Synthesis and Characterization of a Novel Erbium Doped Poly(vinyl alcohol) Films for Multifunctional Optical Materials

Abstract

Polymer films based on poly vinyl alcohol (PVA) doped with different contents (0, 4, 8, 16, 20 and 28) wt% of Erbium(III) ions were synthesized by the simple solution casting technique. The structural characteristics of the films were studied by X-ray diffraction pattern (XRD), Fourier transform infrared (FT-IR) spectroscopy and atomic force microscopy measurements (AFM) measurement whereas the optical behavior of these films have been investigated using UV–Vis-NIR spectroscopy and photoluminescence measurements. The structural parameters of the interplanar (d) spacing, crystallite length (L) and the average interchain separation determined from the XRD and the absorption bands of the active IR groups recorded in FT-IR spectra indicate bonding of positively charged Er3+ ions with negatively charged OH groups of the PVA chains. The average cluster size (D) of the samples estimated from AFM data shows larger values than that obtained from XRD measurements. The optical gaps obtained from absorption spectra fitting and Tauch relations are approximately equal and slightly decreased by Er3+ ions incorporation in the PVA matrix whereas the high frequency refractive indices estimated according to Moss and Dimitrov formulae showing small increase. Three intense peaks of 607 nm, 733 nm and 783 nm wavelengths due to energy levels transitions of erbium were recorded in the photoluminescence spectra PVA–Er3+. The collected data support consideration of PVA–Er3+ films as a promising optical polymer material in microptics, planar polymer waveguides, polymer optical fiber and polymer light emitting diodes applications.