Gallium arsenide vs Silicon
Gallium arsenide and Silicon are genuine alternatives to one another — a choice somebody actually makes — and differ on 2 measured properties, density most clearly.
Gallium arsenide vs Silicon
These are different kinds of thing (compound, element). Fewer properties mean the same thing across both, so a like-for-like reading may not be available.
Gallium arsenide
GaAs
The semiconductor that does what silicon cannot — emit light, and switch fast enough for a radio front end.
Silicon
Si
The second most abundant element in the Earth's crust, and the substrate of essentially all modern electronics.
| Property | Gallium arsenide | Silicon |
|---|---|---|
| Atomic number Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 14 |
| Density | 5.32 g/cm³ higher | 2.329 g/cm³ |
| Melting point | 1238 °C | 1414 °C higher |
| Molar mass Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 28.085 g/mol |
Choosing between them
Gallium arsenide is recorded as a substitute for Silicon — better at temperature, stronger.
What it gives up: No cheap native oxide, smaller and costlier wafers, and fifty years less investment — it wins only where silicon physically cannot go.
In this application, on the evidence cited above.