Oxidation Effects on Luminescence Properties of Eu_2O_3-doped Ca_2Si_5N_8 Phosphors

摘要

Using Eu_2O_3 for doping, Eu~(2+)-activated Ca_2Si_5N_8 phosphor was synthesized and luminescence properties were investigated. Dark yellow and orange day-lightcolored phosphors were achieved with broad and high absorption in UV/visible range of 300 ~ 550 nm. The photoluminescence characteristics with various Eu~(2+)- doping concentrations were observed. The oxidation from Eu_2O_3 influenced not only emission but also excitation spectra of phosphors. Broad band emissions were achieved and strongest peak positions have shifted from 588 to 613 nm with increase of doped Eu_2O_3 concentration. Large emission tunability and high solubility of activators were achieved due to oxygen incorporations. Dependency of luminescence properties on the process conditions was also studied. In spite of oxidations of host, high absorption in UV range and broad red emission make phosphors in this study excellent candidate for UV-LED conversion phosphors.