In this work two solar cell designs have been investigated in order to improve the properties of the backside of Germanium TPV cells. In the first design, Aluminum is used as the backside contact and acts as a back surface field (BSF). The second design combines a dielectric mirror of a-Si/SiO 2 with Al laser-fired point contacts (LFC). This dielectric mirror features high infrared reflection and excellent electrical passivation of the germanium back surface. Lifetime values up to 420 s have been achieved on a Germanium wafer with a resistivity of 0.5-1.5 .cm. For both solar cell designs an efficiency of 16 % has been achieved assuming a microstructured tungsten emitter spectrum at 1100°C with an incident radiation density of 2.5 W/cm2.
