Enhanced up-conversion luminescence and temperature sensing property of Ba Sr Lu4O9:Tm3+/Yb3+ phosphors

Improved up-conversion (UC) luminescence and applications in optical temperature sensors of up-converting materials have attracted growing interest in recent years. Here, we reported a new series of Ba3-xSrxLu4O9 (B3-xSxLO):Tm3+/Yb3+ phosphors. By designing Yb3+→Tm3+ energy transfer and modifying the local lattice environment of activator ions via cationic substitution, highly efficient enhancement of UC luminescence of Tm3+ is realized when excited by a 980 nm laser. Moreover, the representative B2.2S0.8LO:Tm3+/Yb3+ sample displays superior temperature sensing behaviors with highly relative sensitivity of 0.88 % at 428 K, absolute sensitivity of 1.50 % at 573 K, wide sensing range and good stability. All of findings reveal that B3-xSxLO:Tm3+/Yb3+ are promising candidates for optical thermometry.