Bias-assisted improved lateral photovoltaic effect observed in Cu2O nano-films

A large lateral photovoltaic effect (LPE) has been observed in a Cu2O/Si heterojunction structure when its surface is illuminated by a laser. Moreover, with external bias voltage, the maximal LPE sensitivity can reach up to 1114 mV/mm, which is almost 10 times larger compared with its initial non-biased value of 113 mV/mm. We ascribe this phenomenon mainly to the effect of the increased photo-generated holes caused by the bias. Giant output voltage and high sensitivity suggest the potential of Cu2O nano-films could be used in a wide variety of applications for position-sensitive photodetectors.