Modeling and theoretical efficiency of a silicon nanowire based thermoelectric junction with area enhancement

M. Seong, J. S. Sadhu, J. Ma, M. G. Ghossoub, S. Sinha

Research output: Contribution to journalArticlepeer-review

Abstract

Recent experimental work suggests that individual silicon nanowires with rough surfaces possess a thermoelectric figure of merit as high as 0.6 near room temperature. This paper addresses the possibility of using an array of such nanowires in a thermoelectric junction for generation. Employing a model of frequency dependent phonon boundary scattering, we estimate the effective thermal conductivity of the array and investigate heat flow through the junction. We show that charge transport is largely unaffected by the roughness scales considered. Enhancing the area for heat exchange at an individual 200 μm 200×m p-n junction yields significant temperature differences across the junction leading to power >0.6 mW and efficiency >1.5% for a junction with effective thermal conductivity <5 WmK, when the source and sink are at 450 K and 300 K, respectively. We show that relatively short nanowires of ∼50 μm length are sufficient for obtaining peak power and reasonable efficiency. This substantially reduces the challenge of engineering low resistivity electrical contacts that critically affect power and efficiency. This paper provides insight into how fundamental transport in relation to bulk heat transfer and charge transport, affects the performance of thermoelectric junctions based on nanostructured materials.

Original languageEnglish (US)
Article number124319
JournalJournal of Applied Physics
Volume111
Issue number12
DOIs
StatePublished - Jun 15 2012

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Modeling and theoretical efficiency of a silicon nanowire based thermoelectric junction with area enhancement'. Together they form a unique fingerprint.

Cite this