Table 1. Summary of calculations for Si(111) n /Si(SC) superlattices.
| n | lattice | N | E |
 (PBE) |
 (PBE) |
 (G0W0) |
 (G0W0) |
|---|---|---|---|---|---|---|---|
| 1 | BCO | 6 | 89 (QD) | 0.431 | 0.430 | 0.894 | 0.847 |
| Cubic-diamond stacking | |||||||
| 2 | SM | 10 | 46 (QD) | 0.906 | 0.869 | 1.346 | 1.316 |
| 3 | SM | 14 | 42 (D) | 0.807 | 1.197 | ||
| 4 | SM | 18 | 32 (D) | 0.832 | 1.283 | ||
| 5 | SM | 22 | 26 (D) | 0.782 | 1.218 | ||
| 6 | SM | 26 | 22 (QD) | 0.788 | 0.774 | 1.224 | 1.215 |
| 7 | SM | 30 | 19 (QD) | 0.761 | 0.741 | 1.198 | 1.185 |
| 8 | SM | 34 | 17 (QD) | 0.746 | 0.726 | 1.185 | 1.166 |
| 9 | SM | 38 | 16 (QD) | 0.738 | 0.712 | 1.177 | 1.154 |
| 10 | SM | 42 | 13 (QD) | 0.725 | 0.699 | 1.167 | 1.147 |
| Hexagonal-diamond stacking | |||||||
| 2 | SO | 10 | 72 (QD) | 0.562 | 0.527 | 0.980 | 0.961 |
| 3 | SM | 14 | 49 (D) | 0.615 | 1.049 | ||
| 4 | SO | 18 | 39 (D) | 0.578 | 1.008 | ||
| 5 | SM | 22 | 34 (D) | 0.497 | 0.914 | ||
The lattice type, the number of atoms per unit cell (N), the energy relative to cubic-diamond Si (E in meV/atom), the type of band gap, the direct band gap size (
in eV), and the indirect band gap size (
in eV) are compared for the Si(111)n/Si(SC) superlattices with the cubic- and hexagonal-stacking sequences of the Si(111) layers. The quasiparticle G0W0 gaps are also shown for comparison. Here D and QD in parentheses denote direct and quasidirect band gaps, respectively, and lattice types are abbreviated, such as SM: simple monoclinic, SO: simple orthorhombic, and BCO: base-centered orthorhombic.