Features of thermoelectromotive force in Au/p-Ge junctions [and detection of microwave power]

We demonstrate the experimental fact that in Au/p-Ge junctions which are annealed at temperatures close to that of eutectic, the voltage-power characteristic of thermoelectromotive force in microwave electric fields deviates from the linear law. Even more, at certain range of lattice temperatures it becomes non-monotonical and, in definite range of electric fields, the inversion of its sign is observed. We attribute this phenomenon to the hole cooling effect in microwave electric fields. Experiments at various lattice temperatures and in transverse magnetic fields confirmed the validity of the model suggested. The essence of the hole cooling effect in germanium is described and possible features for the application are considered.