0What are semiconductors?
Semicondutcors are substances which have conductivity in between conductors and insulators. Example: Germanium and Silicon.
What are the types of semiconductors?
Intrinsic semiconductors: It is the purest form of semiconductors
Extrinsic semiconductors: When we add impurities to intrinsic semiconductors, they will become extrinsic semiconductors. The process of adding impurities to intrinsic semiconductor is termed as doping and the impurity added is known as dopant.
Extrinsic semiconductors are of two types:
1. n type semi conductor :These types of semiconductors are obtained by adding fifteenth group elements such as arsenic and antimony to intrinsic semi conductors like Ge and Si. As there are four electrons in the valence shell of Ge and Si, and there are five electrons in valence shell of Arsenic and Antimony, there will be an extra electron in the atom after combining. Therefore in a crystal there are so many such electrons. since electron is negative, we consider the semiconductor as an n type semiconductor(n is the first letter of negative).
2. p type semiconductor: These types of semiconductors are obtained by adding thirteenth group elements such as galium and indium to intrinsic semi conductors like Ge and Si. As there are four electrons in the valence shell of Ge and Si, and there are three electrons in valence shell of galium and indium, there will be an extra hole in the atom after combining. Therefore in a crystal there are so many such holes. since hole is positive, we consider the semiconductor as a p type semiconductor(p is the first letter of positive).
