We report on the energy- and momentum-resolved optical response of black phosphorus (BP) in its bulk form. Along the armchair direction of the puckered layers, we find a highly dispersive mode that is strongly suppressed in the perpendicular (zigzag) direction. This mode emerges out of the single-particle continuum for finite values of momentum and is therefore interpreted as an exciton. We arg...

FIG.1. Calculated electron density difference ∆ρ=ρtot(bulk)−Σρtot(monolayers) representing the charge redistribution caused by assembling the bulk structure from isolated monolayers. (a) Diffusion Monte Carlo (DMC) isosurfaces bounding regions of excess electron density (dark brown) and electron deficiency (light brown), with respective values ±6.5×10 e/Å. (b) <∆ρ(z)> for DMC and selected DFT f...

• Defects analysis of bipolar exfoliated phosphorene nanosheets using high-resolution transmission electron microscopy (TEM). Formation the mono- and di-vacancies, ad-atoms, grain boundary defects in nanosheets. The breakage P-P bonds upon surface oxidation results amorphization Chemisorption process high sensitivity to oxygen. Two-dimensional (2D) has gained attention due its exceptional chemi...

We report on the theoretical electronic spectra of twisted phosphorene bilayers exhibiting moir\'e patterns, as computed by means a continuous approximation to superlattice Hamiltonian. Our model is constructed interpolating between effective $\Gamma$-point conduction- and valence-band Hamiltonians for different stacking configurations approximately realized across supercell, formulated symmetr...