Nanomaterials have various applications in semiconductors and solar cells. In solar cells, silicon nanocrystals called porous silicon are used, as well as dye-sensitized solar cells using titanium dioxide nanoparticles and dye molecules. Quantum dot solar cells use nanosized semiconductor crystals such as cadmium sulfide. Polymer solar cells offer flexibility and low cost. Semiconductors are also used in devices like light-emitting diodes and transistors. Common applications of solar cells include powering toys, watches, calculators and remote lighting as well as water pumping and emergency power supplies.

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