Predicted band structures of III-V semiconductors in the wurtzite phase

While non-nitride III-V semiconductors typically have a zinc-blende structure, they may also form wurtzite crystals under pressure or when grown as nanowhiskers. This makes electronic structure calculation difficult since the band structures of wurtzite III-V semiconductors are poorly characterized. We have calculated the electronic band structure for nine III-V semiconductors in the wurtzite phase using transferable empirical pseudopotentials including spin-orbit coupling. We find that all the materials have direct gaps. Our results differ significantly from earlier ab initio calculations, and where experimental results are available (InP, InAs, and GaAs) our calculated band gaps are in good agreement. We tabulate energies, effective masses, and linear and cubic Dresselhaus zero-field spin-splitting coefficients for the zone-center states. The large zero-field spin-splitting coefficients we find may facilitate the development of spin-based devices.

Figure 1

(Color online) (a) Staggered configurations of atom-1 as viewed along [111] for ZB. (b) Eclipsed configuration of atom-1 as viewed along [111] for WZ. Note that nine out of the 12 second-nearest neighbors are in the same position. The other three are rotated by $\pi /3$. (c) Brillouin zone for ZB. (d) Brillouin zone for WZ. $\Gamma$ is at the center of the Brillouin zones.

Figure 2

(Color online) Schematic showing the correspondence between energy levels at the $L$ and $\Gamma$ points in ZB and the $\Gamma$ point in WZ with and without spin-orbit coupling (Ref. 37). The dashed lines show the correspondence between the states. Additional degenerate levels are shown in gray.

Figure 3

(Color online) (a) Zero-field Dresselhaus spin splitting in WZ along $k_x$ for a ${\Gamma }_7$ conduction band. (b) The zero-field spin splitting is not seen along the $k_z$ direction.

Figure 4

(Color online) (a) Calculated band structure for AlP in wurtzite phase. (b) Calculated DOS.

Figure 5

(Color online) (a) Calculated band structure for AlAs in wurtzite phase. (b) Calculated DOS.

Figure 6

(Color online) (a) Calculated band structure for AlSb in wurtzite phase. (b) Calculated DOS.

Figure 7

(Color online) (a) Calculated band structure for GaP in wurtzite phase. (b) Calculated DOS.

Figure 8

(Color online) (a) Calculated band structure for GaAs in wurtzite phase. (b) Calculated DOS.

Figure 9

(Color online) (a) Calculated band structure for GaSb in wurtzite phase. (b) Calculated DOS.

Figure 10

(Color online) (a) Calculated band structure for InP in wurtzite phase. (b) Calculated DOS.

Figure 11

(Color online) (a) Calculated band structure for InAs in wurtzite phase. (b) Calculated DOS.

Figure 12

(Color online) (a) Calculated band structure for InSb in wurtzite phase. (b) Calculated DOS.