An extrinsic semiconductor is a special type of semiconductor material purposely modified by adding certain atoms to change how it conducts electricity. These added atoms are called impurities, and they have either extra electrons (n-type) or fewer electrons (p-type) than the original semiconductor.
For n-type extrinsic semiconductors, impurities like phosphorus or arsenic, which have five electrons in their outermost layer, are mixed into the pure semiconductor. These impurities provide extra free electrons, making them the main charge carriers that enhance the semiconductor’s electrical conductivity.
On the other hand, p-type extrinsic semiconductors use impurities like boron or gallium, which have only three electrons in their outermost layer. When added to the pure semiconductor, they create “holes” in the crystal structure, which act as positive charge carriers and improve the semiconductor’s electrical conductivity.
Engineers can control the type and amount of impurities to customize the electrical properties of extrinsic semiconductors for different electronic applications. Extrinsic semiconductors serve as the foundation for developing Important electronic devices like diodes, transistors, integrated circuits (ICs), and many others that are essential to modern technology.
Also Read:
- N Type Semiconductor
- P Type Semiconductor
- Difference Between Donor and Acceptor Impurities
- Difference Between p-Type and n-Type Semiconductor
- Difference Between Intrinsic and Extrinsic Semiconductor