Gallium Nitride (GaN) is a very hard, mechanically stable, wide bandgap semiconductor. GaN is used in light emitting diodes, lasers, sensors, high-power transistors, and high-frequency transistors. Gallium Nitride forms the wurtzite and zincblende crystal structures.
Crystal structure: Wurtzite Bravais lattice: hexagonal Space group: P63mc = 186 Point group: 6mm = C6v Molecular Weight $83.73$ g/mol Molecular density $n_{atoms}=8.9 \times 10^{22}$ 1/cm³ Density $\rho= 6.15$ g/cm³ |
The primitive GaN wurtzite unit cell contains 4 atoms.
The N atoms are positioned at $[\frac{1}{3}, \frac{2}{3}, 0]$ and $[\frac{2}{3}, \frac{1}{3}, \frac{1}{2}]$ while the Ga atoms are positioned at $[\frac{1}{3}, \frac{2}{3}, \frac{3}{8}]$ and $[\frac{2}{3}, \frac{1}{3}, \frac{7}{8}]$.
The lattice parameters of the conventional unit cell are:
$$a = 0.3180\, \text{nm}, \, b = 0.3180 \,\text{nm}, \, c = 0.5166 \,\text{nm}, \, \alpha = 90^{\circ} , \,\beta = 90^{\circ} ,\,\gamma = 120^{\circ}.$$Properties |
Wurtzite |
Zincblende |
Bandgap Eg |
3.4 eV (direct) |
3.2 eV (direct) |
Effective density of states in conduction band (300 K) Nc |
2.3 × 1024 m-3 |
1.2 × 1024 m-3 |
Effective density of states in valence band (300 K) Nv |
4.6 × 1025 m-3 |
4.1 × 1025 m-3 |
Effective mass electrons |
m* = 0.20 |
m* = 0.13 |
Effective mass holes |
mlh* = 0.3 |
mlh* = 0.19 |
Electric Breakdown Field |
3.3 × 106 V/cm |
GaN is a direct bandgap semiconductor.
Source: Rheinlander, A., Neumann, H. Plasma Faraday Rotation in n-Type GaN. Phys. Status Solidi (b) 64 (1974) K123.
https://onlinelibrary.wiley.com/toc/15213951/64/2
(1 August 1974)
Accessed: 01-02-2021