Nanomaterials Applications : Electronicstiiciiitm.com/profanurag/Physics-Class/INT-3.4.pdf ·...

Nanomaterials Applications

: Electronics

What is Nanoelectronics

Nano Science & Technology

Nanoelectronics make use of scientific methods at atomic scale for

developing the Nano machines. The main target is to reduce the size, risk

factor and surface areas of the materials and molecules. Machines under

nano electronic process undergoes the long range of manufacturing steps

each with accurate molecular treatment.

Nanoelectronics is one of the major technologies of Nanotechnology.

It plays vital role in the field of engineering and electronics.

Advantages of Nanoelectronics

Nano Science & Technology

One of the obvious advantage is that Nanoelectronics reduces size and

scale of the machine with the help of complex integration on the circuit

silicon chips.

Advanced properties of semiconductors can be determined with the

help of Nanoelectronics.

Molecular scale Nanoelectronics is also known as “the next step” in the

miniaturization of electronic devices, with latest electronics theory and

research in the field of nanoelectronics, it is possible to explore the

diverse properties of molecules.

Extreme fabrication also supported the multiple use of single machine.

Parallel processing is also empowered by Nanoelectronics.

Industrial Applications & World Market

Nano Science & Technology

Nanotechnology is continually playing vital role to improve the

capability of electronic products. The technology also made the devices

very light making the product easy to carry or move and at the same

time it has reduced the power requirement. Some Consumer Products

which are using Nanotechnology:

•Computer Hardware

• Display Devices

• Mobile & Communication Products

• Audio Products

• Camera & Films

Major Industries in Electronics Using Nanotechnology

in their Products

•Samsung®

•AMD®

• a123systems

• Starkey, Inc.

• Multiple Manufacturers

• IBM®

• Apple®, Inc.

• Intel®

• Eikos® Inc.

• IOGEAR®, Inc.

• Lenovo

• LG® Electronics

• Asahi® Glass Co., Ltd.

Industrial Applications & World Market

Nanoelectronics based Devices

a. Nanotransistors.b. Memory Storage devices.c. Nano-Sensors d. Smart sensors and smart delivery systems.e. Nano-biosensors.f. Nanoswitch

Graphene's potential in materials science and engineering

Nanotransistors

Carbon Nanotube based FET Fin-FET

Si nanowire based -FET

Graphene based FET

Nanotransistors

(a) Circuit Diagram of Graphene FET, (b) Microscopic view of FET and (c) Transverse characteristics of Graphene-FET

On-State

Off-State

Nanotransistors

Rui Cheng, Jingwei Bai, Lei Liao, Hailong Zhou, Yu Chen, Lixin Liu, Yung-Chen Lin, Shan Jiang, Yu Huang, and XiangfengDuan PNAS July 17, 2012 109 (29) 11588-1159

Nanotransistors

Classification schemes for graphene transistors

Schwierz: Graphene Transistors: Status, Prospects, and Problems Proceedings of the IEEE, Vol. 101, No. 7, July 2013

Nanotransistors

Feature sizes, on/off ratios, and bandgap values of selected semiconducting graphene

materials, including GNRs produced based on the principle of quantum confinement

effect.

Ganhua Lu,a Kehan Yu,a,b Zhenhai Wena and Junhong Chen, Nanoscale, 2012

Nanotransistors

Nanotransistors Important Parameters

Power Consumption (P max):

It is power consumed by nanotransistors. It should be low as much as. Units: Watts

Cutt off Frequency (fco):

The frequency at which the transistor current gain falls to 0.707 of its gain at low and

medium frequencies.

Maximum frequency (fmax):

The frequency at which the power gain of a device is unity.

Drain resistance (Rd):

Resistance offered by the drain terminal in FET. It is the ratio of change in drain to source

voltage to the change in drain current at a constant gate to source voltage

Mobility (μ):

It determines how fast a charge carrier can move in a solid material under applied electric field.

Subthreshold Swing (SS):

The change in gate voltage which must be applied in order to create a one decade increase

in the output current.

Gate- Source Capacitance (Cgs):

The drain and source in FET are insulated from the gate by the gate oxide film(dielectric

medium).

Switching:

The ratio of off-state current by on-state current is used to define switching speed of

transistor. Higher is the ratio, more will be the switching speed of device.

