Unusual angular dependence of the Raman response in black phosphorus.
Anisotropic materials are characterized by a unique optical response, which is highly polarization-dependent. Of particular interest are layered materials formed by the stacking of two-dimensional (2D) crystals that are naturally anisotropic in the direction perpendicular to the 2D planes. Black phosphorus (BP) is a stack of 2D phosphorene crystals and a highly anisotropic semiconductor with a direct band gap. We show that the angular dependence of polarized Raman spectra of BP is rather unusual and can be explained only by considering complex values for the Raman tensor elements. This result can be traced back to the electron-photon and electron-phonon interactions in this material.
†Mackgraphe-Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, 01302-907 São Paulo, Brazil.
Henrique B
HB
Ribeiro
‡Departamento de Física, UFMG, 30123-970 Belo Horizonte, Brazil.
Marcos A
MA
Pimenta
†Mackgraphe-Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, 01302-907 São Paulo, Brazil.
Christiano J S
CJ
de Matos
‡Departamento de Física, UFMG, 30123-970 Belo Horizonte, Brazil.
Roberto Luiz
RL
Moreira
§Centre for Advanced 2D Materials and Graphene Research Centre Faculty of Science, National University of Singapore, 119077 Singapore.
Aleksandr S
AS
Rodin
†Mackgraphe-Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, 01302-907 São Paulo, Brazil.|⊥Universidad de Antioquia, Medellin Colombia.
Juan D
JD
Zapata
†Mackgraphe-Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, 01302-907 São Paulo, Brazil.
Eunézio A T
EA
de Souza
§Centre for Advanced 2D Materials and Graphene Research Centre Faculty of Science, National University of Singapore, 119077 Singapore.|∥Department of Physics Faculty of Science, National University of Singapore, 119077 Singapore.
Antonio H
AH
Castro Neto
black phosphorus; electron−phonon coupling; linear dichroism; phosphorene; polarized Raman spectroscopy