High Figure-of-Merit Macro-Structured Thermoelectric Materials

Period of Performance: 06/17/2015 - 06/17/2016


Phase 1 STTR

Recipient Firm

MicroXact, Inc.
1750 Kraft Drive, Suite 1007 Array
Blacksburg, VA 24060
Firm POC
Principal Investigator

Research Institution

Virginia Polytechnic Institute
Sponsored Programs 0170
Blacksburg, VA 24061
Institution POC


Thermoelectric devices are critical to multiple NASA missions for power conversion with radioisotope sources. At present, commercially available TE devices typically offer limited heat-to-electricity conversion efficiencies, well below the fundamental thermodynamic limit, calling for the development of higher efficiency materials. The team of MicroXact Inc. and Virginia Tech is proposing to develop a revolutionary high efficiency thermoelectric material fabricated on completely new fabrication principles. The proposed material and device will provide NASA with much needed highly efficient (ZT>1.6), macroscopically thick (from 100s of micrometers to over a millimeter) thermoelectric material that will permit >15% conversion efficiency of thermoelectric generation when using high grade space-qualified sources. The proposed material is comprised of PbTe/PbSe three-dimensional "wells" of PbTe/PbSe quantum dot superlattices (QDS) fabricated by a conformal coating of a structured silicon substrate with electrochemical Atomic Layer Deposition (eALD). In Phase I of the project the feasibility of the approach will be demonstrated by proving ZT>1.6. In Phase II the team will fabricate the thermoelectric generator, and will demonstrate conversion efficiencies exceeding 15%. After Phase II, MicroXact will commercialize the technology.