Infrared spectroscopy of large scale single layer graphene on self assembled organic monolayer

Abstract

We study the effect of self-assembled monolayer (SAM) organic molecule substrate on large scale single layer graphene using infrared transmission measurement on Graphene/SAM/SiO2/Si composite samples. From the Drude weight of the chemically inert CH3-SAM, the electron-donating NH2-SAM, and the SAM-less graphene, we determine the carrier density doped into graphene by the three sources-the SiO2 substrate, the gas-adsorption, and the functional group of the SAM's-separately. The SAM-treatment leads to the low carrier density N similar to 4 x 10(11) cm(-2) by blocking the dominant SiO2- driven doping. The carrier scattering increases by the SAM-treatment rather than decreases. However, the transport mobility is nevertheless improved due to the reduced carrier doping. (C) 2014 AIP Publishing LLC.