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- 2080 Baisakh · 4 marks
Occupation probability 3kT above Fermi level
Short answer
Fermi-Dirac distribution f(E)=1/(1+exp((E−E_F)/kT)). With E−E_F=3kT, f=1/(1+e³)=1/21.09=0.0474, i.e., 4.74%.
Evaluate the probability that an energy state 3KT above the Fermi level will be occupied by an electron.
The probability that a state of energy is occupied by an electron is given by the Fermi–Dirac distribution function:
Given: the state is above the Fermi level, so .
Answer: , i.e. about 4.74 %.
The result does not depend on temperature, because the energy is given in units of . A state only above (about 0.078 eV at 300 K) is already rarely occupied; the probability that it is empty is .
✓ Answer checked by Claude Opus 5.5 (high effort)
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