Variable Angle Spectroscopic Ellipsometry Characterization of Graphene Oxide in Methanol Films

Abstract

It has been widely established that solvents modify the functional groups on the graphene oxide (GO) basal plane and, thus, modify its reactivity. Despite the increasing interest in GO films, a less studied aspect is the influence of methanol on the refractive index of GO films. Herein, the Variable Angle Spectroscopic Ellipsometry (VASE) technique has been used to characterize the optical response of GO in methanol films (0.4 mg/mL) dip-coated on glass substrates. The ellipsometric data have been modeled using a Lorentz oscillator model. We have found that the energy of the oscillator at ~3.9 eV for GO in water shifts to ~4.2 eV for GO in methanol films.

Variable Angle Spectroscopic Ellipsometry Characterization of DMOAP-Functionalized Graphene Oxide Films

“…Our previous work [23] utilized the VASE technique to examine the optical response of GO in methanol films, which were dip-coated on glass substrates. This study provided valuable insights into the behavior of GO in different solvent environments, adding another dimension to our understanding of GO's optical properties.…”