LiSrBO3:Tb^3+ green phosphor was synthesized by means of a solid state reaction and its spectral characteristics were studied. The emission spectrum of LiSrBO3:Tb^3+ consists of four major bands at 486, 544, 595 a...LiSrBO3:Tb^3+ green phosphor was synthesized by means of a solid state reaction and its spectral characteristics were studied. The emission spectrum of LiSrBO3:Tb^3+ consists of four major bands at 486, 544, 595 and 620 nm under the excitation of near ultraviolet irradiation, which are originated from the ^5Da→^7F6, ^5D4→^7F5, ^5D4→^7F4 and ^5D4→^7F3 characteristic transitions of Tb^3+, respectively. Monitored at 544 nm, the excitation spectrum of the phosphor extends from 220 nm to 390 nm, with the excitation peaks centered at 242, 277, 368 and 381 nm, respectively. The effect of Tb^3+ concentration on the emission intensity of LiSrBO3:Tb^3+ was also investigated. The results show that firstly the intensity increases with increasing Tb^3+ concentration, reaches a maximum value at 3%(molar fraction) Tb^3+ and then decreases, showing a concentration self-quenching, whose mechanism is proposed as a d-d interaction based on Dexter theory. The emission intensity of LiSrBO3:Tb^3+ was enhanced by co-doping Li^+, Na^+ and K^+.展开更多
This paper reports that a novel yellow phosphor, LiSrBO3:Eu2+, was synthesized by the solid-state reaction. Thc excitation and emission spectra indicate that this phosphor can be effectively excited by ultraviolet ...This paper reports that a novel yellow phosphor, LiSrBO3:Eu2+, was synthesized by the solid-state reaction. Thc excitation and emission spectra indicate that this phosphor can be effectively excited by ultraviolet (360 and 400 nm) and blue (425 and 460 nm) light, and exhibits a satisfactory yellow performance (565 nm). The role of concentration of Eu2+ on the emission intensity in LiSrBO3 is studied, and it is found that the critical concentration is 3 mol%, and the concentration self-quenching mechanism is the dipole-dipole interaction according to the Dexter theory. White light emitting diodes were generated by using an InGaN chip (460 nm or 400 nm) with LiSrBO3:Eu2+ phosphor, the CIE chromaticity is (x = 0.341, y =0.321) and (x = 0.324, y = 0.318), respectively. Therefore, LiSrBOa:Eu^2+ is a promising yellow phosphor for white light emitting diodes.展开更多
基金Supported by the National Science Foundation of China(50902042)the Natural Science Foundation of Hebei Province (E2009000209,E2010000283)the Education Office Foundation of Hebei Province(2009313)
基金Supported by the Developing Foundation of Science & Technology of Hebei Province,China(No.5121510b)the Natural Science Foundation of Hebei Province,China(No.E2009000209)the Education Office Foundation of Hebei Province,China (No.2009313)
文摘LiSrBO3:Tb^3+ green phosphor was synthesized by means of a solid state reaction and its spectral characteristics were studied. The emission spectrum of LiSrBO3:Tb^3+ consists of four major bands at 486, 544, 595 and 620 nm under the excitation of near ultraviolet irradiation, which are originated from the ^5Da→^7F6, ^5D4→^7F5, ^5D4→^7F4 and ^5D4→^7F3 characteristic transitions of Tb^3+, respectively. Monitored at 544 nm, the excitation spectrum of the phosphor extends from 220 nm to 390 nm, with the excitation peaks centered at 242, 277, 368 and 381 nm, respectively. The effect of Tb^3+ concentration on the emission intensity of LiSrBO3:Tb^3+ was also investigated. The results show that firstly the intensity increases with increasing Tb^3+ concentration, reaches a maximum value at 3%(molar fraction) Tb^3+ and then decreases, showing a concentration self-quenching, whose mechanism is proposed as a d-d interaction based on Dexter theory. The emission intensity of LiSrBO3:Tb^3+ was enhanced by co-doping Li^+, Na^+ and K^+.
基金Project supported by the National Natural Science Foundation of China (Grant No. 50902042)the Natural Science Foundation of Hebei Province, China (Grant No. E2009000209)the Research Foundation fo Education Bureau of Hebei Province, China(Grant No. 2009313)
文摘This paper reports that a novel yellow phosphor, LiSrBO3:Eu2+, was synthesized by the solid-state reaction. Thc excitation and emission spectra indicate that this phosphor can be effectively excited by ultraviolet (360 and 400 nm) and blue (425 and 460 nm) light, and exhibits a satisfactory yellow performance (565 nm). The role of concentration of Eu2+ on the emission intensity in LiSrBO3 is studied, and it is found that the critical concentration is 3 mol%, and the concentration self-quenching mechanism is the dipole-dipole interaction according to the Dexter theory. White light emitting diodes were generated by using an InGaN chip (460 nm or 400 nm) with LiSrBO3:Eu2+ phosphor, the CIE chromaticity is (x = 0.341, y =0.321) and (x = 0.324, y = 0.318), respectively. Therefore, LiSrBOa:Eu^2+ is a promising yellow phosphor for white light emitting diodes.