Doping in Semiconductors - in ECET Physics (Chapter Electronics)

 What is Doping in Semiconductors:

• Doping is the process of adding impurities to a semiconductor material to change its electrical properties.
• The impurities are usually atoms of another element with one extra or one less electron than the atoms of the semiconductor material. 
• Doping can increase the number of charge carriers in a semiconductor, making it more conductive.

a. Extrinsic Semiconductors:

• Semiconductors that have been intentionally doped with impurities are called extrinsic semiconductors. 
• The impurities change the number of charge carriers in the semiconductor, which affects its electrical conductivity. 
• Extrinsic semiconductors are used in electronic devices such as transistors and diodes.

b. P-Type and N-Type Semiconductors:

• Doping can create two types of extrinsic semiconductors: p-type and n-type. 
• P-type semiconductors are created by adding impurities that have fewer electrons than the atoms of the semiconductor material, creating holes in the valence band. 
• N-type semiconductors are created by adding impurities that have one extra electron than the atoms of the semiconductor material, creating extra electrons in the conduction band. 
• P-type and n-type semiconductors are used together in electronic devices such as solar cells, where they can generate an electric current by absorbing light.