The 4f-5d transitions of Er3+ ions doped in crystals were widely studi ed due to their potential applications in quantum cutting phosphors and VUV lase rs,etc.The theory to do the calculations of 4f-5d transitions and various rela ted aspects,such as the ways to determining various parameters,were summarized .The impacts of various interactions on the spectra were also demonstrated clea rly with Er3+ ions in crystals CaF2 and LiYF4.Predicted results were compared w ith measured spectra.
Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to Tb3+ was observed for Ce3+/Tb3+ coped samples.There were also some very weak evidences for the energy transfer from Ce3+ to Eu3+.
In order to sensitize the luminescence of Eu3+ ions in heavy metal glass,zinc lead borate glass samples containing various concentrations of Eu3+ and Tb3+ ions were prepared to study the Tb3+ to Eu3+ non-radiative energy transfer phenomena.Energy level structures of Tb3+ and Eu3+ ions were plotted to show the excitation and energy transfer routes.Efficient energy transfer from Tb3+ to Eu3+ was observed and studied qualitatively in terms of doping concentrations.The sensitization turned out to be less effective than expected.Further studies to characterize the oxidation of Tb3+ into tetravalent state and to examine the mechanism of energy transfer are proposed.
Li Li~(1,2),Wei Xiantao~1,Chen Yonghu~1,Guo Changxin~1,Yin Min~(1*) (1.Department of Physics,University of Science and Technology of China,Hefei 230026, P R China) (2.College of Mathematics and Physics,Chongqing University of Posts and Telecommunications, Chongqing 400065,P R China)
