Solution-Processed Copper-Doped Chromium Oxide With Tunable Oxygen Vacancy For Crystalline Silicon Solar Cells Hole-Selective Contacts

Compared with vacuum evaporation, metal oxides deposited by solution process exhibit advantages, for example, dopants can be easily incorporated in a wide range and the contents are easy to be regulated by changing the composition of precursors. Herein, solution-processed p-type copper-doped chromium oxide (Cu:CrOx) films with tunable oxygen vacancy are demonstrated via a postannealing process. The synthetic and postannealing temperature have a significant impact on the chromium cation oxidation state in the Cu:CrOx films, leading to the variation of work function for the oxide films. By adjusting the work function of Cu:CrOx films, a low contact resistivity of 95 m Omega cm(2) can be realized for the Ag/Cu:CrOx/p-Si contact. Finally, the optimized Cu:CrOx films are used as the hole transporting layer in c-Si solar cells, showing an increased power conversion efficiency from 15.2% (without Cu:CrOx) to 16.9% (with Cu:CrOx). The results show an effective stage to use p-type metal oxides as a hole-selective layer in c-Si solar cells.