When the temperature is increased in semiconductor, the density of the charge carriers increase and the resistivity of semiconductor decreases.
The relation between resistivity and temperature is given by following equation.
ρT=ρ0[1+α(T−T0)] Where
ρ0 is the resistivity at a reference temperature
T0 and
ρT its value at temperature
T.
The factor
α is called the temperature coefficient of resistivity and the temperature coefficient is negative for semiconductor.
Hence the curve is non-linear for wide range of temperature as shown in the figure.
Hence, option (c) is represent the temperature (
T ) dependence on resistivity
(ρ) of a semiconductor.