Facile synthesis of La-doped CdS nanoparticles by microwave assisted co-precipitation technique for optoelectronic application

Low-cost microwave assisted technique has been applied to produce La-doped CdS nanoparticles and their structural, morphological, optical, Raman, dielectric and electrical studies were carried out. Broad XRD peaks revealed the growth of low-dimension La-doped CdS nanoparticles with wurtzite structure. Spherical shape morphology of synthesized nanostructures was confirmed by SEM analysis. SEM mapping and EDAX analysis showed the elemental composition and successful incorporation of La in CdS matrix. Diffused reflectance spectroscopy was used to determine the energy gaps and it was observed to be reduced from 2.47 to 2.3 eV upon La doping. Vibrational studies on La:CdS nanoparticles displayed longitudinal optical modes. PL studies exhibited improved luminescence for the band to band transition of the CdS nanoparticles. The ϵ′ values are enhanced in general; though it displayed reduced ϵ′ values at some concentration owing to reduction of polarization. Enhancement in AC conductivity was observed with increasing La concentration and the studies on the involved conduction mechanism revealed that the hopping motion in prepared nanostructures is translation motion with a quick hopping and the behavior is that of ionic conduction.