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

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.