Effects of Na+ cation on the luminescence enhancement and TL dosimetric properties of SrB6O10:Dy3+

Abstract

A 0.5 wt% SrB₆O₁₀: Dy³⁺ powder sample was synthesized successfully and Na⁺ was co-doped in the range of 0.5–20 wt% via the solution combustion synthesis (SCS) method. The crystal structure and morphology were determined by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques, respectively. A double-phase reaction route of the phosphor is confirmed by structural study. It was observed that the crystallinity of the Dy³⁺ doped SrB₆O₁₀ phosphor is improved by Na⁺ co-doping. Effect of Na⁺ co-doping concentration on luminescence was investigated. Based on the observed Photoluminescence (PL) decay curves, the origins of the emission peaks were attributed to 4f-4f transitions of Dy³⁺ ions. Under excitations of 310 nm, the Dy-doped sample emits two sharp peaks at 470 nm (⁴F_9/2→⁶H_15/2) and 570 nm (⁴F_9/2→⁶H_13/2) in the PL spectrum. The ⁴F_9/2 → ⁶H_13/2 transition giving yellow light emission is dominant in all Thermoluminescence (TL) trap regions in the TL emission spectrum. Moreover, the evaluated CIE color coordinates for SrB₆O₁₀:Dy_0.5%,Na_10% sample are (0.2001, 0.1999) lying in the near-white light region. A wide TL glow peak of the SrB₆O₁₀:Dy_0.5%,Na_10% sample was detected at around 150 ºC with a heating rate of 2 °C/s. It presented a linear TL response in the beta dose range of 1–100 Gy. The results show that Na⁺ as a co-dopant improves the luminescence sensitivity of SrB₆O₁₀:Dy phosphor. Our results contribute to the development of the strontium borate phosphors for the blue-yellow-green spectral range. These results indicate that the TL properties of SrB₆O₁₀:Dy,Na samples show potential and warrant further investigation for possible use as a dosimeter material.