Upload
faissal-aka-md-halim
View
1.318
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Polymer-Nanomaterial Composite Solar Cells Group Presentation Presentation date: Friday, 5th November, 2010
Citation preview
Polymer-Nanomaterial Composite Solar Cells
M. Faisal Halim
Dorsinville Group
Friday, 5th November, 2010
Aim
• To make high efficiency solar cells that are:– Cheap– Mechanically Flexible– Have High Efficiency– Are Solution Processible
• Can take Advantage of Molecular Self Assembly• Processes are highly scalable
– Provide for Ease of Fabrication– Producible by Low Toxicity of Processing Methods
Physical Processes to Effect [1]
• Photon Absorption
• EHP Dissociation
• Electron andHole Conduction
Source: Solar Energy Materials and Solar CellsVolume 87, Issues 1-4, May 2005, Pages 733-746
Composite Components
• Quantum Dots(CdSe)
• Carbon Nanotubes(Single Walled),S-SWCNT,M-SWCNT
• Polymer(Semiconducting, p-type)
Absorption Spectrum of CdSe QDs (aq)
Absorption Spectrum of SWCNTs (aq)
Absorption Spectrum of 6 Layer Film of SWCNT in P3OT
What We Want To Do
• Immobilize/Bind/Self-Assemble Quantum Dots onto SWCNTs. [2-10]
• Encapsulate QD covered SWCNTs with a semiconducting polymer (This will give the Active Material) [11-12]– Encapsulation is required for EHP dissociation from
polymer to M-SWCNT– Amount of M-SWCNT in composite high enough (1%
ww) to allow for percolation• Sandwich by spin coating onto PEDOT:PSS
coated ITO covered substrate and evaporating a metal (Al) electrode
QD Immobilization
• Provides PhysicalContact for electrontransfer fromQD to SWCNT– Treatment of QDs
• ATP [2,4-10]
– Treatment ofSWCNTs
• Depends on typeof attachment [2-10]
QD-SWCNT Encapsulation in Polymer
• Dissociates EHP(preventsrecombination)[11-12] – Electron delocalized
and transported toQD or SWCNT
– Hole localized onpolymer chain
What we need to do
• Ligand exchange of decylamine with a conjugated system
• SWCNT Surface Treatments for Non-covalent binding (self assembly, based on available number of quantum dots)
References1. Solar Energy Materials and Solar Cells Volume 87, Issues 1-4, May 2005, Pages 733-7462. Light-Induced Charge Transfer in Pyrene/CdSe-SWNT Hybrids, Volume 20, Issue 5, pages
939–946, March, 20083. Tailored Single-Walled Carbon Nanotube−CdS Nanoparticle Hybrids for Tunable
Optoelectronic Devices, ACS Nano, 2010, 4 (1), pp 506–5124. Synthesis of high quality zinc-blende CdSe nanocrystals and their application in hybrid solar
cells, Lili Han et al 2006 Nanotechnology 17 47365. CdSe quantum dot-single wall carbon nanotube complexes for polymeric solar cells, Solar
Energy Materials and Solar Cells, Volume 87, Issues 1-4, May 2005, Pages 733-7466. Noncovalent attachment of CdSe quantum dots to single wall carbon nanotubes, Materials
Letters, Volume 60, Issues 29-30, December 2006, Pages 3502-35067. Breakthroughs in the Development of Semiconductor-Sensitized Solar Cells, J. Phys. Chem.
Lett., 2010, 1 (20), pp 3046–30528. Materials, Nanomorphology, and Interfacial Charge Transfer Reactions in Quantum
Dot/Polymer Solar Cell Devices, J. Phys. Chem. Lett., 2010, 1 (20), pp 3039–30459. Ligand-Tuned Shape Control, Oriented Assembly, and Electrochemical Characterization of
Colloidal ZnTe Nanocrystals, Chem. Mater., 2010, 22 (16), pp 4632–464110. Controlling Charge Separation and Recombination Rates in CdSe/ZnS Type I Core−Shell
Quantum Dots by Shell Thicknesses, J. Am. Chem. Soc., 2010, 132 (42), pp 15038–1504511. Why is exciton dissociation so efficient at the interface between a conjugated polymer and an
electron acceptor? APPLIED PHYSICS LETTERS VOLUME 82, NUMBER 2512. Exciton Dissociation in Organic Light Emitting Diodes at the Donor-Acceptor Interface, PRL
98, 176403 (2007)
Results of Discussions from the Meeting
• SWCNTs: we will acid treat them (H2SO4, or something else – I will have to look for what we may need to buy) to create defect sites where the QDs can settle and immobilize for QD-SWCNT electron conduction.
• Devices will need to be built to compare acid treated (SWCNT) vs. untreated device performance.
• Z-scan will need to be done for active materials, though it is unlikely that a difference will be noticable for acid treated vs. untreated SWCNT (with QD) devices.
• At some point pump and probe femto second dynamics of treated vs. untreated devices will have to be measured.
• AFM and TEM are unlikely to be able to distinguish between acid treated and untreated devices, though Raman might be able to tell.
• We may have to do ligand exchange of QD surfactant – need to see what surfactant to buy.