Regulation of photophysical and electronic properties of I–III–VI quantum dots for light-emitting diodes

Abstract

Quantum dot light-emitting diodes (QLEDs) have become an important research direction in the pursuit of next-generation display technology owing to their favorable attributes, including high energy efficiency, wide color gamut, and low cost. Breakthroughs in the luminous efficiency and operating life of QLEDs have been achieved by enhancing the photoluminescence efficiency of the quantum dots (QDs) and optimizing the device structure. However, the current mainstream QDs contain heavy metal elements such as lead and cadmium, which restrict the development and application of QD displays. Exploring new types of environmentally friendly QDs is crucial. I–III–VI semiconductor QDs have been developed as luminescent materials for constructing high color rendering index QLEDs, owing to the outstanding photo-physical properties of these QDs, such as composition-dependent tunable bandgap, large Stokes shift, and high-efficiency luminescence. Currently, the microstructures of heterojunctions, especially the surface states and interface states, affect the recombination and transport of carriers in electroluminescent (EL) devices with multilayer thin film structures, which in turn influence the luminous efficiency and stability of the device. This review focuses on the synthesis strategies of I–III–VI multi-component QDs and provides an in-depth understanding of the luminescence mechanism and the regulation of photophysical and electronic properties. Furthermore, the application of I–III–VI QDs in multi-color and white EL QLEDs is discussed and the challenges and outlook are addressed.