Submicron Perovskite Quantum Dot Glass Microspheres for Micro‐LED Displays

ABSTRACT Quantum‐dot (QD) color‐conversion technology is considered a promising strategy for constructing a full‐color micro‐LED display. Perovskite quantum dots (PQDs) are the preferred luminescent materials for constructing color‐conversion micro‐LED pixels, but their poor environmental stability severely limits their practical application in micro‐LED displays. Here, we design a novel submicron‐sized PQD glass microspheres (PQDGMS) with high quantum yield and excellent stability for color conversion micro‐LED displays. Kilogram scale (batch 2 kg) submicron‐sized PQDGMS was prepared by a top‐down strategy including melt‐quenching, secondary recrystallization, and optimized submicronization processes. Ultra‐stability of the PQDGMS was attributed to the passivation and self‐healing effects of PQDs by AgBr additive, and the protection effect of the glass matrix around PQDs. The prepared PQDGMS has excellent environmental stability, with PL intensity maintained over 95% after immersion in water for 10 000 h, over 82% at a temperature of 100°C, and over 86% under continuous blue light irradiation (800 W m −2 ) for 240 h. We prepared the PQDGMS color conversion pixels in a patterned through‐hole glass substrate via capillary filling assistance and constructed color conversion green and red micro‐LED chips with external quantum efficiency of 24.8% and 16.7%, respectively.