Self-powered ZnS Nanotubes/Ag Nanowires MSM UV Photodetector with High On/Off Ratio and Fast Response Speed

• Published in: Scientific reports Vol. 7; no. 1; pp. 4885 - 12
• Main Authors: An, Qinwei, Meng, Xianquan, Xiong, Ke, Qiu, Yunlei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.07.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005/1009; 639/301/357/551; 639/925/927/356; Humanities and Social Sciences; multidisciplinary; Nanotechnology; Nanotubes; Nanowires; Photoresponse; Photovoltaics; Science; Science (multidisciplinary); Self; Vacuum
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-05176-5

In this study, we design and demonstrate a novel type of self-powered UV photodetectors (PDs) using single-crystalline ZnS nanotubes (NTs) as the photodetecting layer and Ag nanowires (NWs) network as transparent electrodes. The self-powered UV PDs with asymmetric metal-semiconductor-metal (MSM) structure exhibit attractive photovoltaic characteristic at 0 V bias. Device performance analysis reveals that the as-assembled PDs have a high on/off ratio of 19173 and a fast response speed (τ r  = 0.09 s, τ f  = 0.07 s) without any external bias. These values are even higher than that of ZnS nanostructures- and ZnS heterostructure-based PDs at a large bias voltage. Besides, its UV sensivity, responsivity and detectivity at self-powered mode can reach as high as 19172, 2.56 A/W and 1.67 × 10 10 cm Hz 1/2 W −1 , respectively. In addition, the photosensing performance of the self-powered UV PDs is studied in different ambient conditions (e.g., in air and vacuum). Moreover, a physical model based on band energy theory is proposed to explain the origin of the self-driven photoresponse characteristic in our device. The totality of the above study signifies that the present self-powered ZnS NTs-based UV nano-photodetector may have promising application in future self-powered optoelectronic devices and integrated systems.