DENSITY OF STATES AND EFFECTIVE MASS OF HEAVY, LIGHT AND SPLIT-OFF HOLES NEAR THE VALENCE VAND EDGE OF SILICON.

The density of states and effective masses for the three types of subband holes of silicon are investigated by using the results of calculation for two energy band structures (the DKK model and Kane model) with various band parameters obtained from cyclotron experiments. For the DKK model, the influence of anisotropy in equi-energy surfaces is represented as modified coefficients. For the Kane model, those of the anisotropy and non-parabolicity in equi-energy surfaces are represented by modified functions. The limiting values of the density of states and effective masses at E equals 0 for heavy and light holes from the Kane model coincide with those of the DKK model and also for split-off holes. The influence of varying the values of band parameters is pronounced in the curvature of the density of states (or effective mass-ratio) and is also found in the asymptotic values of three subbands holes.