Luminescence and tunable color properties of uniphase white-emitting Sr_3B_2SiO_8:Tm~(3+)/Dy~(3+)/Eu~(3+)phosphors by energy transfer for UV-excited white LEDs

摘要

Multi-color single-phase white emission Sr_3B_2SiO_8:Tm~(3+)/Dy~(3+) /Eu~(3+) fluorescent powders were prepared by solid-state fritting method. The fluorescence performance of Tm~(3+), Dy~(3+) and Eu~(3+) ions single-activated Sr_3B_2SiO_8 phosphors were investigated and they exhibit desirable behaviors in their characteristic emissions. Meanwhile, the energy required for migration from Tm~(3+) to Dy~(3+) and from Dy~(3+) to Eu~(3+) in co-doped fluorescent substance was determined by the aids of steady-state and transient-state photoluminescence spectra/ decay measurements. The energy transmission process from Tm~(3+) to Dy~(3+)and Dy~(3+) to Eu~(3+) has been explored to be a dipole-quadrupole interaction and a dipole-dipole interaction of the resonant type, respectively. More significantly, by tuning the molarity ratio of doping Dy~(3+)/Eu~(3+) ions, multicolor emission from yellow to red shall be achieved in Sr_3B_2SiO_8:Dy~(3+), Eu~(3+) phosphors for its potential adhibitions in solid-state lighting applications. The Sr_3B_2SiO_8:Tm~(3+), Dy~(3+) samples can implement white light emission by the appropriate changeable doping molar quantity of Tm~(3+)and Dy~(3+), applying potentially in white LEDs. The energy migrations between co-doped rare earth ions play a decisive role in these processes.