Pressure dependence of the direct energy gap in germanium

Abstract

The pressure dependence of the energy gap corresponding to allowed optical transitions in germanium has been measured at room temperature and pressures up to 7000 kg/cm 2. This direct energy gap is found to increase at a rate of 1.3 ± 0.1 × 10 −5 eV cm 2/ kg, in agreement with previous approximate determinations and with the pressure coefficient of the same energy gap in group 3–5 compounds.