Extrinsic Semiconductors

Extrinsic semiconductors are the type of semiconductor which are doped with impurities. They are intentionally modified to have different electrical properties. Doping introduces extra electrons or electron-deficient areas called holes, which influence how well the material conducts electricity and help regulate the flow of current in electronic circuits.

Doping in Extrinsic Semiconductors

Doping means adding impurities on purpose to change how a semiconductor works. In extrinsic semiconductors, two types of impurities are commonly added through the process of doping:

N-Type doping: Donor impurities, such as phosphorus or arsenic, are added to increase the concentration of electrons, leading to enhanced conductivity

P-Type doping: Acceptors like boron or gallium are used as impurities, which make gaps in the material. This boosts the number of charge carriers and changes how they conduct electricity.

Types of Extrinsic Semiconductors Based on Doping:

1. N-Type Semiconductors: In N-Type Semiconductors some elements are added from Group 15 of the periodic table, like phosphorus or arsenic. Because these impurities have more valence electrons than the atoms in the semiconductor crystal, they introduce extra electrons into the crystal structure. These extra electrons become the majority charge carriers, significantly enhancing the material’s conductivity.

2. P-Type Semiconductors: In P-type semiconductors, elements are added from Group 13 of the periodic table, like boron or gallium to make holes in the material. These elements have fewer valence electrons than the atoms in the semiconductor crystal. As a result, they create “holes” in the crystal structure where electrons are missing. These holes become the majority of charge carriers in P-type materials.

Semiconductors are unique materials that possess moderate conductivity, falling between conductors and insulators. The conductivity of semiconductors proves incredibly advantageous for various applications. When we add energy to semiconductors, like heat or light, it makes some particles move around. This creates empty spots that act like positive charges known as holes. This lets electrons move and electricity flow. Transistors, integrated circuits, and diodes are made from semiconductors, which are useful. They can also be switches, amplifiers, and memory cells. They’re like the important parts that make computers, phones, and many other cool things that have changed our world.