Investigation on structural and optical properties of CuO doped CdS-Zn3(PO4)2 nanocomposite for optoelectronic devices

Abstract

Pure and CuO (0.3, 0.6 and 0.9 mol%) doped CdS-Zn3(PO4)2 semiconducting nanophosphors were synthesized by hydrothermal technique under mild reaction temperatures. The prepared samples were systematically investigated by Powder X-ray diffraction [XRD], Fourier Transform infra-red spectroscopy [FT-IR], Scanning electron microscopy [SEM] with EDAX, UV–Vis diffuse reflectance spectrometer [DRS] and Photoluminescence [PL] techniques. X-ray diffraction pattern shows hexagonal phase of CdS and monoclinic β-phase of Zn3(PO4)2 with good crystalline nature. The average crystallite size of nanocomposites are in the range 13 to 25 nm and found to decrease from 18 nm to 13 nm with increasing dopant concentration. FT-IR spectra indicate that the prepared samples are high in purity. The surface morphology of the samples has shown a hetero structure type morphology in which hexagonal CdS spheres network bonding accumulated on rectangular flakes. The obtained chemical composition of all the samples are identified by EDAX is in agreement with the calculated stoichiometry. The optical band gap values are determined by diffuse reflectance spectra and are found to be in the range 2.49 eV to 2.39 eV. The room temperature Photoluminescence spectra of pure CdS-Zn3(PO4)2 lattice shown a broad strong green emission peak at ~ 518 nm, while upon incorporation CuO ions in host lattice, a sharp luminescence peak around 393 nm has been observed in all the doped samples along with other peaks at 494 nm, 594 nm, 684 nm which are in the violet, blue-green-red fluorescence of UV-Visible region makes them suitable for optoelectronic device applications.