A simple organic synthesis for CdS and Se-doped CdS nanocrystals

A simple and convenient organic synthesis method for preparation of CdS and Se-doped CdS semiconductor nanocrystals (NCs) was developed. Cadmium oxide and sulfur powder or thiourea all of which are inexpensive and easily available, were used as precursors of Cd and S. Cheap, stable and environmentally friendly paraffin and oleic acid were selected as the solvent. Compared with expensive trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO) system, this procedure was simple, green and low-cost. By this new route, a series of CdS and Se-doped CdS NCs was obtained. Low amount of Se doped in CdS NCs could tailor their optical characteristics and emission peaks embodied red-shift with higher Se:S mole ratios. The absorption and room temperature luminescence spectra were used to follow the reaction process and to characterize the optical properties of as-prepared NCs, whose sharp and narrow emission peaks indicated that they had desirable dispersibility, uniformity and good fluorescence properties.