Temperature dependant electronic charge transport characteristics at MX2 (M = Mo, W; X = S, Se)/Si heterojunction devices

Abstract

Nanosheets of two dimensional (2D) transition metal dichalcogenides (WS2, MoS2 and WSe2) have been synthesized by two stage solvothermal mediated sonochemical exfoliation method. The as-synthesized high quality and stable dispersions in the form of few layer nanosheets were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy. The nanosheets were deposited on p-type silicon wafer to from WS2/p-Si, MoS2/p-Si, and WSe2/p-Si, heterojunction diodes. Temperature dependent transport properties and conduction behavior were analyzed using I–V characteristics. Thermionic emission transport model with T0 affected current transport mechanism across the junction was found as the most possible current transport model for all the three prepared diodes. The results provide an easy and large area preparation of 2D layered transition metal dichalcogenide semiconductors for unique electro-optical applications.