Nanotransistors

Parameters Formula Power Consumption (P max) Id X VdS

Cutt off Frequency (fco) gm/2πCgs

Maximum frequency (fmax) (fco/2) X (gm X Rd)1/2

Transconductance (gm) dId/dVg)

Drain resistance (Rd) (dId/dVd)-1

Mobility (μ) L X gm/W X Cgs X Vds

Subthreshold Swing (SS) = [d(log10 Ids)/d(Vgs)]-1

Gate- Source Capacitance

(Cgs)

(k X ɛ X A) /t

Switching Ion/Ioff

Id=Drain current, VdS=Drain current, Vg=Gate Voltage, L =Channel length, k =dielectric contant, A= Area of channel, t= thickness of channel, ɛ = relative permittivity of the material(8.85 x 10-12 F/m)

A sensor is a device that detects events or changes in

quantities and provides a corresponding output, generally

as an electrical or optical signal.

Sensor

One might consider the ears, eyes, nose and fingersto be physical sensors as they detect physicalsensations of sound, light, smell and heatrespectively.

Understanding Sensor: A device for sensing a physical variable of a physical system for an environment.

Sensors are required in many areas:

Environment Pollution: Our Focus is On Toxic GasesWater Pollution: | Noise Pollution: | Automobile, Industry, Health, Robotics etc.

Mechanical quantities: Displacement, Strain, Rotation velocity, Acceleration, Pressure, Force/Torque, Twisting, Weight, Flow

Thermal quantities: Temperature, Heat.Electromagnetic/optical quantities: Voltage, Current, Frequency phase, Visual/Images, Light,

Magnetism.Chemical quantities: Moisture, pH value

India on Pollution Map

• The WHO report reveals that 13 of the 20 most polluted cities in the world are in India.

• The report ranked cities after studying their air for the presence of harmful gases, such as nitrogen dioxide, carbon monoxide and sulphur dioxide, besides particulate matter 10 and 2.5.

• Particulate matter (or small airborne particles) isamong the most detrimental of these pollutants.Studies link it with increased rates of chronicbronchitis, lung cancer and heart disease.

• “Particles smaller than 10 micrometres in diameterpose the greatest threat to human health” “Theycan not only get deep into a person’s lungs but canalso enter the blood stream.”

Health Hazard

Air pollution

2012 October, New Delhi

Air pollution

2012 November, Beijing

What WHO reports….

• The WHO advises that fine particles of less than 2.5micrometres in diameter (PM2.5) should not exceed 10micrograms per cubic metre.

• At the top of the WHO ranking, Delhi had 153 microgramsof PM2.5 per cubic metre.

• Not far behind were Patna with 149 micrograms, Gwaliorwith 144 micrograms and Raipur with 134 micrograms.

• The other Indian cities in the list included Ahmedabad,Lucknow, Kanpur, Firozabad, Amritsar and Ludhiana.

Toxic gas species (CO, SO2, NOx HCN, NH3, PH3 etc.)

Toxic gases are essentially being monitored in cities and homes

Corrosive species (Cl2, F2, HF etc.)

The corrosive gasses are monitored in chemical petrochemical and food

industries

Explosive species (CH4, hydrocarbons, nitrous compounds etc.)

The explosive species are associated to public security.

Targeted gaseous species :

Kaushik A, Kumar R, Arya SK, Nair M, Malhotra B, Bhansali S. Organic-Inorganic Hybrid Nanocomposite-Based Gas

Sensors for Environmental Monitoring. Chemical reviews 2015;115(11):4571-606.

Sensitivity is a change of

measured signal per analyte

concentration unit, i.e., the slope

of a calibration graph. This

parameter is sometimes confused

with the detection limit.

Selectivity refers to characteristics

that determine whether a sensor

can respond selectively to a group

of analytes or even specifically to a

single analyte.

Stability is the ability of a sensor

to provide reproducible results for

a certain period of time. This

includes retaining the sensitivity,

selectivity, response, and recovery

time.

Response time is the time

required for sensor to respond to a

step concentration change from

zero to a certain concentration

value.

Materials Advantages Disadvantages Target Gases and Application Fields

Metal Oxide

Semiconductor

(a) Low cost

(b) Short response time

(c) Wide range of target gases

(d) Long lifetime

(a) Relatively low sensitivity

and selectivity

(b) Sensitive to environmental factors;

(c) High energy consumption.

Industrial applications and civil use

Polymer

(a) High sensitivity

(b) Short response time

(c) Low cost of fabrication

(d) Simple and portable structure

(e) Low energy consumption

(a) Long-time instability

(b) Irreversibility

(c) Poor selectivity

(a) Indoor air monitoring

(b) Storage place of synthetic

products as paints, wax or fuels

(c) Workplaces like chemical

industries.

