Effect of the Substrate on Photoluminescent Properties of Organometallic Perovskite Nanocrystals

The photoluminescent properties of nanocrystalline layers of organometallic perovskites deposited on various semiconductor and dielectric substrates are studied. It has been established that, depending on the substrate, both one and two maxima can be observed in the exciton photoluminescence spectrum for CH 3 NH 3 PbBr 3 nanocrystals with dimensions of tens and hundreds of nanometers at room temperature. The photoluminescence of nanocrystals deposited on an array of silicon nanowires has a longer wavelength of the spectrum maximum as compared to nanocrystals on a flat surface of a single-crystal silicon substrate. The results obtained are explained by the influence of electric fields of bound charges at the interfaces and by processes of photoluminescence absorption.