Quantum confinement in CdSxSe1-x spherical nanocrystals in a fluorophosphate glass matrix

Differential (wavelength-modulated) absorption of sulfoselenide solid-solution nanocrystals has been studied in a glassy fluorophosphate matrix near the fundamental absorption edge at 360-620 nm. The observed oscillations in the absorption are attributed to size quantization of electrons and holes under strong quantum-confinement conditions. The sulfur content in the mixed semiconductor has been refined from Raman scattering spectra in CdSxSe1-x samples with x = 0.30, and the nanocrystal size (R congruent to 30 Angstrom) has been derived from low-frequency Raman scattering spectra. These data were used to calculate the energies of electron-hole transitions in nanocrystals of mixed composition, and their subsequent comparison with experiment. The calculations were found to be in a good agreement with the observed experimental absorption spectrum for nanocrystals about 45 Angstrom in size. The applicability of band-structure simulation for a nonspherical nanocrystal grown in a fluorophosphate glass matrix is discussed. (C) 1999 American Institute of Physics. [S1063-7834(99)03008-7].