Stable CsPbBr3 perovskite quantum dots with high fluorescence quantum yields

Abstract

All-inorganic CsPbX₃ (X = I, Br, Cl) perovskite nanocrystals have emerged as a new class of optoelectronic material with tunable emission wavelengths, narrow full-width at half-maximum (FWHM) and high photoluminescence quantum yields (PLQYs) (≥50% in general). However, the instability caused by high delocalization of surface ions is still the major issue that obstructs their application. The type of surface ligands plays a key role in the stability of perovskite nanocrystals. In this work, stable cubic Br-rich CsPbBr₃ quantum dots (QDs) with uniform particle sizes, high quantum yields and high crystallinity were obtained by a one-step hot-injection synthesis method. Oleylamine (OM) as one of the ligands in the classic synthesis method was replaced with (3-aminopropyl)triethoxysilane (APTES). The stability of the CsPbBr₃ QDs was significantly improved under different testing conditions.