Self-powered dual-mode UV detector based on GaN/(BA)₂PbI₄ heterojunction

Abstract

As an important part of an intelligent photoelectric system, ultraviolet detectors have been widely used in many fields in recent years. The research on self-powered heterojunction photodiode is particularly important. In this paper, a dual-mode self-powered GaN/(BA)₂PbI₄ heterojunction Ultraviolet (UV) photodiode is prepared and discussed. The GaN film was deposited on sapphire by metal-organic chemical vapor deposition (MOCVD), and then the (BA)₂PbI₄ film was spin-coated onto the surface of the GaN film to construct a planar heterojunction detector. The X-ray diffraction (XRD), EDS mapping and SEM measurements were used to determine the quality of GaN and (BA)₂PbI₄ thin films. When exposed to the 365 nm light illumination with a power density of 421 μW/cm² at 5 V bias, the responsiveness (R) and external quantum efficiency (EQE) are 60 mA/W and 20%, respectively. In self-powered mode, the rise time (τ_r) and decay time (τ_d) are 0.12 s and 0.13 s, respectively; illustrating the fast photogeneration and recombination processes for photo-excited electron-hole pairs. And, the <i>R</i> is 1.96×10^-4 mA/W owing to the development of space charge region across the interface of GaN and (BA)₂PbI₄ thin films. The outcomes of this study unequivocally demonstrate the extensive potential and wide-ranging applicability of self-powered UV photodiodes based on the GaN/(BA)₂PbI₄ heterojunction configuration. Moreover, this research presents a new concept that provides a way for novel avenues and innovative approaches in the ongoing development of intelligent optoelectronic systems.