NANO SCIENCE IN SOLAR ENERGY UNDER THE GUIDANCE OF xxxxxxxxxxxxxxxxxx BY xxxxxxxxxxxxxxxxxxxxx

Contents Introduction Photovoltaic cells Factors Affecting Conversion Efficiency First generation solar cells Second generation solar cells Third generation solar cells Quantum Dots Carbon nano tubes Conclusion

Introduction The use of conventional energy sources led to global warming and also their depletion. The photovoltaic (PV) cells that uses sunlight to generate clean electric power is a solution. Solar cells are simply not efficient enough and are currently too expensive to manufacture for large-scale electricity generation By using nanotechnology we can decrease cost of production and increase efficiency.

Photovoltaic cell A photon from the Sun generates an electron-hole pair in a semiconductor. The electron is pulled to the front, the hole to the back of the solar cell, thereby creating a battery.

Factors Affecting Conversion Efficiency Wavelength of Light Natural Resistance Temperature Reflection Electrical Resistance

Three generations of solar panels First generation These solar cells uses very high quality crystalline silicon. These are expensive to manufacture, and have a fairly low theoretical efficiency limit of around 20%.

Second generation PV cells use thin film technologies with other semiconducting materials such as cadmium telluride (CdTe) and copper indium gallium selenide (CIGS). These materials can significantly reduce processing costs, and promise much higher theoretical efficiencies than silicon-based PV materials.

Third generation: NANOTECH SOLAR CELLS In order to improve the conversion efficiency, the major research in third-generation PV cells is directed towards absorbing more sunlight using nanotechnology. Technologies often considered part of this third generation include quantum dots, nanostructured semiconductors

Quantum dot Solar cells Quantum dots are particles of semi conductor material with the size so small. This solar cell have many layers with different band gap in stack. each layer utilizes different wavelengths. Light absorption of quantum dot layers are more

Nanotubes In PV cells technology, the nanometer-scale tubes, coated by the special p-type and n-type semiconductor (p/n) junction materials can be used to generate electrical current, which would increase the surface area available to produce electricity.

Conclusion The production of solar energy, from the available sunlight, and its usage is more clean, safe and efficient. They are commercially available and are being utilized. The new upcoming technologies in renewable resources like nanotechnology solar cells helps us to increase the efficiency

THANK YOU!