Gallium arsenide vs Gallium nitride
Gallium arsenide and Gallium nitride are genuine alternatives to one another — a choice somebody actually makes — and differ on 2 measured properties, density most clearly.
Gallium arsenide vs Gallium nitride
Gallium arsenide
GaAs
The semiconductor that does what silicon cannot — emit light, and switch fast enough for a radio front end.
Gallium nitride
GaN
The semiconductor that made blue light possible, and is now making phone chargers small — a wide band gap, and thirty years of work to grow it on anything.
| Property | Gallium arsenide | Gallium nitride |
|---|---|---|
| Crystal system Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | hexagonal |
| Density | 5.32 g/cm³ | 6.15 g/cm³ higher |
| Melting point | 1238 °C | 2500 °C higher |
| Molar mass Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 83.73 g/mol |
| Refractive index Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 2.4–2.5 |
| Thermal conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 130–230 W/(m·K) |
Choosing between them
Gallium nitride is recorded as a substitute for Gallium arsenide — better at temperature, stronger.
What it gives up: Noisier and more expensive at low power, so gallium arsenide keeps the low-noise front end — a different requirement rather than a lost argument.
In this application, on the evidence cited above.