Synthesise, energy transfer and tunable emission properties of Ba2La2ZnW2O12:Sm3+ phosphors

In this work, we synthesize a series of Ba2La2ZnW2O12:Sm3+ (BLZWO:Sm3+) phosphors and research their crystal structure, morphology, and luminescence properties. The emission spectrum of host BLZWO with excitation at 370 nm can be observed in the range of 390-800 nm because of the W6+ - O2- transition in [WO6] group. BLZWO:Sm3+ phosphor with excitation at 370 nm emits yellow light with the emission spectrum in the range of 390-800 nm due to the W6+ - O(2-)transition in [WO6] group and the (4)G(5/2) -> H-6(9/2) transition of Sm3+ ion. BLZWO:Sm3+ phosphor excited at 408 nm emits red light and its emission spectrum in the range of 550-740 nm includes four narrow emission bands (550-580 nm, 580-625 nm, 625-685 nm, and 685-740 nm), which are derived from the (4)G(5/2) -> H-6(5/2), H-6(7/2), H-6(9/2), and H-6(11/2) transitions of Sm3+ ion, respectively. We investigate the concentration-dependent excitation and emission spectra of samples. The lifetime of BLZWO:Sm3+ phosphor under excitation 408 nm decreases from 799.6 mu s to 686.7 mu s with increasing Sm3+ doping concentration. The energy transfer and luminous mechanism in BLZWO:Sm3+ phosphor are explained.