 thin films deposited under different
pH values ranging from 1.1 to 2.0. The XRD patterns were found to be polycrystalline with
orthorhombic structure. For the films prepared at pH 1.1, six peaks at 2 = 28.7, 30.2,
35.1, 39.0, 47.3 and 50.6 corresponding to interplanar distances of 3.11, 2.96, 2.56, 2.32,
1.93 and 1.81 Å, respectively were observed. As the pH was increased to 1.3 and 1.5, the
Cu4SnS4 peak increased to seven and finally nine, respectively. All these peaks are well
matched with the standard Joint Committee on Powder Data Standard pattern. However, as
the pH further increases to 2, the number of peaks reduced to six as can be seen in Figure
5.19d.
Figure 5.20 shows the three-dimensional representation of a 20 m X 20 m area of
the Cu4SnS4 thin films deposited at different pH values varied from 1.1 to 2.0. Larger grain
sizes were observed on the surface of Cu4SnS4 films deposited at pH 1.1 (Figure 5.20a) and
1.3 (Figure 5.20b). As the pH was increased to 1.5, the grain size of this film was much
smaller and has complete coverage over the substrate surface (Figure 5.20c). However, at
higher pH, the AFM image shows low appearance of grains over the surface of substrate as
shown in Figure 5.20d.
(a)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 62
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
(b)
(c)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 63
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.20 Atomic force microscopy images of Cu4SnS4 thin films prepared at different pH
values (a) pH 1.1 (b) pH 1.3 (c) pH 1.5 (d) pH 2.0
Figure 5.21 shows the absorbance spectra of Cu4SnS4 films at different pH values.
The film deposited at pH 1.5 produced the largest absorption value as compared with other
pH values. This response associated with the fact that more Cu4SnS4 materials were formed
at pH 1.5. This also indicated that the smaller grain size has complete coverage over the
substrate surface providing better absorption value. This result was consistent with the
observation from X-ray diffraction pattern and atomic force microscopy images. Thus,
deposition at pH 1.5 produced better quality of Cu4SnS4 films on ITO glass substrate.
(d)
Preparation and characterization of electrodeposited Cu4SnS4 thin films 64
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.21 Optical absorbance versus wavelength of Cu4SnS4 films deposited at different pH
values (a) pH 1.5 (b) pH 1.3 (c) pH 1.1 (d) pH 2
The band gap energy and transition type was derived from mathematical treatment of
data obtained from optical absorbance versus wavelength with the following relationship for
near-edge absorption:
hv
EhvkA
n
g ][2/
(1)
where v is the frequency, h is the Planck’s constant, k equals to constant while n carries the
value of either 1 or 4. The value of n is 1 and 4 for the direct transition and indirect transition,
respectively. The band gap (Eg) could be obtained from a straight line plot of (Ahv)2/n as a
function of hv. The line to determine the band gap was plotted by using Microsoft Excel
software (least square method). The R2 value obtained from the graph shown is 0.9978 which
is almost to the value of 1. This value shows that all the data is fitted well by using this least
square method technique. Extrapolation of the line to the base line, where the value of
(Ahv)2/n is zero, will give Eg. The Figure 5.22 showed the band gap energy of Cu4SnS4 film
which prepared at pH 1.5 was 1.5 eV with direct transition.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 65
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
Figure 5.22 Plot of (Ahv)2/n versus hv when n=1 for Cu4SnS4 films deposited at pH 1.5
There are several reports have pointed out interesting semiconducting performances in
some terms of the Cu-Sn-S semiconductor compounds [1-30]. These materials have been
prepared by using various deposition methods. The obtained films have been investigated
using different tools in order to characterize physical, optical and electric properties.
References:
1. Lokhande, A.C., Gurav, K.V., Jo, E., Lokhande, C.D. & Hyeok, K.J. (2016).
Chemical synthesis of Cu2SnS3 (CTS) nanoparticles: a status review. Journal of
Alloys and Compounds, 656, 295-310.
