Color tunable up-conversion emission from ZrO2:Er3+,Yb3+ textile fibers

Abstract

ZrO₂:xEr³⁺,yYb³⁺ fibers (diameters of approximately 1 μm) with good flexibility and toughness were synthesized via electrospinning technology. The composition, morphology, and up-conversion photoluminescence properties of the fibers were investigated. The up-conversion photoluminescence mechanisms of ZrO₂ fibers singly doped with Er³⁺ ions or co-doped with Er³⁺,Yb³⁺ ions are also discussed in detail, including decay curves, and lifetimes. The main mechanisms in ZrO₂:xEr³⁺,yYb³⁺ fibers were energy transfer from Yb³⁺ to Er³⁺ and cross relaxation processes between Yb³⁺ and Er³⁺ or between adjacent Er³⁺ ions. When the concentration of Yb³⁺ was 4 mol%, emission intensity over the entire spectrum and lifetime of the ²H_11/2/⁴S_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 transitions in ZrO₂:Er³⁺,Yb³⁺ fibers were maximized using 980 nm excitation light. When the concentration of Yb³⁺ was 20 mol%, pure red emission could be obtained. Different colors—green, yellow, and red—could be obtained with Er³⁺/Yb³⁺ concentrations. Given the chemical, thermal, and mechanical stability of zirconia, Er³⁺/Yb³⁺ co-doped ZrO₂ up-conversion luminescence fibers may be an attractive choice for photonic materials.