A) decreases exponentially with increasing band gap
B) increases exponentially with increasing band gap
C) decreases with increasing temperature
D) is independent of the temperature and the band gap
Correct Answer: A
Solution :
The fermi function \[f(E)\] gives the probability that a given available electron energy state will be occupied at a given temperature. The fermi function comes from Fermi-Dirac statistics and has the form \[f(E)=\frac{1}{{{E}^{(E-{{E}_{F}})/kT}}+1}\] The basic nature of this function dictates that at ordinary temperatures, most of the levels up to the fermi level are filled. At higher temperature, a larger fraction of the electrons can bridge this gap and participate in electrical conduction. Hence, at finite temperature, the probability decreases exponentially with increasing band gap.You need to login to perform this action.
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