Types of Transistors
The transistor are of two types:
- NPN: when a p-type is sandwiched between two n-type, the resulting transistor is a n-p-n transistor. Here N denotes N-doped semiconductor.
- PNP : A p-n-p transistor is obtained by sandwiching a n-type semiconductor between two p-type semiconductors. Here P denotes P-doped semiconductor.
In 2006, Walter de Heer and his team had successfully built an all-graphene transistors. The graphene is one atom thick pure carbon layer.
The advantage of using graphene as a substitute is that it offer very little resistance to the flow of electrons so it can perform large number of operations without heating much and moreover it is good thermal conductor so the heat can be dissipated from it very quickly.