1D and 2D

Materials

(a) Ultra-sensitive

(b) Great adsorptive capacity

(c) Large surface-area-to-volume

ratio

(d) Quick response time

(e) Low weight

(a) Difficulties in fabrication and

repeatability

(b) High cost

HCN, NH3, NO2, CH4, CO, PH3, NO etc.

Methods

Optical Methods

(a) High sensitivity, selectivity

and stability

(b) Long lifetime

(c) Insensitive to environment

change

(a) Difficulty in miniaturization

(b) High cost.

(a) Remote air quality monitoring

(b) Gas leak detection systems with

high accuracy and safety

(c) High-end market applications

Gas

Chromatograph

(a) Excellent separation

performance

(b) High sensitivity and selectivity

(a) High cost;

(b) Difficulty in miniaturization for

portable applications.

Typical laboratory analysis

Few Popular sensing Materials/Methods

Graphene as Sensor in 2007

Graphene Foam :Detects Explosives, Emissions Better Than Today's Gas Sensors

• Prof. Hui-Ming Cheng, from Chinese Academy of Sciences’ Shenyang National Laboratory forMaterials Science, and Nikhil Koratkar, a Professor at Rensselaer Polytechnic Institute, hasused graphene foam as a gas sensor to detect harmful explosive chemicals, paving the way tothe commercialization of the next-generation of gas sensors based on nanostructures.

• The discovery opens the door for a new generation of gas sensors to be used by bombsquads, law enforcement officials, defense organizations, and in various industrial settings.

Nanosensors

Nanosensors are nano scale sized device that can be used to detect the presence of

chemical species and nanoparticles, or monitor physical parameters such as temperature,

via using nanomaterials or nanoparticles.

External Force

Nanosensors

Adsorption:

The process in which a molecule becomesadsorbed onto a surface of another phase.

CASE I – Physical Adsorption (Physisorption):

In the case of pure physisorption (e.g.Ar /metals), the only attraction between theadsorbing species and the surface arises fromweak, van der Waals forces.

CASE II– Chemical Adsorption(Chemisorption):

Involves the formation of new chemical bondsbetween the adsorbed species and the surfaceatoms of the substrate

Nano-Sensors

Physisorption

Chemisorption

Nano-Sensors …

Test a material as Sensor?

Current – Voltage Analysis

Nano-Sensors

Adsorption Energy:

𝑬𝒂𝒅𝒔𝒐𝒑𝒕𝒊𝒐𝒏

= 𝑬𝑻𝒐𝒕𝒂𝒍 − 𝑬𝑴𝒐𝒍𝒆𝒄𝒖𝒍𝒆 + 𝑬𝑮𝒓𝒂𝒑𝒉𝒆𝒏𝒆

ETotal is the total energy of the system, EMolecule and EGraphene represent the total energy of the individual molecule and

graphene.

Formation Energy:

𝑬𝑪𝒐𝒉𝒆𝒔𝒊𝒗𝒆 =𝑬𝑻𝒐𝒕𝒂𝒍 − 𝒏𝒙𝑬𝒙

𝑵ETotal is the total energy of the system. Whereas nx, Ex and N are the no. of atoms, energy of individual atom and N is total no. of atoms respectively, beside x represents an individual atom

Sensitivity:

S is sensitivity, G is final conductance after absorption of molecule, G0 is initial conductance of system before adsorption.

Recovery time:

𝛕 = 𝝂−𝟏 𝐞𝐱𝐩 (−𝑬𝒂𝒅𝒔𝒐𝒓𝒑𝒕𝒊𝒐𝒏/𝑲𝒃𝐓)

ν is the attempt frequency, Kb is Boltzmann constant and T is temperature

System Ead d (Å) Q (e)

