搜索

x
中国物理学会期刊

荧光粉CaWO4:Eu3+中WO42-与Eu3+间的能量转递

CSTR: 32037.14.aps.62.183302

Energy transfer between WO42- groups and Eu3+ in CaWO4:Eu3+ phosphor

CSTR: 32037.14.aps.62.183302
PDF
导出引用
  • 通过高温固相法分别制备了CaWO4和CaWO4:1%Eu3+ 样品. 测量了样品不同温度(10–300 K)的荧光光谱、荧光衰减曲线和 时间分辨荧光光谱. 样品的荧光光谱表明: 在240 nm紫外光激发下, 两个样品在430 nm处都展现出来源于WO42-的蓝色发射; 样品CaWO4:Eu3+的Eu3+(5D0→7F1, 2, 3,4)的特征发射则归属于WO42-到Eu3+ 间的能量传递.由样品室温(300K)荧光衰减曲线发现: 纯CaWO4的荧光寿命为8.85μs,Eu3+掺杂之后WO42-的荧光寿命缩短至6.27μs,这从另一方面证明了WO42-与Eu3+间能量传递的存在. 由荧光寿命得到T=300K时, CaWO4: 1%Eu3+中WO42-与Eu3+间的能量传递效率(ηET)为29.2%, 能量传递速率(ωET)为4.65×104 s-1.通过时间分辨荧光光谱, 获得了从WO42-到Eu3+之间的能量传递的时间演变过程,当温度由10 K增加到300 K时, 能量传递出现的时间单调变小. 测试了不同温度(10–300 K)对CaWO4:Eu3+的荧光寿命的影响, 发现在10–50K时,Eu3+的荧光寿命增加, 但温度超过50K时发生猝灭, 荧光寿命开始下降; WO42-的荧光寿命则是随着温度的升高逐渐缩短.

     

    The pure CaWO4 and 1%Eu3+ doped CaWO4 phosphors are successfully prepared by the conventional solid state reaction method. The photoluminescence (PL) spectra, decay cures, and time-resolved PL spectra are measured at depend on different temperatures. Fluorescence spectra at room temperature (300 K) and low temperature (10 K) show that these two samples each have a broad band at about 430 nm, originating from the WO42- groups under 240 nm excitation, while the CaWO4:Eu3+sample exhibits the characteristic emission of Eu3+ corresponding to 5D0→7F1, 2, 3,4 transitions due to the absorbed energy transfer from WO42- groups to Eu3+ ions. And the red light at 616 nm of CaWO4: Eu3+ can be excited efficiently by UV (395 nm) and blue (465 nm) light. The decay curves at 300 K illustrate that the lifetime of WO42- group in pure CaWO4 is about 8.85 s but is shortened to 6.27 μs after Eu3+ions have been doped, which is a further good evidence for demonstrating the existence of WO42-–Eu3+ energy transfer process. The energy transfer efficiency (ηET)) and rate (ωET) between WO42- and Eu3+in CaWO4: 1%Eu3+ are 29.2% and 4:65×104 s-1 respectively, when T = 300 K. The energy transfer process is studied in detail by the time-resolved PL spectra, and the lifetime for the appearance of Eu3+ emission in CaWO4 decreases monotonically as temperature increases from 10 K to 300 K. The temperature dependence of luminescence decay time is performed and the results indicated that the lifetime of Eu3+ increases in a temperature range of 10-50 K, when the temperature is more than 50 K, thermal quenching of Eu3+ begins and the lifetime is shortened. However, the lifetime of WO42- reduces constantly with the increase of temperature.

     

    目录

    /

    返回文章
    返回