title: Rapid and Large-Area Characterization of Exfoliated Black Phosphorus Using Third-Harmonic Generation Microscopy.
abstract: Black phosphorus (BP) is a layered semiconductor that recently has been the subject of intense research due to its novel electrical and optical properties, which compare favorably to those of graphene and the transition metal dichalcogenides. In particular, BP has a direct bandgap that is thickness-dependent and highly anisotropic, making BP an interesting material for nanoscale optical and optoelectronic applications. Here, we present a study of the anisotropic third-harmonic generation (THG) in exfoliated BP using a fast scanning multiphoton characterization method. We find that the anisotropic THG arises directly from the crystal structure of BP. We calculate the effective third-order susceptibility of BP to be ∼1.64 × 10-19m2V-2. Further, we demonstrate that multiphoton microscopy can be used for rapid, large-area characterization indexing of the crystallographic orientations of many exfoliated BP flakes from one set of multiphoton images. This method is therefore beneficial for samples of areas ∼1 cm2in future investigations of the properties and growth of BP.
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.
authors.forename: Anton
authors.identifier: http://orcid.org/0000-0002-7783-1991
authors.initials: A
authors.lastname: Autere
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Ryder
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.|Institute of Photonics, University of Eastern Finland , Yliopistokatu 7, FI-80101 Joensuu, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Säynätjoki
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.
authors.forename: Lasse
authors.initials: L
authors.lastname: Karvonen
authors.affiliation: College of Optical Sciences, University of Arizona , 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Babak
authors.initials: B
authors.lastname: Amirsolaimani
authors.affiliation: College of Optical Sciences, University of Arizona , 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Norwood
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.|Institute of Photonics, University of Eastern Finland , Yliopistokatu 7, FI-80101 Joensuu, Finland.|College of Optical Sciences, University of Arizona , 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Nasser
authors.initials: N
authors.lastname: Peyghambarian
authors.affiliation: College of Optical Sciences, University of Arizona , 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Khanh
authors.initials: K
authors.lastname: Kieu
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Lipsanen
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Mark C
authors.identifier: http://orcid.org/0000-0003-4120-1426
authors.initials: MC
authors.lastname: Hersam
authors.affiliation: Department of Electronics and Nanoengineering, Aalto University , Tietotie 3, FI-02150 Espoo, Finland.
authors.forename: Zhipei
authors.initials: Z
authors.lastname: Sun