Synthesis, DFT studies, fabrication, and optical characterization of the [ZnCMC]TF polymer (organic/inorganic) as an optoelectronic device

Abstract

A novel carboxymethyl cellulose zinc thin film [ZnCMC]^TF was fabricated using the sol–gel technique. Different characterization techniques such as Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, ultraviolet–visible spectroscopy (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and the optical properties were used to study the properties of [ZnCMC]^TF. The molecular structure, FTIR, and optical properties were optimized. The Raman spectrum of the [ZnCMC]^TF complex shows several bands in the range of 72–556 cm⁻¹ due to (ν_Zn–O) stretching and (Zn–O) bending, which is an obvious distinction between the FTIR and Raman spectra of [ZnCMC]^TF. The optimization was performed using density functional theory (DFT) by DMol³ and Cambridge Serial Total Energy Package (CASTEP) program. The chemical structure was confirmed by spectroscopic and structural properties for both CMC and [ZnCMC]^TF; the XRD results showed the same crystal structure (Monoclinic 2). [ZnCMC]^TF has a larger grain size than CMC and has a similar behavior in the optical gap energy. The optical constants increased with increasing photon energy, refractive index n, absorption index k, and optical conductivity. The SEM images provide very good evidence in favor of the reaction of zinc transition metal with CMC for the formation of the [ZnCMC]^TF complex. The resulting [CMC] spherical thin film and the [ZnCMC]^TF polymeric nanorods were examined by different techniques including TEM and EDX. The optical properties obtained from the simulated FTIR, XRD, and CASTEP are in good agreement with those obtained from the experimental studies on CMC and ZnCMC. Based on the optical findings, [ZnCMC]^TF is a promising candidate in applications such as solar cells and optoelectronic devices.