Influence of SnO₂, ZnO and TiO₂ layer on the performance of CIGS and CdTe solar cells

As a type electron transmission layer, SnO₂, ZnO and TiO₂ layer were applied as a buffer between transparent conductive oxide and n-CdS layer in CIGS and CdTe solar cells. J-V curve of device with three different buffer layer were simulated theoretically through Poisson equation and electron-hole continuity equation. Open-circuit voltage, short-circuit current, fill factor and conversion efficiency were derived. It's shown that for CdTe solar cells, performance of device with three kind of buffer layers SnO₂, ZnO and TiO₂ did not differ two much. While for the CIGS solar cells, device with TiO₂ showed a small fill factor, then leading to a lower conversion efficiency. Transparent oxide SnO₂ and ZnO were suggested for the buffer layer for optimization CIGS and CdTe solar structure depending on the art of manufacturing.