Investigation of luminescent properties of Ca 0.3 Sr 0.7 Al 2 O 4 :Tb 3+ ,Eu 3+ excited using different excitation sources

tThe structure and luminescent properties of Tb3+–Eu3+co-activated Ca0.3Sr0.7Al2O4powder phosphorprepared via solution combustion (SC) method were investigated. The phosphor was analyzed usingUV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron (XPS), time offlight secondary ion mass spectroscopy (ToF-SIMS), photoluminescence spectroscopy, synchrotron radi-ation spectroscopy and cathodoluminescence spectroscopy. In particular, the unintended reduction ofEu3+to Eu2+was illustrated from the ToF-SIMS, XPS and luminescent spectroscopy data. This reduction isknown to occur under certain conditions and possible mechanisms for the reduction are discussed. Thechemical imaging performed with ToF-SIMS illustrated how individual ions were distributed in the crys-tal. Tunable luminescence was observed when the phosphor was optically-excited by different excitationsources including a 325 nm He-Cd laser, synchrotron radiation and high energy electrons. This phosphorwas evaluated for application in different types of light emitting devices.AcknowledgementsThis work was financially supported by the competitive pro-gramme for rated researchers (CPRR) of the National ResearchFoundation (NRF) (Grant No. CPR20110724000021870), the SouthAfrican Research Chairs Initiative of the Department of Science andTechnology (DST) and NRF, the rental pool programme of the SouthAfrican national laser centre (NLC) (Grant No. NLC-LREGM00-CON-001).tThe structure and luminescent properties of Tb3+–Eu3+co-activated Ca0.3Sr0.7Al2O4powder phosphorprepared via solution combustion (SC) method were investigated. The phosphor was analyzed usingUV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron (XPS), time offlight secondary ion mass spectroscopy (ToF-SIMS), photoluminescence spectroscopy, synchrotron radi-ation spectroscopy and cathodoluminescence spectroscopy. In particular, the unintended reduction ofEu3+to Eu2+was illustrated from the ToF-SIMS, XPS and luminescent spectroscopy data. This reduction isknown to occur under certain conditions and possible mechanisms for the reduction are discussed. Thechemical imaging performed with ToF-SIMS illustrated how individual ions were distributed in the crys-tal. Tunable luminescence was observed when the phosphor was optically-excited by different excitationsources including a 325 nm He-Cd laser, synchrotron radiation and high energy electrons. This phosphorwas evaluated for application in different types of light emitting devices