Visible photoluminescence from Er3+-doped TiO2 nanofibres by electrospinning

Er3+-doped TiO2 nanofibres were fabricated by electrospinning followed by annealing in air at 420, 600, 800 and 1000 C, respectively. The obtained nanofibres were relatively straight and had an average diameter of about 75 nm. XRD measurements showed that the crystal structure transformed from anatase to rutile with increasing annealing temperature. Visible photoluminescence peaks at 528.1, 566.6 and 669.3 nm were detected ascribed to 2H11/2 to 4I15/2, 4S3/2 to 4I15/2 and 4F9/2 to 4I15/2 transitions of Er3+ ions and the PL intensities increased with increasing annealing temperature. At high annealing temperatures, a near-IR photoluminescence peak at 815 nm due to the defect states associated with Ti3+ ions was also found. The strong green photoluminescence of Er3+ ions may have potential applications in one-dimensional luminescent nanodevices. 10 refs.