SANS study of CdS and CdSe quantum dot crystal growth in a silica matrix by sol-gel

Size and size distribution of the semiconductor nanocrystals embedded in a dielectric matrix play a dominant role in line broadening and the exciton q uantum confinement level. The results show new aspects of the CdS and CdSe crystal growth as quantum dots using small-angle neutron scattering techniq ues (SANS). Thus, the crystal growth influences the aggregation process of the silica network. The intensity difference of the scattering between the silica matrix and the composite accounts for the crystal size and their vol ume fraction. Under similar conditions CdS nanocrystals grow faster and big ger than CdSe ones.