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Information × Registration Number 0219U000897, 0116U004041 , R & D reports Title Improving the efficiency of luminescence of lanthanide ions and their complexes for functionalization of ligands and encapsulation in a solid matrix popup.stage_title Head Efryushina N.P., Registration Date 13-03-2019 Organization A.V. Bogatsky, Physico-Chemical Institute of the National Academy of Sciences of Ukraine popup.description2 Activated by Ce3+ ions Ca3Sc2Si3O12 and CaSc2O4 - potential phosphors for energy-saving light-emitting diodes (LED) - were obtained by solid-phase reactions at 1300-1320 °C. It was found that the use of NaF as a flux-mineralizer allows one to increase the integral luminescence intensity of Ce3+ in Ca3Sc2Si3O12 by ~ 20%. For the first time, the luminescent properties of the materials obtained were studied in the range of 77-800 K. It was shown that in the temperature range of 293-700 K, the temperature dependences of the decay time and the integral luminescence intensity of Ce3+ ions in Ca3Sc2Si3O12 differ markedly. It was concluded that (a) the luminescence decay time of Ce3+ ions (71 ns) is constant up to 700 K, i.e. the temperature quenching of the Ce3+ luminescence in Ca3Sc2Si3O12 starts at extremely high temperatures (? 750 K) and in comparison with commercial phosphor for white LEDs Y3Al5O12:Се3+ is much less pronounced; (b) a decrease in the luminescence intensity of Ce3+ ions in Ca3Sc2Si3O12 with increasing temperature in the range of 350-700 K is not due to the temperature quenching of the luminescence, but is caused by temperature dependence of the absorption coefficient in the region of 410-480 nm. It was shown that the longer-wavelength position of the luminescence maximum of Ce3+ ions in CaSc2O4 (?max = 512 nm) compared to other oxide compounds of alkaline-earth metals is due to two factors: a significant splitting of the 5d configuration of the Ce3+ ion by a crystal field and a relatively high degree of covalency of metal-oxygen bond. It was found that a decrease in the luminescence intensity of Ce3+ ions upon excitation in the range of 410-480 nm with increasing temperature in the range of 350-500 K is a result of thermally stimulated ionization of the impurity Ce3+ ions, and significant differences in the thermal stability of the luminescence of Ce3+ in CaSc2O4 and Ca3Sc2Si3O12 are due to differences in electronic structure of these compounds. Product Description popup.authors Є.М. Фадеев І.В. Березовська І.В. Починок І.В. Стоянова А.В. Егорова А.О. Кучер В.П. Антонович В.П. Доценко З.Д. Клименко М.М. Семенишин Н.В. Русакова Н.О. Чивирева Н.П. Єфрюшина О.І. Теслюк О.В. Коровін О.В. Хоменко П.Г. Дога С.С. Смола Ю.В. Скрипінець popup.nrat_date 2020-04-02 Close