title: Extraordinary photoresponse in two-dimensional In(2)Se(3) nanosheets.
abstract: We demonstrate extraordinary photoconductive behavior in two-dimensional (2D) crystalline indium selenide (In2Se3) nanosheets. Photocurrent measurements reveal that semiconducting In2Se3 nanosheets have an extremely high response to visible light, exhibiting a photoresponsivity of 3.95 × 10(2) A·W(-1) at 300 nm with an external quantum efficiency greater than 1.63 × 10(5) % at 5 V bias. The key figures-of-merit exceed that of graphene and other 2D material-based photodetectors reported to date. In addition, the photodetector has a fast response time of 1.8 × 10(-2) s and a specific detectivity of 2.26 × 10(12) Jones. The photoconductive response of α-In2Se3 nanosheets extends into ultraviolet, visible, and near-infrared spectral regions. The high photocurrent response is attributed to the direct band gap (EG = 1.3 eV) of In2Se3 combined with a large surface-area-to-volume ratio and a self-terminated/native-oxide-free surface, which help to reduce carrier recombination while keeping fast response, allowing for real-time detection under very low-light conditions.
authors.affiliation: SUNY College of Nanoscale Science and Engineering, State University of New York , Albany, New York 12203, United States.
authors.forename: Robin B
authors.initials: RB
authors.lastname: Jacobs-Gedrim
authors.forename: Mariyappan
authors.initials: M
authors.lastname: Shanmugam
authors.forename: Nikhil
authors.initials: N
authors.lastname: Jain
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Durcan
authors.forename: Michael T
authors.initials: MT
authors.lastname: Murphy
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Murray
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Matyi
authors.forename: Richard L
authors.initials: RL
authors.lastname: Moore
authors.forename: Bin
authors.initials: B
authors.lastname: Yu