<p>Nanocrystals of metal halide perovskites have attracted attention due to their unique luminescent properties, making them promising for optoelectronic applications. However, the stability and emission efficiency of perovskite nanocrystals can decrease depending on the synthesis and storage conditions. To address this challenge, ligand environments around the nanocrystals have been explored. Here we propose using (3-mercaptopropyl)trimethoxysilane as a ligand in the post-synthetic treatment of CsPbBr₃ nanocrystals. This treatment has been shown to increase the photoluminescence quantum yield of perovskites as well as their long-term luminescence efficiency. These effects are attributed to stronger interactions of the -SH group with lead compared to the amino group and the formation of bonds between ligand molecules, leading to a more stable ligand shell. The results obtained are useful in the development of perovskite-based LEDs.</p>