Photoluminescence and energy transfer studies of YAl3(BO3)(4):Sm3+/Tb3+ phosphors for solid state lighting applications

Abstract

Trivalent samarium (Sm3+)/terbium (Tb3+) co-doped YAl3(BO3)(4) (YAB) phosphors were prepared by solid-state reaction method. The phase, structure, optical and energy transfer studies were systematically characterized through X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence (PL) and decay measurements, respectively. Upon 406 nm excitation, both Sm3+ single- and Sm3+/Tb3+ co-doped YAB phosphors emit orange-red luminescence with peak maximum at 602 nm. The YAB:Tb3+ phosphor emits green luminescence at 546 nm when excited with 375 nm near UV wavelength. The YAB:Sm3+/Tb3+ phosphors emit green-to-white luminescence as a function of Sm3+ concentration upon an excitation wavelength of 375 nm. The Tb3+ acts as an efficient sensitizer of luminescence of Sm3+ under 375 nm excitation in YAB phosphors. Doped Sm3+ and Tb3+ ions were located at the inversion symmetry sites of YAB lattice. The Commission International de l'Eclairage chromaticity coordinates were calculated from the PL spectra. The energy transfer from Tb3+ to Sm3+ ions was described in detail. The YAB:Sm3+/Tb3+ phosphors can be used as a promising material for solid state lighting devices.