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Author(s): |
Yong-qing Zhai, College of Chemistry and Environmental Science, Hebei University, Hebei Baoding, P.R. China, 071002
Xin Wang, College of Chemistry and Environmental Science, Hebei University, Hebei Baoding, P.R. China, 071002
Man-de Qiu, College of Chemistry and Environmental Science, Hebei University, Hebei Baoding, P.R. China, 071002
Shao-qiang Han, College of Chemistry and Environmental Science, Hebei University, Hebei Baoding, P.R. China, 071002
Li-li Xu, College of Chemistry and Environmental Science, Hebei University, Hebei Baoding, P.R. China, 071002 |
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Abstract: |
A new red-emitting phosphor La2Si2O7:Eu3+ was synthesized by gel-combustion method. The structure and luminescence properties of as-synthesized phosphors were investigated by XRD and Fluorescence spectrophotometer respectively. The results show that the goal product La2Si2O7:Eu3+ can be obtained by the precursor calcined at 1000℃ for 2h. The as-synthesized sample has hexagonal crystal structure and unit cell parameter is a=b=0.6846 nm, c=2.4855 nm. The excitation spectrum of La2Si2O7:Eu3+ is composed by two parts，the broad band from 200 nm to 350 nm is due to the charge transfer(CT) band of the Eu3+- O2- and the strongest excitation peak is at 263 nm; A series of excitation peaks from 350nm to 450nm are ascribed to f-f transition of Eu3+,and the strongest excitation peak is at 395 nm. The emission spectrum excited by 395 nm is similar to that excited by 263 nm, indicating that the two excitation peaks belong to the same luminescence center. The main emission peak is at 618 nm with strong red-emitting, due to the 5D0-7F2 electric dipole transition of Eu3+. Co-doping Li+ ions have little effect on the shape of the excitation and emission spectra, but the intensity of excitation and emission peaks increases significantly, which indicates that co-doping Li+ ions can effectively enhance the luminescence performance of La2Si2O7:Eu3+.
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