Air-Stable Self-Driven UV Photodetectors on Controllable Lead-Free CsCu<sub>2</sub>I<sub>3</sub> Microwire Arrays
Zhihong Zhang, Shanshan Yan, Yulong Chen, Zhen Dong Lian, Ai Fu, Youchao Kong, Lin Li, Shichen Su, Kar Wei Ng, Zhipeng Wei, Hongchao Liu, Shuangpeng Wang
Abstract
High Resolution Image Download MS PowerPoint Slide The rapid evolution of the Internet of Things has engendered increased requirements for low-cost, self-powered UV photodetectors. Herein, high-performance self-driven UV photodetectors are fabricated by designing asymmetric metal–semiconductor–metal structures on the high-quality large-area CsCu 2 I 3 microwire arrays. The asymmetrical depletion region doubles the photocurrent and response speed compared to the symmetric structure device, leading to a high responsivity of 233 mA/W to 355 nm radiation. Notably, at 0 V bias, the asymmetric device produces an open-circuit voltage of 356 mV and drives to a short-circuit current of 372 pA; meanwhile, the switch ratio ( I ph / I dark ) reaches up to 10 3, indicating its excellent potential for detecting weak light. Furthermore, the device maintains stable responses throughout 10000 UV-light switch cycles, with negligible degradation even after 90-day storage in air. Our work establishes that CsCu 2 I 3 is a good candidate for self-powered UV detection and thoroughly demonstrates its potential as a passive device.