Enhanced green emission from UV down-converting Ce3+–Tb3+ co-activated ZnAl2O4 phosphor

• Published in: Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena Microelectronics and nanometer structures processing, measurement and phenomena, 2012-05, Vol.30 (3)
• Main Authors: Tshabalala, K. G., Nagpure, I. M., Swart, H. C., Ntwaeaborwa, O. M., Cho, S.-H., Park, J.-K.
• Format: Article
• Language: English
• ISSN: 1071-1023; 2166-2746; 1520-8567; 2166-2754
• DOI: 10.1116/1.3696720

Ce3+–Tb3+ co-activated ZnAl2O4 powder phosphors were prepared by a solution combustion method using urea as a fuel. X-ray diffraction characterization showed that all the powders crystallized in the well known cubic spinel phase of ZnAl2O4. An enhanced down-converted green emission associated with the 5 D 4→ 7 F 5 transitions of Tb3+ ions was observed at 543 nm from the ZnAl2O4:Ce3+, Tb3+ powders with different concentrations of Ce3+ and Tb3+. It was inferred from the fluorescence decay data that the enhancement was due to energy transfer from Ce3+ to Tb3+. Further, cathodoluminescence intensity degradation of the ZnAl2O4:Ce3+, Tb3+ powder phosphors was investigated when the powders were irradiated with 2 keV electrons. X-ray photoelectron spectroscopy was used to analyze the chemical and electronic states of individual elements before and after electron irradiation. The ZnAl2O4:Ce3+, Tb3+ phosphor was evaluated to be used as a UV down-converting layer in conventional silicon photovoltaic cells or as a source of green light in field emission display technologies.