Up-conversion luminescence of NaY(WO 4 ) 2 : Yb, Er under 1550 and 980 nm excitation

Abstract Er 3+ single-doped and Er 3+ , Yb 3+ co-doped NaY(WO 4 ) 2 phosphors were synthesized at 1100 °C by a solid-state reaction method. The samples were characterized by XRD and emission spectral analysis, and the luminescence properties of the phosphors were studied using different excitation sources. The maximum emission intensity of the phosphor was achieved at 24 mol% of the Er 3+ ion single-doped under 980 and 1550 nm excitation. The red emission of the phosphor was not changed by increasing Yb 3+ ion concentrations, and the material exhibited excellent color purity and color stability. When excited by the 1550 nm laser, the fraction of red emission slightly increased compared with that observed under 980 nm excitation but the main bright green emission. The brightness of Yb 3+ , Er 3+ co-doped NaY(WO 4 ) 2 is about 4 times more intense than that of conventional Er 3+ single-doped NaY(WO 4 ) 2 . The UCL mechanisms of the phosphor at 980 and 1550 nm are completely different.