why is n-p-n transistor preferred over p-n-p transistor???
NPN transistors are preferred over PNP transistors because of the following reasons:
- The mobility of electrons in N type of material is more than the mobility of holes in P type material.
- Silicon is used to make N type semiconductors. Since it is found abundantly in nature, NPN transistors are preferred.
1. NPN transistors have two n-regions, n-type region is formed from silicon which is abundant in nature. Moreover n-type conductivity offers less leakage current.
2. NPN is mostly used because in npn electron current is greater the hole current, whereas in pnp hole current is greater than electron current.