Enhancement of thermoelectric efficiency by uniaxial tensile stress in n-type GaAs nanowires

Author

Paul, Abhijeet ; Miao, Kai ; Hegde, Ganesh ; Mehrotra, Saumitra ; Luisier, Mathieu ; Klimeck, Gerhard

Author_Institution

Sch. of Electr. & Comput. Eng. & Network for Comput. Nanotechnol., Purdue Univ., West Lafayette, IN, USA

fYear

2011

fDate

15-18 Aug. 2011

Firstpage

1352

Lastpage

1357

Abstract

The thermoelectric power-factor (PF) and efficiency (ZT) of GaAs nanowires (NWs) can be improved by (i) choosing a proper wire growth and channel orientation, (ii) by applying uniaxial tensile stress, and (iii) suitable wire cross-section size. In this work we study the impact of these three factors on the PF and the ZT. Tensile stress, channel direction and cross-section size allows bandstructure engineering to tune the electronic conductance (G) and the Seebeck coefficient (S). [110] GaAs NWs grown on (111) surface provide maximum PF (~3X) and ZT (~1.3X) compared to [100]/(100) NWs, which can be attributed to the G enhancement induced by the L valley contribution under strain.

Keywords

III-V semiconductors; Seebeck effect; band structure; electrical conductivity; gallium arsenide; nanowires; tensile strength; thermoelectric power; (111) surface; GaAs; Seebeck coefficient; bandstructure engineering; channel direction; channel orientation; electronic conductance; n-type nanowires; thermoelectric efficiency; thermoelectric power-factor; uniaxial tensile stress; wire cross-section size; wire growth; Conductivity; Gallium arsenide; Nanowires; Scattering; Strain; Thermal conductivity; Wires; GaAs; Tight-binding; thermoelectricity; uniaxial-stress;

fLanguage

English

Publisher

ieee

Conference_Titel

Nanotechnology (IEEE-NANO), 2011 11th IEEE Conference on

Conference_Location

Portland, OR

ISSN

1944-9399

Print_ISBN

978-1-4577-1514-3

Electronic_ISBN

1944-9399

Type

conf

DOI

10.1109/NANO.2011.6144525

Filename

6144525