Reverse Micelle Templated Construction of Strongly Confined Ultra‐Small Perovskite Quantum Dots with Exceptionally Narrow Blue Emission

Abstract Strongly confined quantum dots (QDs) have the advantages of a narrow full width at half maximum (FWHM) and rapid radiative recombination, making them promising candidates for realizing high‐end display devices with exceptional color purity. However, the synthesis of stable and ultra‐small perovskite QDs (UsPQDs) with a uniform size remains a critical challenge because of the difficulty of controlling picosecond ionic metathesis reactions. In this study, a novel reverse micelle soft‐template strategy is demonstrated for achieving the precise nanoconfinement of CsPbBr 3 UsPQDs, yielding ultra‐small monodisperse particles with an average diameter of 2 nm. The obtained CsPbBr 3 UsPQDs exhibited deep‐blue emission at 443 nm and a narrow FWHM of less than 10 nm, accompanied by a near‐unity photoluminescence quantum yield. The scalability and universality of this reverse micelle soft‐template methodology are demonstrated, realizing the controllable synthesis of MAPbBr 3 and FAPbBr 3 UsPQDs with narrow blue emissions. A liquid‐state light‐emitting diode fabricated using the UsPQDs exhibited deep blue emission (CIE: 0.157, 0.018). A patterned dot‐matrix display of 50‐µm pixels fabricated via aerosol jet printing and photolithography demonstrated the viability of achieving wide‐gamut augmented reality/virtual reality microdisplays.