Ge/SiGe superlattices for nanostructured thermoelectric modules

Autor: Jacopo Frigerio, Daniel Chrastina, James P. Hague, Elisabeth Müller, Tanja Etzelstorfer, Stefano Cecchi, L. Ferre Llin, J. Stangl, Giovanni Isella, Douglas J. Paul, Antonio Samarelli
Rok vydání: 2013
Předmět:
Zdroj: Thin Solid Films. 543:153-156
ISSN: 0040-6090
DOI: 10.1016/j.tsf.2013.01.002
Popis: Thermoelectrics are presently used in a number of applications for both turning heat into electricity and also for using electricity to produce cooling. Mature Si/SiGe and Ge/SiGe heteroepitaxial growth technology would allow highly efficient thermoelectric materials to be engineered, which would be compatible and integrable with complementary metal oxide silicon micropower circuits used in autonomous systems. A high thermoelectric figure of merit requires that electrical conductivity be maintained while thermal conductivity is reduced; thermoelectric figures of merit can be improved with respect to bulk thermoelectric materials by fabricating low-dimensional structures which enhance the density of states near the Fermi level and through phonon scattering at heterointerfaces. We have grown and characterized Ge-rich Ge/SiGe/Si superlattices for nanofabricated thermoelectric generators. Low-energy plasma-enhanced chemical vapor deposition has been used to obtain nanoscale-heterostructured material which is several microns thick. Crystal quality and strain control have been investigated by means of high resolution X-ray diffraction. High-resolution transmission electron microscopy images confirm the material and interface quality. Electrical conductivity has been characterized by the mobility spectrum technique.
Databáze: OpenAIRE
Externí odkaz: