title: Identifying the crystalline orientation of black phosphorus using angle-resolved polarized Raman spectroscopy.
abstract: An optical anisotropic nature of black phosphorus (BP) is revealed by angle-resolved polarized Raman spectroscopy (ARPRS), and for the first time, an all-optical method was realized to identify the crystal orientation of BP sheets, that is, the zigzag and armchair directions. We found that Raman intensities of Ag(1), B2g, and Ag(2) modes of BP not only depend on the polarization angle α, but also relate to the sample rotation angle θ. Furthermore, their intensities reach the local maximum or minimum values when the crystalline orientation is along with the polarization direction of scattered light (es). Combining with the angle-resolved conductance, it is confirmed that Ag(2) mode intensity achieves a relative larger (or smaller) local maximum under parallel polarization configuration when armchair (or zigzag) direction is parallel to es. Therefore, ARPRS can be used as a rapid, precise, and nondestructive method to identify the crystalline orientation of BP layers.
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, Key Laboratory for the Physics and Chemistry of Nanodevices, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871 (P.R. China); Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871 (P.R. China).
authors.forename: Juanxia
authors.initials: J
authors.lastname: Wu
authors.forename: Nannan
authors.initials: N
authors.lastname: Mao
authors.forename: Liming
authors.initials: L
authors.lastname: Xie
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
keywords: anisotropy; black phosphorus; crystalline orientation; phosphorene; polarized Raman spectroscopy