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Semiconductor |
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A group of materials that conduct electricity better than an insulator but less efficient than metal conductors.
Elements commonly used as semiconductors include silicon, germanium and selenium.
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Doping process |
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Process of adding small amounts of foreign atoms such as antimony and boron atoms.
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Types of semiconductors
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- n-type semiconductor
- Silicone (4 valence electrons) is doped with pentavalent atoms such as antimony, phosphorus or arsenic to increase the number of free electrons.
 - This silicone has electrons as the majority charge carrier.
- p-type semiconductor
- Silicone is doped with trivalent atoms such as boron, indium and gallium which have more positive holes.
 - This silicone has a positive hole as the majority charge carrier.
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Semiconductor diode |
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It is obtained when the p-type and n-type semiconductors are combined.
It acts as a tool that allows the current to flow in one direction only.
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The diode works in two ways:
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- Forward-biased
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The depletion layer shrinks, R decreases
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The junction voltage decreases
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The supplied V is higher than the junction voltage
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Current flows
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Reverse-biased
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The depletion layer thickens, R increases
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The junction voltage increases
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The supplied V is lower than the junction voltage
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Current does not flow
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