Yu. I. Hutych

Interplay of factors affecting Raman scattering in cadmium chalcogenide nanocrystals in dielectric media

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.

Resonant Raman scattering studies of Cd1-xZnxS nanocrystals

Optical phonons in Cd1-xZnxS 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.

X-ray irradiation-induced ionization of CdS1−xSex nanocrystals embedded in borosilicate glass

Optical absorption spectra of x-ray irradiated CdS1−xSex 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.

Emission cross-sections of the In2 + ion VUV laser transitions at electron?In+ ion collisions

Crossed beams of electrons and In + ions were used to measure the relative emission cross-sections of the ionization-with-excitation process of the In 2+ ion laser transitions at λ185.0 nm and λ153.3 nm from the threshold up to 120 eV. A pronounced structure is observed for both energy dependences in the region from the threshold up to 80 eV. The structure results mostly from the contributions of cascade transitions from both 4d 10 nl ordinary and 4d 9 5snl Beutler states of the In 2+ ion as well as the excitation-autoionization process. It was discovered that, contrary to the Cd + ion case, the relative emission cross-section of the 4d 9 5s 2 2 D 5/2 → 4d 10 5p 2 P 3/2 In 2+ ion transition is smaller than that of the 4d 9 5s 2 2 D 3/2 → 4d 10 5p 2 P 1/2 In 2+ ion transition in the whole investigated region.