configuration
1.The atoms electrons orbit the nucleus in a specific shell
2. each shell has a predefined capacity and is always filled from the inside(a) shell to outer shell, or valence shell
3. The number of electrons in valence shell determines how the atom depart react with separate atoms
The atoms with four valence electrons are not changeless and will tend to combine chemically with other atoms to acheive a stable state. This menas that the atom will try to obtain 8 electrons in its valence shell. This process of sharing electrons is called covalent attachmenting.
N fount SEMI-CONDUCTORS
manufacturers introduce specific impurities into the semiconductor material in narrate to change their electrical characteristics. This process called doping. Doping changes the crystals electrical characteristics by simplification the internal resistance of the crystal. Materials dope with impurities containing excess electrons (five- arsenic) are called N type semiconductors. In N tpe semiconductors the electrons are called the majority postman and any free holes introduced is caled the nonage carrier.
P TYPE SEMICONDUCTORS
Materials doped with impurities containing less valence electrons (three - atomic number 13) are called P type semiconductors.
When aluminium is used to dope silicon crystals, an incomplete covalent bond is formed. This missing bond in the crystal acts as convinced(p) charge and attractive free electrons. These positive charges can be thought of as holes and move through the crystal rightful(prenominal) as electrons do but in the opposite direction.In P tpe semiconductors the holes are called the majority carrier and any free electrons introduced is caled the minority carrier.
Thermal effects
The warmness increases the number of minority carriers. As heat enters the crystal, electrons gain more energy and break their covalent bond. all(prenominal) broken bond perplexs a free electron and a free hole and therefore be said to produce carriers in pairs. This increase the number of...If you want to get a full essay, order it on our website: Ordercustompaper.com
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