 |
| Junction Transistor |
|
| It is a semiconductor device having two junctions and three terminals. The two types of transistors are p-n-p transistor and n-p-n junction transistors. A p-n-p transistor is obtained by sandwiching a n-type semiconductor between two p-type semiconductors. Similarly when a p-type is sandwiched between two n-type, the resulting transistor is a n-p-n transistor. |
| |
 |
| |
 |
| |
| The three regions are called emitter (E), base (b), collector (c). The direction of arrows indicate the conventional current in the above symbol. The junction between emitter and base is called emitter base (EB) junction. (The junction between base and collector is called collector base junction.) |
| |
| Emitter (E) is a heavily doped region of the device and is a supplier of majority charge carriers to the base. |
| |
| Base (B) is made thin and is lightly doped. This is done to reduce the recombination process. |
| |
| Collector (c) is moderately doped and collects majority carriers through base. |
| |
