Structural investigation and luminescent properties of BaZr(BO3)2:Eu3+ phosphors containing Si

Abstract

Si 4+ -doped BaZr(BO 3 ) 2 :Eu 3+ phosphors are prepared by a conventional solid-state reaction. The influence of Si 4+ addition on the charge transfer state of Eu 3+ -O 2-and photoluminescence (PL) properties of BaZr(BO 3 ) 2 :Eu 3+ are discussed. Room temperature PL spectra indicated that efficient emission is obtained by Si doping. Increased values for the peak-peak ratio (PPR) of BaZr(BO 3 ) 2 :Eu 3+ at higher Si doping concentrations implied that the Eu 3+ ion is located in a more asymmetric environment in BaZr 0.8 Si 0.2 (BO 3 ) 2 :Eu 3+ than in the undoped samples. The Judd-Ofelt parameters Ω λ (λ=2,4) were calculated from the PL data, giving results that were consistent with those from the PPR. The maximum radiative quantum efficiency was achieved at a Si doping concentration of 20 mol%. BaZr(BO 3 ) 2 :Eu 3+ , charge transfer state, peak-peak ratio, Judd-Ofelt theory Citation: Zhang Z P, Li G M, Zhang X S, et al. Structural investigation and luminescent properties of BaZr(BO 3 ) 2 :Eu 3+ phosphors containing Si.In recent years, many researchers have focused on improving the luminescence properties of traditional materials [1-3] and preparing new luminescent phosphors with high performance [4,5]. Xing et al. [3] reported an enhancement of the luminescent intensity of Gd 2 O 2 S:Tb phosphors through the use of a new synthetic method. Luo et al.[5] reviewed the recent progress in alkaline earth silicate host luminescent materials with broad excitation bands for phosphor-converted white light emitting diodes. Borate-based systems have the advantages of low synthesis temperature, high UV transparency and good thermal stability. Eu 3+ is commonly adopted as an activator in commercial red phosphors [1,2]. There are two main radiative transitions that occur in the 4f levels of Eu 3+ . The emission centered at 591 nm is caused by a magnetic dipole transition of 5 D 0 -7 F 1 and

Thermal degradation of BaAl2Si2O8:Eu2+ phosphor excited by near ultraviolet light

“…white light emitting diodes (LEDs) fabricated with near ultraviolet (UV) chips [1][2][3][4]. The emission spectrum of Eu 2+ ions is usually comprised of broad bands that range from UV to red regions caused by transitions between the 4f 7 ground state and the crystal field components of the 4f 6 5d…”

“…Aluminosilicate is well known as a long-persistent phosphor host with high chemical stability and water resistance. In alkaline-earth feldspars MAl 2 Si 2 O 8 (M=Ca, Sr, Ba), the framework structures are formed from an array of interlinked corner-sharing tetrahedral SiO 4 and AlO 4 species, with charge-compensating cations Ca 2+ , Sr 2+ , and Ba 2+ occupying large cavities within the structure [7]. A series of solid solutions containing isostructural members with slightly different size cations as hosts [such as MAl 2 Si 2 O 8 (M=Ca, Sr, Ba)] would be an ideal system to study the effect of crystal chemical variation on the luminescence of Eu 2+ ions, and may offer possibilities for commercial application [8].…”