NASA SBIR 2010 Solicitation


PROPOSAL NUMBER: 10-1 S3.02-8827
SUBTOPIC TITLE: Thermal Control Systems
PROPOSAL TITLE: High Coefficient of Performance HgCdTe And Metallic Superlattice-Based Thermoelectric Coolers

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
EPIR Technologies, Inc.
590 Territorial Drive
Bolingbrook, IL 60440 - 4881
(630) 771-0203

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Silviu Velicu
590 Territorial Drive
Bolingbrook, IL 60440 - 4881
(630) 771-0203

Estimated Technology Readiness Level (TRL) at beginning and end of contract:
Begin: 2
End: 6

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
We propose the development of nanoscale superlattices (SLs) as the active elements of high efficiency thermoelectric coolers.
Recent models predict that the thermoelectric figure of merit ZT can reach 4 for elements fabricated from HgCdTe-based SLs and
could exceed 6 for related metal/semiconductor SLs. The feasibility of using HgCdTe and metal-based SL materials with embedded
nanodefects for increased hot-carrier transport during thermoelectric cooling will be demonstrated in the proposed Phase 1 effort. We
will perform calculations to optimize the material parameters of HgCdTe- and metal-based SL structures to maximize ZT. Next, we will
use our extensive experience in molecular beam epitaxy to grow the designed structures. Finally, we will develop device structures
and metallization methods appropriate for performing ZT measurements, measure the ZTs of fabricated devices and compare results
with theory.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Thermoelectric coolers have long contributed to NASA missions. For example, thermoelectric devices cool HgCdTe-based infrared
imaging cameras such as those on the Hubble Space Telescope. They are employed as refrigerators in various space science
experiments. Thermal loop spacecraft temperature control systems employ them as well. The same materials also hold great
potential in thermionic energy conversion. All these applications will benefit from the improved efficiency of Hg1-xCdxTe- and
metal-based SL thermoelectric coolers, together with the already realized benefits of solid state coolers, namely reliability,
ruggedness and low cost. In particular, the possible monolithic integration of thermoelectric coolers and HgCdTe-based infrared focal
plane arrays promises major reductions in the weight, size and cost of missions employing air- and space-borne high performance
infrared imaging instruments

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
High efficiency thermoelectric coolers possess a myriad of applications including portable cooling and precise temperature control for
electronics, optics and medical systems. Present commercial thermoelectric devices operate at about 10% of the Carnot efficiency,
whereas the efficiency of a compressor-based refrigerator varies from 30% to 90% depending on the refrigerator size. The
temperature differences required in air conditioning are usually within the capacity of thermoelectric heat pumps, but their relatively
poor coefficient of performance prohibits wide deployment. An increase of the thermoelectric figure of merit ZT above 3 is needed
before thermoelectric technology can be used on large scales and potentially replace current refrigeration and air conditioning
technologies. Our proposed coolers have a predicted ZT above 3 and hence can play a major role in next generation refrigerators
and air conditioning systems.

TECHNOLOGY TAXONOMY MAPPING (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.)
Active Systems

Form Generated on 09-03-10 12:12