Balanced Photodetection in Mixed-Dimensional Phototransistors Consisting of CsPbBr3 Quantum Dots and Few-Layer MoS2

Balanced photodetection endows photoconductive detectors with high photoresponsivity and fast photoresponse speed. Here, we report a mixed-dimensional phototransistor consisting of CsPbBr3 colloidal quantum dots and few-layer MoS2 that is capable of balanced photodetection. In the heterojunction, the generation region and the transport channel of carriers are separated by the built-in electric field. Thus, the device exhibits a high photoresponsivity of 10(4) A W-1 and a fast photoresponse speed of 8 ms. All of these results demonstrate that the mixed-dimensional phototransistor is successful in balanced photodetection, and it has great application potential in communication and imaging.