Significant enhancement of photoresponsive characteristics and mobility of MoS2-based transistors through hybridization with perovskite CsPbBr3 quantum dots

Abstract

Inorganic perovskite CsPbBr3 quantum dots (QDs) are potential nanoscale photosensitizers; moreover, two-dimensional (2-D) molybdenum disulfide (MoS2) has been intensively studied for application in the active layers of optoelectronic devices. In this study, heterostructures of 2D-monolayered MoS2 with zero-dimensional functionalized CsPbBr3 QDs were prepared, and their nanoscale optical characteristics were investigated. The effect of n-type doping on the MoS2 monolayer after hybridization with perovskite CsPbBr3 QDs was observed using laser confocal microscope photoluminescence (PL) and Raman spectra. Field-effect transistors (FETs) using MoS2 and the MoS2–CsPbBr3 QDs hybrid were also fabricated, and their electrical and photoresponsive characteristics were investigated in terms of the charge transfer effect. For the MoS2–CsPbBr3 QDs-based FETs, the field effect mobility and photoresponsivity upon light irradiation were enhanced by ~ 4 times and a dramatic ~ 17 times, respectively, compared to the FET prepared without the perovskite QDs and without light irradiation. It is noteworthy that the photoresponsivity of the MoS2–CsPbBr3 QDs-based FETs significantly increased with increasing light power, which is completely contrary to the behavior observed in previous studies of MoS2-based FETs. The increased mobility and significant enhancement of the photoresponsivity can be attributed to the n-type doping effect and efficient energy transfer from CsPbBr3 QDs to MoS2. The results indicate that the optoelectronic characteristics of MoS2-based FETs can be significantly improved through hybridization with photosensitive perovskite CsPbBr3 QDs.