title: Effect of electrical contact on the performance of Bi₂S₃ single nanowire photodetectors.
abstract: Bi2S3 single-crystalline nanowires are synthesized through a hydrothermal method and then fabricated into single nanowire photodetectors. Due to the different contact barrier between the gold electrode and Bi2S3 nanowires, two kinds of devices with different electrical contacts are obtained and their photoresponsive properties are investigated. The non-ohmic contact devices show larger photocurrent gains and shorter response times than those of ohmic contact devices. Furthermore, the influence of a focused laser on the barrier height between gold and Bi2S3 is explored in both kinds of devices and shows that laser illumination on the Au-Bi2S3 interface can greatly affect the barrier height in non-ohmic contact devices, while keeping it intact in ohmic contact devices. A model based on the surface photovoltage effect is used to explain this phenomenon.
authors.affiliation: State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (P.R. China).
authors.forename: Renxiong
authors.initials: R
authors.lastname: Li
authors.forename: Juehan
authors.initials: J
authors.lastname: Yang
authors.forename: Nengjie
authors.initials: N
authors.lastname: Huo
authors.forename: Chao
authors.initials: C
authors.lastname: Fan
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Lu
authors.forename: Tengfei
authors.initials: T
authors.lastname: Yan
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Wei
authors.forename: Jingbo
authors.initials: J
authors.lastname: Li
keywords: bismuth; nanostructures; photochemistry; semiconductors; sulfur