One-dimensional van der Waals material InSeI with large band-gap for optoelectronic applications

Abstract

We experimentally demonstrate for the first time that the bulk InSeI crystals can be effectively delaminated by micromechanical exfoliation into a few nanometer-scale InSeI nanowires, due to the presence of weak van der Waals (vdWs) interaction within the crystal lattice. The exfoliated InSeI nanowires show one-dimensional (1D) bundle structure, and the work function of InSeI measured by Scanning Kelvin probe microscopy shows strong dependency on its thickness. The InSeI has a large bandgap corresponding to 2.12 eV, and when applied to a UV-detecting device, it was confirmed that the device with excellent sen-sitivity can be obtained, because there is little interference in the infrared and visible light regions. Based on these results, InSeI could be a excellent candidate as an additional 1D vdWs material for optoelectronics, including photodetectors or photovoltaic devices.(c) 2022 Elsevier B.V. All rights reserved.