Physical Properties
| Material | GaAs | InP | GaN |
| Crystal structure | Zinc blende | Zinc blende | Wurtzite |
| Lattice constant (300K) | 5.654 Å | 5.869 Å |
(a) 4.189 Å (c) 5.125 Å |
| Atomic density (300K) | 4.43 ×10²² cm⁻³ | 3.96 ×10²² cm⁻³ | 8.9 ×10²² cm⁻³ |
| Melting point | 1238 °C | 1060 °C | 2500 °C |
| Density (300K) | 5.315 g cm⁻³ | 4.81 g cm⁻³ | 6.15 g cm⁻³ |
| Linear thermal expansion coeffi cient (300K) | 6.03 ×10⁻⁶ K⁻¹ | 4.60 ×10⁻⁶ K⁻¹ |
(a) 5.59 ×10⁻⁶ K⁻¹ (c) 3.17 ×10⁻⁶ K⁻¹ |
| Thermal lattice conductivity (300K) | 0.48 W cm⁻¹ K⁻¹ | 0.68 W cm⁻¹ K⁻¹ | 1.3 W cm⁻¹ K⁻¹ |
| Specific heat (300K) | 0.325 J g⁻¹ K⁻¹ | 0.31 J g⁻¹ K⁻¹ | 0.49 J g⁻¹ K⁻¹ |
| Energy gap (300K) | 1.42 eV | 1.344 eV | 3.39 eV |
| Electron mobility (300K) | 8800 cm² V⁻¹ s⁻¹ | 5400 cm² V⁻¹ s⁻¹ | 1000 cm² V⁻¹ s⁻¹ |
| Hole mobility (300K) | 450 cm² V⁻¹ s⁻¹ | 200 cm² V⁻¹ s⁻¹ | 200 cm² V⁻¹ s⁻¹ |
| Effective electron mass | 0.068 m₀ | 0.08 m₀ | 0.20 m₀ |
| Elastic constants C11 C44 C12 |
11.88 ×10¹⁰ Pa 5.49 ×10¹⁰ Pa 5.38 ×10¹⁰ Pa |
10.11 ×10¹⁰ Pa 5.61 ×10¹⁰ Pa 4.56 ×10¹⁰ Pa |
29.6 ×10¹⁰ Pa 2.41 ×10¹⁰ Pa 13.0 ×10¹⁰ Pa |
| Mohs hardness | 4.5 | 4.0 | 8.0 |
| Vickers hardness for (0.05 .. 1) N | 6.52 ×10⁹ Pa | 3.94 ×10⁹ Pa | 10.2 ×10⁹ Pa |
Band Structure of GaAs
Phase Diagram of GaAs
Homogeneity Region of GaAs (detail of phase diagram)