Ultrastable and Highly Luminescent Quantum Dots Coating Highly Dense Protective Layers of Na‐Poly(Al‐O‐Si) Nanocomposites for Light‐Emitting Diodes

Abstract Quantum dot white light‐emitting diodes (QD‐WLEDs) have a potential for wide color gamut displays. Their applications to QD‐on‐chip package are limited by their poor stability. In this study, highly dense protective layers of Na‐poly(Al‐O‐Si) nanocomposite (NPAS NC) coating on QDs are developed for the first time. They enhanced the photoluminescence quantum yield at ≈1.74‐fold and stability. In addition, the effects of specific surface area (SSA) of NC structures on the reliability of QD‐WLEDs are investigated. The synthesized NPAS NCs via a sol‐gel method with catalyst showed the lowest SSA (2.39 m² g⁻¹) with almost no pore, thereby demonstrating the best reliability analysis (RA) results for QD‐WLEDs. QDs@NPAS WLEDs present a highly luminous efficacy of 133 lm W⁻¹ compared with pristine QD‐WLEDs (79 lm W⁻¹) under an electric input power of 21.4 mW. RA test on the QDs@NPAS WLEDs with an operational lifetime of 1,560 h is performed. A 16.6‐fold enhancement is observed compared with pristine QD‐WLEDs (≈94 h). QDs@NPAS WLEDs also exhibit an excellent display performance with a wide color gamut (≈91%) based on Rec. 2020 color standard. This approach can enhance the reliability of QDs for display applications, thereby providing a strategy for mini‐ and micro‐QD‐WLEDs.