For the first time the segregation of doped ions in YVO4:Pr3+ and YVO4:Er3+,Yb3+ nanocrystals was revealed by means of spectroscopic techniques. Luminescence spectra are modified due to doped ions redistribution within nanocrystal volume. Variation of heat treatment temperature allows us to determine the diffusion-depended nature of observed doped ions redistribution within the volume of nanocrystal and to trace this process.
Optical Materials 34(12), 1998–2001 (2012)

Strong temperature controlled segregation of doped ions in Y2SiO5:Pr3+ nanocrystals detected by spectroscopic techniques is reported. The elastic interactions stimulate Pr3+ segregation thus leading to non-uniform distribution of doped ions, pair formation and, as a consequence, to abnormal low threshold of luminescence concentration quenching for Y2SiO5:Pr3+ nanocrystals.
Journal of Luminescence ,132(9), 2443–2446 (2012)

Comparing the luminescence properties of nanosized and macroscopic LaPO4:Ce,Tb powders are performed in wide spectral range using synchrotron radiation. In the present study, LaPO4:Ce,Tb nanopowder was produced by means of a microwave-induced synthesis in ionic liquids, whereas the bulk sample represents a commercial lamp phosphor. Emission and excitation of both, Ce3+ and Tb3+ luminescence, is observed to be different when comparing bulk and nanosized LaPO4:Ce,Tb. In particular, it was shown that the fine structure of the Ce3+ as well as the Tb3+ related emission is poorly resolved for the nanomaterial. It is suggested that the nanoparticles surface plays a key role regarding the perturbation of rare-earth ions and changes their luminescence properties. Furthermore, it is demonstrated that allowed f–d transitions on Tb3+ at high energy are significantly suppressed for nanosized LaPO4:Ce,Tb. Energy transfer is required to initiate Tb3+ emission even in the vacuum ultraviolet spectral range.
Optical Materials, Vol.33, 2011, pp. 1102-1105

Optical properties of the films with high concentration of semiconductor core-shell CdSe/ZnS nanocrystals under action of visible laser radiation in a wide range of power densities have been investigated. It's shown that in the films with ultimate concentration ofthe nanocrystals a quantum-size effect is observed. High concentration of the nanocrystals in the films and the presence of dipoles caused by nanoparticles asymmetry lead to strong shift of quantum-size peaks in absorption and luminescence spectra compared to the solution and the films with low concentration of the nanoparticles. The altitude of the shift depends on the thickness of the films and varies from 35 nm to 50 nm. The luminescence spectra of the films don't change until the power density of exciting laser radiation exceeds 1x106 W/cm2. The regimes of laser action on the films of the nanoparticles with power densities beyond the threshold of films destruction (from 5x10^6 W/cm^2 to 1x10^9 W/cm^2) have been investigated.