- Multi Layer (Tandem) Solar Cells
Better conversion efficiencies are possible by using multiple layers of differing semiconductor materials, optimised for different wavelengths, in a single device. This can raise the theoretical efficiency limit, currently about 30% for a single junction device, to about 45% for a three junction cell.
Efficiencies of over 33% have already been achieved in practical devices.
Materials such as Gallium Arsenide, Copper Indium Diselenide, Cadmium Telluride and Indium Nitride have been employed to provide particular characteristics to optimise solar cells for specific applications.
Gallium Arsenide is used for military and aerospace applications in a variety of cells in combination with other elements because of it's suitability for capturing high energy photons (ultra violet radiation), high potential conversion efficiency and its ability to withstand high temperatures. It is however more difficult to manufacture and cells using Gallium Arsenide can be 100 times more expensive than commercial silicon based cells.
Copper Indium Diselenide and Cadmium Telluride are used in polycrystalline form in low cost thin film cells because of their ease of manufacture and reasonable yields. Efficiencies are however low ranging from 8% to 14%
Indium Nitride is suitable for capturing low energy photons (infra red radiation) making it suitable for full spectrum devices when used in tandem solar cells in combination with other materials such as Gallium Arsenide which capture the high energy photons.
- Electrochemica l Solar Cells - Dye Sensitised Solar Cells (DSSC or Grätzel Cells)
Relatively new, these cells are low cost devices which use dye sensitised Titanium dioxide in combination with a liquid electrolyte to generate the current. Up to now they are only available in small sizes with efficiencies between 7% and 10%
- Sola r energy doesn’t pollute the air like power plants that rely on combustion of fossil fuels.
- Solar doesn’t produce atmospheric emissions that causes acid rain or green house gases.
- The Solar is free with modern technology it can be captured efficiently.
- Economic benefits, it is one of the lowest priced renewable energy technologies available today.
- This greatly benefits the economy in Industrial areas.
- Eco friendly
- Easy handling.
- More efficient.
- Less effort more power
- Save of power.
- Very cheap
- It is a limit less resource
- Energy generated without polluting environment
- The power generated produced can be harnessed to send power across the gird.
- It can be used for any moving automation
- In material management system
- For lifting heavy objects
- Also for human locomotion
- For transportations
- Can be implanted at shopping mall