title: High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus.
abstract: Two-dimensional crystals are emerging materials for nanoelectronics. Development of the field requires candidate systems with both a high carrier mobility and, in contrast to graphene, a sufficiently large electronic bandgap. Here we present a detailed theoretical investigation of the atomic and electronic structure of few-layer black phosphorus (BP) to predict its electrical and optical properties. This system has a direct bandgap, tunable from 1.51 eV for a monolayer to 0.59 eV for a five-layer sample. We predict that the mobilities are hole-dominated, rather high and highly anisotropic. The monolayer is exceptional in having an extremely high hole mobility (of order 10,000 cm(2) V(-1) s(-1)) and anomalous elastic properties which reverse the anisotropy. Light absorption spectra indicate linear dichroism between perpendicular in-plane directions, which allows optical determination of the crystalline orientation and optical activation of the anisotropic transport properties. These results make few-layer BP a promising candidate for future electronics.
authors.affiliation: 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China [3].
authors.forename: Jingsi
authors.initials: J
authors.lastname: Qiao
authors.affiliation: 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China [3].
authors.forename: Xianghua
authors.initials: X
authors.lastname: Kong
authors.affiliation: 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China.
authors.forename: Zhi-Xin
authors.initials: ZX
authors.lastname: Hu
authors.affiliation: 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China [3] College of Physics and Electronic Engineering, Institute of Solid State Physics, Sichuan Normal University, Chengdu 610068, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yang
authors.affiliation: 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ji