Adsorption Site-Dependent Mobility Behavior in Graphene Exposed to Gas Oxygen

0498916 - ÚFCH JH 2019 RIV US eng J - Journal Article
Blechta, Václav - Drogowska, Karolina - Valeš, Václav - Kalbáč, Martin
Adsorption Site-Dependent Mobility Behavior in Graphene Exposed to Gas Oxygen.
Journal of Physical Chemistry C. Roč. 122, č. 37 (2018), s. 21493-21499. ISSN 1932-7447. E-ISSN 1932-7455
R&D Projects: GA ČR GA18-20357S; GA MŠMT(CZ) LTC18039
Institutional support: RVO:61388955
Keywords : field-effect transistors * chemical-vapor-deposition * walled carbon nanotube * doped graphene * layer graphene * grown graphene
OECD category: Physical chemistry
Impact factor: 4.309, year: 2018

Transport characteristics of graphene field-effect transistors were measured in situ in oxygen/nitrogen atmospheres and at various temperatures. Mobilities of holes were extracted from transport characteristics as well as the doping level depending on the time of graphene exposure to oxygen/nitrogen atmosphere. The hole mobility showed significant decrease upon the oxygen adsorption to low energy adsorption sites (sp(2) carbon). However, it remained unaffected by the oxygen adsorption to high-energy adsorption sites which are represented by defects, impurities, transfer residuals, edges, and functional groups on graphene. The Dirac point was upshifted for both the low- and high-energy adsorption events. Activation energy of oxygen adsorption/desorption was estimated from temperature-dependent desorption rate coefficients as 215 and 450 meV for the low- and high-energy adsorption sites, respectively.
Permanent Link: http://hdl.handle.net/11104/0291202