Find the relative number of electrons with energies 0.10 eV, 1.0 eV, and 10 eV above the valence band at room temperature (293 K).
Strategy Equation (9.34) for the Fermi-Dirac factor may be used for this comparison. Note that 1.0 eV =1.60 \times 10^{-19} J. The Fermi energy is at the top of the valence band, so the energy above the valence band is E-E_{ F }.
F_{ FD }=\frac{1}{\exp \left[\beta\left(E-E_{ F }\right)\right]+1} (9.34)