2021/05/31 by Jouda Jemaa Khabthani, Ahmed Missaoui, Didier Mayou +1
Chemistry · Materials Science · Physics and Astronomy · #Band gap #Bilayer graphene #Charge carrier #Chemical physics #Chemistry #Condensed matter physics #Doping #Electronic structure #Graphene #Graphene research and applications #Materials science #Nanotechnology #Physics #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Thermal properties of materials #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.104.245125
published as Phys. Rev. B 104, 245125 (2021) · 18 pages, 14 figures
openalex publication_date 2021/12/15 · arxiv created 2021/12/16 · arxiv updated 2021/12/17 · openalex created_date 2021/12/31 · openalex updated_date 2026/08/05
Monitoring electronic properties of two-dimensional (2D) materials is an essential step to open a way for applications such as electronic devices and sensors. From this perspective, Bernal bilayer graphene (BLG) is a fairly simple system that offers great possibilities for tuning electronic gap and charge carriers' mobility by selective functionalization (adsorptions of atoms or molecules). Here we present a detailed numerical study of BLG electronic properties when two types of adsorption site are present simultaneously. We focus on realistic cases that could be realized experimentally with adsorbate concentration c varying from 0.25% to 5%. For a given value of c, when the electronic doping is lower than c, we show that quantum effects, which are ignored in usual semiclassical calculations, strongly affect the electronic structure and the transport properties. A wide range of behaviors is indeed found, such as gap opening, metallic behavior, or abnormal conductivity, which depend on the adsorbate positions, the c value, the doping, and eventually the coupling between midgap states which can create a midgap band. These behaviors are understood by simple arguments based on the fact that BLG lattice is bipartite. We also analyze the conductivity at low temperature, where multiple scattering effects cannot be ignored. Moreover, when the Fermi energy lies in the band of midgap states, the average velocity of charge carriers cancels but conduction is still possible thanks to quantum fluctuations of the velocity.