Glycolthermal synthesis and characterization of hexagonal CdS round microparticles in flower-like clusters

Hexagonal CdS round microparticles in flower-like clusters were synthesized by glycolthermal reactions of CdCl2 and thiourea as cadmium and sulphur sources in 1,2-propylene glycol (PG) at 100-200 degrees C for 10-30 h. Phase and morphology were detected using X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM, TEM). The products were pure phase of hexagonal wurtzite CdS. The quantitative elemental analysis of Cd:S ratio was detected using energy dispersive X-ray (EDX) analyzer. Raman spectrometer revealed the presence of fundamental and overtone modes at 296 and 595 cm(-1), corresponding to the strong 1LO and weak 2LO modes, respectively. Photonic properties were investigated using UV-visible and photoluminescence (PL) spectroscopy. They showed the same absorption at 493-498 nm, and emission at 431 nm due to the excitonic recombination process. A possible formation mechanism was also proposed, according to experimental results. (C) 2011 Elsevier B.V. All rights reserved.