Compound Semiconductor Solar Cells On Si Substrate For Medium Concentrator Photovoltaic Applications

摘要

We investigated the triple and dual junction solar cells on Si substrate, using III-V compound semiconductor for medium concentrator photovoltaic (MCPV) applications by using TCAD tool (APSYS 2010). The conversion efficiency was investigated as a function of threading dislocation density (TDD) for two different candidate device structures. The multi-junction solar cells on Si showed that heterobarrier can be the main source of series resistance (R_s) of device. Si and Ge doping concentration should be higher than 5×10~(18) cm~(-3) to evade solar cell fill factor reduction due to heterobarrier at the interface of Ge and Si. Based on simulation results, compound semiconductor on Si substrate can achieve over 30% conversion efficiency at 100 suns with TDD of 10~6 cm~(-2). Simulation results show that III-V multi-junction solar cell on Si is a good candidate for low cost CPV market, especially for medium concentration photovoltaic application.