Work function and conductivity changes due to molecular adsorption in epitaxial graphene on 6H-SiC

Author

Nomani, Md W K ; Singh, A. ; Shields, V. ; Spencer, M. ; Tompa, G. ; Sbrockey, N. ; Koley, G.

Author_Institution

Dept. of Electr. Eng., Univ. of South Carolina, Columbia, SC, USA

fYear

2011

fDate

15-18 Aug. 2011

Firstpage

1317

Lastpage

1321

Abstract

Charge carrier transport properties and molecular doping in graphene grown epitaxially on both Si and C-faces of 6H-SiC have been investigated. Our results indicate that in C-face multiplayer graphene (MLG) p-type charge carriers are dominant and in Si-face few layer graphene (FLG), charge carriers are mostly n-type. A strong correlation between conductance change and SWF change due to molecular doping in C and Si-faces epitaxial graphene has been found based on type of carrier, Fermi level shifts, and carrier density of the graphene film. An analytical model for the dependence of conductivity on the adsorbate-induced doping and impurities is being developed based on work function change and Boltzmann transport theory.

Keywords

Fermi level; adsorption; carrier density; doping; electrical conductivity; epitaxial growth; epitaxial layers; graphene; impurities; work function; 6H-SiC surface; Boltzmann transport theory; C; C-face multiplayer graphene; Fermi level shifts; Si; Si-face few layer graphene; SiC; adsorbate-induced doping; carrier density; charge carrier transport; electrical conductivity; epitaxial graphene; impurities; molecular adsorption; molecular doping; p-type charge carriers; work function; Charge carriers; Conductivity; Epitaxial growth; Gases; Sensors; Silicon;

fLanguage

English

Publisher

ieee

Conference_Titel

Nanotechnology (IEEE-NANO), 2011 11th IEEE Conference on

Conference_Location

Portland, OR

ISSN

1944-9399

Print_ISBN

978-1-4577-1514-3

Electronic_ISBN

1944-9399

Type

conf

DOI

10.1109/NANO.2011.6144426

Filename

6144426