Solvent-Mediated Synthesis of Small-Sized Perovskite Quantum Dots for a Color-Enhanced Micro-LED Display

Abstract

Perovskite quantum dots (PeQDs) have garnered significant attention as new-generation color-conversion materials for potential applications in microlight-emitting-diode (micro-LED)-based display devices. However, they still face challenges in achieving uniform size synthesis and ultrahigh color conversion efficiency. Here, all-inorganic PeQDs with uniform size and excellent stability were achieved through an optimized solvent-mediated synthesis using dodecyl acrylate (DA). This solvent not only enhances the solubility of the precursor, facilitating the rapid formation of intermediate monomers, but also induces abundant carbon–oxygen bonds for interface passivation, thereby enabling the controllable and slow nucleation of small-sized PeQDs. The highest photoluminescence quantum yield (PLQY) of 94.9% and 91.1% has been recorded for green and red PeQD solutions, respectively. The mechanisms behind the size-dependent improvement in luminescence performance have been elucidated and validated through transient absorption measurements and an emission–reabsorption model derived from simulations. Furthermore, our designed mixed-color film composed of green and red PeQDs exhibited ultrahigh overall stability, maintaining 76.7% of its initial intensity after being aged at 85 °C and 40 W m –2 for 600 h. These promising mixed-color films were successfully utilized to enhance micro-LED displays, achieving a high luminous efficacy of 150 lm W –1 and a color gamut of 130.2% of NTSC and 93.4% of BT.2020.