Sensitization of Nd 3+ near infrared emission in Ca 2 PO 4 Cl host
Sensitization of Nd 3+ near infrared emission in Ca 2 PO 4 Cl host
复制标题
DOI：
10.1016/j.jlumin.2018.01.007
复制
发表时间：
2018-05
影响因子：
3.6
通讯作者：
R. Talewar;C. P. Joshi;S. Moharil
中科院分区：
文献类型：
--
作者：
R. Talewar;C. P. Joshi;S. Moharil
采用常规固相反应合成了新型高效近红外发光荧光粉Ca2PO4Cl:Eu2+， Nd3+，并用x射线衍射、光致发光发射、光致发光激发光谱和荧光衰减测量对其进行了表征。在400 nm激发下，该荧光粉在450 nm处产生宽带发射，对应于Eu2+的5d→4f跃迁，在800 ~ 1400 nm范围内产生强烈的近红外发射，对应于Nd3+离子的419 /2、11/2、13/2跃迁。详细研究了可见光和近红外辐射与寿命和能量传递效率（ηETE）的关系。利用脉冲激发下的PLE和PL谱以及供体衰减曲线，建立了Eu2+-Nd3+离子之间的能量传递机制。单掺杂和共掺杂样品中Eu2+寿命得到的Eu2+→Nd3+能量转移效率可达41%。计算出Ca2PO4Cl宿主体内Eu2+与Nd3+的临界距离为11.68 Å。应用inokti - hirayama （I-H）模型分析了Eu2+-Nd3+共掺杂Ca2PO4Cl的非指数荧光衰减。由I-H曲线拟合可知，电偶极-偶极相互作用是Eu2+→Nd3+能量传递的主要过程。结果表明，通过Eu2+在Ca2PO4Cl宿主体内的4f-5d跃迁，Nd3+可能具有敏化作用。
Novel and efficient near infrared (NIR) emitting phosphor, Ca2PO4Cl:Eu2+, Nd3+was synthesized by conventional solid state reaction and characterized with X-ray diffraction, photoluminescence emission, photoluminescence excitation spectra and fluorescence decay measurements. When excited with 400 nm, the phosphor gives broadband emission at 450 nm, which corresponds to the allowed 5d→4f transition of Eu2+and intense NIR emissions in the range 800–1400 nm, which are assigned to the characteristic4I9/2,11/2,13/2transitions of Nd3+ions. The dependence of visible and NIR emissions, lifetime and the energy transfer efficiency (ηETE) were investigated in detail. The PLE and PL spectra along with donor decay curves obtained under pulsed excitation have been used to establish the energy transfer mechanism between Eu2+-Nd3+ions. The Eu2+→Nd3+energy transfer efficiency obtained from the Eu2+lifetimes in the single doped and co-doped samples reaches up to 41%. The critical distance between Eu2+and Nd3+in Ca2PO4Cl host was calculated, as 11.68 Å. The Inokuti-Hirayama (I-H) model of sensitizer to activator energy transfer is applied in analysis of the non-exponential fluorescence decays of Eu2+-Nd3+co-doped Ca2PO4Cl. From I-H curve fitting, it is inferred that the electric dipole–dipole interaction is the main process responsible for the energy transfer from Eu2+→Nd3+. The results indicate that sensitization of Nd3+is possible via 4f-5d transition of Eu2+in Ca2PO4Cl host.