Control of Thermal and Electronic Transport in Defect-Engineered Graphene Nanoribbons

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Justin Haskins - , University of Texas at Austin (Autor:in)
  • Alper Kinaci - , Texas A&M University (Autor:in)
  • Cem Sevik - , University of Texas at Austin (Autor:in)
  • Haldun Sevincli - , Technische Universität Dresden (Autor:in)
  • Gianaurelio Cuniberti - , Professur für Materialwissenschaft und Nanotechnik, Österreichische Akademie der Wissenschaften, Leibniz-Institut für Polymerforschung Dresden, Pohang University of Science and Technology (Autor:in)
  • Tahir Cagin - , University of Texas at Austin (Autor:in)

Abstract

The influence of the structural detail and defects on the thermal and electronic transport properties of graphene nanoribbons (GNRs) is explored by molecular dynamics and non-equilibrium Green's function methods. A variety of randomly oriented and distributed defects, single and double vacancies, Stone Wales defects, as well as two types of edge form (armchair and zigzag) and different edge roughnesses are studied for model systems similar in sizes to experiments (>100 nm long and >15 nm wide). We observe substantial reduction in thermal conductivity due to all forms of defects, whereas electrical conductance reveals a peculiar defect-type-dependent response. We find that a 0.1% single vacancy concentration and a 0.23% double vacancy or Stone Wales concentration lead to a drastic reduction in thermal conductivity of GNRs, namely, an 80% reduction from the pristine one of the same width. Edge roughness with an rms value of 7.28 angstrom leads to a similar reduction in thermal conductivity. Randomly distributed bulk vacancies are also found to strongly suppress the ballistic nature of electrons and reduce the conductance by 2 orders of magnitude. However, we have identified that defects close to the edges and relatively small values of edge roughness preserve the quasi-ballistic nature of electronic transport. This presents a route of Independently controlling electrical and thermal transport by Judicious engineering of the defect distribution; we discuss the implications of this for thermoelectric performance.

Details

OriginalspracheEnglisch
Seiten (von - bis)3779-3787
Seitenumfang9
FachzeitschriftACS Nano
Jahrgang5
Ausgabenummer5
PublikationsstatusVeröffentlicht - Mai 2011
Peer-Review-StatusJa

Externe IDs

WOS 000290826800043
PubMed 21452884
Scopus 80051521172

Schlagworte

Schlagwörter

  • Carbon, Electronic transport, Graphene, Thermal transport, Thermoelectric, molecular dynamics