Efficient and Stable Perovskite White Light-Emitting Diodes for Backlit Display

High-quality backlit display puts forward urgent demand for color-converting materials. Recently, metal halide perovskites (MHPs) with full spectral tunability, high photoluminescence quantum yields (PLQYs), and high color purity have found potential application in wide-color-gamut display. Regrettably, naked MHPs suffer from long-term instable issue and cannot pass harsh stability tests. Herein, amorphous-glass-protected green/red CsPbX₃ quantum dots (QDs) are prepared by elaborately optimizing glass structure, perovskite concentration, and in situ crystallization. PLQYs of green CsPbBr₃@glass and red CsPbBr_1.5I_1.5@glass reach 94% and 78%, respectively, which are the highest ones of CsPbX₃@glass composites reported so far and comparable to colloidal counterparts. Benefited from complete isolation of QDs from external environment by glass network, CsPbX₃@glass can endure harsh commercial standard aging tests of 85 °C/85%RH and blue-light-irradiation, which are applied to construct white light-emitting diodes (wLEDs) with high external quantum efficiency of 13.8% and ultra-high luminance of 500 000 cd m⁻². Accordingly, the perovskite wLED arrays-based backlit unit and a prototype display device are designed for the first time, showing more vivid and wide-color-gamut feature benefited from narrowband emissions of CsPbX₃ QDs. This work highlights practical application of CsPbX₃@glass composite as an efficient and stable light color converter in backlit display.