title: Chemical sensing with switchable transport channels in graphene grain boundaries.
abstract: Grain boundaries can markedly affect the electronic, thermal, mechanical and optical properties of a polycrystalline graphene. While in many applications the presence of grain boundaries in graphene is undesired, here we show that they have an ideal structure for the detection of chemical analytes. We observe that an isolated graphene grain boundary has ~300 times higher sensitivity to the adsorbed gas molecules than a single-crystalline graphene grain. Our electronic structure and transport modelling reveal that the ultra-sensitivity in grain boundaries is caused by a synergetic combination of gas molecules accumulation at the grain boundary, together with the existence of a sharp onset energy in the transmission spectrum of its conduction channels. The discovered sensing platform opens up new pathways for the design of nanometre-scale highly sensitive chemical detectors.
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Poya
authors.initials: P
authors.lastname: Yasaei
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Bijandra
authors.initials: B
authors.lastname: Kumar
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Hantehzadeh
authors.affiliation: Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Morteza
authors.initials: M
authors.lastname: Kayyalha
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Artem
authors.initials: A
authors.lastname: Baskin
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Nikita
authors.initials: N
authors.lastname: Repnin
authors.affiliation: Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Canhui
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Klie
authors.affiliation: 1] Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA [2] Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Yong P
authors.initials: YP
authors.lastname: Chen
authors.affiliation: 1] Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA [2] Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Petr
authors.initials: P
authors.lastname: Král
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Amin
authors.initials: A
authors.lastname: Salehi-Khojin