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CH1012
n-TYPE
SEMICONDUCTORS
There
are two types of extrinsic semiconductors in
widespread use in the semiconductor industry.
widespread use in the semiconductor industry.
n- type Semiconductors : negative charge carriers.
• eg. P dopant atoms are added to
Si
P: has 5 valence e- Si: has 4 valence e-
P: has 5 valence e- Si: has 4 valence e-
•Each P adds an extra electron to the
solid.
•A new energy level called a donor band forms at the bottom
of the conduction band.
•The extra P
electrons (1 per
atom) are
found in the donor
band and so the
conductivity
increases.
electrons (1 per
atom) are
found in the donor
band and so the
conductivity
increases.
e-
e-
