Flexibility of Key Electronic and Optical Properties of Reduced Graphene Oxide Through Its Controlled Synthesis

Abstract

Recently, graphene oxides (GOs), reduced GO (rGO), and their derivatives have been focused on as a superior flexible material due to having easy processability and high carrier mobility. Here, we report an inexpensive green synthesis of GO/rGO at a relatively low temperature of 150 °C. The scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX), X-ray diffraction (XRD), Raman, Fourier transformed IR (FTIR), and UV–visible spectroscopy confirm the successful fabrication of rGO with an enhanced carbon–0carbon (sp2/sp3) component with an enhanced carbon-to-oxygen ratio (C/O) from 0.93 to 2.76. Here, a work function tuning of 5.6–4.5 eV, a bandgap modulation of 3.93–2.63 eV, a charge carrier density tuningfrom <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.12\times10$ </tex-math></inline-formula> 16 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.14\times10$ </tex-math></inline-formula> 21 cm−3, and a mobility tuning from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.51\times10$ </tex-math></inline-formula> −2 to 59.663 cm2/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> are made through its controlled reduction of GOs, which are much better than the results obtained at high temperature >1000 °C. The flexible nature of both electronic and optical properties of rGO nanostructures assures it as an excellent material for electronics and optoelectronics devices.