Geometrical Structure Optimization Design of High-Performance Bi2Te3-Based Artificially Tilted Multilayer Thermoelectric Devices

• DOI: 10.1007/s11664-020-08324-2
• Publication Date: 2020-07-22T17:03:46Z
• Authors: Yuzheng Li; Ping Wei; Hongyu Zhou; Xin Mu; Wanting Zhu; Xiaolei Nie; Xiahan Sang; Wenyu Zhao
• Keywords: Thermoelectric cooling; Thermoelectric generator

Artificially tilted multilayer thermoelectric devices (ATMTDs) are a kind of thermoelectric device that can directly convert heat into electricity based on transverse thermoelectric effect. Although the devices have a simplified multilayer structure, their geometrical optimization is a complicated task. In this work, n-type Bi2Te2.7Se0.3 and p-type Bi0.1Sb1.9Te3 materials, which have the most important commercial applications in conventional thermoelectric devices, were selected as the component materials to assemble a promising high-performance Bi2Te3-based ATMTD. A numerical analysis method was employed to optimize the device length, device width, and thickness of the component materials. The results revealed that a large device width/length ratio, a small device aspect ratio, and a small thickness of component materials are favorable for achieving a high conversion efficiency. The temperature and charge distributions inside the ATMTD are studied based on finite element simulation. The nonuniform distribution of temperature field inside the device strongly depends on the thermal conductivity of component materials. The accumulation of a transverse electric field, accompanied with the cancellation of longitudinal electric field, is a consequence of different electric field distributions in the two component materials. This work provides a better understanding on the anisotropic electrical and thermal transport behaviors in transverse thermoelectric devices.