Preparation and luminescent properties of CaF2:Ln3+ (Ln:Er, Er/Yb)/Nafion composite films

Abstract

Abstract In this work, CaF2:Ln3+ (Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Composite films are transparent and CaF2:Ln3+ (Ln:Er,Er/Yb) nanoparticles are well dispersed in Nafion films. The thicknesses of CaF2:Er3+/Nafion and CaF2:Er3+,Yb3+/Nafion composite film are about 77 and 73\xa0μm, respectively. The nanoparticles in composite film possess cubic phase. CaF2:Er3+,Yb3+/Nafion composite film has stronger characteristic emission of Er3+ around 1530\xa0nm with full width at half-maximum (FWHM) of 73\xa0nm and longer luminescence lifetimes of 22.04\xa0μs (25.03%) and 100.77\xa0μs (74.97%).