Electronic Structure of Black Phosphorus in Tight Binding Approach

The energy band structure of black phosphorus is calculated for the first time using the tight binding approach. It is shown that black phosphorus is a narrow gap semiconductor with the direct energy gap at the zone edge in the (0 0 k_z) direction. The pressure dependence of the energy gap is calculated to be -2.61× 10^-2 eV/kbar, its experimental counterpart being -2.51× 10^-2 eV/kbar. The optical absorption and the electrical conductivity of black phosphorus single crystals are discussed in terms of the calculated band structure.