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Synthesis and characterization studies of cadmium doped MgO nanocrystals for optoelectronics application

K. Kaviyarasu and Prem Anand Devarajan

II – VI semiconductor nanocrystals are recently developed class of nanomaterials whose unique photophysical properties are helping to create a new generation in the field of photonics and microelectronics. In this review, we examine the progress in adapting these nanomaterials for several predominantly photonics device fabrication by autocombustion method followed by characterization studies. Magnesium oxide (MgO) and Cd doped Magnesium oxide nanoparticles were characterized by X-ray powder diffraction and the peaks are quite agreeable with the pure phase cubic structure. The XRD pattern confirms the crystallinity and phase purity of the pure and doped samples. Uv-vis-NIR study of the samples indicated a blue shift in the band gap for both the pure and doped ones. Photoluminescence measurements reveal the systematic shift of the emission band towards the lower wavelength thereby ascertaining the quantum confinement effect. Photoluminescence spectra of pure MgO and Cd doped MgO were investigated, showing emission peaks around 475 nm relating to new energy levels induced by defects or defect levels generation. The SEM results reveal that the resultant nanopowders are porous and agglomerated with polycrystalline nano entities. Field emission scanning electron microscopic studies showed that the average size of the nanoparticles were 20 nm and 33 nm respectively. The dielectric loss of the pure and Cd doped MgO samples decreases with increase in frequency. Similar trend is observed for the dielectric constant also.