Thioacetamide-ligand-mediated synthesis of CsPbBr3–CsPbBr3 homostructured nanocrystals with enhanced stability

Abstract

Cesium lead halide perovskite nanocrystals (NCs) have compelling photoelectric properties while their poor stability severely impedes their practical applications. Herein, we demonstrate novel CsPbBr₃–CsPbBr₃ homostructured NCs induced by a thioacetamide-oleylamine (TAA-OAm) ligand system via a facile room temperature re-precipitation method. The TAA-OAm ligand system could form long-chain N-substituted thioamides and short-chain S²⁻ ligands, resulting in two different growth rates of CsPbBr₃ NCs and finally forming CsPbBr₃–CsPbBr₃ homostructured NCs. The performed structural and compositional characterizations corroborate the existence of CsPbBr₃–CsPbBr₃ homostructured NCs. The obtained CsPbBr₃–CsPbBr₃ homostructures exhibit green emission of 510 nm and superior stability at room temperature in air. Our study provides a new approach to improve the stability of halide perovskite NCs, which may pave the way for future optoelectronic applications.