Optical thermometry of Er³⁺ in electrospun yttrium titanate nanobelts

Er³⁺/Yb³⁺ co-doped Y₂Ti₂O₇ (YTOEY) nanobelts with a thickness of ∼100 nm are synthesized by electrospinning, which exhibit a high sensitivity and rapid responsiveness in temperature sensing. The fluorescence intensity ratio of two green intense signals that originated from the transitions of Er³⁺ ions can be developed for non-contact temperature measurements. Moreover, the nanoscale dimensions, porous structures and large surface area of the prepared YTOEY nanobelts allow the photothermal signals to pass through them quickly. The maximum absolute sensitivity at 513 K and the extreme relative sensitivity at 303 K are calculated to be 0.37% K^-1 and 1.17% K^-1, respectively, indicating that the nanobelts have attractive optical temperature sensing characteristics. These extraordinary results demonstrate that YTOEY nanobelts are a promising candidate for accurate temperature monitoring in thermo-sensitive equipment.