Influence of Yb3+/Mg2+ ions on photoluminescence intensity of Tm3+ doped ZnWO4 phosphor for photonic applications

Abstract

In this work, the Tm3+/Yb3+/Mg2+ tri-doped ZnWO<inf>4</inf> phosphors have been synthesized with different concentrations of Yb3+ and Mg2+ ions through solid-state reaction method. The Tm3+ doped ZnWO<inf>4</inf> phosphor has strong excitation bands at 311 and 360 nm due to charge transfer band (CTB) and 4f-4f transition of Tm3+ ion, respectively. The Tm3+ doped ZnWO<inf>4</inf> phosphor sample emits strong blue and weak red emissions at (458, 482) and 561 nm wavelengths on excitation with 360 nm, respectively. When the Yb3+ ion is incorporated in the Tm3+ doped phosphor; the photoluminescence intensity of blue band decreases regularly. This is due to downconversion cooperative energy transfer (CET) from 1G<inf>4</inf> level of Tm3+ ion to 2F<inf>7/2</inf> level Yb3+ ion. The photoluminescence intensity of the Tm3+/Yb3+ co-doped ZnWO<inf>4</inf> phosphor also decreases in presence of Mg2+ ion, which is due to increase in local crystal structure of the ZnWO<inf>4</inf> phosphor. The lifetime value of 1D<inf>2</inf> level of the Tm3+ ion also decreases as a result of CET from Tm3+ to Yb3+ ions in the Tm3+/Yb3+/Mg2+ tri-doped ZnWO<inf>4</inf> phosphor. Therefore, the Tm3+/Yb3+/Mg2+ tri-doped ZnWO<inf>4</inf> phosphor may be applicable in photonic and display devices. © 2025 Elsevier B.V.