Characterization of CdS,CdXZn1-XS and ZnS Nanocrystallites Grown by Chemical Route

A simple chemical reduction route at room temperature is adopted for the synthesis of CdS, CdXZn1-XS and ZnS nanocrystallites. Anhydrous CdCl2 or ZnCl2, S and NaBH4 react in organic solvent THF. The nanoparticles are characterized by X-ray diffraction, UV-Vis absorption, Photoluminescence and TCSPC study. The particle size ranges from 5 to 10 nm. There is a change of phase from CdS to CdXZn1-XS and finally to ZnS. The lattice changes from hexagonal phase to cubic phase with an increasing percentage of Zn in the ternary compound. The nanoparticles exhibit an absorption peak that shifts towards the lower wavelength side with an increasing percentage of Zn in CdXZn1-XS. The band gap increases as the phase changes from CdS to CdXZn1-XS. Also, the band gap is found to be greater than the bulk value due to the formation of nanoparticles. Photoluminescence and Fluorescence Lifetimes are determined through PL and TCSPC measurements for each composition. The composition-controlled growth of CdXZn1-XSnanostructures is essential for utilizing them in the fabrication of laser diodes.