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采用固相法制备了LiBaBO3:Ce3+发光材料.测得LiBaBO3:Ce3+材料的发射光谱为一不对称的单峰宽谱,主峰位于440 nm;监测440 nm发射峰,可得其激发光谱为一主峰位于370 nm的宽谱.利用van Uitert公式计算了Ce3+取代LiBaBO3中Ba2+时所占晶体学格位,得出438 nm发射带归属于九配位的Ce3+发射,而469 nm发射带起源于八配位的Ce3+发射.研究了Ce3+浓度对LiBaBO3:Ce3+材料发光强度的影响,结果显示,随Ce3+浓度的增大,发光强度呈现先增大后减小的趋势,Ce3+浓度为3mol%时强度最大,造成其浓度猝灭的原因为电偶极-偶极相互作用.引入Li+,Na+或K+可增强LiBaBO3:Ce3+材料的发射强度.利用InGaN管芯(370 nm)激发LiBaBO3:Ce3+材料,获得了很好的蓝白光发射,色坐标为(x=0.291,y=0.297).
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关键词:
- 白光发光二极管 /
- LiBaBO3:Ce3+ /
- 晶体学格位 /
- 发光特性
LiBaBO3:Ce3+ phosphor was prepared by solid-state method,and its luminescence characteristics were investigated. LiBaBO3:Ce3+ phosphor shows one asymmetrical band at 440 nm. Monitored at 440 nm,the excitation spectrum has a broad band at 370 nm. The crystallographic sites of Ce3+ in LiBaBO3 were calculated by van Uitert formula,the results show that the emission band centered at 438 nm originates from the Ce3+ center of the nine compounds,and at 469 nm originates from the Ce3+ center of the eight compounds. The effect of Ce3+ concentration on luminescent intensity of LiBaBO3:Ce3+ phosphor was investigated,the result shows that the luminescent intensity firstly increases with increasing Ce3+ concentration,and reaches the maximal value at 3mol% Ce3+, then decreases. The concentration quenching mechanism is the dipole-dipole interaction by Dexter theory. Under the condition of doping charge compensator Li+,Na+ or K+,the emission intensity of LiBaBO3:Ce3+ was all heightened. The relative emission spectrum of the InGaN-based LiBaBO3:Ce3+ light emitting diode(LED) was investigated,and the CIE chromaticity of InGaN-based LiBaBO3:Ce3+ LED is (x=0.291,y=0.297),and shows the blue white emission.-
Keywords:
- white light emitting diode /
- LiBaBO3:Ce3+ /
- crystallographic sites /
- luminescence characteristics
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