title: NIR Schottky photodetectors based on individual single-crystalline GeSe nanosheet.
abstract: We have synthesized high-quality, micrometer-sized, single-crystal GeSe nanosheets using vapor transport and deposition techniques. Photoresponse is investigated based on mechanically exfoliated GeSe nanosheet combined with Au contacts under a global laser irradiation scheme. The nonlinearship, asymmetric, and unsaturated characteristics of the I-V curves reveal that two uneven back-to-back Schottky contacts are formed. First-principles calculations indicate that the occurrence of defects-induced in-gap defective states, which are responsible for the slow decay of the current in the OFF state and for the weak light intensity dependence of photocurrent. The Schottky photodetector exhibits a marked photoresponse to NIR light illumination (maximum photoconductive gain ∼5.3 × 10(2) % at 4 V) at a wavelength of 808 nm. The significant photoresponse and good responsitivity (∼3.5 A W(-1)) suggests its potential applications as photodetectors.
authors.affiliation: Department of Physics, National University of Singapore (NUS) , 2 Science Drive 3, Singapore 117542.
authors.forename: Bablu
authors.initials: B
authors.lastname: Mukherjee
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Cai
authors.forename: Hui Ru
authors.initials: HR
authors.lastname: Tan
authors.forename: Yuan Ping
authors.initials: YP
authors.lastname: Feng
authors.forename: Eng Soon
authors.initials: ES
authors.lastname: Tok
authors.forename: Chorng Haur
authors.initials: CH
authors.lastname: Sow