Room-Temperature Synthesis and Characterization of Nanocrystalline CdS, ZnS, and CdxZn1-xS

A novel and simple chemical reduction route at room temperature is described to synthesize nanocrystalline CdS, ZnS, and Cd x Zn 1 - x S. In the method, anhydrous CdCl 2, or ZnCl 2, S, and KBH 4 powders react at room temperature in various organic solvents, and the effect of the solvent on the quality of the nanoparticle product is investigated. Among the solvents used, tetrahydrofuran is shown to produce the highest quality single-phase nanoparticles. The nanoparticles are characterized by X-ray diffraction, transmission electron microscopy, UV−vis absorption, and photoluminescence. The particle size ranges from 4 to 8 nm. In the Cd x Zn 1 - x S, the lattice structure gradually changes from cubic to hexagonal with increasing percentage of Zn in the ternary compound Cd x Zn 1 - x S. The nanoparticles exhibit broad emission peaks that shift to shorter wavelength with increasing percentage of Zn in the ternary compound Cd x Zn 1 - x S. The control of the composition of Cd x Zn 1 - x S nanoparticles may lead to the development of ideal materials for short wavelength diode laser applications.