What is a semiconductor?
A material whose conductivity lies between conductors and insulators.
Give two examples of semiconductors.
Silicon and Germanium.
What happens to semiconductors at low temperatures?
They behave like insulators.
What is doping in semiconductors?
The process of adding impurities to increase electrical conductivity.
What is an intrinsic semiconductor?
A pure semiconductor with equal numbers of electrons and holes.
What is a hole in a semiconductor?
A vacancy left behind when an electron escapes its position.
What is an extrinsic semiconductor?
A doped semiconductor with improved conductivity.
What is a p-type semiconductor?
A semiconductor doped with trivalent atoms creating more holes than electrons.
What is an n-type semiconductor?
A semiconductor doped with pentavalent atoms creating more electrons than holes.
What is the majority carrier in a p-type semiconductor?
Holes.
What is the majority carrier in an n-type semiconductor?
Electrons.
What is a p-n junction?
A junction formed by joining p-type and n-type materials.
What is a diode?
A p-n junction device that allows current to flow in one direction.
What is forward bias?
When the positive terminal of a battery is connected to the p-region and the negative to the n-region.
What is reverse bias?
When the negative terminal is connected to the p-region and the positive to the n-region.
What does a diode do under reverse bias?
It allows minimal or no current flow (high resistance).
What is a half-wave rectifier?
A circuit using one diode to pass only one half of the AC cycle.
What is a full-wave rectifier?
A circuit using two diodes to convert both halves of the AC cycle to DC.
What is the function of a filter circuit in rectifiers?
To smoothen the fluctuations in the DC output using inductors and capacitors.
Give two advantages of p-n junction diodes over thermionic diodes.
Smaller size and no warm-up time required.
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