多孔GaN/MoO₃异质结窄带响应紫外光电探测器

Narrow-Band UV Photodetector Based on Porous GaN/MoO₃ Heterojunction

摘要: 紫外光电探测器在空间天文望远镜、军事导弹预警、非视距保密光通信、野外火灾遥感和生化检测等方面具有非常广泛的应用前景。本文介绍了一种基于GaN纳米孔阵列/MoO₃异质结紫外光电探测器。通过简单的光电化学刻蚀方法，将平面u-GaN刻蚀成均匀的纳米孔，以减少表面缺陷，增强光吸收。在多孔GaN材料上沉积MoO₃薄膜，制成多孔GaN/MoO₃异质结。实验结果表明，该紫外光探测器在−3 V偏压下的光开/关比超过10³；与纯多孔GaN器件相比，异质结器件的响应度和外量子效率均提高了两个数量级。此外，该异质结器件具有窄带响应，半峰宽度仅10 nm。这种具有高开关比、高量子效率和窄带响应特性的光电探测器有望实现在荧光检测、成像和紫外光通信方面的应用。

Abstract: UV photodetectors have very broad application prospects in space astronomy, military missile early warning, non-line-of-sight confidential optical communication, remote sensing and biochemical detection etc. In this paper, a porous GaN/MoO₃ heterojunction UV photodetector is introduced. By a simple photoelectrochemical etching method, planar u-GaN was etched into uniform nanopores to reduce surface defects and enhance light absorption. The porous GaN/MoO₃ heterojunction was then constructed by depositing a thin MoO₃ film. Results show that the UV photodetector has a high light-to-dark of more than 10³ at −3 V bias; while the responsivity and external quantum efficiency of the heterojunction device are improved by two orders of magnitude compared to the pure porous GaN device. In addition, the heterojunction device exhibits a narrow-band response with a FWHM of only 10 nm. This porous GaN/MoO₃ photodetector featuring high on/off ratio, high quantum efficiency and narrow-band response characteristics may find applications in fluorescence detection, imaging and ultraviolet optical communication.