Studies on the dielectric properties of CdS nanoparticles

Abstract

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.

Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles

“…The dipole moment can easily follow the changes in the electric field, especially at low frequencies. Hence, the contributions to dielectric constant increase through space charge polarization and rotation polarization, which occur mainly in interfaces 15 . Therefore dielectric constant of nanostructured materials should be larger than that of the conventional materials.…”

Investigations on the Synthesis, Optical and Electrical Properties of TiO2 Thin Films by Chemical Bath Deposition (CBD) method

“…In the low frequency region, high energy loss is observed, which may be due to the dielectric polarization, space charge and rotation direction polarization occurring in the low frequency range. The high values of dielectric loss at low frequencies could be related to the charge lattice defect of the space charge polarization 28 .…”

Investigation on Structural, Surface Morphological and Dielectric Properties of Zn-doped SnO2 Nanoparticles

“…Due to the thermionic emission and the tunneling of charge carriers across the barrier, the conductivity increased with the temperature. Because of the small size of the particles, more charge carriers reached the surface of the particles, easily enabling the electron transfer by thermionic emission or tunneling to enhance the conductivity 26 . The ac conductivity of the Zn-doped SnO 2 nanoparticles could be calculated by the following relation: …”