title: Resolving and Tuning Mechanical Anisotropy in Black Phosphorus via Nanomechanical Multimode Resonance Spectromicroscopy.
abstract: Black phosphorus (P) has emerged as a layered semiconductor with a unique crystal structure featuring corrugated atomic layers and strong in-plane anisotropy in its physical properties. Here, we demonstrate that the crystal orientation and mechanical anisotropy in free-standing black P thin layers can be precisely determined by spatially resolved multimode nanomechanical resonances. This offers a new means for resolving important crystal orientation and anisotropy in black P device platforms in situ beyond conventional optical and electrical calibration techniques. Furthermore, we show that electrostatic-gating-induced straining can continuously tune the mechanical anisotropic effects on multimode resonances in black P electromechanical devices. Combined with finite element modeling (FEM), we also determine the Young's moduli of multilayer black P to be 116.1 and 46.5 GPa in the zigzag and armchair directions, respectively.
authors: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors: Zenghui
authors: Z
authors: Wang
authors: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors: Hao
authors: H
authors: Jia
authors: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors: Xu-Qian
authors: XQ
authors: Zheng
authors: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors: Rui
authors: R
authors: Yang
authors: G J
authors: GJ
authors: Ye
authors: X H
authors: XH
authors: Chen
authors: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors: Philip X-L
authors: PX
authors: Feng
keywords: 2D materials; Black phosphorus; mechanical anisotropy; multimode resonances; nanoelectromechanical systems (NEMS); spatial mapping