Thermoelectric properties of Ge/Si heterostructures: A combined theoretical and experimental study

• DOI: 10.1002/pssa.201532486
• Publication Date: 2015-11-30T10:02:44Z
• Authors: Gregor Fiedler; Lukas Nausner; Yang Hu; Peixuan Chen; Armando Rastelli; Peter Kratzer
• Keywords: 02 engineering and technology; Physik (inkl. Astronomie); 0210 nano-technology

We present a combined experimental and theoretical investigation of the thermoelectric properties p-doped Ge/Si superlattices grown on Si(001) substrates by molecular beam epitaxy. Electrical conductivity is measured both in direction parallel perpendicular to interfaces means modified transfer length method. Electronic transport strongly anisotropic, with cross-plane being about five times lower than plane. This result very good agreement predictions based tight-binding method Boltzmann equation applied experimentally investigated structure. The thermal doped differential 3 compared that undoped alloys similar average Ge content. comparison reveals have reduced conduction alloys, doping increases their 50%. Considering used level, this increase appears surprising. Seebeck coefficient structures addressed theoretically displays less pronounced anisotropy electric conductivity. Combined knowledge other parameters, we conclude that, while Si/Ge may be as model systems for nanostructured materials, relevance application limited.