Stable white emission and color-tunable electroluminescence achieved from n-ZnO/p-GaN nano-heterojunction decorated with CsPbBr3 and CsPbI3 quantum dots

Abstract

The development of wavelength adjustable electrically driven panchromatic display light-emitting devices (LEDs), a future direction for lighting sources, still seems necessary because of great development prospects and practical significance. Herein, perovskite quantum dots (QDs) of CsPbBr3 and CsPbI3 with multi-color luminescence feature were employed into n-ZnO/p-GaN nano-heterojunction LEDs. A thin polystyrene cover layer was intentionally inserted between CsPbBr3 and CsPbI3 to prevent the undesired halogen anion-exchange reaction. A color-tunable electroluminescence (EL) could be achieved by changing the molar ratio of these two types of perovskite QDs. By further optimizing the molar ratio between CsPbBr3 and CsPbI3, that is, the evolution of the share of red, green and blue-violet luminescence in EL spectra, a stable white light emission was obtained. The current research not only achieves multi-color EL emissions in a three-dimensional nano-architecture, but also proposes an effective and clever strategy for preparing and developing single-chip white LEDs.