Temperature sensitivity based on Er3+ fluorescence fluctuation in Gd2Ti2O7: Er3+-Yb3+ porous nanofibers

(Gd 1−x−y Er x Yb y ) 2 Ti 2 O 7 (GTOEY) fibers were synthesized by electrospinning technique and heat-treatment processes, in which nano-scale fibers vested with homogeneous porous morphology, high crystallinity and elevated temperature heat-resistance. Under 977 nm laser excitation, GTOEY nanofibers exhibit effective frequency upconversion (UC) fluorescence, therefore, the violent green and dimmed red UC emissions are identified as two-photon absorption processes, attributing to 2 H 11/2 / 4 S 3/2  →  4 I 15/2 and 4 F 9/2  →  4 I 15/2 radiation transitions of Er 3+ , respectively. Moreover, the temperature sensitivity based on UC emission fluctuation of Er 3+ over a wide temperature range of 303–633 K has been derived. Thereby, having used a 980 nm laser and achieved green UC luminescence of GTOEY fibers centered at 525 and 545 nm, the maximum absolute and relative sensitivity values are obtained to be 0.382% K −1 and 1.12% K −1 , respectively. These significant results demonstrate that the GTOEY nanofibers with distinct porous structure and admirable photothermal sensitivities can be regarded as a promising temperature sensing material used for overheating alarm and safety protection equipment.