High efficiency semimetal/semiconductor nanocomposite thermoelectric materials

Journal Article · Wed Dec 15 04:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3514145· OSTI ID:21537989

Zide, J M. O. ^[1]; Bahk, J -H; Zeng, G; Bowers, J E ^[2]; Singh, R; Zebarjadi, M; Bian, Z X; Shakouri, A ^[3]; Lu, H; Gossard, A C ^[4]; Feser, J P; Xu, D; Singer, S L; Majumdar, A ^[5]

---

1. Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716 (United States)
2. Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)
3. Jack Baskin School of Engineering, University of California, Santa Cruz, California 95064 (United States)
4. Department of Materials, University of California, Santa Barbara, California 93106 (United States)
5. Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States)

Rare-earth impurities in III-V semiconductors are known to self-assemble into semimetallic nanoparticles which have been shown to reduce lattice thermal conductivity without harming electronic properties. Here, we show that adjusting the band alignment between ErAs and In{sub 0.53}Ga{sub 0.47-X}Al{sub X}As allows energy-dependent scattering of carriers that can be used to increase thermoelectric power factor. Films of various Al concentrations were grown by molecular beam epitaxy, and thermoelectric properties were characterized. We observe concurrent increases in electrical conductivity and Seebeck coefficient with increasing temperatures, demonstrating energy-dependent scattering. We report the first simultaneous power factor enhancement and thermal conductivity reduction in a nanoparticle-based system, resulting in a high figure of merit, ZT=1.33 at 800 K.

• OSTI ID: 21537989
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 108; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOY SYSTEMS
ALLOYS
ALUMINIUM COMPOUNDS
ARSENIC ALLOYS
ARSENIC COMPOUNDS
COMPOSITE MATERIALS
CRYSTAL GROWTH METHODS
DIMENSIONLESS NUMBERS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRICITY
ENERGY DEPENDENCE
EPITAXY
ERBIUM ALLOYS
FILMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
MATERIALS
MOLECULAR BEAM EPITAXY
NANOSTRUCTURES
PHYSICAL PROPERTIES
POWER FACTOR
QUATERNARY ALLOY SYSTEMS
RARE EARTH ADDITIONS
RARE EARTH ALLOYS
SEMICONDUCTOR MATERIALS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
THERMOELECTRIC MATERIALS
THERMOELECTRIC PROPERTIES
THERMOELECTRICITY