Nonlinear screening of charges induced in graphene by metal contacts

Share/Save/Bookmark

Khomyakov, P.A. and Starikov, A.A. and Brocks, G. and Kelly, P.J. (2010) Nonlinear screening of charges induced in graphene by metal contacts. Physical Review B: Condensed matter and materials physics, 82 (11). p. 115437. ISSN 1098-0121

[img] PDF
Restricted to UT campus only
: Request a copy
148kB
Abstract:To understand the band bending caused by metal contacts, we study the potential and charge density induced in graphene in response to contact with a metal strip. We find that the screening is weak by comparison with a normal metal as a consequence of the ultrarelativistic nature of the electron spectrum near the Fermi energy. The induced potential decays with the distance from the metal contact as x−1/2 and x−1 for undoped and doped graphene, respectively, breaking its spatial homogeneity. In the contact region, the metal contact can give rise to the formation of a p-p′, n-n′, and p-n junction (or with additional gating or impurity doping, even a p-n-p′ junction) that contributes to the overall resistance of the graphene sample, destroying its electron-hole symmetry. Using the work functions of metal-covered graphene recently calculated by Khomyakov et al. [Phys. Rev. B 79, 195425 (2009)], we predict the boundary potential and junction type for different metal contacts.
Item Type:Article
Copyright:© 2010 The American Physical Society
Faculty:
Science and Technology (TNW)
Research Group:
Link to this item:http://purl.utwente.nl/publications/73189
Official URL:http://dx.doi.org/10.1103/PhysRevB.82.115437
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page