title: Rediscovering black phosphorus as an anisotropic layered material for optoelectronics and electronics.
abstract: Graphene and transition metal dichalcogenides (TMDCs) are the two major types of layered materials under intensive investigation. However, the zero-bandgap nature of graphene and the relatively low mobility in TMDCs limit their applications. Here we reintroduce black phosphorus (BP), the most stable allotrope of phosphorus with strong intrinsic in-plane anisotropy, to the layered-material family. For 15-nm-thick BP, we measure a Hall mobility of 1,000 and 600 cm(2)V(-1)s(-1) for holes along the light (x) and heavy (y) effective mass directions at 120 K. BP thin films also exhibit large and anisotropic in-plane optical conductivity from 2 to 5 μm. Field-effect transistors using 5 nm BP along x direction exhibit an on-off current ratio exceeding 10(5), a field-effect mobility of 205 cm(2)V(-1)s(-1), and good current saturation characteristics all at room temperature. BP shows great potential for thin-film electronics, infrared optoelectronics and novel devices in which anisotropic properties are desirable.
authors.affiliation: 1] Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511, USA [2].
authors.forename: Fengnian
authors.initials: F
authors.lastname: Xia
authors.affiliation: 1] IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, USA [2].
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Yichen
authors.initials: Y
authors.lastname: Jia