Solution-Processed P-type Copper Gallium Oxide as a Back Buffer Layer for CdTe Solar Cells

Here, we report the solution-based synthesis of CuGaOX thin film, and its optimization for application as a back buffer layer in CdS/CdTe solar cells. The CuGaOX composition was optimized for best results by varying copper source concentration and annealing time post spin-coating. Minority carrier lifetimes and device parameters were recorded. For glass-side illumination, the best cell exhibited an improved efficiency of 14.6% mainly due to a significant increase in V OC (V OC = 863 mV, FF = 74.4%, J SC = 22.7 mA/cm2) compared to the standard device (Cu/Au back contact) best cell efficiency of 13.0% (V OC = 818 mV, FF = 75.9%, J SC = 21.0 mA/cm2).