Self-Powered Broadband Schottky Junction Photodetector Based on a Single Selenium Microrod

The design of self-powered photodetectors that can operate under harsh conditions attracts widespread research attention, because of their potential applications in space exploration and environmental monitoring. Herein, we report a convenient approach to fabricate Se microrods and subsequently to develop self-powered Schottky junction photodetectors by depositing liquid In–Ga alloy on one side of a single Se microrod. The low dark current (200 fA), high responsivity (408 mA/W), strong detectivity (1.30 × 1013 Jones), and ultra-short response/decay time (124/146 μs) are achieved for this Se microrod-based photodetector. A binary response phenomenon, that is, the detected current alternates between the positive and negative state when the light is switched on and off, is observed at a low reverse bias. More interestingly, the device exhibits a stable and quick photoresponse even at an operating temperature as low as 100 K, demonstrating its promising utilization in space exploration.