NONLINEAR ABSORPTION AND PHOTOLUMINESCENCE OF CUCL CRYSTALLITES UNDERSIZE QUANTIZATION OF EXCITONS

Excitonic processes in CuCl nanospheres of mean radius ranging from 20 to 150 angstrom embedded in a glass matrix are investigated. Specific features resulting from quantum confinement are analyzed. Exciton-exc iton interaction and relaxing the k-selection rule lead to size-depend ent linear and nonlinear optical properties resulting in the light-ind uced blue shift of excitonic bands, slowing down of radiative decay an d drastic changes in the excitation and relaxation dynamics of exciton s confined in a quantum box. In addition to the standard classificatio n of the weak (DELTAE(exc) much less than Ry) and the strong (DELTAE( exc) > Ry) confinement regime, the peculiarities of the range in whic h E(LO) less-than-or-equal-to DELTAE(exc) much less than Ry discussed .