Nanoscale-Thick CuPc/β-Ga<sub>2</sub>O<sub>3</sub> p–n Junctions for Harsh-Environment-Resistant Self-Powered Deep-UV Photodetectors
Tianli Zhao, Huaile He, Chao Wu, Li Lai, Yanxiu Ma, Yang Hu, Haizheng Hu, Aiping Liu, Daoyou Guo, Shunli Wang
Abstract
Due to their crucial role in ultraviolet communication and monitoring, deep-ultraviolet (DUV) photodetectors have garnered much interest. Recently, Ga 2 O 3 has emerged as the best material for DUV photodetectors because of its ultrawide bandgap (4.5–4.9 eV), excellent UV photon absorption coefficient, high structural stability, and affordability. However, there are several difficulties in realizing high-performance Ga 2 O 3 -based DUV photodetectors with a high tolerance for harsh environments. In this work, nanoscale-thick CuPc/β-Ga 2 O 3 p–n junctions were used to build high-performance DUV photodetectors by a straightforward solution-processing approach. The p–n junction photodetectors exhibit improved photoelectric performance compared to a single device made of β-Ga 2 O 3 or CuPc, with a photo-to-dark current ratio of 3700 and a fast response time of ∼20 ms under a bias of 0 V. Due to the excellent stability of the nanoscale-thick CuPc film, the device can maintain a high photocurrent even at high temperatures or under long-term DUV irradiation. Our work provides an effective strategy toward highly harsh-environment-resistant DUV photodetectors.