Green synthesis of pure and doped semiconductor nanoparticles of ZnS and CdS

Nanoparticles of pure and Cu/Ag-doped CdS and ZnS have been synthesized via chemical bath deposition without using any capping or toxic reagents. The synthesis was carried out through a simple and less expensive green method. The XRD result shows that both pure CdS and ZnS and their doped derivatives are of high crystalline with hexagonal packing structure. The average crystalline size of all nanoparticles was calculated using Debye-Scherrer formula. The crystalline size of nanoparticles of pure samples varied with that of the doped sample. The average crystalline sizes of all nanoparticles are found to be in the range of 5.5-2.2 nm for CdS (from pure to doped) and 4.3-3.4 nm for ZnS, respectively. The band gap values obtained from UV-visible spectra are in the range of 3.5-2.1 eV for CdS and 3.3-2.7 eV for ZnS derivatives, respectively. The FTIR spectral data give characteristic peaks for Cd-S, Cu-S, Ag-S and Zn-S bonds and confirm the formation of respective nanoparticles. The peaks corresponding to the microstructural formation are also observed. The FE-SEM images show the granular morphological structure for all the samples. The agglomeration size of the samples in the range of 10-50 nm for CdS:Cu and 50-100 nm for ZnS:Cu is observed.