We know that a semiconductor have two types of charge carriers – free electrons and holes. Motion of electrons in a conductor is well-known to us. So, we can expect the similar motion of electrons in a semiconductor too. But, how do holes move in a semiconductor? Let’s check it in this post. Here, we are going to discuss what is a hole in semiconductor, How are holes produced and movement of holes in semiconductors.
People also ask
- What is hole in semiconductor?
- Define hole in semiconductor.
- How the holes produce in semiconductor?
- How can a hole move in semiconductor?
What is a hole in Semiconductor?
Holes are not the physical objects. They are the absence of electrons. When an electron jumps to the conduction band from the valence band of a semiconductor crystal, a vacant place arises in the valence band. This vacant place is called a hole.
There are so many examples like this –
- Darkness is the absence of light.
- Cold or coolness is the absence of heat.
As an electron has negative charge, the absence of electron is the reduction of negative charge by the same amount as the charge of an electron. That means the vacant place will have the positive charge which is equal to the charge of electron. Therefore, the charge of a hole is positive and the amount of charge of a hole is equal to that of an electron.
How is a hole produced in semiconductor crystal?
If you supply heat to a semiconductor crystal, electrons absorbs heat energy and get excited. After getting a sufficient amount of energy, electrons jump to the conduction band from the valence band. As a result, vacant places arise in the valence band due to absence of those electrons. Those vacant places are nothing but the holes. This is how holes produce in a semiconductor crystal .
How the holes move in a semiconductor crystal?
In above, we learn that hole is not a physical object. So, it cannot move. But we use the term like “the movement of hole causes current flow in semiconductor”. Lets understand what is the fact.
Actually, a hole is a vacant place or the absence of electron in valence band. Again, a semiconductor crystal has large number of electrons in the valence band. Let there is a hole or a vacant place at point A. Now, if an electron comes from point B to fill the vacant at point A, an vacant will arise at point B. Then we can say that the vacant place or the hole moved from point A to point B. Thus, the movement of holes is nothing but the movement of electrons in opposite direction.
This is all from this post on how do holes move in semiconductors. If you have any question related to this, you can ask me in the comment section.
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