Ultrasensitive dynamic ultraviolet imaging based on a Ga2O3 photodetector array.

Abstract

Defects and noise in Ga₂O₃ detectors have traditionally limited their practical application. In this work, by reducing the triethylgallium flow from 200 sccm to 50 sccm, oxygen vacancy was effectively suppressed, leading to a transition in noise from Lorentzian to flicker-type, with a significant decrease in noise current from 0.15 nA to 1.01 pA. This improvement enhanced the detector's performance, yielding high sensitivity (3.72 A/W), fast response time (τ_d1/τ_d2 = 1.6/13 ms), and solar-blind detection characteristics. Leveraging this low-noise detector, an 8 × 8 photodetector array and UV imaging system were developed, capable of target identification at distances up to 3 m, detecting UV radiation at intensities of 2.6 μW/cm², and capturing real-time spatial movement of point light sources. These advancements mark a significant contribution to the development of high-speed, high-sensitivity, solar-blind UV imaging systems.