On the optical design of thin film amorphous silicon solar cells

We have developed an optical analysis method to design the structure of multi-layer thin film solar cells. The optimised thickness of the individual layers in any single as well as tandem type thin film a-Si:H solar cells ban be obtained. By minimising the reflectance using an optimal anti-reflection coating layer and selecting a suitable rear contact material, a significant increase in the photon collection efficiency at long wavelength can be achieved. The effect of the variation in the thickness of different layers on the performance characteristics of a cell is discussed. The calculated results and analyses show that the present theoretical approach can be used directly to design any thin film solar cell with an optimised structure for a desired high conversion efficiency