Role of dopants to mend morphology and emission in CdO powder

Abstract

Cadmium Oxide (CdO) is the widely acceptable transparent conducting oxide from the II-VI series of elements. In the fast-growing field of nanoscience & technology, researchers have focused on processing, and manufacturing II-VI oxide semiconductors simply by tailoring the size and morphology near to Bohr-exciton radius. To perform the presented experimental work, a few metal ions like copper (Cu), manganese (Mn), and their binary combination are used as efficient dopants. The precursors of cadmium and dopants were synthesized with an efficient co-precipitation method at nanoscale dimensions. In the undoped sample, no specific shape of crystallites has been observed in respective SEM micrographs while planer plates appeared in Cu doped sample, rod shape particles in Mn-doped, and almost spherical particles are found in Cu-Mn doped sample. Energy dispersive X-ray spectroscopy (EDS) of individual nanostructures has emphasized the appropriate stoichiometry of elements which further confirms the presence of each doping element. The luminescent spectra were accomplished at 350 nm excitation wavelength. The emission in the undoped sample depicts the strong violet-blue bands at 410 and 463 nm which shift toward a higher wavelength in the doped sample. The color coordinates of each sample in the corresponding range of white spectra are exhibited by CIE chromaticity graphs. The constituent emitting wavelengths originated possibly from excitonic, near band edge, deep trap states, and structural defects along with the characteristic dopant’s transition. It is suggested that the emission has been significantly tailored within the whole visible range by varying doping elements of different ionic radii. The obtained results endorse the tremendous potential of doped CdO powder in optical display devices.