CDTE QUANTUM DOTS BY MELT HEAT-TREATMENT IN BOROSILICATE GLASSES

CdTe quantum dots in borosilicate glasses were produced and their grow th kinetics, the effects of quantum confinement for electrons and phon ons and the time resolved optical transmission were studied. Quantum d ots in the range of 10 to 25 Angstrom with a 5% size dispersion were g rown. The growth kinetics were studied by small angle X-ray scattering using synchrotron light. A spherical k . p model for the electron con finement explains absorption data and selection rules, and a dielectri c continuum model for the phonon confinement could explain the resonan t longitudinal and surface optical phonons, as well as their overtone combinations. The time response of absorption was studied by a pump-pr obe measurement on the femtosecond time scale. For samples showing a l arge amount of surface traps the recovery time can be as fast as 300 f s, while for an almost surface trap free sample it remains on the 1-3 ps time scale. (C) 1997 Elsevier Science B.V.