TIME-RESOLVED LUMINESCENCE AND OPTICAL GAIN IN II-VI QUANTUM DOTS

The population and depopulation of the lowest electron-hole pair state s have been investigated in CdSe and CdSSe quantum dots by time-resolv ed luminescence experiments on a picosecond time scale, Auger-like sca ttering processes within the two-pair system created under high excita tion present an efficient relaxation mechanism. In nanosecond pump-and -probe experiments the absorption bleaching has been investigated up t o the evidence of gain. Gain has been observed both for quantum dots w ith radii below and above the Bohr radius.