Temperature dependent photoresponse of MoS2/VO2 heterojunction

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.