Member • Oct 16, 2012
Is Carbon a Semiconductor? It's Complicated!
I think there is a lot of confusion over whether Carbon is a semiconductor or not. Let me answer this question for you. But let me tell you the answer is not straightforward.
What is a Semiconductor?
In the simplest terms, a semiconductor is a type of material that is neither a good conductor of electricity (like metals) nor a poor conductor (like insulators). Semiconductors fall somewhere in the middle of this spectrum.
The most common semiconductors you might be familiar with are silicon and germanium, and they are fundamental to our electronic devices.
Now, let's talk about carbon. Carbon is a very versatile element, and it can be found in various forms, each with distinct properties. Two well-known forms of carbon are diamond and graphite.
Diamond, which is a form of carbon where each carbon atom is connected to four other carbon atoms in a tetrahedral lattice structure, is actually an excellent insulator. This means that it doesn't conduct electricity well because its electrons are not free to move around.
On the other hand, graphite, which is a form of carbon where the atoms are arranged in sheets of a hexagonal lattice, is a good conductor of electricity. This is due to the presence of "delocalized" electrons that are free to move within the layers.
However, neither of these forms of carbon is a semiconductor in the traditional sense.
They don't have the property where their conductivity can be significantly altered by adding small amounts of impurities (a process called "doping"), which is a key characteristic of semiconductors.
That being said, there is a form of carbon that behaves as a semiconductor: carbon nanotubes. These are tiny tube-shaped structures made of carbon atoms, and their properties can range from being similar to metals to being semiconductors, depending on their structure and geometry.
Furthermore, graphene, a single layer of carbon atoms arranged in a 2D honeycomb lattice, also exhibits some interesting properties. Its behavior is somewhat unique and doesn't fit neatly into the categories of conductor, insulator, or semiconductor.
It behaves more like a semi-metal or zero-gap semiconductor, given its unique electronic structure where the conduction and valence bands meet at the Fermi level.
So, in summary: not all forms of carbon are semiconductors, but certain forms of carbon (like certain types of carbon nanotubes) can exhibit semiconductive properties.
And graphene, while not a typical semiconductor, has unique electronic properties that make it of great interest to the field of electronics.
