Enhanced up‐conversion luminescence and optical thermometry characteristics of Er 3+ /Yb 3+ co‐doped Sr 10 (PO 4 ) 6 O transparent glass‐ceramics

In this paper, the Yb 3+ /Er 3+ co‐doped parent glass (PG) with composition (in mol%) of 30P 2 O 5 ‐10B 2 O 3 ‐38SrO‐22K 2 O and transparent glass‐ceramics (GCs) containing hexagonal Sr 10 (PO 4 ) 6 O nanocrystals (NCs) were synthesized for the first time by melt‐quenching method and subsequent heating treatment in air. Under 980 nm laser prompting, the GCs samples showed intense red and green up‐conversion emissions compared to those characteristics for the PG sample. The emission intensities varied with Er 3+ concentration and heat treatment conditions. Furthermore, in Yb 3+ /Er 3+ co‐doped GCs specimens, the optical thermometry was researched by means of fluorescence intensity ratio (FIR) of 4 S 3/2 and 2 H 11/2 levels. The GC sample heated at 620°C for 5 hours possessed a high relative temperature sensitivity ( S r ) of 0.769% K −1 at 303 K and the maximal absolute temperature sensitivity ( S a ) of 5.951 × 10 −3 K −1 at 663 K, respectively. It is expected that the as‐fabricated GC materials with Sr 10 (PO 4 ) 6 O NCs are promising efficient up‐conversion materials for optical temperature sensor.