Recent advances in perovskite nanocrystal light-emitting diodes: synthesis, device engineering, and film processing

Abstract

Metal halide perovskite nanocrystals (PeNCs) are one of the most promising emissive materials for next-generation light-emitting diodes (LEDs). Their intrinsic advantages, such as narrow emission linewidths, high photoluminescence quantum yield, and composition-dependent bandgap tunability, make them ideal for realising full-colour displays that meet the Rec. 2020 standard. Recently, intensive research has propelled external quantum efficiencies to ∼30% in green, >25% in red, and >20% in blue device, placing PeNC-LEDs on par with mature organic and quantum-dot technologies. This review provides a comprehensive overview of progress spanning synthetic chemistry, device design, and film fabrication. Advances in bottom-up and top-down synthesis—including hot-injection, ligand-assisted reprecipitation, microwave-assisted, flow-reactor, and bead-milling methods—have enabled precise control of crystal size, composition, and surface chemistry. In blue PeNC-LEDs, phase instability and halide migration limit durability; green devices deliver record efficiencies via ligand and interfacial engineering; red devices employing halide mixing or quantum-confinement control for spectrally pure emission; and near-infrared systems broaden applications to bioimaging, communications, and photonics. Additionally, progress in film deposition and patterning technologies, from spin coating to scalable photolithography, inkjet, and transfer printing, has led to high-resolution, uniform emissive layers compatible with large-area manufacturing. However, device stability, operational lifetime, and environmental sustainability remain key challenges, particularly for lead-based compositions. Future progress will rely on synergistic advances in surface passivation, defect control, lead-free materials, and scalable processing strategies. By integrating insights from materials chemistry, surface and interface science, and device engineering, PeNC-LEDs are poised to reshape optoelectronics across the visible and near-infrared spectrum.