Enhancing efficiency of a heteroface solar cell

A p-AlGaAs/p/sup +/-GaAs/n-GaAs/n-AlGaAs has been analyzed to evaluate the effectiveness of GaAs/AlGaAs heterojunction at the back end of a p/n heteroface solar cell. The difference in the band gaps of GaAs and AlGaAs, together with their excellent lattice match, works as an effective minority carrier mirror at the back end and hence reduces the overall minority carrier recombination. It has been found that the conversion efficiency of such a cell due to the use of GaAs-AlGaAs heterojunction at the back, improves by around 3% compared to that of a conventional p/n heteroface cell.