Semimetal/Semiconductor Nanocomposites for Thermoelectrics

• Published in: Advanced materials (Weinheim) 2011-05, Vol.23 (20), p.2377-2383
• Main Authors: Lu, Hong, Burke, Peter G., Gossard, Arthur C., Zeng, Gehong, Ramu, Ashok T., Bahk, Je-Hyeong, Bowers, John E.
• Format: Article
• Language: English
• Subjects: MATERIALS SCIENCE; Metals, Rare Earth - chemistry; molecular beam epitaxy; nanocomposites; Nanocomposites - chemistry; power generator; rare earth; Semiconductors; solar (photovoltaic), solid state lighting, phonons, thermoelectric, bio-inspired, energy storage (including batteries and capacitors), electrodes - solar, defects, charge transport, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing); Temperature; thermoelectrics
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201100449

In this work, we present research on semimetal‐semiconductor nanocomposites grown by molecular beam epitaxy (MBE) for thermoelectric applications. We study several different III‐V semiconductors embedded with semimetallic rare earth‐group V (RE‐V) compounds, but focus is given here to ErSb:InxGa1‐xSb as a promising p‐type thermoelectric material. Nano­structures of RE‐V compounds are formed and embedded within the III‐V semiconductor matrix. By codoping the nanocomposites with the appropriate dopants, both n‐type and p‐type materials have been made for thermoelectric applications. The thermoelectric properties have been engineered for enhanced thermoelectric device performance. Segmented thermoelectric power generator modules using 50 μm thick Er‐containing nanocomposites have been fabricated and measured. Research on different rare earth elements for thermoelectrics is discussed. Rare‐earth doped III‐V semiconductors are engineered for use in thermoelectric power generation applications. Codeposition by molecular beam epitaxy results in embedded semimetallic nanoparticles (as seen in the illustration) that enhance the thermoelectric properties of the III‐V semiconductors. Segmented thermoelectric power generator modules are fabricated using 50 μm thick Er‐containing nanocomposite films.