title: High-Performance Self-powered Photodetectors Based on ZnO/ZnS Core-Shell Nanorod Arrays.
abstract: In recent years, there is an urgent demand for high-performance ultraviolet photodetectors with high photosensitivity, fast responsivity, and excellent spectral selectivity. In this letter, we report a self-powered photoelectrochemical cell-type UV detector using the ZnO/ZnS core-shell nanorod array as the active photoanode and deionized water as the electrolyte. This photodetector demonstrates an excellent spectral selectivity and a rapid photoresponse time of about 0.04 s. And the maximum responsivity is more than 0.056 (A/W) at 340 nm, which shows an improvement of 180 % compared to detectors based on the bare ZnO nanorods. This improved photoresponsivity can be understood from the step-like band energy alignment of the ZnO/ZnS interface, which will accelerate the separation of photoexcited electron-hole pairs and improve the efficiency of the photodetector. Considering its uncomplicated low-cost fabrication process, and environment-friendly feature, this self-powered device is a promising candidate for UV detector application.
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Hailing
authors.initials: H
authors.lastname: Lin
authors.affiliation: School of Microelectronics, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Cuncun
authors.initials: C
authors.lastname: Wu
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China. cyx@sdu.edu.cn.
authors.forename: Yanxue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Shishen
authors.initials: S
authors.lastname: Yan
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Liangmo
authors.initials: L
authors.lastname: Mei
authors.affiliation: Department of Mechanical and Materials Engineering, Portland State University, P.O. Box 751, Portland, OR, 97207-0751, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiao
keywords: Nanorod arrays; Self-powered; Ultraviolet photodetectors; ZnO/ZnS heterojunction