Defects suppression and Co–O–Co bonding mediated influences to enhance the luminescence characteristics of Co doped ZnO nanoparticles

Abstract

Abstract Co–O–Co bonding mediated influences are discussed on the structural, defect content, magnetization and luminescence characteristics of Co doped ZnO nanoparticles. X-ray diffraction (XRD) studies indicated an increased fraction of secondary phase while varying Co doping levels from 0.45 to 5\xa0mol%. Contrarily, a reverse trend is noted on the concentration of Zinc interstitials, Zni and Oxygen vacancies, Vo defects through Photoluminescence (PL) spectroscopy. For 5\xa0mol% doping level, Bound Magnetic Polaron (BMP) model fitting of Magnetization versus magnetic field, M(H, 300\xa0K) curve yields an exceptionally low level of BMP density i.e., 3.22\xa0×\xa0107/cm3 thereby governing the dominance of Co–O–Co exchange interactions over Vo based Co–Vo–Co interactions; while PL result displays an enhanced UV emission efficiency suitable for short wavelength optical devices.