PERSISTENT SPECTRAL HOLE-BURNING IN SEMICONDUCTOR MICROCRYSTALS

The persistent hole-burning phenomenon in nanometer-sized semiconductor microcrystals CdSe and CuCl was observed for the first time. The differential absorption spectra at 2 K consist of the narrow bleaching hole and the induced absorption which are conserved for more than 10 min after laser irradiation. The long-lived induced absorption is ascribed to the spectral antihole produced by a photophysical mechanism. It is clearly shown that the generally accepted model of inhomogeneous broadening of quantum dots cannot be used for explanation of the observed phenomenon.