Flexible assembly of the PEDOT: PSS/ exfoliated β-Ga<sub>2</sub>O<sub>3</sub> microwire hybrid heterojunction for high-performance self-powered solar-blind photodetector
Zhihua Zheng, Wen Wang, Feng Wu, Zhiyuan Wang, Maocheng Shan, Yongming Zhao, Weijie Liu, Pengcheng Jian, Jiangnan Dai, Hai Lu, Changqing Chen
Abstract
Motivated by the goals of fabricating highly reliable, high performance, and cost-efficient self-powered photodetector (PD) for numerous scientific research and civil fields, an organic-inorganic hybrid solar-blind ultraviolet (UV) PD based on PEDOT: PSS/exfoliated β-Ga 2 O 3 microwire heterojunction was fabricated by a flexible and cost-effective assembly method. Benefiting from the heterojunction constructed by the highly crystalline β-Ga 2 O 3 and the excellent hole transport layer PEDOT: PSS, the device presents a high responsivity of 39.8 mA/W at 250 nm and a sharp cut-off edge at 280 nm without any power supply. Additionally, the ultra-high normalized photo-to-dark current ratio (> 10 4 mW -1 cm 2 ) under reverse bias and the superior detectivity of 2.4×10 12 Jones at zero bias demonstrate the excellent detection capabilities. Furthermore, the hybrid PD exhibits a rapid rise time (several milliseconds) and high rejection ratio (R 250 /R 365 : 5.8 × 10 3 ), which further highlights its good spectral selectivity for solar-blind UV. The prominent performance is mainly ascribed to the efficient separation of the photogenerated carriers by the large built-in electric field of the advanced heterojunction. This flexible assembly strategy for solar-blind UV PD combines the advantages of high efficiency, low cost and high performance, providing more potential for PD investigation and application in the future.