Temperature dependent photoresponse of MoS2/VO2 heterojunction

Abstract

Van der Waals (VdW) heterojunctions composed of transition metal dichalcogenides and strongly correlated electronic materials have attracted great interest for feasible control of the optoelectrical properties. The MoS2/VO2 heterojunction is one of the typical structures whose optoelectrical property can be modulated by the metal insulator transition (MIT) of VO2. Here, we show a systematic investigation on the temperature dependent photoresponse across the MIT temperature of VO2. In-situ mapping on the junction surface potential confirms that both the MIT and depletion of MoS2 improve the quality of Schottky junction. As a result, photoresponse of the MoS2/VO2 heterojunction is significantly improved, especially, rapid improvement around MIT temperature and reduction of dark current are observed. The results clear reveal the temperature dependent energy structure of MoS2/VO2 heterojunction, and should be helpful to understand the optoelectrical behavior of similar vdW heterojunction.