Opto-Electrical Properties of Graphene Oxide Liquid Crystal Films

Abstract

Graphene Oxide Liquid Crystal (GOLC) was prepared using the improved Hummer’s method. A particular purification methodology is used to reduce the disadvantages of the common purification methods. The thin films of GOLC were prepared using a wasteless low-cost drop-casting method. The optical parameters are determined for GOLC films of different thicknesses in the range from 400 nm to 2000 nm. The spectral distribution of transmittance and reflectance of GOLC films was investigated in the wavelength range from 300 nm to 2000 nm. The refractive index of GOLC films was analyzed according to the single oscillator model. The oscillator and dispersion energies are estimated using the Wemple-DiDomenico (WDD) method. The allowed transitions in GOLC films are found to be indirect, with the energy gap decreasing gradually with increasing film thickness in the investigated range. The optical and electrical conductivities as functions of photon energy are explored. Also, the third-order susceptibility and non-linear refractive index are calculated.