title: Low Schottky barrier black phosphorus field-effect devices with ferromagnetic tunnel contacts.
abstract: Black phosphorus (BP) has been recently unveiled as a promising 2D direct bandgap semiconducting material. Here, ambipolar field-effect transistor behavior of nanolayers of BP with ferromagnetic tunnel contacts is reported. Using TiO2/Co contacts, a reduced Schottky barrier <50 meV, which can be tuned further by the gate voltage, is obtained. Eminently, a good transistor performance is achieved in the devices discussed here, with drain current modulation of four to six orders of magnitude and a mobility of μh ≈ 155 cm(2) V(-1) s(-1) for hole conduction at room temperature. Magnetoresistance calculations using a spin diffusion model reveal that the source-drain contact resistances in the BP device can be tuned by gate voltage to an optimal range for injection and detection of spin-polarized holes. The results of the study demonstrate the prospect of BP nanolayers for efficient nanoelectronic and spintronic devices.
authors.affiliation: Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296, Göteborg, Sweden.
authors.forename: M Venkata
authors.initials: MV
authors.lastname: Kamalakar
authors.forename: B N
authors.initials: BN
authors.lastname: Madhushankar
authors.forename: André
authors.initials: A
authors.lastname: Dankert
authors.forename: Saroj P
authors.initials: SP
authors.lastname: Dash
keywords: Black phosphorus; ferromagnetism; field-effect transistors; magnetoresistance; phosphorene; spintronics; tunnel contact