Improvements in Photoluminescence Efficiency and Stability of CsPbBr3 Nanocrystals Through 3-Aminopropyltriethoxysilane Treatment

A representative metal halide perovskite, CsPbX₃, has received much attention for its high photoluminescence (PL) efficiency and broad emission spectral range covering ultraviolet to infrared. Even with the focused investigations, they still suffer from poor emission stability from surface-induced defects. The inherent instability of perovskites is caused by moisture in the ambient, which leads to a reduction in the luminescence efficiency and deterioration of emission stability. In this study, we report a method to annihilate the surface defects in CsPbBr₃ nanocrystals (NCs), which enhances their photoluminescence efficiency by forming a SiO_x shell structure using a 3-aminopropyltriethoxysilane (APTES). The APTES was treated during the synthesis of CsPbBr₃ NCs through supersaturation and re-precipitation processes. The optical investigations confirmed that the PL intensity and emission stability of the CsPbBr₃ NCs improved with the APTES treatment. The structural investigations using X-ray diffraction and transmission electron microscopy showed that optical analysis was carried out through photoluminescence and laser optical analysis using lasers at 400 nm and 365 nm wavelengths. These findings present an innovative solution to the instability issues of CsPbBr₃ and suggest possibilities for its utilization in various application fields. Future research should focus on further understanding the scalability of this method and its practical applicability.