2018/01/12 by Yoshiaki Nakamura · 2 citations
Materials Science · Engineering · #Advanced Thermoelectric Materials and Devices #Thermal properties of materials #Thermal Radiation and Cooling Technologies #Materials science #Thermal conductivity #Thermoelectric materials #Phonon scattering #Thermoelectric effect #Nanodot #Phonon #Optoelectronics #Scattering #Silicon #Nanostructure #Thermal conduction #Amorphous solid #Nanotechnology #Electrical resistivity and conductivity #Condensed matter physics #Composite material #Optics #Crystallography #Electrical engineering
paper · pdf · doi:10.1080/14686996.2017.1413918
openalex publication_date 2018/01/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/21
The design and fabrication of nanostructured materials to control both thermal and electrical properties are demonstrated for high-performance thermoelectric conversion. We have focused on silicon (Si) because it is an environmentally friendly and ubiquitous element. High bulk thermal conductivity of Si limits its potential as a thermoelectric material. The thermal conductivity of Si has been reduced by introducing grains, or wires, yet a further reduction is required while retaining a high electrical conductivity. We have designed two different nanostructures for this purpose. One structure is connected Si nanodots (NDs) with the same crystal orientation. The phonons scattering at the interfaces of these NDs occurred and it depended on the ND size. As a result of phonon scattering, the thermal conductivity of this nanostructured material was below/close to the amorphous limit. The other structure is Si films containing epitaxially grown Ge NDs. The Si layer imparted high electrical conductivity, while the Ge NDs served as phonon scattering bodies reducing thermal conductivity drastically. This work gives a methodology for the independent control of electron and phonon transport using nanostructured materials. This can bring the realization of thermoelectric Si-based materials that are compatible with large scale integrated circuit processing technologies.