Ultrasensitive and Ultrafast Self-Powered Ultraviolet Photodetector Array for Solar-Blind and Weak-Light Imaging.

Deng, Weilong; Fan, Xiangyu; Du, Yuxuan; Ma, Shengyu; Zhang, Hanxu; Liu, Mengting; Zhang, Hao; Chen, Shuo et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

Self-powered ultraviolet (UV) photodetectors (PDs) based on wide bandgap semiconductors (WBGSs) and their heterostructures face challenges in ultrasensitive and ultrafast weak-light detection capabilities. In this work, an 8 × 8 UV photodetector array based on CuNiO<sub>2</sub>/SiC p-n heterojunctions is demonstrated to operate in both solar-blind and weak-light conditions. The device achieves a weak-light detection limit of 4.6 nW·mm<sup>-2</sup>, a fast response time of 45 ns, and a high responsivity of 104.2 mA·W<sup>-1</sup> and a detectivity of 3.4 × 10<sup>12</sup> Jones, outperforming self-powered UV PDs based on SiC and Ga<sub>2</sub>O<sub>3</sub>-based WBGSs and their heterostructures. This excellent performance of the device originates from the high interface quality, large built-in electric field, Fowler-Nordheim tunneling (FNT) of charge transport, and enhancing light absorption at the heterostructures. Moreover, the detector exhibits a low noise power density below 10<sup>-22</sup> A<sup>2</sup>·Hz<sup>-1</sup> and a high cutoff frequency of 5 kHz, enabling it to maintain high-contrast real-time reflection imaging capability under solar illumination.