Semiconductors

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Physics of Electronic Devices and Circuits

1. In electronics, we have 3 primary materials used, the conductors, semiconductors, and insulators. As their names imply, those materials have different electric properties. Conductors allow easy flow of electricity. Even a small amount of electric energy can flow though it. Conductors are made from metallic elements, such as copper, silver, aluminum, and gold. Metallic elements provide very high conductivity of electricity because their atoms contain valence electrons that they can easily give up from their outer most shell. The outer most shell of metallic elements are very far from the atom's nucleus and has very few electrons, which only has 1 to 3 electrons, that is why the valence electrons can easily be knocked out of the shell when an electromotive force is applied. Applied electricity to conductors makes the valence electrons flow through the material, producing electric current and powering electric and electronic devices.

Insulators are opposite of conductors, specifically in their electric characteristics. Insulators are materials that prevent electricity from flowing through them. It will take a great amount of electric energy to force them to conduct. Insulators are made from non-conducting materials, such as rubber, wood, plastic and glass. The elements that compose those insulators are non-metallic, such as carbon. Gases are also insulators, as electricity cannot easily flow through them. The valence electrons of non-metallic elements are hard to move because their outer most shell is either stable with 8 valence electrons, the outer most shell has many electrons that are tight or it is very close to the nucleus that has very strong attractive force, which is the case for carbon. The elements of insulators have greater than 3 valence electrons. The ...