Thermo-emf anisotropy and thermoefficiency parameter of the elastically deformed germanium and silicon with different doping levels

The thermo-emf anisotropy and the thermoefficiency parameter are the most important characteristics that determine the suitability of thermoelectrically anisotropic materials for their practical use. Such characteristics determine the voltage generated by the anisotropic thermoelement, and the second one determines its efficiency coefficient. In this work, the features of changes in the thermo-emf anisotropy and the thermoefficiency parameter of the elastically deformed germanium and silicon crystals at 85 K depending on their doping level were investigated. It was revealed that in the case of a low doping level, the thermo-emf anisotropy of the deformed n-Si crystals exceeds Da of n-Ge crystals more than 4 times. It was shown that a rapid decrease in Da for n-Si is observed with an increase in the doping level. A qualitative similarity is obtained between the changes in the thermoefficiency parameter for elastically deformed germanium and for silicon with an increase in the charge carrier concentration; although in the case of n-Ge the maximum Za is much larger and is achieved at the higher doping level than in the case of n-Si. The results obtained can be useful in calculating effects based on the theory of anisotropic scattering in a wide range of concentrations.