Room Temperature Photoluminescence Studies on Mn Doped and Sr Co-doped CuO Nanostructures

Abstract

Nanoparticles of Copper Oxide (CuO), Manganese (Mn)-doped CuO, and Mn and Strontium (Sr) co-doped CuO were synthesised via co-precipitation method. The XRD results show that the particles were monoclinic in structure, and the crystallite size increased from 23.83 nm for CuO, 25.47 nm for CuO: Mn (0.1), 26.10 nm for CuO: Mn (0.2), 26.65 nm for CuO: Mn (0.3) and 28.31 nm for CuO: Mn (0.3): Sr co-doped samples. The band gap of the nanoparticles decreases in the same sequence from 2.97 eV for CuO to 2.40 eV for the co-doped samples. Morphological analyses were carried out using FESEM. The polygon shape of CuO particle changes to a stacked platelet-like structure with high porosity. Mn and Sr co-doped particles exhibit highly stacked platelet structures with less porosity, which showed a variation in sample morphology with doping. From EDS analysis, the Mn atomic percentage for CuO:Mn (0.1), CuO:Mn (0.2) and CuO:Mn(0.3) samples were found to be increased in accordance with the increase in doping concentration of Mn in the samples. Room temperature PL spectra obtained at excitation wavelengths 400 and 500 nm for CuO, CuO:Mn(0.1), CuO:Mn(0.2), CuO:Mn(0.3) and CuO:Mn(0.3):Sr samples show prominent defect level emissions.