Enhancement in upconversion luminescence of Yb2WO6: Er3+ phosphor by Y3+ ions doping for optical temperature sensing

Yb 2 WO 6 : Er 3+ , Y 3+ phosphors were successfully synthesized using the high-temperature solid-state method. • Y 3+ doping significantly enhances the upconversion luminescence intensity of Yb 2 WO 6 : Er 3+ phosphor. • The red and green emission intensities are increased by 2.17 and 2.20 times. • The maximum of relative sensitivity and absolute sensitivity is 6.97%·K⁻¹ at 450 K and 1.90%·K −1 at 523 K, respectively. Er 3+ and Y 3+ ions co-doped Yb 2 WO 6 phosphors were synthesized via a high-temperature solid-state method. Under 980 nm excitation, the Y 3+ -substituted Yb 2 WO 6 :Er 3+ phosphors exhibit green emission near 545 nm and red emission near 657 nm, assigned to the Er 3+ 4 S 3/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 transitions, respectively. At the optimum Y 3+ content of x  = 0.20, the red and green emission intensities are 2.17 and 2.20 times those of the Y 3+ -free sample, respectively. Yb 3+ ions act as the primary sensitizers by absorbing 980 nm photons and transferring energy to Er 3+ . Sequential Yb 3+ →Er 3+ energy-transfer steps, together with phonon-assisted relaxation among Er 3+ levels, populate the 4 S 3/2 and 4 F 9/2 emitting states. The enhanced upconversion emission and the measured temperature-dependent fluorescence-intensity ratio indicate that the phosphor is a potential candidate for non-contact optical thermometry over 298–523 K. S R reaches its maximum value of 6.97%·K −1 at 450 K. while S A attains its maximum of 1.90%·K −1 at 523 K. Download: Download high-res image (167KB) Download: Download full-size image