Enhancement through sensitization of VUV-excited luminescence in red-emitting pentaborate phosphors

摘要

We studied the feasibility of using sensitization for the improvement of the VUV-to-visible conversion efficiency of red-emitting pentaborate phosphor. It is shown that Tb~(3+) ions that exhibit a strong absorption throughout the 160-230 nm wavelength range facilitate enhancement of Eu~(3+) emission in TbMgB_5O_(10)-Eu at excitation in this spectral range. Thernmaximum increase of the Eu~(3+) emission efficiency in a pentaborate host at excitation with 150nm photons is ca. 10%. It is also shown that substitution of Zn for Mg in Gd(Mg,Zn)B_5O_(10)-Mn phosphor results in strong (up to 2.4 times) enhancement of the intensity of Mn~(2+) emission. A possible reason for the observed host sensitization effect is discussed.