Electrospinning preparation and upconversion luminescence of Y2Ti2O7:Tm/Yb nanofibers

Nanoscale Y 2 Ti 2 O 7 :Tm 3+ /Yb 3+ fibers were fabricated through electrospinning followed by calcining at high temperatures. The resulting Y 2 Ti 2 O 7 :Tm 3+ /Yb 3+ fibers were characterized by XRD, SEM, TEM, EDX, and ICP-OES. The average diameter of the Y 2 Ti 2 O 7 :Yb/Tm nanofibers is about 80 nm and they are hundreds of microns long. Their upconversion (UC) intensity was found to increase with increasing Yb 3+ concentration within the working current range of 1.50–2.50 A under 980-nm laser irradiation. The mechanism of energy transfer between Yb 3+ to Tm 3+ ions in the Y 2 Ti 2 O 7 :Yb/Tm nanofibers was also elucidated The three-photon processes and the two-photon processes were confirmed to be involved in blue emissions and red and near-infrared emission by analyzing the UC-intensity dependence on the operating current of the 980-nm exciting laser.