TABLE OF CONTENTS GaSb is an intermediate-gap semiconductor, since its gap of 0.8 eV is neither as wide as that of GaAs and InP nor as narrow as that of InAs and InSb. It is particularly interesting as a substrate material because it is lattice matched to solid solutions of various ternary and quaternary III-V compounds whose bandgaps cover a wide spectral range from 0.3 to 1.58 eV (i.e., 0.8 4.3 ?m), as has been shown in Figure 7.2. GaSb, AlSb, and InAs and their related compounds form a nearly lattice-matched family of semiconductors known as the 6.1 family, because the lattice constants of these material are about a = 6.1 . The physical properties of GaSb are summarized in Table 7.5.
| Lattice constant ( ) | 6.094 |
| Density (g/cm 3) | 5.61 |
| Melting point (K) | 985 |
| Expansion coefficient | 6.2 10 -6 |
| Thermal conductivity(WK -1cm -1) | 0.4 |
| Energy gap (eV) | 0.725 at 300K 0.822 at OK |
| Spin-orbit splitting energy, ? 0 (eV) | 0.76 |
| Electron mobility (cm 2 N s) | 5,000 at 300K |
| Hole mobility (cm 2/V s) | 880 at 300K 2,400 at 77K |
| Electron effective mass | 0.042 m 0 |
| Hole effective mass | |
| Heavy hole mass | 0.28 m 0 |
| Light hole mass | 0.05 m 0 |
| Spin-orbit split mass | 0.13 m 0 |
| LO phonon energy at zone center | 28.8 meV |
| TO phonon energy at zone center | 27.7 meV |
| Refractive index | 3.84... |
