LONG-LIVED SPECTRAL-HOLE BURNING IN CUBR NANOCRYSTALS EMBEDDED IN GLASS

We have observed the long-lived spectral-hole in the exciton absorptio n band of CuBr nanocrystals. With the resonant excitation of Z(12) exc iton band, the exciton band in the spectrum is bleached and the magnit ude of the change at the delay time of 0.1 s is about similar to 1% of the absorption peak. The shape of the spectral change depends on the crystallite size. For crystallites with the radii of > 100 Angstrom, t he exciton band is changed without showing a spectral hole at the exci tation energy position.