Crystallization and Luminescence Properties of Stable Cspbbr3 Nanocrystals in Li2b4o7 Glass

Abstract

All-inorganic CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs), have achieved unprecedented advances in opto-electronic applications. However, issues such as poor stability and the volatility of halides in the preparation process continue to hinder their practical applications. Here, lithium tetraborate (Li2B4O7) was chosen as the glass matrix to prepare CsPbBr3 NCs glasses through traditional melting-quenching and heat treatment processes, effectively reducing the glass synthesis temperature to 940 °C. The heat treatment temperature and duration are examined. The Li2B4O7 glass matrix exhibits a uniform structure and high transmittance and CsPbBr3 NCs precipitated uniformly after heat treatment. Among these glasses, the sample heat-treated at 510 °C for 5 h exhibited an optimal photoluminescence quantum yield of 76.1% and the narrowest full width at half maximum values of 24 nm. Its photoluminescence intensity maintained 96.6% of its original value after multiple thermal cycles and thermal shocks, demonstrating the sample's robust thermal stability. Finally, by integrating the CsPbBr3 NCs glass sample with a blue chip in simple device packaging, a green light-emitting diode was successfully fabricated, featuring excellent luminescence stability and a color purity of up to 96.4%, promising for applications in solid-state lighting and display technologies.

Keywords: lithium tetraborate (Li2B4O7), luminous stability, color purity, CsPbBr3 nanocrystals (NCs), light-emitting diode (LED)