CH1012
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9
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-
