Thermoelectric transport in heterogeneous medium: the role of thermal boundary resistance

¹ AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, P.R. China
² LTCS, College of Engineering, Peking University, Beijing 100087, P.R. China
³ Department of Mechanical Engineering, University of Washington, Seattle, WA 98195-2600, USA

^a e-mail: haofengokli@126.com

Received: 25 February 2012
Revised: 27 April 2012
Accepted: 4 May 2012
Published online: 6 June 2012

Abstract

To investigate the effect of thermal boundary resistance (TBR) on thermoelectric transport, the discontinuity in temperature is considered at the interface through Kapitza’s definition. The effect depends on two factors: the length of thermoelectric element and the value of TBR. More importantly, it is found that TBR has dramatic impact on the reduction in thermoelectric conversion efficiency, which decays exponentially with increasing TBR. The ratio of thermal boundary resistance to the length of thermoelectric element leading to the decrease of effective Seebeck coefficient largely accounts for the degradation of thermoelectric performance at the micro-scale.