In this article we will discuss about the types of semiconductors. We learn about N type and P type semiconductor working. We know about the main type of semiconductor.
Types of Semiconductors
There are two types of semiconductors which are...
1. Intrinsic semiconductors
2. Extrinsic semiconductors
1. Intrinsic semiconductos
An intrinsic semiconductor is one which is pure. With no impurities. It has equal numbers of negative carriers. It has equal number of negative carriers and positive carriers. For example, a silicon crystal is an intrinsic semiconductor because every atom in the crystal is a silicon atom.
For knowing better about types of semiconductors, we need to know about formation of Holes
Formation of Holes
In an intrinsic semiconductor, when we provide sufficient that, then a valance electron of an element is moved away from the covalent bond and the covalent bond is broken and that electron becomes a free electron to move in a crystal. When this electron breaks a covalent bond moves away, a is known as hole. In other words, when a free electron is released, a hole is formed. It is the one of the main types of semiconductor.
2. Extrinsic Semiconductor
An extrinsic semiconductor is the one which is made by adding impurities to an intrinsic semiconductor. The conductivity of a semiconductor can easily be modified by introducing the impurities into their crystal lattice. The process of adding controlled impurities to a semiconductor is called doping.
Based on the impurities added to the semiconductors, the two types of semiconductors are possible, that is N-type semiconductor and P-type semiconductor.
For knowing more about types of semiconductor we need know about N and P types of semiconductor and their working.
A semiconductor with surplus of electrons is known is known as N-type semiconductor. To obtain excess free electron, the elements such arsenic, antimony or phosphorous are doped in the semiconductor material. Each donor atom has 5 electrons (pentavailent) in its outer orbit.
When a donor atom replaces an atom in the crystal lattice, only four electrons are shared with the surrounding atoms. The fifth, valences becomes a free electron as shown in figure. As in the N-type semiconductors, the number of free electrons is greater than the number of holes so, the free electrons are the majority carriers and the holes are minority carriers.
P-types of semiconductors
A P-type semiconductor has surplus of holes. It is made by doping an element (accepter impurity) with semiconductor material. The elements like gallium, born or indium (trivalent) are the main accept-or impurities.
Hence it is the main types of semiconductors and their working. If you will find any incorrect above please comment below in comment box.
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