An upconversion luminescence and temperature sensor based on Yb3+/Er3+ co-doped GdSr2AlO5

GdSr2AlO5:Yb3+/Er3+ 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 GdSr2AlO5 has a contracted tetragonal cell and has irregular Nock shaped particles with sizes of about 5 mu m. During upconversion, green ( H-2(11/2), S-4(3/2) -> I-4(15/2)) (527 nm, 549 nm) and red ( F-4(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 GdSr2AlO5:Yb3+/Er3+ micro-particles may have potential application in high temperature environments for safety signs.