Tuning epitaxial graphene sensitivity to water by hydrogen intercalation
arXiv:1804.09499 · doi:10.1039/C6NR09465A
Abstract
The effects of humidity on the electronic properties of quasi-free standing one layer graphene (QFS 1LG) are investigated via simultaneous magneto-transport in the van der Pauw geometry and local work function measurements in a controlled environment. QFS 1LG on 4H-SiC(0001) is obtained by hydrogen intercalation of the interfacial layer. In this system, the carrier concentration experiences a two-fold increase in sensitivity to changes in relative humidity as compared to the as-grown epitaxial graphene. This enhanced sensitivity to water is attributed to the lowering of the hydrophobicity of QFS 1LG, which results from spontaneous polarization of 4H-SiC(0001) strongly influencing the graphene. Moreover, the superior carrier mobility of the QFS 1LG system is retained even at the highest humidity. The work function maps constructed from Kelvin probe force microscopy also revealed higher sensitivity to water for 1LG compared to 2LG in both QFS 1LG and as-grown systems. These results point to a new field of applications for QFS 1LG, i.e., as humidity sensors, and the corresponding need for metrology in calibration of graphene-based sensors and devices.
arXiv comment16 pages, 4 figures
References in corpus (10)
- Detection of Individual Gas Molecules Absorbed on Graphene
- Electronic transport in two dimensional graphene
- Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
- First-principles studies of water adsorption on graphene: The role of the substrate
- The quasi-free-standing nature of graphene on H-saturated SiC(0001)
- The Origin of Doping in Quasi-Free Standing Graphene on Silicon Carbide
- On the mechanism of hydrophilicity of graphene
- Atmospheric doping effects in epitaxial graphene: correlation of local and global electrical measurements
- Ab initio study of the relationship between spontaneous polarization and p-type doping in quasi-freestanding graphene on H-passivated SiC surfaces
- Surface and interface structure of quasi-free standing graphene on SiC