2. Anuar, K., Tan, W.T., Atan, M.S., Dzulkefly, K., Ho, S.M., Jelas, H.M. & Saravanan,
N. (2007). Cyclic voltammetry study of copper tin sulfide compounds. Pacific
Journal of Science and Technology, 8, 252-260.
3. Vummadi, P., Minnam, R., & Reddy, K.T. (2013). Influence of source substrate
distance of Cu4SnS4 thin films grown by co-evaporation. Advanced Materials
Research, 768, 103-108.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 66
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
4. Anuar, K., Ho, S.M., Tan, W.T., Atan, S., Kuang, Z., Haron, M.J., & Saravanan, N.
(2008). Effects of Bath Temperature on the Electrodeposition of Cu4SnS4 Thin
Films. Journal of Applied Sciences Research, 4, 1701-1707.
5. Tan, Q., Sun, W., Li, Z., & Li, J. (2016). Enhanced thermoelectric properties of earth
abundant Cu2SnS3 via in doping effect. Journal of Alloys and Compounds, 672, 558-
563.
6. Anuar, K., Ho, S.M., Tan, W.T., Atan, M.S., Kuang, D., Jelas, H.M., & Saravanan, N.
(2008). Effects of solution concentration on the properties of Cu4SnS4 thin films,
Materials Science (Medziagotyra), 14, 101-105.
7. Tipcompor, N., Thongtem, S., & Thongtem, T. (2015). Effect of microwave radiation
on the morphology of tetragonal Cu3SnS4 synthesized by refluxing method.
Superlattices and Microstructure, 85, 488-496.
8. Ho, S.M., Anuar, K., Tan, W.T., Atan, S., Zulkefly, K., Jelas, H., & Saravanan, N.
(2008). Cathodic electrodeposition of chalcogenide thin films Cu4SnS4 for solar cells.
Chiang Mai University Journal of Natural Sciences, 7, 317-326.
9. Zawadzki, P., Baranowski, L.L., Peng, H., Toberer, E.S., Ginley, D.S., Tumas, & W.,
Lany, S. (2013). Evaluation of photovoltaic materials within the Cu-Sn-S family.
Applied Physics Letters, 103, 253902.
10. Anuar, K., Ho, S.M., Tan, W.T., Atan, S., & Saravanan, N. (2009). Effect of
deposition period and bath temperature on the properties of electrodeposited Cu4SnS4
films. Solid State Science and Technology, 17, 226-237.
11. Andrea, G., Giordano, M., & Francesco, D.B. (2016). Stability of naturally relevant
ternary phases in the Cu-Sn-S system in contact with an aqueous solution. Minerals,
6,
doi:10.3390/min6030079
12. Anuar, K., Tan, W.T., Ho, S.M., & Saravanan, N. (2009). Influence of Bath
Temperature and pH Value On Properties of Chemically Deposited Cu4SnS4 Thin
Films. Journal of the Chilean Chemical Society, 54, 256-259.
13. Xu, B., Zhao, Y., Sun, A., Li, Y., Li, W., & Han, X. (2017). Direct solution coating of
pure phase Cu2SnS3 thin films without sulfurization. Journal of Materials Science:
Materials in Electronics, 28, 3481-3486.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 67
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
14. Kassim, A., Nagalingam, S., Shariff, A.M., Kuang, D., Haron, M.J., & Ho, S.M.
(2009). Effects of pH value on the electrodeposition of Cu4SnS4 thin films. Analele
Universitatii din Bucuresti, 18, 59-64.
15. Vani, V., Miles, R., & Reddy, K.T.R. (2013). Preparation and properties of Cu4SnS4
thin films. Journal of Optoelectronic Engineering, 3, 1-5.
16. Anuar, K., Tan, W.T., Atan, M.S. & Ho, S.M. (2009). Preparation and
characterization of chemically deposited Cu4SnS4 thin films. Journal of Ultra
Chemistry, 5.
