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The paper reports the effect of low-temperature annealing (up to 150°C) and light irradiation from a quartz mercury lamp (up to 20 min) on the structural, optical, and electrical properties of Indium tin oxide (ITO) films. 0.8 μm thick ITO films were obtained by RF magnetron sputtering of a commercial target on the optically transparent glass substrates in an argon atmosphere without heating. Information about the morphology of the ITO films' surface was obtained and the surface parameters were calculated using the method of atomic force microscopy. It has been found that the low temperature annealing for one hour and short-term irradiation with a quartz mercury lamp lead to an increase in the average size of crystallites and root-mean-square (RMS) surface roughness, a decrease in the resistivity of ITO films as well as an increase in the optical transparency in the visible spectral range. After annealing the ITO film at 150°C, the average crystallite size and RMS roughness of the surface increased approximately three times, and after 20 min irradiation – approximately 1.6 times, respectively. The lowest optical transparency in the visible spectral range among the studied experimental samples was found to be for the non-annealed and non-irradiated ITO films, whereas the highest – for the samples annealed at the highest temperature (150°C) and irradiated for 5 min with the light from the DRT-125 lamp. On the basis of the analysis of optical absorption spectra of ITO films, we detected an increase in their optical band gap from 3.59 eV for the unannealed film up to 3.66 eV with an increase in the annealing temperature of the samples up to 150°C. The resistivity of ITO films decreases with an increase in the annealing temperature up to 150°C and with an increase in the irradiation time with a light of the quartz mercury lamp up to 20 minutes. These results may be useful in the engineering of electronic devices based on the materials of low thermal stability. [ABSTRACT FROM AUTHOR]

The experimental dependence of the luminescence intensity of YVO4:Eu nanoparticles on their size in the range from 8 to 16 nm is studied. R has been shown that the decrease of the X-ray excited luminescence intensity with the decreasing size of the nanoparticle is caused both by quenching resulting from the interaction of luminescent centres with surface defects and by losses of excitation energy at the stage of thermalisation. A method of calculating the dependence of the X-ray excited luminescence intensity on the nanoparticle size is proposed based on the assumption that only the charge carries not reaching the near-surface layer of particle after the thermalization process give contribution to the recombination luminescence. The length of thermalisation was calculated taking into account the dependence of the effective mass of electrons on their kinetic energy. The average value of the effective mass of electrons in the conduction band with the kinetic energy in the range [0, Eg] is estimated to be 1,5me. The distribution of secondary electrons by the thermalisation lengths for YVO4 is obtained and its average value is estimated to be 6 nm. The minimum size of YVO4 nanoparticles possessing the intensity of X-ray excited luminescence approximately twice smaller comparing to the bulk crystal is theoretically estimated to be 27 nm. This value is significantly smaller than any visible light wavelengths that minimize all processes of light scattering and it gives an opportunity to create composite polymer-inorganic materials based on these nanoparticles for X-ray registration. [ABSTRACT FROM AUTHOR]