You must have heard the term semiconductor, especially if you are from a science background. But what exactly a semiconductor is? Well, to define it in simple terms, a semiconductor is a crystalline solid which can conduct electricity. Semiconductors are sued for the production of a wide variety of electronic devices like transistors, diodes, smartphones and more. Semiconductors have unique electrical properties because of which they can be sued in the production of electrical devices. Silicon is the most common material that is used in the production of a semiconductor. The process of manufacturing a semiconductor is quite lengthy and complicated.
Semiconductors are divided into two classes. The first is an intrinsic semiconductor and the second is an extrinsic semiconductor. By intrinsic semiconductor we mean, the semiconductor which doesn’t come with any impurities. It is because of this reason that it has a very low conductivity level. Whereas when it comes to the extrinsic semiconductor, it does contain some amounts of suitable metallic impurities. Unlike intrinsic semiconductors, it has a high conductivity level.
Also, there are other types of semiconductor known as the N-type and the P-type. By N-type semiconductors we mean, the semiconductors that contain an excess of electrons. However, as far as p-type semiconductors are concerned, they are known to have a shortage of electrons.
Semiconductors are known to contain certain special properties which make them useful in an electronic device. Semiconductors have a resistivity higher than an insulator but less than a conductor. Also, the current conducting property of semiconductor changes when a suitable impurity is added to it. The resistance of a semiconductor rises with a decrease in temperature and vice versa. These are all the basic properties of a semiconductor. Apart from these semiconductors also come with certain electrical properties which makes it good for electrical devices.
Well, now you know the properties of a semiconductor which makes it good enough for electrical devices. It’s because of its electrical properties that semiconductors are used in the production of various electrical devices.
The world of metals and non-metals surrounds us. Iron, copper, aluminum are a few of the commonly used metals, whereas rubber, plastic, ceramic, etc., are some of the non-metals used daily. Metals are generally very good conductors of electricity, whereas the non-metals are mostly insulators. But there remain certain substances like silicon, germanium, etc., which do not conduct electricity in their pure state. When certain impurities are added to them, they start conducting electricity. At lower temperatures, the semiconductors have higher resistivity (i.e., lower conductivity), but as the temperature rises, their resistivity decreases, and they start conducting electricity.
Semiconductors are of two types, depending on the type of impurities added to them.
n-type semiconductors are formed when a semiconducting material like silicon, germanium, etc., is doped with a pentavalent impurity like phosphorus and arsenic.
The majority of charge carriers are electrons.
p-type semiconductors are formed when we use trivalent impurities like aluminum or boron for doping. The majority of charge carriers are holes.
Now the properties of semiconductors make them useful in electronic devices.
Semiconductors are free from filaments, and hence no energy is wasted in heating the filaments for electrons emission.
Semiconductors do not require to be heated up and, hence, set into action immediately as the circuit is switched.
No rattling noise is produced when the semiconductor is in action.
Semiconductors are shockproof.
Semiconductors are pocket-friendly and are easily available.
Semiconductors require a very low voltage for operation.
The circuits which are developed using semiconductors are very compact.
Semiconductors have an unlimited lifetime.
When compared to vacuum tubes, semiconductors do not have any vacuum deterioration trouble.
Semiconductors have very low interelectrode capacitances, which makes them useful in high-frequency devices.
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