An upconversion luminescence and temperature sensor based on Yb(3+)/Er(3+) co-doped GdSr(2)AlO(5)

GdSr(2)AlO(5):Yb(3+)/Er(3+) micro-particles were synthesized by a simple solid state method. The structure, morphology, size and upconversion luminescence features have been characterized. These results indicated that GdSr(2)AlO(5) has a contracted tetragonal cell and has irregular block shaped particles with sizes of about 5 μm. During upconversion, green ((2)H(11/2), (4)S(3/2) → (4)I(15/2)) (527 nm, 549 nm) and red ((4)F(9/2) → (4)I(15/2)) (665 nm) emissions had been observed, both of which occurred via a two-photon population process. In addition, green UC emission characteristics were studied, and it was found that its temperature ranged from 293 K to 473 K and the sensitivity was 0.0054 K(−1) at 473 K. This indicated that GdSr(2)AlO(5):Yb(3+)/Er(3+) micro-particles may have potential application in high temperature environments for safety signs.