N-type semiconductor facts for kids
An N-type semiconductor is a special material used in electronics, like in your phone or computer. It's made by adding tiny bits of another material, called an impurity, to a pure semiconductor like silicon or germanium. This impurity is often phosphorus or arsenic. We call these impurities donors because they "donate" or give away extra electrons. These extra electrons help the material conduct electricity much better than it could before. Think of it like adding more lanes to a highway to let more cars (electrons) pass through!
Contents
What is an N-type Semiconductor?
Materials like silicon and germanium are called semiconductors. They are special because they can sometimes conduct electricity and sometimes not. Each atom of silicon or germanium has four electrons in its outer shell. This outer shell is called the valence shell. These four electrons are busy forming strong connections, called bonds, with nearby atoms. Because of these bonds, there are not many free electrons available to move around and carry electricity.
How N-type Semiconductors are Made
To make an N-type semiconductor, we add a very small amount of an impurity. These impurities are special elements that have five electrons in their outer shell. Examples include phosphorus or arsenic. When these impurities are added to silicon, four of their five electrons form bonds with the silicon atoms.
This leaves one electron from the impurity atom completely free! This free electron is not tied down in a bond. Since electrons have a negative charge, and we now have many free negative charges, the material is called an N-type (or negative type) semiconductor. The process of adding these impurities is called doping, and the impurity itself is called a dopant.
Why are they called 'N-type'?
The "N" in N-type stands for "negative". This is because the extra charge carriers in this material are electrons. Electrons carry a negative electrical charge. By adding the impurities, we create many more free electrons. These free electrons can easily move through the material, making it much better at conducting electricity.
Related Pages
