Distributed semiconductor heterojunctions of ZnO–Cu2O for ultraviolet photodetection

Abstract

Semiconductor heterojunctions, because of their unique optoelectronic properties, have gained significant attention for integrated photonic devices. UV photodetectors based on semiconductor heterojunctions are promising due to their enhanced light absorption, efficient charge separation, and tunable electronic properties, which collectively lead to superior sensitivity and performance. An inter-band transition-based UV photodetector utilizing Cu2O/ZnO distributed heterojunctions has been demonstrated. We propose an integrated photonic structure based on semiconductor heterojunctions in the form of Cu2O–ZnO grating for ultraviolet photodetection yielding a low dark current and improved efficiency. The Cu2O–ZnO grating heterostructure, in comparison to individual planar heterojunction, boosts light-matter interaction enabling higher absorption and enhanced responsivity. The device depicts a responsivity of 0.7A/W at 360nm wavelength. The device exhibits a broadband absorption which remains good over a broad wavelength range from 250nm to 450nm. The reported UV photodetector may find applications in environmental monitoring, UV light communication, biomedical diagnostics, and industrial safety. © 2024