2008/03/05 by Shaffique Adam, S. Adam, S. Das Sarma · 2 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Advancements in Battery Materials #Bilayer graphene #Chemical physics #Chemistry #Condensed matter physics #Conductivity #Coulomb #Electron #Graphene #Graphene nanoribbons #Graphene research and applications #Impurity #Materials science #Nanopore and Nanochannel Transport Studies #Nanotechnology #Optics #Physical chemistry #Physics #Scattering #Substrate (aquarium) #cond-mat.mtrl-sci
paper · pdf · doi:10.1016/j.ssc.2008.03.021
published as Solid State Communications 146, 356 (2008) · 6 pages, 4 figures. Related papers available at http://www.physics.umd.edu/cmtc/
arxiv created 2008/03/05 · openalex publication_date 2008/03/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Motivated by recent experiments on suspended graphene showing carrier mobilities as high as 200,000 cm2/Vs, we theoretically calculate transport properties assuming Coulomb impurities as the dominant scattering mechanism. We argue that the substrate-free experiments done in the diffusive regime are consistent with our theory and verify many of our earlier predictions including (i) removal of the substrate will increase mobility since most of the charged impurities are in the substrate, (ii) the minimum conductivity is not universal, but depends on impurity concentration with cleaner samples having a higher minimum conductivity. We further argue that experiments on suspended graphene put strong constraints on the two parameters involved in our theory, namely, the charged impurity concentration nimp and d, the typical distance of a charged impurity from the graphene sheet. The recent experiments on suspended graphene indicate a residual impurity density of 1-2 × 1010 cm-2 which are presumably stuck to the graphene interface, compared to impurity densities of ~1012 cm-2 for graphene on SiO2 substrate. Transport experiments can therefore be used as a spectroscopic tool to identify the properties of the remaining impurities in suspended graphene.