Spectroscopic and morphological properties of white light emitted electrospun PVA@ZnO:xDy3+ nanofibers

In this study, ZnO:Dy nanoparticles were obtained using the precipitation technique by adding Dy³⁺ at 1, 2, 3, 5, and 7 % by weight and structurally analyzed by the powder XRD technique. The resulting ZnO:Dy³⁺ nanoparticles were incorporated into a PVA polymer matrix to produce PVA@ZnO:xDy³⁺ (x = 0, 1, 2, 3, 5, and 7 wt%) nanofibers by using the electrospinning technique. The PVA@ZnO:xDy³⁺ nanofibers were characterized using various techniques, including Fourier Transform Infrared (FTIR) spectroscopy, solid-state UV absorption spectroscopy, field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and photoluminescence (PL) spectroscopy to reveal the structural, morphological, thermal, and optical properties. PL studies performed to understand the effect of Dy³⁺ ion doping on the luminescent behavior show that while the pure nanofibers emit greenish-blue light, the Dy³⁺-doped PVA@ZnO:xDy nanofibers emit light close to white. Dy³⁺ ions, known for their characteristic blue and yellow emissions, can produce white light when the intensity ratio of these emissions is optimized, and in this study, the CIE coordinates for the 2 wt% Dy³⁺ doping concentration at which the PL intensity maximum is reached are 0.3004;0.3302, which is very close to the ideal value of white light (0.333;0.333). Due to this feature, the obtained fibers may be an attractive candidate for the design and production of white light-emitting devices.