p-GaN/n-ZnO Nanoplate/CsPbBr3 Quantum Dots Heterojunction Light-Emitting Diode for Dual-Wavelength Emission

摘要： In this paper, we report a p-GaN/n-ZnO nanoplate/CsPbBr3 quantum dots (QDs) heterojunction light-emitting diode (LED) for dual-wavelength emission. ZnO nanoplates were prepared by vapor phase transport on the GaN thin film to form the p-GaN/n-ZnO nanoplate heterojunction. Afterwards, green CsPbBr3 QDs (band gap of 2.25 eV) were deposited on ZnO nanoplates to realize green light emission. The structure and photoluminescence of the ZnO nanoplates and CsPbBr3 QDs were characterized. The as-prepared LED device with turn-on voltage of ~ 2.7 V displays a typical rectification behavior. The electroluminescence spectra with narrow emission peaks reveal the device presents commendable dual-wavelength electroluminescence performance at ~ 385 nm and ~ 512 nm and the electroluminescence intensity saturates at about 65 mA/cm2. Moreover, the detailed electroluminescence mechanism including emission originate of n-ZnO/p-GaN heterojunction was discussed based on the band diagram. Thus, our work indicates compelling potential for the practical application of perovskite LEDs.