Impact of Ce content on cubic phase cerium–cadmium oxide (Ce–CdO) nanoparticles and its n-CeCdO/p-Si junction diodes

Abstract

Microwave irradiation method was adopted to synthesize Ce doped CdO nanoparticles. The n-CeCdO/p-Si junction diode was fabricated and it’s parameters have been studied at different doping concentrations (0, 5, 10, and 15 wt%) of Ce. The Ce doping effect was analyzed by various characterization techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photo electron spectroscopy (XPS), ultra violet–visible spectroscopy (UV–Vis) and DC conductivity (I–V) studies. From XRD analysis, the Ce–CdO nanoparticles depicted a crystalline nature and showed the cubic phase. The crystallite size of the samples varied from 18.72 to 14.68 nm. TEM images reveal that the Ce–CdO nanoparticles have nail-like structure. The presence of the elements Ce, Cd and O were confirmed by EDX and XPS studies. The optical bandgap value decreases with the increasing doping concentration and the minimum band gap energy of 2.70 eV is obtained for 15 wt% Ce–CdO sample. I–V curve represents the semiconducting behavior of Ce–CdO nanoparticles. Variation of current in Ce doped CdO nanoparticles exhibits linear response to applied voltage. The diode behavior was studied under darkness and illumination environment. The major diode parameters, ideality factor and barrier height of n-CeCdO/p-Si junction diode were examined using J–V method.