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.
Replies
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Abhishek RawalC-C bonds forms crystal & electrons are not obtained in crystals as they are tightly bound .Hence it is not used in semiconductor. -
lalSimply saying, there is nothing to carry the current. No free electrons or no holes. Eith valency 4, every electrons in the outermost orbit take part in the bonding.
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Jeffrey Arulraj
What exactly is the valency of Carbon thenlalSimply saying, there is nothing to carry the current. No free electrons or no holes. Eith valency 4, every electrons in the outermost orbit take part in the bonding. -
Abhishek Rawal
In Si & even in Ge, all e- takes part in formation of covalent bond.lalSimply saying, there is nothing to carry the current. No free electrons or no holes. Eith valency 4, every electrons in the outermost orbit take part in the bonding.
But due to temperature(heat) those bonds are easily broken & e- are produced, resulting in flow of e-. -
Jeffrey ArulrajYeah but can't the same thing be achieved in C it also has only four bonds and so the breaking of bonds can be done right
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Abhishek RawalNope as i said C-C covalent bond forms crystal. (eg diamond)
Current in crystal is practically impossible.
Also C6, so electronic configuration is 1s2 2s2 2p2, so more energy is required to remove an e- from the bond.The amount of energy required is not available at room temperature.
So, one of the most essential property of semiconductor is lacking. -
Jeffrey ArulrajSo more electrons must be present preferrably the d subshell to tolerate the nuclesr forces and bring down the ionisation potential
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lalCarbon as graphite is but a semiconductor, diamond is not. That means, troll, as u said the crystaline form cant conduct. Right?
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Jeffrey Arulraj
But in any cost we use crystalline Silicon but as troll said omit the crystalline carbon for the reason of higher ionisation energylalCarbon as graphite is but a semiconductor, diamond is not. That means, troll, as u said the crystaline form cant conduct. Right? -
Abhishek RawalCrystalline Carbon cant conduct.
Because C-C are tightly bounded.
But doping can change result (I am not sure though)
SiC is one eg where C is doping element in Si. -
Jeffrey Arulraj
Boss SiC is a compound used as an insulator and not as a semi conductor I am not sure either but Silicon carbide is better known for its high temperature resistance and high insulating propertiesTroll_So_HardCrystalline Carbon cant conduct.
Because C-C are tightly bounded.
But doping can change result (I am not syre though)
SiC is one eg where C is doping element in Si. -
Abhishek RawalSiC is a semiconductor which is used in high voltage semiconductor electronics.
It is also used in LEDs 'cause it emits "blue" light. -
Jeffrey ArulrajCool thanks for the info am going to know more of this now 😀
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lalPretty interesting this is.
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[Prototype]Carbon does exhibits semiconductor property but it will require a lots of energy to work. The more an electron is near to the nucleus, the stronger is the covalent bond. Since carbon has only 2 shells, the valence electrons are pretty tightly bonded, while in case of silicon, its ideal i.e. 3 shells. Germanium is not a preferred semiconductor and is used in very few applications because the valence electrons are so loosely coupled that it starts conduction even at room temperature.
To conclude,
Carbon -> Require lots of energy to work.
Silicon -> Mid range, not to high, not to low.
Germanium -> Very low.
The first and last both are not acceptable. The only reason because Germanium is used as its properties can be controlled, but in case of carbon as TSH mentioned, it just goes to form a crystalline structure. -
Jeffrey Arulrajthe Ge threshold also pays a role of it not being popular if my calculations are right the presence of d subshell has brought the break over voltage from over 8 V in C to lesser than 1 V in Si and .3 V in Ge
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sowmiya vdelectricity can conduct through carbon but it has no resistance and all electrical energy will be wasted in the form of heat and it forms crystalline structure(diamond).
the latest form of carbon which is known as graphene and it is very superior than other convention semiconductors. -
Jeffrey ArulrajGraphene is more familiar for its Piezo electric nature friend and so this is not a common replacement for Si in the semi conductor region
sowmiya vdelectricity can conduct through carbon but it has no resistance and all electrical energy will be wasted in the form of heat and it forms crystalline structure(diamond).
the latest form of carbon which is known as graphene and it is very superior than other convention semiconductors. -
sowmiya vdgraphene conducts electricity 30 times faster than silicon!!but the use of graphene as semiconductor in replacement with silicon is still under research....
link...
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Jeffrey Arulraj
Hey friend you are forgetting some thing very important if the conduction is very high then why is it not out in the market now ?sowmiya vdgraphene conducts electricity 30 times faster than silicon!!but the use of graphene as semiconductor in replacement with silicon is still under research....
link...
#-Link-Snipped-#
The reason is simple Si and Ge SiC SiAsP all are dependent on the atmospheric temperature only this makes them more predictable in their responses to a great extent the effect of external forces are absent in them
But the Graphene model as far as I know has higher conductivity but poorer stability in real world It is temperature dependent but more dependent on other external forces acting on the crystal due to piezo electric nature.This implies more stability concern extra stabilizers are needed for effective operation -
[Prototype]
Totally inter-related with what I said. What is providing voltage? Its giving external energy. What dies temperature do? It gives external energy.jeffrey samuelthe Ge threshold also pays a role of it not being popular if my calculations are right the presence of d subshell has brought the break over voltage from over 8 V in C to lesser than 1 V in Si and .3 V in Ge
Why Ge starts conduction at room temperature? Evident from neglibile threshold required i.e. 0.3 v.
Thats the reason I have writen energy to genralize it. It could be voltage or temperature. -
Jeffrey ArulrajWell true #-Link-Snipped-# the reason for it having negligible Barrier potential is that that is it no worries though
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ambrish gautamAl through carbon belongs to fourth group of periodic table, but properties of carbon are highly unstable, unpredictable . And has a energy band of more than 1.5 ev.
so sometimes carbon is the influence of temperature behave as insulator where as some times carbon works as semiconductor. So that's why we don't consider carbon as semiconductor material.
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