High Performances for Solution‐Pocessed 0D–0D Heterojunction Phototransistors

Abstract All‐inorganic cesium lead halide perovskite nanocrystals have emerged as attractive optoelectronic nanomaterials due to their stabilities and highly efficient photoluminescence. High‐sensitivity photodetection covering a large spectral range from ultraviolet to near‐infrared is dominated by phototransistors. To overcome existing limitations in sensitivity and cost of state‐of‐the‐art systems, new‐style device structures and composite material systems are needed with low‐cost fabrication and high performance. Here, field‐effect phototransistors (FE p Ts) based on CsPbBr 3 –PbS colloidal quantum dot heterostructure dominate to obtain a wide response spectral range and high performance. The large spectral detection spectrum is from 400 to 1500 nm similar to PbS quantum dots' response. It is worth mentioning that the device shows responsivity up to 4.5 × 10 5 A W −1 , which is three orders of magnitude higher than the counterpart of individual material‐based devices. Furthermore, other high performance of hybrid CsPbBr 3 –PbS FEpTs including a short photoresponse time (less than 10 ms) is ascribed to the assistance of heterojunction on the transfer of photoexcitons. The solution‐based fabrication process and excellent device performance strongly underscore CsPbBr 3 –PbS quantum dot as a promising material for future photoelectronic applications.