Improved photoluminescence and multi-mode optical thermometry of Er3+/Yb3+ co-doped (Ba,Sr)3Lu4O9 phosphors

Abstract

Contactless optical thermometers have attracted extensive attentions for applications in scientific research and technological fields due to their apparent advantages. Herein, a novel sequence of Ba 3-x Sr x Lu 4 O 9 (B 3-x S x LO):Er 3+ /Yb 3+ phosphors were successfully prepared to investigate the temperature sensing property. By establishing energy transfer from Yb 3+ to Er 3+ and regulating the local lattice environment, up-conversion luminescence of Er 3+ is dramatically improved when excited by 980 nm laser. This can effectively promote signal-noise ratio and reduce the errors in temperature detection. Furthermore, a multi-mode optical thermometry, which includes the fluorescence intensity ratio (FIR) from two thermally coupled levels of 2 H 11/2 / 4 S 3/2 , FIR based on non-thermally coupled system of 2 H 11/2 / 4 F 9/2 and fluorescence lifetime of 4 S 3/2 state of Er 3+ , was explored systematically. The fabricated samples exhibit the superior temperature measurement performances containing wide temperature-sensing range, superior signal discriminability, high sensitivity and favorable repeatability, indicative of the enormous utilization prospects of B 3-x S x LO:Er 3+ /Yb 3+ for thermometry.