Large Irreversible Lateral Photovoltaic Effect in $\hbox {Cu}_{2}\hbox {O/Si}$ Heteroepitaxial Junction

A rather large irreversible lateral photovoltage (LPV) effect has been observed in Cu₂O/Si heteroepitaxial junctions. Large output voltage and high linearity indicate that a Cu₂O/Si heterojunction is competent to be a new candidate for position-sensitive photodetectors. The irreversible LPV on both sides of the junction challenges the Dember effect which was usually introduced to explain this phenomenon in oxide heterojunctions. A mechanism based on the difference of carrier mobility in each side of the junction has been applied, and a diffusion recombination model is later confirmed experimentally by applying an external bias.