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

Abstract

A series of Ba₂ZnB₂O₆:Eu³⁺ 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 Eu³⁺ in Ba₂ZnB₂O₆ and luminescence properties of Ba₂ZnB₂O₆:Eu³⁺ 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 Eu³⁺ ions prefer to occupy Zn (1) (4a) and Zn (2) (4a) sites simultaneously. The PL intensity is improved with increasing Eu³⁺ 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 non-radiative transition. The PL emission intensities of Ba₂ZnB₂O₆:0.05Eu³⁺ 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 Ba₂ZnB₂O₆:0.05Eu³⁺ are very close to the CIE of standard red light.