Georgia Institute of Technology per Sidorov, Anton N. Naval Research Laboratory (U.S.) per Gaskill, D. Kurt. University of North Texas; Oak Ridge National Laboratory per Buongiorno Nardelli, Marco Naval Research Laboratory (U.S.) per Tedesco, Joseph L. Naval Research Laboratory (U.S.) per Myers-Ward, Rachel L. Naval Research Laboratory (U.S.) per Eddy, Charles R. Oak Ridge National Laboratory per Jayasekera, Thushari North Carolina State University per Kim, Ki Wook University of Louisville per Jayasingha, Ruwantha University of Louisville per Sherehiy, Andriy University of Louisville per Stallard, Robert University of Louisville per Sumanasekera, Gamini U. [College Park, Maryland] American Institute of Physics 2012-06-05 eng Article discussing research on charge transfer equilibria in ambient-exposed epitaxial graphene on (0001) 6 H-SiC. 6 p. ab initio calculations charge transfer states electrical conductivity graphene thermoelectric power Journal of Applied Physics, 2012, College Park: American Institute of Physics Journal of Applied Physics 111 11 True UNTSW UNTCAS public text_article text 10.1063/1.4725413 Physics Chemistry Copyright 2012 American Institute of Physics. The Journal of Applied Physics, 111, 113706, http://dx.doi.org/10.1063/1.4725413 Abstract: The transport properties of electronic materials have been long interpreted independently from both the underlying bulk-like behavior of the substrate or the influence of ambient gases. This is no longer the case for ultra-thin graphene whose properties are dominated by the interfaces between the active material and its surroundings. Here, the authors show that the graphene interactions with its environments are critical for the electrostatic and electrochemical equilibrium of the active device layers and their transport properties. Based on the prototypical case of epitaxial graphene on (0001) 6 H-SiC and using a combination of 'in-situ' thermoelectric power and resistance measurements and simulations from first principles, the authors demonstrate that the cooperative occurrence of an electrochemically mediated charge transfer from the graphene to air, combined with the peculiar electronic structure of the graphene/SiC interface, explains the wide variation of measured conductivity and charge carrier type found in prior reports. lwaugh DC ark:/67531/metadc132974 2013-01-16, 12:47:13 lwaugh 2014-05-12, 14:52:57 False