H2S on Graphene

CO on Graphene

NO on graphene

NH3 on Graphene

NH3 on B-Graphene

NH3 on Si-Graphene

0.03

0.05

0.02

0.14

0.10

0.55

3.81

3.74

4.35

3.30

3.26

2.53

0.03

0.12

0.06

0.001

0.001

0.22

NH3 on Boron Nitride 0.53 3.32 0.05

NO on Silicene Sheet

NO on Al-Silicene

NO on P-Silicene

0.27

0.27

4.35

1.76

1.62

0.67

-0.53

-0.82

-0.61

NH3 on Phospherene 0.50 3.05 0.10

NO2 on Phsospherene 0.90 1.98 -0.20

NH3 on Arsenene 0.87 3.01 0.11

NO2 on Arsenene 0.81 1.88 -0.95

NH3 on Antimonene 0.04 3.44 0.07

NO2 on Antimonene 0.39 2.49 -0.30

Few Examples

Chiral CNT as HCN sensorBinding energy: 0.08eV

Mulliken Charge transfer is 0.03e

Pristine I-HCN adsorbed 2-HCN adsorbed

Sumit Jain, Anurag Srivastava, Rajeev Ahuja, V. K. Rao, Journal of Molecular Modeling (2015)

Sumit Jain, Anurag Srivastava, Rajeev Ahuja, V. K. Rao, Journal of Molecular Modelling (2015)

Conductance as a function of Temperature for pristine and with single and double HCN molecule at CNT surface

Sumit Jain, Anurag Srivastava, Rajeev Ahuja, V. K. Rao, Journal of Molecular Modelling (2015)

Current vs electrode biasing plot of SWCNT for different cases

Accepted in Journal of Molecular Modeling (Springer)

10,0 CNT as Methane sensor

Fig-1(a) Geometry of (10,0) Carbon nanotube and (b) Two probe device model for conductance measurement in presence of methane molecule

NO2 adsorption behavior on germanene

a)

b)

c)

a) Pristine germenene

b) Indium substituted germanene

c) Phosphorus substituted germanene

a) NO2 adsorbed on position ‘A’ (Upper layer Ge-

atom)

b) NO2 adsorbed on position ‘B’ (lower layer Ge-

atom)

a)

b)

c) NO2 adsorbed on position upper layer In-atom)

d) NO2 adsorbed on position lower layer In-atom)

c)

d)

e) NO2 adsorbed on position upper layer P-atom)

f) NO2 adsorbed on position lower layer P-atom)

e)

f)

Calculated energy, dipole moment and point group of germanene nanosheets

Electronic transport properties of BN sheet on adsorption of ammonia (NH3) gas

Initial structure of (a) pristine BN sheet and (b) ammonia molecule

A schematic representation of two probe model of black phosphorene

device and optimized structure of two probe configuration with length

of scattering region (covering both cyan and white region in Z-

direction) is 28Å and length of free standing BP layer(covering white

region along Z-direction is 20Å.

M. S. Khan, A. Srivastava and R. Pandey Applied Surface Science 356 (2015) 881–887

NH3 and NO2 sensing through Black Phospherene

Observation ATK-VNL Gaussian03 Other report

Bond lengthIn-Plane (P-P) 2.24Å 2.24 Å 2.22Å

Other orientation (P-P) 2.27 Å 2.29 Å 2.28Å

Charge transfer NH3( to surface) 0.1e 0.08e

NO2(from surface) 0.196e 0.163e

Minimum surface-

molecule distance

NH3 3.05 2.96 Å 2.14Å

NO2 1.98 1.85Å 2.22Å

Adsorption EnergyNH3 0.5eV 0.12eV 0.5eV

NO2 0.9eV 0.23eV 0.62eV

Comparative description observed with ATK-VNL and Gaussian03 calculations

M. S. Khan, Anurag Srivastava and R. Pandey RSC Advances (Royal Society of Chemistry). 6, 72634, 2016.

NH3/NO2 adsorbed buckled arsenene monolayer

Transmission spectra at different applied bias voltage for (a)

arsenene, (b) NH3-arsenene and (c) NO2-arsenene.

I–V relationship for pristine and NH3/NO2

exposed arsenene sheet.

Arsenene-based device: current–voltage characteristics

NH3/NO2 sensitivity of Buckled antimonene: A DFT study

Optimized Super cell consist of 32 Sb atoms with some geometrical parameters.

a)

b)

Front and side view of optimized a) NH3 and b) NO2 over antimonene surface.

Schematic presentations of two probe device modelwith antimonene as electrodes and conductingchannel. Scattering region consist of three partsnamely, left electrode extension, central region andright electrode extension.

0.0 0.5 1.0 1.5 2.0 2.5 3.0

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

13000

14000

15000

16000

Cu

rre

nt

(in

nA

)

Bias Voltage (in eV)

Antimonene

NH3-Antimonene

NO2-Antimonene

Current -voltage plot derived fromtransmission coefficient of antimonenein pristine and with NH3/NO2

presence.