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(C) The conductivity of a semiconductor is given by $\sigma = e(n_e \mu_e + n_h \mu_h)$.As the temperature increases,the number density of charge carr

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number density of charge carriers increases,relaxation time decreases,but the effect of the decrease in relaxation time is much less than the increase in number density

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(C) The conductivity of a semiconductor is given by $\sigma = e(n_e \mu_e + n_h \mu_h)$.As the temperature increases,the number density of charge carriers ($n_e$ and $n_h$) increases exponentially according to the relation $n = C T^{3/2} \exp(-E_g / 2kT)$.Although the relaxation time $(	au)$ decreases with an increase in temperature due to increased scattering,the exponential increase in the number density of charge carriers far outweighs the decrease in mobility caused by the reduction in relaxation time.Therefore,the net effect is an increase in the conductivity of the semiconductor.

The conductivity of a semiconductor increases with an increase in temperature because

Similar Questions

Carbon, silicon, and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $(E_g)_C$, $(E_g)_{Si}$, and $(E_g)_{Ge}$ respectively. Which one of the following relationships is true in their case?

The forbidden energy band gaps in conductors,semiconductors,and insulators are $E_{G1}$,$E_{G2}$,and $E_{G3}$ respectively. The relation among them is:

The band gap in Germanium and Silicon in $eV$ respectively is

Assertion: If the temperature of a semiconductor is increased,then its resistance decreases.
Reason: The energy gap between the conduction band and the valence band is very small.

What type of semiconductor is $CdS$?

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