TABLE OF CONTENTS (Edited by R.J. Turton)
R.J. Turton
October 1997
The band structure of bulk silicon has probably been the subject of more studies, both experimental and theoretical, than that of any other semiconductor. The Datareviews in this chapter cover various aspects of the band structure of crystalline bulk silicon.
Silicon is an indirect gap semiconductor, as can be seen from FIGURE 1. The lowest energy interband transition occurs between the valence band maximum at ? and the six-fold degenerate conduction band minima which occur at approximately 0.84 (2 ?/a) along the [100] and equivalent axes. The heavy and light hole states are degenerate at the top of the valence band at ?, with the split off state slightly lower in energy. These states have ? 8 and ? 7 symmetry, respectively. However, since the spin-orbit splitting is very small in silicon (see Datareview 7.3), it is usual to assume that the state is threefold degenerate and it is denoted by the single group notation as ? 25'. The single group symmetry labels are used in FIGURE 1 and TABLE 1. Other conduction minima occur at the L and ? points, lying at approximately 1 eV and 2 eV above the conduction band edge, respectively. The ? 15c minimum is three-fold degenerate and the slightly higher lying ? 2'c state is singly degenerate.
