SYNTHESIS, MORPHOLOGY AND OPTICAL-PROPERTIES OF THIOL-STABILIZED CDTENANOCLUSTERS IN AQUEOUS-SOLUTION

Thiol-stabilized CdTe nanoclusters with sizes ranging from 1.3 to 2.4 nm have been prepared in aqueous solution and separated as oxidize-sta ble powders. Investigation of CdTe nanoclusters by means of X-ray diff raction (XRD) and high resolution transmission electron microscopy (HR TEM) indicates the cubic (zincblende phase) CdTe crystalline structure . Pronounced electronic transitions in the absorption spectra are shif ted dramatically towards higher energies in comparison with bulk CdTe as a consequence of quantum confinement in nanosized CdTe particles. T wo kinds of size-and surface-dependent photoluminescence (''excitonic' ' and trapped) of CdTe nanoclusters in aqueous solution were observed. A further growth of CdTe nanoclusters leads to a shift of both absorp tion edge and ''excitonic'' photoluminescence band towards longer wave lengths.