adminSEMICONDUCTORS
Semiconductors are materials which have conductivity in between conductors which are generally metals and non-conductors or insulators such as ceramics.
There are various types of semiconductor material and they are; elemental semiconductors, compound semiconductors and alloy semiconductors.
Elemental semiconductors are made from a single element such as silicon (si) or germanium (Ge).
Compound semiconductors are made from a combination of two or more elements such as gallium arsenide (GaAs) or indium phosphide (InP).
Alloy semiconductors are made from a mixture of two or more elements such as silicon-germanium (SiGe) or alluminium gallium arsenide (AlGaAs).
Also semiconductors can be classified as intrinsic and extrinsic conductors.
Intrinsic types of semiconductors are made up of very pure materials chemically. That is they are made up of single elements such as germanium (Ge) and silicon (Si).
Extrinsic semiconductors are semiconductors are semiconductors that has been formed by doping, that is by adding impurities or a small number of suitable replacement atoms to the material.
Semiconductors work by using a combination of electrons and holes to control the flow of electric current. Holes and electrons are the types of charge carriers used for the flow of current or electrons in semiconductors. Holes are positively charged electric charge carriers whereas electrons are negatively charged particles. When a semiconductor is exposed to an electric field the electrons and the holes move in opposite directions, creating an electric current.
Conversely when sunlight hits a semiconductor material it excites the electrons in the material causing them to flow freely. Thus the energy from sunlight creates electron-hole pairs in the semiconductor material, since the electrons are negatively charged while the holes are positively charged. The electrons flow through the semiconductor material creating electric current.
The advantages of semiconductors are; semiconductors can switch on and off very quickly making them ideal for high speed electronic devices. Semiconductors can operate at very low power levels making them suitable for battery powered devices. Semiconductors are highly reliable and can withstand extreme temperatures and other environmental stresses. Semiconductors are very small making them ideal for use in compact electronic devices. Semiconductors are relatively inexpensive to produce, making them cost effective solution for many electronic devices.
The disadvantages of semiconductors are semiconductors can be sensitive to temperature and light changes, which can affect their performance. Semiconductors can be prone to oxidation which can affect their performance over time. Semiconductors require special handling and storage to prevent damages. Semiconductors can be difficult to manufacture requiring specialized equipment and expertise.
Semiconductors find application in a variety of devices and equipment. Semiconductors are used in the production of computers, smartphones, cameras and other electronic devices. Semiconductors are used in the production of solar panels which converts sunlight into electricity. Semiconductors are used in the production of LED lights which are energy efficient and long lasting. Semiconductors are used to produce various devices and components for a variety of industries such as automobile, medical, industrial automation and so on.
The prediction for the future of semiconductors is based on the trends and the development in the following technologies; electrical and electronics technology, computing and information technology, solar technology, space technology, telecommunication and other technologies too numerous to mention especially in the development of more efficient and effective semiconductor material.
SOURCES:
- Semiconductor devices: physics and technology by S.M Sze and M.K Lee.
- Semiconductor physics and devices by Doald A. Neamen.
- The physics of semiconductors by Maurius Grundmann.
- Semiconductor materials and devices by S.O. Kasnap.
- Handbook of semiconductor manufacturing technology by Robert Doering and Yoshio Nishi.
