Ultrasensitive dynamic ultraviolet imaging based on a Ga <sub>2</sub> O <sub>3</sub> photodetector array
Tiwei Chen, Nan Liu, Suzhen Cheng, Xiaodong Zhang, Peng Ding, Chunhong Zeng, Li Zhang, Gaofu Guo, Yang An, Yu Hu, Zibo Li, Dengrui Zhao, Huanyu Zhang, Shige Dai, Jiawei Ye, Jingwu Gong, Zhanqiang Ru, Wenhua Shi, Zhongming Zeng, Helun Song, Baoshun Zhang
Abstract
Defects and noise in Ga 2 O 3 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/cm 2 , 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.