Studies on the dielectric properties of CdS nanoparticles

CdS is one of the most important II–VI semiconductors with applications in solar cells, optoelectronics and electronic devices. CdS nanoparticles were synthesized by the wet chemical method. The crystal structure and grain size of the particles were determined by X-ray diffraction. The optical properties were studied by the ultraviolet–visible absorption spectrum. The dielectric properties of CdS nanoparticles were studied in the frequency range of 50 Hz–5 MHz at different temperatures. The frequency dependence of the dielectric constant and dielectric loss is found to decrease with an increase in the frequency at different temperatures. The dielectric properties of CdS nanoparticles are found to be significantly enhanced specially in the low frequency range due to confinement. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the CdS nanoparticles were calculated. The AC electrical conductivity measurements reveal that the conduction depends on both the frequency and the temperatures.