Formula Energy band gap of germanium (temperature dependence)

$$E_{\text g} ~=~ 0.742\,\text{eV} - 3.90 \cdot 10^{-4} \, \frac{ \text{eV} }{ \text{K} } \cdot T$$ $$E_{\text g} ~=~ 0.742\,\text{eV} - 3.90 \cdot 10^{-4} \, \frac{ \text{eV} }{ \text{K} } \cdot T$$

Energy gap

$ E_{\text g} $ Unit $ \text{eV} $

Energy gap of germanium (Ge), that is, the energy gap between the valence band maximum and conduction band minimum..

Energy band gap of germanium for three different temperatures.
Temperature $T$	Energy gap $E_{\text g}$
0 K	0.742 eV
300 K	0.625 eV
1000 K	0.352 eV

This formula for the temperature dependence of the band gap is an experimental fit.

Temperature

$ T $ Unit $ \text{K} $

Temperature of the germanium material in Kelvin. The band gap increases linearly with temperature.