title: Al2C Monolayer Sheet and Nanoribbons with Unique Direction-Dependent Acoustic-Phonon-Limited Carrier Mobility and Carrier Polarity.
abstract: The intrinsic acoustic-phonon-limited carrier mobility (μ) of Al2C monolayer sheet and nanoribbons are investigated using ab initio computation and deformation potential theory. It is found that the polarity of the room-temperature carrier mobility of the Al2C monolayer is direction-dependent, with μ of electron (e) and hole (h) being 2348 and 40.77 cm(2)/V/s, respectively, in the armchair direction and 59.95 (e) and 705.8 (h) in the zigzag direction. More interestingly, one-dimensional Al2C nanoribbons not only can retain the direction-dependent polarity but also may entail even higher mobility, in contrast to either the graphene nanoribbons which tend to exhibit lower μ compared to the two-dimensional graphene or the MoS2 nanoribbons which have reversed polarity compared to the MoS2 sheet. As an example, the Al-terminated zigzag nanoribbon with a width of 4.1 nm exhibits μ of 212.6 (e) and 2087 (h) cm(2)/V/s, while the C-terminated armchair nanoribbon with a width 2.6 nm exhibits μ of 1090 (e) and 673.9 (h) cm(2)/V/s; the C-terminated zigzag nanoribbon with a width 3.7 nm exhibits μ of 177.6 (e) and 1889 (h) cm(2)/V/s, and the Al-terminated armchair nanoribbon with a width 2.4 nm exhibits μ of 6695 (e) and 518.4 (h) cm(2)/V/s. The high carrier mobility, μ, coupled with polarity and direction dependence endows the Al2C sheet and nanoribbons with unique transport properties that can be exploited for special applications in nanoelectronics.
authors.affiliation: School of Mathematics and Physics, Jiangsu Collaborative Innovation Center for Photovoltaic Science and Engineering, Jiangsu Province Cultivation Base for State Key Laboratory of Photovoltaic Science and Technology, Changzhou University , Changzhou, 213164 Jiangsu, China.|Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Dai
authors.affiliation: Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Xiao Cheng
authors.initials: XC
authors.lastname: Zeng
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D016880:Anisotropy; D055119:Elastic Modulus; D008956:Models, Chemical; D037742:Nanotubes, Carbon / Q000737:chemistry*; D060739:Phonons; D012666:Semiconductors
chemical_list: D037742:Nanotubes, Carbon; D000535:Aluminum