Structural and optical properties of CdS nanorods and CdS/ZnS nanoslabs

CdS nanorods having diameter, 22 nm, and CdS/ZnS nanoslabs, having thickness of ∼85 nm, have been synthesized solvothermally at 160 °C, using ethylenediamine (En) as the solvent and the chelating ligand. In this two-step solvothermal process, CdS nanorods synthesized in the first step have been used as an ingredient for the second step, resulting in CdS/ZnS nanostructures with CdS nanorods embedded in ZnS nanoslabs. Both the samples have been compared structurally, morphologically and optically using, respectively, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis absorption studies and photoluminescence (PL) studies. CdS and CdS/ZnS nanostructures have hexagonal wurtzite phase of CdS and ZnS. Fourier transform infrared spectroscopy (FTIR) has been carried out to find the organic composition of the samples, especially to confirm the presence of En. Comparison between the PL spectra of the two samples has shown distinct peaks centered at 420 and 484 nm due to the presence of ZnS, in addition to the CdS related luminescence peaks centered at 530 and 544 nm.