Gallium dopant-induced tunable electrical properties of reduced graphene oxide using metal organic chemical vapor deposition

In this study, we develop a gallium-doped reduced graphene oxide (Ga-rGO) material with desirable electrical properties by a metal-organic chemical vapor deposition system using the pulsed mode technique. The effect of doping level on Ga bonding in rGO layer controlled via the pulsed mode of doping conditions, such as dopant source injection and interruption durations, is investigated using the X-ray photoelectron spectroscopy (XPS). The XPS data indicated that the pulsed mode of doping conditions resulted in a higher Ga composition and a larger O-Ga bonding portion in the Ga-rGO layer. Additionally, the Dirac point of Ga-rGO layer with the pulsed mode was observed to shift toward positive voltage in the bottom-gate field effect transistor device, leading to a p-type behavior. The higher work function of Ga-rGO affected the Schottky contact between the Ga-rGO layer and n-type Si leading to lower fermi-energy level in the energy-band structure. Consequently, this work proposes a simplistic approach of Ga doping in graphene materials that can modulate the tunable electrical properties.