Tb^（3＋） and Yb^（3＋） codoped LuPO_4 phosphors were prepared by the reverse-strike co-precipitation method.The obtained LuPO_4：Tb^（3＋）,Yb^（3＋） phosphors were characterized by X-ray diffraction（XRD）,photol...Tb^（3＋） and Yb^（3＋） codoped LuPO_4 phosphors were prepared by the reverse-strike co-precipitation method.The obtained LuPO_4：Tb^（3＋）,Yb^（3＋） phosphors were characterized by X-ray diffraction（XRD）,photoluminescence（PL） spectra and decay kinetics to understand the near-infrared quantum cutting（QC） phenomena.The XRD results showed that all the phosphors exhibited good crystallinity and had a pure tetragonal phase of LuPO_4.The experimental results showed that the strong green emission around 545 nm from Tb^（3＋）（~5D_4→~7F_5） and near-infrared（NIR） emission at 1003 nm from Yb^（3＋）（~2F_（5/2）→~2F_（7/2）） of LuPO_4：Tb^（3＋）,Yb^（3＋）phosphors were observed under 489 nm excitation,respectively.The Yb^（3＋） concentration dependence on luminescent properties and lifetimes of both the visible and NIR emissions were also investigated.The quenching concentration of Yb^（3＋） ions approached as high as 10 mol.%.The excellent luminescence properties of the LuPO_4：Tb^（3＋）,Yb^（3＋） indicated its potential application in improving the energy conversion efficiency of the silicon based solar cells by converting one blue photon to two NIR ones.展开更多
Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse proce...Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse process happen that a high energy photon is cut into three NIR photons？ This work demonstrated an example of three-photon quantum cutting （QC） phosphor, CaF2：Ce^3＋,Yb^3＋, in which three clustered Yb^3＋ ions （Yb^3＋-trimer） cooperatively and indirectly received a 306 nm ultraviolet （UV） photon energy transferred from a Ce^3＋ ion in 5d excited state and emitted three 975 nm near-infrared （NIR） photons. The cluster destruction experiments were designed to verify the necessity of the presence of Yb^3＋-trimers for QC. The dynamical analysis on luminescence of Ce^3＋ ions confirmed the energy transfer from Ce^3＋ ions to Yb^3＋-trimers. The doping concentration effect on luminescence was investigated. Furthermore, the maximum energy transfer （ET） efficiency and the corresponding QC efficiency were estimated to be 61% and 222%, respectively. Therefore, the reported three-photon QC phosphor has an attractive prospect in efficiently harvesting solar energy for silicon solar cells.展开更多
基金supported by the National Natural Science Foundation of China(11404047,11674044,11604037)Chongqing Research Program of Basic Research and Frontier Technology(CSTC2016JCYJA0113,CSTC2016JCYJA0207,CSTC2015JCYJA50005)Research Training Program for Undergraduates of Chongqing University of Posts and Telecommunications(A2015-86,A2016-53)
文摘Tb^（3＋） and Yb^（3＋） codoped LuPO_4 phosphors were prepared by the reverse-strike co-precipitation method.The obtained LuPO_4：Tb^（3＋）,Yb^（3＋） phosphors were characterized by X-ray diffraction（XRD）,photoluminescence（PL） spectra and decay kinetics to understand the near-infrared quantum cutting（QC） phenomena.The XRD results showed that all the phosphors exhibited good crystallinity and had a pure tetragonal phase of LuPO_4.The experimental results showed that the strong green emission around 545 nm from Tb^（3＋）（~5D_4→~7F_5） and near-infrared（NIR） emission at 1003 nm from Yb^（3＋）（~2F_（5/2）→~2F_（7/2）） of LuPO_4：Tb^（3＋）,Yb^（3＋）phosphors were observed under 489 nm excitation,respectively.The Yb^（3＋） concentration dependence on luminescent properties and lifetimes of both the visible and NIR emissions were also investigated.The quenching concentration of Yb^（3＋） ions approached as high as 10 mol.%.The excellent luminescence properties of the LuPO_4：Tb^（3＋）,Yb^（3＋） indicated its potential application in improving the energy conversion efficiency of the silicon based solar cells by converting one blue photon to two NIR ones.
基金Project supported by the National Natural Science Foundation of China(11274139)
文摘Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse process happen that a high energy photon is cut into three NIR photons？ This work demonstrated an example of three-photon quantum cutting （QC） phosphor, CaF2：Ce^3＋,Yb^3＋, in which three clustered Yb^3＋ ions （Yb^3＋-trimer） cooperatively and indirectly received a 306 nm ultraviolet （UV） photon energy transferred from a Ce^3＋ ion in 5d excited state and emitted three 975 nm near-infrared （NIR） photons. The cluster destruction experiments were designed to verify the necessity of the presence of Yb^3＋-trimers for QC. The dynamical analysis on luminescence of Ce^3＋ ions confirmed the energy transfer from Ce^3＋ ions to Yb^3＋-trimers. The doping concentration effect on luminescence was investigated. Furthermore, the maximum energy transfer （ET） efficiency and the corresponding QC efficiency were estimated to be 61% and 222%, respectively. Therefore, the reported three-photon QC phosphor has an attractive prospect in efficiently harvesting solar energy for silicon solar cells.
