Work

Thermoelectric property enhancement via pore confinement in template grown bismuth telluride nanowire arrays

Year: 2017

Type: article

Abstract: Nanostructuring of thermoelectric materials can lead to thermal-to-electrical conversion efficiencies comparable with mechanical energy conversion. Theory predicts that characteristic length scales of <10 nm are necessary to achieve high thermoelectric figures of merit ( zT > 3). While sub-10 nm diameter nanowire arrays have been difficult to fabricate, we present here a novel template for sub-10 nm thermoelectric nanowire array fabrication using anodized aluminum oxide followed by silica wall coating for pore confinement. Electrodeposited bismuth telluride nanowires displayed increasing electrical-to-thermal conductivity ratio as the pore diameter decreased, in agreement with theoretical predictions. Achieving the desired stoichiometric ratio of Bi 2 Te 3 through electrodeposition was non-trivial, which limited the Seebeck coefficient of the nanowires. However, hydrolysis of the nanopore walls led to improved electrodeposition, achieving near stoichiometric bismuth-to-tellurium ratios and ultimately p-type thermoelectric nanowire arrays with a Seebeck coefficient of up to 79 μ V K −1 .

Source: Nanotechnology

DOI: 10.1088/1361-6528/aa9733

Authors: Ryan D Reeves, Leigh A Crosser, Gregory E Chester, Justin J Hill

Institution: Mainstream Engineering Corporation (United States)

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: bronze

Funders: U.S. Department of Defense, Naval Air Systems Command, Naval Air Warfare Center, Aircraft Division