Izai V. Influence of ion implantation on optical properties of crystals and thin films based on Cu6PS5X (X= I, Br)

The thesis is devoted to the studies of the influence of ion implantation by sulphur and phosphorus on phase transitions, structural and optical properties of Cu6PS5X (X= I, Br) crystals and thin films on their base. Structural and optical studies of unimplanted and implanted with different fluence values Cu6PS5X (X= I, Br) crystals were carried out using techniques of SEM, AFM, EDX, X-ray diffraction as well as techniques of Raman scattering, optical absorption, and photoluminescence. Ion implantation by sulphur and phosphorus leads to the formation of induced structural defects on the crystal surface as well as to substantial effects on Raman scattering, photoluminescence, phase transitions, the absorption edge parameters, parameters of exciton-phonon interaction and structural disordering in Сu6PS5X (X= I, Br). Structural and optical properties of Сu6PS5I thin films deposited by non-reactive radiofrequency magnetron sputtering were studied. It is shown that ion implantation by sulfur and phosphorus causes changes of the optical pseudogap and the Urbach energy in Сu6PS5I thin films by an order of magnitude higher than in the corresponding crystals.