Effect of CsPbBr3 Content in Mechanochemically Obtained CsPbBr3/h-BN Nanocomposites on Their Photoluminescent Characteristics

A number of CsPbBr₃/h-BN nanocomposites with different contents of inorganic halide perovskite (IHP) nanoparticles, which are characterized by bright photoluminescence (PL) in the green region of the spectrum, were obtained by mechanochemical synthesis. It is shown that the use of a mechanochemical approach leads to a significant delamination of boron nitride (both at the stage of preliminary grinding of h-BN with cesium bromide and in the process of mechanochemical production of nanocomposites), the degree of which decreases in the range of CsBr/h-BN = 1:10 > 1 :50 > 1:100 > 1:250. The increase in the content of boron nitride in the reaction mixture during the mechanochemical synthesis of CsPbBr₃/h-BN nanocomposite contributes to a reduction of the size of the formed perovskite nanoparticles leading to a significant increase in the PL intensity (I_PL). Optimal content of IHP in the synthesized nanocomposites (~25 wt.%) for obtaining the material with the highest PL intensity has been estimated from the extreme dependence between the I_PL value of CsPbBr₃/h-BN nanocomposites and their CsPbBr₃ content.