Abstract: Thioglycolic acid(TGA)-stabilized CdTe nanocrystals(NCs) were prepared with sodium tellurite as   tellurium source, which avoids the cumbersome processes associated with H2Te or NaHTe sources. Fluorescent CdTe/SiO2 composites were synthesized by a sol-gel method without the exchange of surface ligands. The     phase structure of CdTe NCs was investigated by X-ray diffractometry. For comparison, some characterizations  were done for both the CdTe NCs and the composites. CdTe NCs and CdTe/SiO2 composites were characterized with TEM, digital camera and fluorescence spectrophotometer. The stability of CdTe NCs and the composites were    investigated in phosphate-buffered saline(PBS) buffer and the fluorescent properties of the composites were discussed in detail.

Key words: CdTe nanocrystal, Sodium tellurite, CdTe/SiO2