Wide‐Color‐Gamut, Eco‐Friendly Full‐Color QLED Displays Enabled by SEL‐WQLEDs With Interference Color Filters

ABSTRACT Quantum dot light‐emitting diodes (QLEDs) are widely recognized as a promising next‐generation display technology. Yet, they face critical challenges, including the toxicity of cadmium/lead (Cd/Pb)‐based heavy metals and the lack of mature, simple, and cost‐effective arraying techniques. Herein, we employed heavy‐metal‐free red/green/blue QDs (R‐/G‐/B‐QDs) as tricolor emissive centers to fabricate single‐emissive‐layer white QLEDs (SEL‐WQLEDs). By regulating charge distribution and Förster resonant energy transfer (FRET) in the R‐/G‐/B‐QD mixed emissive layer (EML), the electroluminescence (EL) performance and spectrum of SEL‐WQLEDs were simultaneously improved. The optimal device exhibited a peak external quantum efficiency (EQE) of 4.9% and emitted relatively balanced R/G/B light. Furthermore, we proposed a full‐color display technical route in which interference color filters (ICFs) were transferred onto SEL‐WQLED pixels. Benefitting from the narrow bandpass and high transmittance characteristics of the ICFs, the resulting QLED display achieved an exceptional color gamut of 113% NTSC (National Television System Committee) and excellent viewing‐angle spectral stability over a range of 0°–30°, meeting the application requirements of near‐eye displays, i.e., virtual reality/augmented reality (AR/VR). Based on the technical route, we designed a Google Glass‐inspired prototype and successfully demonstrated its display functionality. This work offers a promising eco‐friendly technical route for developing full‐color QLED displays.