Difference between Extrinsic and Intrinsic Semiconductor
Semiconductors are materials that have electrical conductivity between that of conductors and insulators. They are the foundation of modern electronics, from microchips to solar panels. Semiconductors are divided into two categories: extrinsic and intrinsic. In this article, we will explore the difference between the two.
Intrinsic Semiconductor
An intrinsic semiconductor is a pure form of semiconductor that is made of a single element, such as silicon, germanium, or diamond. It has a perfectly balanced number of electrons and holes, which means that it has no impurities. Intrinsic semiconductors are sometimes referred to as undoped semiconductors.
Because of their pure form and perfect balance of electrons and holes, intrinsic semiconductors have a relatively low level of electrical conductivity. However, their conductivity can be increased by subjecting them to high temperatures or by adding impurities.
Extrinsic Semiconductor
An extrinsic semiconductor is a semiconductor that has been doped with impurities. Impurities are atoms of a different element that are added to the semiconductor in order to change its electrical properties. Extrinsic semiconductors are also known as doped semiconductors.
There are two types of impurities that can be added to an extrinsic semiconductor: n-type and p-type. N-type impurities have extra electrons, which means that they have a negative charge. P-type impurities have missing electrons, which means that they have a positive charge.
When n-type and p-type semiconductors are combined, they create a p-n junction. A p-n junction is the basis of many electronic devices, including diodes, transistors, and solar cells.
The Difference between Intrinsic and Extrinsic Semiconductors
The main difference between intrinsic and extrinsic semiconductors is the presence of impurities. Intrinsic semiconductors are pure and have no impurities, while extrinsic semiconductors have been doped with impurities.
Another difference between the two is their level of conductivity. Intrinsic semiconductors have a relatively low level of conductivity, while extrinsic semiconductors can have a much higher level of conductivity, depending on the type and amount of impurities that have been added.
In conclusion, both intrinsic and extrinsic semiconductors play an important role in modern electronics. Intrinsic semiconductors are used in their pure form, while extrinsic semiconductors are used in combination with impurities to create specific electrical properties. Understanding the difference between the two is important for anyone who wants to understand how semiconductors work and how they are used in electronic devices.
Table difference between extrinsic and intrinsic semiconductor
| Property | Extrinsic Semiconductor | Intrinsic Semiconductor |
|---|---|---|
| Dopants Added | Dopants are intentionally added to the semiconductor to alter its electrical properties. | No dopants are added to the semiconductor. |
| Conductivity | Can be either n-type (more free electrons) or p-type (more holes) depending on the type of dopant added. | Depends on temperature and bandgap energy. |
| Charge Carriers | Have either excess electrons (n-type semiconductor) or holes (p-type semiconductor) which contribute to conductivity. | The number of charge carriers is determined by the temperature and bandgap energy. |
| Applications | Extrinsic semiconductors are used extensively in electronics such as transistors, diodes and integrated circuits. | Intrinsic semiconductors are used mainly as test material to study the fundamental principles of semiconductors. |