Deposition of earth-abundant p-type CuBr films with high hole conductivity and realization of p-CuBr/n-Si heterojunction solar cell

We present details of the deposition of transparent and earth-abundant p-type CuBr films with high hole conductivity and the fabrication and characterization of a prototype solar cell based on p-CuBr/n-Si heterojunctions. p-type CuBr films with typical resistivities and hole concentrations of 7×10−1 Ω cm and 7.5×1019 cm−3, respectively, are deposited by thermal evaporation followed by oxygen plasma treatment. The transparent p-type films show strong room temperature photoluminescence at ~2.97 eV. The current voltage (I-V) characteristics of the heterojunctions show good diode behaviour. Power conversion efficiency of ~2% was achieved for the heterojunction device without any optimization of the cell structure under AM 1.5 illumination condition with a short circuit current (Jsc) and open circuit voltage (Voc) of 13.2 mA/cm2 and 0.44 V, respectively.