Does the resistance of a semiconductor increases as temperature increases and difference between P type and n-type semiconductor?
Conductivity of doped semiconductors usually passes through a maximum and a (shallow) minimum as temperature increases.
For, e.g., boron in Si, the boron accepts electron from Si to produce a hole p:
B B(-) + p(+) .
At high temperatures, the equilibrium is completely shifted to the right (endothermic process), and every boron atom present produces a hole; the number of carriers, [p], is thus fixed to the total B (saturation); the specific conductivity per carrier, however, decreases with the temperature (like in metals).
At lower temperature, boron is only partially ionized, and the 'degree of dissociation' alpha increases with temperature - initially exponentially (freeze-out). The conductivity in this region increases proportionally to [p] = alpha*(total B).
At very high temperatures, the intrinsic conductivity starts to dominate, i.e. Si starts to produce e(-) and p(+) - another exponential growth region.
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