The photoluminescence spectra of CuI samples containing different numbers of intrinsic defects are studied at the temperature 80 K. The samples were excited with continuous-wave (cw) and pulse optical excitation. Emission peaks related to bound and free excitons, and to the recombination of electrons at shallow and deep crystal-lattice defect levels are observed. It is found that CuI crystals subjected to high-temperature annealing contain hexagonal phase inclusions.

The effect of the vacuum annealing of p-CuI crystals on their resistivity, transmittance, temperature-dependent conductivity, and photoconductivity in the visible and ultraviolet spectral regions is studied. It is shown that the conductivity and transmittance of CuI increase at low annealing temperatures and decrease, as the temperature of vacuum annealing is increased over 60 min. It is established that these systematic features are connected with the formation of intrinsic donor or acceptor defects in the CuI crystal lattice.

The effect of ultraviolet radiation of polycrystalline zinc oxide films (with a thickness of 200 nm) on their resistivity, transparency, and luminescence in the visible and violet spectral regions is studied. It is shown that, under irradiation of the films in air and vacuum, the conductivity, transmittance, and edge luminescence intensity increase with characteristic times of about 100 min. It is established that the corresponding processes controlled by desorption of oxygen atoms and molecules from the surface of nanocrytals in the ZnO films are reversible.

Monodisperse red phosphor particles 100 nm in diameter with the Lu_1.90Eu_0.10O₃ composition have been prepared using the developed technique for synthesizing spherical colloidal lutetium oxide particles with a size dispersion in the range 10–15%. The structure of spherical nanoparticles has been investigated, their excitation and photoluminescence spectra have been analyzed, and the lifetime of the ⁵ D ₀ excited state of Eu³⁺ ions has been considered. It has been found that the luminescence decay time for spherical particles increases by a factor of 1.39 compared to that for a powdered phosphor Lu₂O₃: Eu (5 at %) prepared and treated under the same temperature conditions as the Lu₂O₃: Eu (5 at %) spherical particles. This effect has been associated with the change in the photonic local density of states in spherical optical cavities consisting of particles of the phosphor.

The luminescence properties of spherically shaped Y₂O₃-ZnO nanocomposites with average diameters of 132 and 179 nm are studied. The nanocomposites are produced by synthesis from a solution, and their size dispersion is about 15%. Narrow peaks of lasing upon exciton radiative recombination in zinc oxide are observed in the ultraviolet spectral region. It is shown that, for small cavities (100–200 nm in diameter), individual nanospheres of the composite exhibit only one laser mode. The initiation of stimulated luminescence with a peak at 376 nm corresponding to the bound photon mode of nanocavities 179 nm in diameter is observed as the optical pumping power is increased to >130 kW cm⁻².

The spectra of spontaneous and stimulated luminescence of Lu₂O₃: Eu (7 at %) nanopowders at different optical pumping intensities have been investigated. The obtained results—changes in the shape of the red luminescence spectra and in the lifetime of the ⁵ D ₀ excited state of Eu³⁺ ions—indicate the onset of superluminescence with an increase in the excitation power. It has been found that an increase in the optical pumping intensity leads to a decrease in the luminescence decay time of the Lu₂O₃: Eu (7 at %) phosphor in the stimulated luminescence regime and to an increase in the quantum efficiency of red luminescence with a maximum at 611 nm.