a1 Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
a2 Department of Electrical Engineering, University of California, Los Angeles, CA 90024
a3 Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90024
a4 Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
a5 Department of Electrical Engineering and Computer Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
In bulk form, Si1-xGex is a promising thermoelectric material for high temperature applications. In this paper, we report results from an experimental study as well as theoretical modeling of the quantum confinement effect on the enhancement of the thermoelectric figure of merit. Si/Si1-xGex, multiple quantum well structures are fabricated using molecular beam epitaxy (MBE) on SOI (Silicon-on-Insulator) substrates in order to eliminate substrate effects, especially on the Seebeck coefficient. A method to eliminate the influence of the buffer layer on the thermoelectric characterization is presented. An enhancement of the thermoelectric figure of merit within the quantum well over the bulk value is observed.