Host emission from BaMgAl₁₀O₁₇ and SrMgAl ₁₀O₁₇ phosphor: Effects of temperature and defect level

Understanding the mechanism of blue-light emission in Eu-doped BAM phosphor as well as its sensitive degradation is required because this is a very important material in fluorescent lamps and plasma-display panels. In this study, both theoretical and experimental investigations on the host emissions in BaMgAl₁₀O₁₇ and SrMgAl₁₀O₁₇ were performed. Host emissions from BaMgAl₁₀O₁₇ and SrMgAl ₁₀O₁₇ by photoluminescence and thermoluminescence spectra were observed. Photoluminescence spectra suggested that the host emission from SrMgAl₁₀O₁₇ was easily quenched by thermal vibrations. The thermoluminescence spectra showed the existence of shallow and deep defect levels in BaMgAl₁₀O₁₇ and SrMgAl₁₀O ₁₇ phosphors. It was shown that SrMgAl₁₀O₁₇ and its conduction plane could undergo degradation during irradiation of vacuum-ultra-violet (VUV) lights based on the calculated energy of formation of an oxygen vacancy. Moreover, the structural defects, such as oxygen vacancies, would cause localizing levels in the upper level in the valence band and in the conduction band. The results suggest the contribution of the host emission to the energy transfer to the Eu atoms would not be significant and the oxygen vacancies would act as the traps for excited carriers.