[en] Effect of hydrostatic pressure on the optical absorption spectrra of CdS_1-xSe_x nanocrystals embedded in borosilicate glass matrix, is studied. A pressure-induced blue shift of the optical absorption edge and confinement-related maxima is observed. Energy band gap pressure variation coefficients are determined, their compositional and size behaviour being discussed in view of possible structural difference within the nanocrystal ensemble

[en] Optical absorption spectra of x-ray irradiated CdS_1-xSe_x nanocrystals embedded in a borosilicate glass matrix are studied. The observed transformation of the confinement-related features in the spectra is related to the x-ray-induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The radiation-induced changes and their relaxation upon postirradiation storage as a function of nanocrystal size and composition are discussed.

[en] Raman and photoluminescence (PL) spectra of amorphous As₂Se₃:Cd films show that laser irradiation can result in the local formation of CdSe nanocrystals (NCs). Due to a pronounced laser-induced drastic drop of the film viscosity, a strong local enhancement of diffusion of atoms in the laser spot area results in a material transfer from the laser spot (evidenced by SEM and AFM data) and simultaneously facilitates the formation of CdSe NCs. The difference of the PL maximum positions measured at a high laser power density P _exc and subsequently (from the same spot) at a lower P _exc value can be explained either by local heating of the sample by the high-P _exc illumination, or by the flexoelectric effect (additional strain in the CdSe NCs induced by the electric field gradient caused by the charging of the NC surface). Based on the spectral positions of the PL maximum, with the account of the Stokes shift, the average radii of the CdSe NCs formed are estimated. (paper)

[en] Optical phonons in Cd_1-xZn_xS nanocrystals embedded in borosilicate glass are studied by resonant Raman scattering. A Raman-based assessment of the nanocrystal composition is performed. Compositional dispersion of the nanocrystals within the ensemble is revealed. The effect of confinement-related selection rules relaxation, scattering by surface phonons, and host matrix pressure on the Raman lineshape is analyzed

[en] Resonant Raman scattering spectra of glass-embedded CdS_1-xSe_x nanocrystals are measured and complemented with TEM and optical absorption as well as photoluminescence data. The selectivity of the resonant Raman process not only for the size, but also for the composition of nanocrystals within the ensemble, is directly observed in the dependence of phonon band frequency, linewidth and shape on the excitation wavelength

[en] Micro-Raman spectra of CdS and CdSe nanocrystals embedded in different dielectric media (borosilicate glass, gelatin, polyacrylamide, polyvinyl alcohol) are studied. The observed Raman features are discussed with the account of confinement-related selection rules relaxation, scattering by surface phonons, and host matrix pressure. For nanocrystals grown in borosilicate glass a pronounced resonant dependence of surface phonon frequency on the excitation wavelength is observed. The effect of the excitation wavelength is much stronger than that of the nanocrystal size or the dielectric matrix type