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

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 CsPbBr 3 and CsPbI 3 with multi-color luminescence feature were employed into n-ZnO/p-GaN nano-heterojunction LEDs. A thin polystyrene cover layer was intentionally inserted between CsPbBr 3 and CsPbI 3 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 CsPbBr 3 and CsPbI 3 , 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.