Influence of lanthanide ion on the morphology and luminescence properties of cadmium sulphide nanocrystals

An interesting shape evolution of cadmium sulphide nanocrystals is observed in the presence of a multidendate ligand, ethylenediamine tetra acetic acid (EDTA). In our study, EDTA is used as a capping agent and a ligand forming complex with the trivalent gadolinium ion for the synthesis of cadmium sulphide (CdS) nanoparticles. EDTA-capped CdS nanocrystals and gadolinium (Gd) doped CdS nanoneedles have been synthesized using wet chemical route. Addition of Gd as a dopant to the nanocrystals resulted in formation of luminescent CdS nanoneedles. Fourier transform infrared spectroscopy, energy dispersive X-ray analysis, X-ray diffraction, optical absorption, photoluminescence measurements, scanning and transmission electron microscopic measurement techniques were employed to characterize the samples. Photoluminescence investigation revealed the highly luminescent behavior of the CdS nanoneedles. Further, cathodoluminescence mapping confirmed the excellent luminescent properties, which can be exploited for the fabrication of optoelectronic devices.

► Shape controlled synthesis of CdS nanoparticles. ► EDTA acts as an efficient sequestering agent. ► Addition of rare earth ions influences the changes in morphology and luminescence properties.