Tm^(3+)/Yb^(3+)掺杂NaLu(WO_(4))_(2)荧光粉的量子剪裁机理与效率  

Quantum Cutting Mechanism and Efficiency in Tm^(3+)/Yb^(3+)-doped NaLu(WO_(4))_(2)Phosphors

作　　者：杨梅 高端 沙雪竹 陈昕 王礼 张艳秋 张翔清 陈宝玖 YANG Mei;GAO Duan;SHA Xuezhu;CHEN Xin;WANG Li;ZHANG Yanqiu;ZHANG Xiangqing;CHEN Baojiu(College of Science,Dalian Maritime University,Dalian 116206,China)

机构地区：[1]大连海事大学理学院,大连116026

出　　处：《光子学报》2025年第2期218-227,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.11774042);中国博士后科学基金(No.2023M730461);中央高校基本科研业务费项目(No.3132023519)。

摘　　要：采用高温固相法合成了Tm^(3+)单掺杂及Tm^(3+)/Yb^(3+)共掺杂的NaLu(WO_(4))_(2)荧光粉,利用X射线衍射对样品的晶体结构进行了分析。为了实现有效的量子剪裁,采用光谱测量确定了Tm^(3+)的最佳掺杂浓度为1 mol%。通过对Tm^(3+)/Yb^(3+)共掺杂样品的光谱和荧光衰减曲线的分析,证实Tm^(3+)敏化Yb^(3+)的量子剪裁发光是通过两步能量传递实现的,即Tm^(3+)通过第一步能量传递^(1)G_(4)(Tm)+^(2)F_(7/2)(Yb)→^(3)H_(4)(Tm)+^(2)F_(5/2)(Yb)产生Yb^(3+)离子的一个980 nm光子发射,然后通过第二步能量传递^(3)H_(4)(Tm)+^(2)F_(7/2)(Yb)→^(3)H_(6)(Tm)+^(2)F_(5/2)(Yb)再产生Yb^(3+)离子的一个980 nm光子发射。利用Tm^(3+)和Yb^(3+)荧光衰减数据计算了Tm^(3+)/Yb^(3+)共掺杂NaLu(WO_(4))_(2)荧光粉的量子剪裁效率,研究发现由于两步能量传递的能量失配较大,导致能量传递效率偏低,致使量子剪裁效率不高。此外,还发现Yb^(3+)到Tm^(3+)反向能量传递^(3)H_(6)(Tm)+^(2)F_(5/2)(Yb)→^(3)H_(5)(Tm)+^(2)F_(7/2)(Yb)对量子剪裁起负面作用,也是导致Tm^(3+)/Yb^(3+)共掺杂材料量子剪裁效率不高的重要原因。Quantum cutting is a promising approach to enhance the efficiency of silicon solar cells.The Yb^(3+)is chosen as the acceptor ion since it has been extensively used for its near-infrared emission around 980 nm(^(2)F_(5/2)→^(2)F_(7/2)),which is just above the bandgap of Si-based solar cells.The efficiency of quantum cutting mechanism via two-step energy transfer from Tm^(3+)to Yb^(3+)is investigated in Tm^(3+)/Yb^(3+)co-doped NaLu(WO_(4))_(2)phosphors.Tm^(3+)-doped and Tm^(3+)/Yb^(3+)co-doped NaLu(WO_(4))_(2)phosphors were prepared by a high temperature solid-state reaction method.The crystal structure of the samples was analyzed by X-ray Diffraction(XRD).X-ray diffraction shows that all of samples are pure tetragonal-phased NaLu(WO_(4))_(2)powders.It is known that the high doping concentration will result in the concentration quenching which further depresses the quantum cutting efficiency.Through the dependences of emission intensities for all transitions of Tm^(3+),it can indicated that the population of the metastable levels reaches its maximum at around 1 mol%.To achieve effective quantum cutting,the optimum concentration of Tm^(3+)was determined to be 1 mol%through optical spectral measurements.By analyzing the spectra and luminescence decays of Tm^(3+)/Yb^(3+)co-doped samples,it was confirmed that Tm^(3+)-sensitized-Yb^(3+)quantum cutting is achieved via two-step energy transfer processes,namely,the first energy transfer^(1)G_(4)(Tm)+^(2)F_(7/2)(Yb)→^(3)H_(4)(Tm)+^(2)F_(5/2)(Yb)results in the emission of a 980 nm photon from Yb^(3+),and the second energy transfer^(3)H_(4)(Tm)+^(2)F_(7/2)(Yb)→^(3)H_(6)(Tm)+^(2)F_(5/2)(Yb)results in the emission of another 980 nm photon from Yb^(3+).The luminescence lifetime decay curve of Tm^(3+)with different Yb^(3+)concentrations is gradually shortened with the increase of Yb^(3+)ions concentration,which indicates energy transfer efficiency and quantum efficiency can be improved with the increase of Yb^(3+)ions concentration.The quantum cutting efficiencies of Tm^(3+

关 键 词：高温固相法 能量传递 荧光衰减 量子剪裁 量子效率 

分 类 号：O482.31[理学—固体物理]