Tunable white light emission by variation of composition and defects of electrospun Al2O3-SiO2 nanofibers

Composite nanofibers consisting of Al2O3-SiO2 were prepared by electrospinning in combination with post-calcination in air. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to investigate the crystalline phase and microstructure of the composite nanofibers. Photoluminescence experiments indicated that the resulting white light emission can be tuned by the relative intensity of the individual spectral components, which are related to the individual defects such as: violet-blue emission from O defects, green emission from ≡Si(Al)-O-C∙=O, and red emission from intersystem radiative crossing. White light emission was realized at a Al/(Al-Si) ratio of 40 and 60 mol %. This research may offer a deeper understanding of the preparation of efficient and environmentally friendly, white luminescence materials.