Angular dependence of nonparabolicity factor of energy band structures

This paper describes an angular dependence of the nonparabolicity factor of energy band structures and the influence on the density of states (DOS). The angular dependence of the nonparabolicity factor is investigated using the silicon band structure data calculated by the first principle calculation. In order to investigate the influence of the angular dependence on DOS, we propose a macroscopic model to estimate the average nonparabolicity factor calculated from the information of the band structure in several directions. It is found that the angular dependence of the nonparabolicity factor is essential to model not only DOS but also E-k dispersion relations.