Inverse Metamorphic III-V/epi-SiGe Tandem Solar Cell Performance Assessed by Optical and Electrical Modeling

Recent developments have unlocked the main issues arising from the combination of III-V and silicon and have opened a new way to fabricate tandem solar cells. We here propose to evaluate such tandem concept based on inverse metamorphic growth of c-Si(Ge) on GaAs by means of numerical simulation. Electrical and optical models are first faced to experimental realizations of single junction cells to calibrate material parameters and to assess the electrical quality of the epi-SiGe layer. Then the tandem structure is optimized, current matching conditions are given and the benefit of using a 2D grating at the back-side is studied.