NONLINEAR SPECTROSCOPY OF PHOSPHATE-GLASSES CONTAINING CADMIUM SELENIDE NANOPARTICLES

An investigation was made of the photoluminescence and differential ab sorption spectra of phosphate glasses containing embedded CdSe nanopar ticles, These spectra were determined by the pump-and-probe method. Th e photoluminescence spectrum included a short-wavelength band resultin g from direct recombination of electron - hole (eh) pairs and a long-w avelength band associated with carrier recombination via deep levels o f defects. Two peaks, attributed to the 1S(e) --> 1S(3/2) and 1S(e) -- > 2S(3/2) transitions, were observed in the short-wavelength photolumi nescence band at high excitation rates. The kinetics of the differenti al absorption spectra was explained by saturation of the absorption of the exciton (eh) transitions and by the appearance, in the excited na noparticles, of the absorption corresponding to two-pair (2eh) states.