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Free-standing ZnO nanorods alloyed with Er/Mo were synthesized by the hydrothermal growth method. To characterize them, the number of experimental techniques was applied including X-ray diffraction (XRD), scanning emission microscopy (SEM), electron paramagnetic resonance (EPR), photo- and radioluminescence (PL, RL). EPR confirmed the existence of F+ centres common for ZnO-based structures in the ZnO:Er(30%) nanorods whereas in the ZnO:Mo(30%) this kind of defect was absent. Air annealing at elevated temperatures results in the reduction of F+ centres in all the materials studied. Moreover, Er3+ EPR signal also undergoes changes including broadening in the ZnO:Er. This allowed suggesting oxidation of Er ions on the ZnO nanorods surface. Red luminescence (~680 nm) appears in all studied samples regardless the dopant origin and doping level after the annealing in air. The exciton-related band at 380 nm never observed in the samples before the annealing appears upon the annealing at 350 °C in ZnO:Mo(10%) and ZnO:Er(30%). No such band was observed in the ZnO:Mo(30%) sample under the same conditions. According to SEM there are nanorods no more but microrods upon the content of Mo/Er as compared to the as-grown untreated ZnO as reported in a recent work.

In this work we present a methodological approach to the temperature dependence of photoluminescence (PL) emission spectra of the silicon-vacancy centre in diamond thin films prepared by chemical vapour deposition. The PL spectra were measured in the temperature range of 11 -300 K and used to determine the temperature dependence of the zero-phononline full-width at half-maximum and of the peak position. Experimental data were fitted by models of lattice contraction, quadratic electron-phonon coupling, homogeneous and inhomogeneous broadening. We found that the shift of peak position and peak broadening reflect polynomial dependence on temperature. Moreover, a proper setting of monochromator slits width is discussed with respect to line profile broadening.K e y w o r d s: silicon-vacancy centres, photoluminescence, low temperature, diamond, CVD