Ca2SiO4:Dy3+材料的制备及其发光特性

采用高温固相法制备了Ca₂SiO₄:Dy³⁺发光材料.在365nm紫外光激发下，测得Ca₂SiO₄:Dy³⁺材料的发射光谱为一多峰宽谱，主峰分别位于486nm，575nm和665nm处；监测575nm发射峰，测得材料的激发光谱为一多峰宽谱，主峰分别位于331nm，361nm，371nm，397nm，435nm，461nm和478nm处.研究了Dy³⁺掺杂浓度对Ca₂SiO₄:Dy³⁺材料发射光谱及发光强度的影响，结果显示，随Dy³⁺浓度的增大，黄、蓝发射峰强度比(Y/B)逐渐增大，利用Judd-Ofelt理论解释了其原因；随Dy³⁺浓度的增大，Ca₂SiO₄:Dy³⁺材料发光强度先增大，在Dy³⁺浓度为4 mol%时到达峰值，而后减小，根据Dexter理论其浓度猝灭机理为电偶极-电偶极相互作用.研究了电荷补偿剂Li⁺，Na⁺和K⁺对Ca₂SiO₄:Dy³⁺材料发射光谱的影响，结果显示，不同电荷补偿剂下，随电荷补偿剂掺杂浓度的增大，Ca₂SiO₄:Dy³⁺材料发射光谱强度的演化趋势相同，即Ca₂SiO₄:Dy³⁺材料发射峰强度先增大后减小，但不同电荷补偿剂下，材料发射峰强度最大处对应的补偿剂浓度不同，对应Li⁺，Na⁺和K⁺时，浓度分别为4mol%，4mol%和3mol%. 关键词： 白光LED 2SiO₄:Dy³⁺')" href="#">Ca₂SiO₄:Dy³⁺ 发光特性 电荷补偿

Preparation and luminescence characteristics of Ca2SiO4:Dy3+ phosphor

The Ca₂SiO₄:Dy³⁺ phosphor was synthesized by high temperature solid-state method. The emission spectrum of Ca₂SiO₄:Dy³⁺ shows bands at 486nm，575nm and 665nm under the 365nm excitation. The excitation spectrum for 575nm emission has excitation bands at 331nm，361nm，371nm，397nm，435nm，461nm and 478nm. The effect of Dy³⁺ concentration on the emission spectrum and luminescent intensity of Ca₂SiO₄:Dy³⁺ was investigated.The result shows that the ratio (Y/B)of yellow emission (575nm)to blue emission (486nm)increases with increasing Dy³⁺ concentration，and the reason was explained by Judd-Offelt theory. The luminescent intensity firstly increases with the increasing Dy³⁺ concentration，then decreases，and the concentration self-quenching mechanisms are the d-d interaction according to the Dexter theory. The effect of Li⁺，Na⁺ and K⁺ on the emission spectra of Ca₂SiO₄:Dy³⁺ phosphor was studied. The results show that the emission spectrum intensity of Ca₂SiO₄:Dy³⁺ phosphor is greatly influenced by Li⁺，Na⁺ and K⁺，and the evolvement trend is the same for different charge compensations，i.e.，the emission spectrum intensity firstly increases with increasing charge compensation concentration，then decreases. However, the charge compensation concentration corresponding to the maximum emission intensity is different for different charge compensations，and the concentrations are 4，4 and 3 mol% for the Li⁺，Na⁺ and K⁺，respectively.