Versatile and Tunable Electrical Properties of Doped Non-oxidized Graphene using Alkali Metal Chloride

With the emergence of wearable and flexible electronics, graphene has recently been developed for transparent electrodes in field effect transistors, light-emitting diodes, and organic photovoltaic cells. Graphene doping methods can decrease sheet resistance and modulate work function while retaining high transparency, for transparent conductive electrodes (TCEs). In this work, a chemical doping method, which incorporates metal chlorides (NaCl, KCl and AuCl3) and organic compounds (HNO3) as chemical dopants, was used to control the charge carrier density, band gap and work function, without damage to the carbon network. Furthermore, we synthesized non-oxidized graphene with large lateral sizes of more than 5 μm using ternary graphite intercalation compounds (t-GICs). The resulting graphene flake films (DGFFs) doped with AuCl3 exhibited the lowest reported sheet resistance (2.008 X 105 S/m at ~75% transmission), to the best of our knowledge, and controlled the work function from 4.32 eV to 5.1 eV. Doping w...