Rational synthesis of bandgap-tunable MS2(1-x)Se2x (M = Mo, W) alloys and their physical properties

摘要

Band gap engineering has been opening a way to enhance the performance of two-dimensional (2D) material devices. Here we report a synthesis of ternary MS2(1-x)Se2x (M = Mo, W) alloys with a band gap tunability of similar to 170 meV using a solid state reaction method. X-ray photoelectron spectroscopy and Raman scattering characterizations reveal that the change of Se contents can be utilized to tune the composition of the ternary MS2((1-x))Se-2x(M = Mo, W) alloys. UV-vis-NIR absorption results conform the realization of tunable band gap in MS2(1-x)Se2x(M = Mo, W) alloys tailored by different Se contents. The electrical transport investigation of the ternary alloys exhibits an n-type semiconductor behavior demonstrated by back-gated field effect transistors. (C) 2017 Elsevier B.V. All rights reserved.