CH1012
L1 /
‹#›
L1 /
7
CONDUCTIVITY
Metal –
the valence and conduction bands overlap,
there is no band gap ® high conductivity.
Conductivity decreases with temperature T
there is no band gap ® high conductivity.
Conductivity decreases with temperature T
Semiconductor -
there is a small band gap and so thermally
excited electrons will cross the gap
® low conductivity. Conductivity increases with T
® low conductivity. Conductivity increases with T
Insulator - a
large band gap ® no conductivity.
The energy gap
between the valence band and
the conduction band is usually called the band gap
the conduction band is usually called the band gap
