INORGANIC CHEMISTRY

1. INSTITUTE OF SCIENCE.
15, MADAM CAMA ROAD

2.  what are the applications of nanomaterials in the
field of semiconductors and solar cell ? [ march 15, 14 ]
Questions

3. Introduction…
 NANOTECHNOLOGY:
Is science of understanding the structure & behaviour of materials
at atomic or molecular level.
 NANOMATERIALS:
materials of which single unit size is between 1 to 100nm.
 SEMICONDUCTORS:
Are materials whose electric properties lie between conductor &
insulator
 Example : fine crystalline solids (silicon , germanium)

4.  Application of semiconducting materials :
 Silicon :
prime material in semiconductor industry & widely used in
manufacturing of integrated circuit.
Si wafer in photovoltaic cells used to convert
light energy to electrical energy.
Porous silicon :
Nanocrystalline silicon is called porous silicon.
It has interesting biological application .
Also it is used in glucose monitoring system.
Application of semiconductor

5.  Application of semiconductor devices:
 Semiconductor diode ;
 It is simple p-n junction diode which
used to generate light ,
light emitting diodes &
laser diodes.
 Transistors :
 Device used to amplify and
switch electronic signals.

6.  Device that convert solar energy directly to electrical
energy .
 It is clean form of energy without consumption of any fuel.
 Types of solar cell:
 1. Photovoltaic solar cell i.e. P-N diode
 2. Dye sensitized photovoltaic solar cell
 3.Quantum dot solar cell
 4. Organic / polymer photovoltaic cell
Solar cell

7.  Simplest form is P-N diode in single material.
 The diode is formed by diffusing n-type dopant from one side of p-
type semiconductor or diffusing p-type dopant in n-type semiconductor.
Photovoltaic solar cell

8.  When photon of energy larger than the energy gap is
incident on the cell , electrons are excited to
conduction band and various processes as depicted.
 It can be seen that there are different sources of
losses of photons & charges.
 Efficiency of solar cell is

9.  First solar cell based on nanomaterials & called Grazel cell .
 Use nanoparticle of TiO2 & dye molecule .
 Efficiency of cell is only ~11%
 Working:
TiO2 particles are deposited on
glass substrate with conducting
coating like FTO .
Iodine layer acts as electrolyte.
Another glass substrate coated
With platinum serve as second electrode this two connected by external
circuit.
 TiO2 nanoparticles are randomly deposited. This obstacle for generation
of charge carriers to reach electrode which reduced efficiency of cell.
Dye sensitized photovoltaic solar cell

10.  Quantum dots are nanosized semiconducting crystals made up of
100-100,000 atoms.
 Solar cells are used quantum dots of CdS , CdSe , PbS and PbSe .
 These cell absorb visible and or / IR part of solar spectrum.
 They can be replace liquid dye used in dye sensitized solar cell.
Quantum dot solar cell

11.  Polymer solar cell is type of flexible solar cell.
 They are more stable .
 These are light weight which is important for small
autonomous sensors.
 The most important advantage of use of organic/
polymer is their low cost & possibility to easy
processing & they are disposable.
Organic / polymer photovoltaic cell

12.  Three types of organic solar cell .

13.  Toys , watches , calculators
 Remote lighting systems
 Electric fences
 Water pumping
 Emergency power
 Portable power supplies
 Satellites
Application of solar cell

14.  SOLID STATE PHYSICS 7th EDITION BY S.O.PILLAI
 NANOTECHNOLOGY : PRINCIPLES AND PRACTICES 3rd
EDITION BY DR. SULBHA KULKARNI
References

15.  Thank you