  In this work, we correlated the angular dependence of the Raman response of
black phosphorus to its crystallographic orientation by using transmission
electron microscopy and Raman spectroscopy. It was found that the intensity of
the A2g mode reached a maximum when the polarization direction of the incident
light was parallel to the zigzag crystallographic orientation. Notably, it was
further confirmed that the zigzag crystallographic direction exhibited superior
conductance and carrier mobility. Because of the lattice extension along the
armchair direction, an intensification of the anisotropic Raman response was
observed. This work provides direct evidence of the correlation between
anisotropic properties and crystallographic direction and represents a turning
point in the discussion of the angular-dependent electronic properties of black
phosphorus.
