Electronic Structure of Black Phosphorus in Self-Consistent Pseudopotential Approach

The energy band structure of black phosphorus is calculated by using self-consistent pseudopotential method. The resulting band structure has the direct minimum gap at the point Z in the Brillouin zone in agreement with the result of the tight-binding approach. Effective electron and hole masses and the level shift of the band edge by pressure are calculated from the bands obtained. The pressure dependence of the energy gap is in good agreement with experiment, but the anisotropy of the effective masses contradicts that of the electrical conductivity measured for the single crystal. The nature of the optical absorption edge is discussed in terms of the calculated band structure.