Efficiency of Heterojunction Solar Cells Based on Optical Band Gap

Electric energy production by fuel burning produces dangerous pollutants. The photovoltaic solar cell is a suitable alternative. For thin film solar cells, efficiency improvement should be carried out through continued development of their characteristics. The homojunction solar cell has reached its optimum. In the present work, a relationship between optical band gap and solar cell efficiency of heterojunctions has been established. Suitable band gaps of a pair of heterojunctions are required to get maximum efficiency for an appropriate frequency of solar radiation. The efficiency of a couple of extrinsic semiconductors can be calculated theoretically. An optimum band gap of a pair of heterojunctions with the highest efficiency may be found by this process. The efficiency of a few heterojunctions has been calculated using reported data. The results show that efficiency is increased with optical band gaps, and type-I is more efficient than type-II heterojunctions. The work may help to improve the solar cell efficiency.