GaN/Cu2O Heterojunctions for Photovoltaic Applications

Several growth methods were employed to investigate the photovoltaic behavior of GaN/Cu2O heterojunctions by depositing cuprous oxide thin films on top of gallium nitride templates. The templates consist of a thin layer of GaN:Si grown on a sapphire substrate by metal organic vapor deposition. The deposition procedure was followed up by photolithographic structuring and thermal evaporation of metal contacts. For device characterization, J-V characteristics and external quantum efficiency were measured, pointing to a possible energy barrier in the conduction band. To gain further insight X-ray photoelectron spectroscopy was applied.