CH1012
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8
SEMICONDUCTORS
A
semiconductor conducts (electricity) and the conductivity
increases with temperature.
There are two main types of semiconductors:
There are two main types of semiconductors:
1. Intrinsic -
naturally occurring eg. Si, Ge.
- empty conduction
band - filled
valence band
2. Extrinsic
- May be an insulator or intrinsic semiconductor
where the conductivity
is controlled by adding
small amounts of
impurities called
dopants to the solid
to increase the
number of mobile
charge carriers.
- May be an insulator or intrinsic semiconductor
where the conductivity
is controlled by adding
small amounts of
impurities called
dopants to the solid
to increase the
number of mobile
charge carriers.
