An upconversion luminescence and temperature sensor based on Yb/Er co-doped GdSrAlO.

GdSrAlO:Yb/Er 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 GdSrAlO has a contracted tetragonal cell and has irregular block shaped particles with sizes of about 5 μm. During upconversion, green (H, S → I) (527 nm, 549 nm) and red (F → I) (665 nm) emissions had been observed, both of which occurred 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 at 473 K. This indicated that GdSrAlO:Yb/Er micro-particles may have potential application in high temperature environments for safety signs.