title: Field Effect Optoelectronic Modulation of Quantum-Confined Carriers in Black Phosphorus.
abstract: We report measurements of the infrared optical response of thin black phosphorus under field-effect modulation. We interpret the observed spectral changes as a combination of an ambipolar Burstein-Moss (BM) shift of the absorption edge due to band-filling under gate control, and a quantum confined Franz-Keldysh (QCFK) effect, phenomena that have been proposed theoretically to occur for black phosphorus under an applied electric field. Distinct optical responses are observed depending on the flake thickness and starting carrier concentration. Transmission extinction modulation amplitudes of more than two percent are observed, suggesting the potential for use of black phosphorus as an active material in mid-infrared optoelectronic modulator applications.
authors.forename: William S
authors.identifier: 0000-0001-5269-2967
authors.initials: WS
authors.lastname: Whitney
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Sherrott
authors.forename: Deep
authors.initials: D
authors.lastname: Jariwala
authors.forename: Wei-Hsiang
authors.initials: WH
authors.lastname: Lin
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Hans A
authors.initials: HA
authors.lastname: Bechtel
authors.forename: George R
authors.initials: GR
authors.lastname: Rossman
authors.forename: Harry A
authors.identifier: 0000-0001-9435-0201
authors.initials: HA
authors.lastname: Atwater
keywords: Black phosphorus; Burstein−Moss shift; mid-infrared; optical modulator; quantum-confined Franz-Keldysh effect; tunable optical properties