The Effects of Pressure and Temperature on the Resistance of $p-n$ Junctions in Germanium

According to Shockley's theory, the low voltage resistance, $R_0$, of a $p-n$ junction is proportional to $\exp \left(\frac{E_G}{\mathrm{kT}}\right)$, where $E_G$ is the energy gap. Measurements of the change with pressure of the characteristics of a junction in a single crystal of germanium indicate a change $\frac{\Delta R_0}{R_0}$ of 12.5 percent, corresponding to a change $\Delta E_G$ of about 3.1×${10}^{-3\mathrm{}}$ ev, for a pressure change of 10,000 lbs/${\mathrm{in}}^2$. Analysis of measurements made at temperatures between 16.5°C and 20.5°C give values of $E_G$ averaging about 0.72 ev. These values are in agreement with those obtained from the change in intrinsic resistivity with temperature and pressure.