Site occupancy and photoluminescence properties of Eu³⁺-activated Ba₂ZnB₂O₆ phosphor

Abstract

A series of Ba 2 ZnB 2 O 6 :Eu 3+ phosphors with a red-emitting band centered at 616 nm were prepared by traditional high temperature solid-state reaction methods. The site-preferred occupancy of Eu 3+ in Ba 2 ZnB 2 O 6 and luminescence properties of Ba 2 ZnB 2 O 6 :Eu 3+ were studied combined with X-ray diffraction (XRD), photoluminescence excitation (PLE) spectra and emission (PL) spectra as well as temperature-dependent PL and decay curves. The Rietveld refinements indicate that the Eu 3+ ions prefer to occupy Zn (1) (4a) and Zn (2) (4a) sites simultaneously. The PL intensity is improved with increasing Eu 3+ content and the optimal dopant content is 0.05. The temperature-dependent PL spectra indicate that the emission intensity decreases with the temperature because of the enhancement of the nonradiative transition. The PL emission intensities of Ba 2 ZnB 2 O 6 :0.05Eu 3+ phosphors with Li + , Na + and K + as charge compensators are enhanced significantly, and the phosphor compensated by Li + ions emits the strongest emission. The Commission Internationale de I'Eclairage (CIE) color coordinates of Ba 2 ZnB 2 O 6 :0.05Eu 3+ are very close to the CIE of standard red light.

Dual-enhancement of photoluminescence and cathodoluminescence in Eu3+-activated SrMoO4 phosphors by Na+ doping

“…On the other hand, from the elemental mapping ( Fig. 6,24 Compared with other excitation peaks, the bands centered at 290 and 393 nm had stronger intensities. 20 Furthermore, the absorption bands located at about 393 and 462 nm are related to the 4f-4f electron transition of Eu 3+ ions, which coincides well with that of excitation spectra result (see Fig.…”

“…Aer that, the nonradiative (NR) process takes place (see Fig. 24,26 When the concentration of Eu 3+ ions in SrMoO 4 host lattice reached to a certain value, the distance between the neighboring Eu 3+ ions became small. Finally, the characteristic emissions of Eu 3+ ions corresponding to the D 1 / 7 F 1 , 5 D 1 / 7 F 2 , 5 D 0 / 7 F 1 , 5 D 0 / 7 F 2 , 5 D 0 / 7 F 3 , and 5 D 0 / 7 F 4 transitions are observed due to the radiative transition.…”

“…24,28 Generally, the exchange interaction is dominant when the distance between the RE ions is shorter than 5Å. For SrMoO 4 host lattice, V ¼ 349.72Å 3 , N ¼ 4 and the x c is 0.07.…”

“…24,30 To eliminate the Sr vacancies, the alkali metal Na + ions were codoped with the Eu 3+ ions. However, these vacancies make the structure unstable and the energy can be easily transferred from the Eu 3+ ions to the Sr vacancies, leading to the poor PL property.…”

Luminescent properties and performance tune of novel red-emitting phosphor CaInBO4: Eu3+

“…Notably, trivalent europium ion is a frequently used activator for red-emitting phosphors [21,22], because of an excellent red emission corresponding to its 5 D 0 e 7 F J (J ¼ 0, 1, 2, 3, 4) transition [23,24]. Moreover, it has been reported that the Eu 3þ / O 2À charge-transfer (CT) state could be located at a relatively low energy [25].…”