Synthesis of CdS nanocrystals using cadmium dichloride and trioctylphosphine sulfide

The synthesis of CdS nanocrystals has been carried out by the thermolysis of cadmium dichloride with trioctylphosphine sulfide as the sulfur source, in tri-n-octylphosphine oxide at 250 degrees C. The material shows quantum size, effects in the optical spectrum. The onset of absorption for CdS is at approximate to 480 nm (bulk CdS, 515 nm), a blue shift in the absorption edge. The spectrum also shows a second excitonic peak at 379 nm (S. Modes and P, Lianos, J. Phys. Chem., 1989, 93, 5854). The sample is composed of particles of diameter ca. 4.5 nm.