17. Han, J., Zhou, Y., Tian, Y., Huang, Z., Wabg, X., Zhong, J., & Xia, Z. (2014).
Hydrazine processed Cu2SnS3 thin film and their application for photovoltaic devices.
Frontiers of Optoelectronics,7, 37-45.
18. Anuar, K., Tan, W.T., Ho, S.M., & Saravanan, N. (2010). Effects of Electrolytes
Concentration On the Chemically Deposited Cu4SnS4 Thin Films. Asian Journal of
Chemistry, 22, 222-232.
19. Chen, Q., Dou, X., Ni, Y., Cheng, S., & Zhuang, S. (2012). Study and enhance the
photovoltaic properties of narrow band gap Cu2SnS3 solar cell by p-n junction
interface modification. Journal of Colloid and Interface Science, 376, 327-330.
20. Zulkefly, K., Atan, S., Tan, W.T., Ho, S.M., Anuar, K., & Saravanan, N. (2010).
Preparation and studies of chemically deposited Cu4SnS4 thin films in the presence of
complexing agent Na2EDTA. Indian Journal of Engineering & Materials Sciences,
17, 295-298.
21. Jessica, D.W., Erika, V.C.R., Brahime, E.A., Daniel, A., & Phillip, J.D. (2016).
Secondary phase formation during monoclinic Cu2SnS3 growth for solar cell
application. Solar Energy Materials and Solar Cells, 157, 259-265.
22. Saravanan, N., Anuar, K., Tan, W.T., & Ho, S.M. (2010). Effects of deposition period
on the chemical bath deposited Cu4SnS4 thin films, Revista de la Sociedad Quimica
del 76, 54-60.
23. David, A., Nair, M.T.S., & Nair, P.K. (2010). Cu2SnS3 and Cu4SnS4 thin films via
chemical deposition for photovoltaic application. Journal of the Electrochemical
Society, 157, D346-D352.
24. Li, B., Xie, Y., Huang, J., & Qian, Y. (2000). Synthesis, characterization and
properties of nanocrystalline Cu2SnS3. Journal of Solid State Chemistry, 153, 170-
173.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 68
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in
25. Tan, W.T., Anuar, K., Abdul, H.A., Saravanan, N., & Ho, S.M. (2010). Deposition
and characterization of Cu4SnS4 thin films by chemical bath deposition method,
Macedonian Journal of Chemistry and Chemical Engineering, 29, 97-103.
26. Chen, X., Wang, X., An, C., Liu, J., & Qian, Y. (2003). Preparation and
characterization of ternary Cu-Sn-E (E=S,Se) semiconductor nanocrystallines via a
solvothermal element reaction route. Journal of Crystal Growth, 256, 368-376.
27. Nair, M.T.S., Lopez, C., Gomez, O., & Nair, P.K. (2013). Copper tin sulfide
semiconductor thin films produced by heating SnS-CuS layers deposited from
chemical bath. Semiconductor Science and Technology, 18,0755-760.
28. Zulkefly, K., Anuar, K., Atan, S., Jelas, H., Tan, W.T., & Ho, S.M. (2010). Effects of
deposition potential on Cu4SnS4 thin films prepared by electrodeposition technique.
The Arabian Journal for Science and Engineering, 35, 83-92.
29. Vani, V.P.G., Reddy, M.V., Reddy, K.T.R. (2013). Thickness dependent physical
properties of coevaporated Cu4SnS4 films. ISRN Condensed Matter Physics,
http://dx.doi.org/10.1155/2013/142029.
30. Wu, D., Knowles, C.R., & Chang, L.Y. (1986). Copper tin sulphides in the system
Cu-Sn-S. Mineralogical Magazine, 50, 323-325.
Preparation and characterization of electrodeposited Cu4SnS4 thin films 69
Ideal International E-Publication Pvt. Ltd.
www.isca.co.in