Photoluminescent semiconductor nanocrystals or quantum dots(QDs)are usually produced using expensive ligands and solvents at high temperature above 280◦C to ensure high-quality optical properties,particularly the photoluminescence of QDs.The reproducibility of highly stable photoluminescence in QD preparation,in most cases,varies depending on many effects,such as the ligand used and temperature.Here a facile preparation of photoluminescent semiconductor CdTe nanocrystals or quantum dots(QDs)is conducted in the presence of caprylic acid at moderate temperatures between 80–140◦C,which are much lower than the high temperatures used in conventional organic-phase preparation of CdTe QDs.The results show that the optical properties of CdTe QDs depend considerably on the reaction time,temperature and ligand used.