Synthesis, characterization, and electrical properties studies of cadmium selenide nanoparticle

A new solvothermal route was used for the preparation of CdSe nanoparticles at 160 degrees C for 10 h using ethylenediamine as a solvent. Xray powder diffraction and transmission electron microscope were employed to characterize the size, morphology, and crystalline structure of the as-prepared sample. The formation process was discussed and it revealed a uniform hexagonal shape of CdSe nanoparticle with good dispersion, with an average size of 35 nm. Fourier transform infrared and ultraviolet-visible spectroscopies were used to follow the reaction and to determine the optical band gap. DC and AC electrical conductivities were studied and the activation energies were determined as well as the conduction mechanism. The results indicated that CdSe behaves as a semiconducting material. The dielectric properties were measured as a function of temperature at different frequencies ranging from 100 Hz to 100 kHz. The increase of the dielectric constant with increasing temperature was discussed on the basis of increasing polarizability, while its decrease with increasing frequency is attributed to the dielectric dispersion. (C) 2007 Elsevier B.V. All rights reserved.