Birefringence-Directed Raman Selection Rules in 2D Black Phosphorus Crystals.

The incident and scattered light engaged in the Raman scattering process of low symmetry crystals always suffer from the birefringence-induced depolarization. Therefore, for anisotropic crystals, the classical Raman selection rules should be corrected by taking the birefringence effect into consideration. The appearance of the 2D anisotropic materials provides an excellent platform to explore the birefringence-directed Raman selection rules, due to its controllable thickness at the nanoscale that greatly simplifies the situation comparing with bulk materials. Herein, a theoretical and experimental investigation on the birefringence-directed Raman selection rules in the anisotropic black phosphorus (BP) crystals is presented. The abnormal angle-dependent polarized Raman scattering of the Ag modes in thin BP crystal, which deviates from the normal Raman selection rules, is successfully interpreted by the theoretical model based on birefringence. It is further confirmed by the examination of different Raman modes using different laser lines and BP samples of different thicknesses.

[1]  Yihong Wu,et al.  Interference enhancement of Raman signal of graphene , 2008, 0801.4595.

[2]  M. Sanjuán,et al.  Raman selection rules in uniaxial media: The nonpolar modes of Mn Ga2 Se4 , 2005 .

[3]  S. Porto,et al.  Raman scattering of YVO4 , 1972 .

[4]  Severin T. Schneebeli,et al.  Polarized Raman spectroscopy of oligothiophene crystals to determine unit cell orientation. , 2012, The journal of physical chemistry. A.

[5]  Hyeonsik Cheong,et al.  Anomalous polarization dependence of Raman scattering and crystallographic orientation of black phosphorus. , 2015, Nanoscale.

[6]  F. Beltram,et al.  The optical visibility of graphene: interference colors of ultrathin graphite on SiO(2). , 2007, Nano letters.

[7]  A. Morita,et al.  Band structure and optical properties of black phosphorus , 1984 .

[8]  A. M. van der Zande,et al.  In-Plane Anisotropy in Mono- and Few-Layer ReS2 Probed by Raman Spectroscopy and Scanning Transmission Electron Microscopy. , 2015, Nano letters.

[9]  Daniel Wolverson,et al.  Raman spectra of monolayer, few-layer, and bulk ReSe₂: an anisotropic layered semiconductor. , 2014, ACS nano.

[10]  Schubert,et al.  Polarization-dependent optical parameters of arbitrarily anisotropic homogeneous layered systems. , 1996, Physical review. B, Condensed matter.

[11]  Zongfu Yu,et al.  Extraordinary photoluminescence and strong temperature/angle-dependent Raman responses in few-layer phosphorene. , 2014, ACS nano.

[12]  P. Ye,et al.  Semiconducting black phosphorus: synthesis, transport properties and electronic applications. , 2014, Chemical Society Reviews.

[13]  Sefaattin Tongay,et al.  Monolayer behaviour in bulk ReS2 due to electronic and vibrational decoupling , 2014, Nature Communications.

[14]  K. Murase,et al.  Pressure Dependence of the Lattice Vibration in the Orthorhombic and Rhombohedral Structures of Black Phosphorus , 1981 .

[15]  T. C. Damen,et al.  Depolarization of Raman Scattering in Calcite , 1966 .

[16]  DEPOLARIZATION OF RAMAN SCATTERING IN LaCl . , 1968 .

[17]  F. Xia,et al.  Rediscovering black phosphorus as an anisotropic layered material for optoelectronics and electronics. , 2014, Nature communications.

[18]  Peide D. Ye,et al.  Anisotropic in-plane thermal conductivity observed in few-layer black phosphorus , 2015, Nature Communications.

[19]  S. Sugai,et al.  Raman and infrared reflection spectroscopy in black phosphorus , 1985 .

[20]  Yihong Wu,et al.  Graphene thickness determination using reflection and contrast spectroscopy. , 2007, Nano letters.

[21]  Hua Xu,et al.  Identifying the crystalline orientation of black phosphorus using angle-resolved polarized Raman spectroscopy. , 2015, Angewandte Chemie.

[22]  Wanglin Lu,et al.  Probing the anisotropic behaviors of black phosphorus by transmission electron microscopy, angular-dependent Raman spectra, and electronic transport measurements , 2015, 1509.05953.

[23]  X. Ling,et al.  Interference Phenomenon in Graphene-Enhanced Raman Scattering , 2011 .

[24]  Arunava Gupta,et al.  MonitoringB-site ordering and strain relaxation in NiFe2O4epitaxial films by polarized Raman spectroscopy , 2011 .

[25]  A. Farrell,et al.  Atlantic salmon show capability for cardiac acclimation to warm temperatures , 2014, Nature Communications.

[26]  R. Loudon,et al.  The Raman effect in crystals , 1964 .

[27]  R. L. Moreira,et al.  Unusual angular dependence of the Raman response in black phosphorus. , 2015, ACS nano.

[28]  Wei Ji,et al.  High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus , 2014, Nature communications.

[29]  Hugen Yan,et al.  Phonon softening and crystallographic orientation of strained graphene studied by Raman spectroscopy , 2009, Proceedings of the National Academy of Sciences.

[30]  M. Dresselhaus,et al.  Low-Frequency Interlayer Breathing Modes in Few-Layer Black Phosphorus. , 2015, Nano letters.