Cesium Lead Bromide Quantum Dot Light-Emitting Field-Effect Transistors.

Solution-processable perovskite quantum dots are considered as promising optical materials for light-emitting optoelectronics. Light-emitting field-effect transistors (LEFETs) that can be operated under a relatively lower potential with a high energy conversion efficiency are yet to be realized with perovskite quantum dots. Here, we present the CsPbBr quantum dot-based LEFET. Surprisingly, unipolar transport characteristics with strong electroluminescence were observed at the interface of the CsPbBr QD-LEFET along with an exceptionally wide recombination zone of 80 μm, an order of magnitude larger than that of organic/polymer LEFETs. Based on the systematic analysis for the electroluminescence of the CsPbBr NC-LEFET, we revealed that the increased diffusion length determined by the majority carrier mobility and the lifetime well explains the remarkably wide recombination zone. Furthermore, it was found that the energy-level matching and transport geometry of the heterostructure also determine the charge distribution and recombination, substantially affecting the performance of the CsPbBr QD LEFET.