Optical resonances in nanostructures for modification of radiative recombination in halide perovskites

The dissertation is devoted to the creation and research of approaches to control radiation recombination using optical resonances in nanostructures based on perovskites. This thesis discusses various approaches to enhance photoluminescence based on both individual perovskite nanoparticles and a combination of perovskite quantum dots with resonant dielectric topological nanostructures, as well as continuous perovskite layers with embedded layered metal-dielectric nanoparticles. The main goal of this work is to study the effect of optical resonances in various nanostructures on radiative recombination in halide perovskites. The main tasks of this work are: • Experimental and numerical study of the dependence of the position of the photoluminescence peak on the size of CsPbBr3 nanoparticles due to the effect of exciton nonlocality. • Modeling and fabrication of a dielectric topological lattice of the kagome type with high-Q corner states. • Deposition of inorganic perovskite CsPb(Br,I)3 nanoparticles on topological structures of the kagome type. • Study of the optical properties and light amplification in an active topological kagome grating. • Numerical study of the light amplification in halide perovskite lightemitting diodes with embedded core/shell SiO2/Au nanoparticles. The scientific statements presented for the defence: • The blue shift of the photoluminescence peak up to 150 meV for perovskite MAPbBr3 nanoparticles with a size of 20-200 nm is associated with the effect of exciton nonlocality and with the contribution of Mie resonances. • The silicon-based topological kagome lattice maintains the local enhancement of photoluminescence from a layer of perovskite CsPb(Br,I)3 nanocrystals at locations and wavelengths corresponding to the highorder resonant topological corner states. • Nanoparticles with a gold core about 40 nm in diameter and a silicon dioxide shell about 10 nm integrated into the active layer of the perovskite FAPbBr2I light-emitting diode are increasing the radiative recombination rate in perovskite up to 4 · 104 times due to the formation of a metal-oxide-semiconductor structure and, therefore, a transport channel for the holes. Key novelty of this work includes: 1. The first demonstration that strong excitonic nonlocality affects the optical response of halide perovskite nanoparticles supporting Mie modes. It was discovered for the first time that the optical features in scattering, absorption and photoluminescence are shifted to the blue region near the exciton even for relatively large nanoparticles (more than 20 nm), where the quantum confinement becomes insignificant. 2. The enhancement of photoluminescence of perovskite nanoparticles at the corner states in a topological structure of the kagome type in the optical range is shown for the first time experimentally and theoretically. 3. The first theoretical demonstration of the presence of a giant amplification of electroluminescence in perovskite light-emitting diodes with embedded core-shell (SiO2/Au) nanoparticles due to the formation of a metal-oxide-semiconductor interface, which enhances the radiative recombination. Scientific and practical importance of the work lies in the fact that the author proposed new approaches to the creation of new more efficient light-emitting devices based on halide perovskites. It was shown that it is possible to create topological nanostructures based on a silicon metasurface with a layer of perovskite nanoparticles, which is capable to locally enhance the photoluminescence at high-Q topological zero-dimensional corner states. This approach will make it possible to create the topological lasers based on perovskites. I