颜色可调Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+)荧光粉的制备、发光性能及能量传递

Preparation,Luminescence Properties and Energy Transfer of Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+) Phosphors with Tunable Color

本文利用高温固相反应法制备了高效黄绿色多色发光荧光粉Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+),其主要窄发射带来自Tb^(3+)的547 nm处,并且由于Dy^(3+)的敏化作用而在250~400 nm区域具有宽激发带,将Dy^(3+)和Tb^(3+)共掺到Ca_(2)LaTaO_(6)(CLTO)基质中,构建能量传递体系。通过激发/发射光谱及寿命衰减曲线测试证实了Dy^(3+)到Tb^(3+)的能量传递过程。Dy^(3+)→Tb^(3+)的能量传递以偶极-四极相互作用为主,能量传递效率可达80%甚至更高。基于该能量传递过程,在Dy^(3+)的特征激发下,通过改变Dy^(3+)和Tb^(3+)的相对掺杂浓度,可以使发光颜色由黄色渐变为绿色,说明发光颜色可调的多色发光荧光粉Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+)在荧光粉转换的白光LED中具有潜在的应用前景。

High-efficiency yellow-green polychromatic luminescent phosphors Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+)were obtained by high-temperature solid-state reaction method.The main narrow emission comes from the 547 nm of Tb^(3+)and a wide excitation band is located in the region of 250~400 nm due to the sensitization of Dy^(3+).The energy transfer system was constructed by co-doping Dy^(3+)and Tb^(3+)into Ca_(2)LaTaO_(6)(CLTO)matrix.Furthermore,the energy transfer for Dy^(3+)→Tb^(3+)was confirmed by excitation/emission spectra and lifetime decay curve measurements.The energy emigration is dominated by dipole-quadrupole interaction,and the efficiency can reach 80%or even higher.Under the characteristic excitation of Dy^(3+),the luminescence color changes from yellow to green by adjusting the relative doping concentration of Dy^(3+)and Tb^(3+)based on the energy transfer.The results indicate that Ca_(2)LaTaO_(6)∶Dy^(3+),Tb^(3+)phosphor with adjustable emission color has potential applications in phosphor-converted white LEDs.