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 (similar to 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.