A temperature dependent measurement of the carrier velocity vs. electric field characteristic for as-grown and H-intercalated epitaxial graphene on SiC
2013 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 113, no 19Article in journal (Refereed) Published
A technique for the measurement of the electron velocity versus electric field is demonstrated on as-grown and H-intercalated graphene. Van der Pauw, coplanar microbridge, and coplanar TLM structures are fabricated in order to assess the carrier mobility, carrier concentration, sheet resistance, and contact resistance of both epi-materials. These measurements are then combined with dynamic IV measurements to extract a velocity-field characteristic. The saturated electron velocity measurements indicate a value of 2.33 × 107cm/s for the as-grown material and 1.36 × 107cm/s for the H-intercalated material at 300 K. Measurements are taken as a function of temperature from 100 K to 325 K in order to estimate the optical phonon energy Eso of 4H-SiC by assuming an impurity scattering model. The extracted values of Eso are 97 meV for the as-grown sample and 115 meV for the H-intercalated sample. The H-intercalated result correlates to the anticipated value of 116 meV for 4H-SiC, while the as-grown value is significantly below the expected value. Therefore, we hypothesize that the transport properties of epitaxial graphene on SiC are influenced both by intercalation and by remote phonon scattering with the SiC substrate.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2013. Vol. 113, no 19
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-94605DOI: 10.1063/1.4807162ISI: 000319295200029OAI: oai:DiVA.org:liu-94605DiVA: diva2:633599
Funding Agencies|Swedish Foundation for Strategic Research (SSF)||Knut och Alice Wallenberg Foundation (KAW)||European Science Foundation (ESF)||2013-06-272013-06-272016-06-02Bibliographically approved