Rapid Room Temperature Entropy‐Stabilized Synthesis Enabling Super‐Stable Metal Halide Perovskite Semiconductor Colloidal Nanocrystals

Abstract Although high‐entropy materials have garnered extensive attention due to their substantially enhanced performance, their formation generally demands prolonged high‐temperature synthetic processes. Moreover, research on entropy‐stabilized halide perovskite (ESHP) semiconductor colloidal nanocrystals (NCs) is scarce. Herein, a highly efficient and rapid room temperature (RT) entropy‐stabilized approach in air is proposed, involving the concurrent incorporation of multi‐metal cations for the synthesis of high‐quality all‐inorganic ESHP NCs with near‐unity quantum yield and excellent colloidal stability. Remarkably, even after 8 months of aging in air, the ESHP NCs exhibited superior emission characteristics with a single‐exponential decay and maintained the initial NC monodispersity. Density functional theory calculations further demonstrated that the outstanding performance of ESHP NCs originated from the diminished crystal defects and a more robust octahedral structure. Significantly, this RT entropy‐driven synthesis can be extended to metal halide semiconductor NCs with diverse composition systems. The findings inspire new perspectives for entropy‐stabilized, high‐performance metal halide perovskite NCs toward versatile applications.