Bottom-Up (Cu, Ag, Au)/Al2O3/Bi2Te3 Assembled Thermoelectric Heterostructures

Zhenhua Wu; Shuai Zhang; Zekun Liu; Cheng Lu; Zhiyu Hu

doi:10.3390/mi12050480

Bottom-Up (Cu, Ag, Au)/Al₂O₃/Bi₂Te₃ Assembled Thermoelectric Heterostructures

Micromachines (Basel). 2021 Apr 22;12(5):480. doi: 10.3390/mi12050480.

Authors

Zhenhua Wu^{1

2

3}, Shuai Zhang^{1

2

3}, Zekun Liu^{1

2

3}, Cheng Lu^{1

2

3}, Zhiyu Hu¹

Affiliations

¹ National Key Laboratory of Science and Technology on Micro-Nano Fabrication, Shanghai Jiao Tong University, Shanghai 200240, China.
² Department of Micro/Nano-Electronics, Shanghai Jiao Tong University, Shanghai 200240, China.
³ Institute of Nano-Micro Energy, Shanghai Jiao Tong University, Shanghai 200240, China.

Abstract

The interface affects the transmission behavior of electrons and phonons, which in turn determines the performance of thermoelectric materials. In this paper, metals (Cu, Ag, Au)/Al₂O₃/Bi₂Te₃ heterostructures have been fabricated from bottom to up to optimize the thermoelectric power factor. The introducing metals can be alloyed with Bi₂Te₃ or form interstitials or dopants to adjust the carrier concentration and mobility. In addition, the metal-semiconductor interface as well as the metal-insulator-semiconductor interface constructed by the introduced metal and Al₂O₃ would further participate in the regulation of the carrier transport process. By adjusting the metal and oxide layer, it is possible to realize the simultaneous optimization of electric conductivity and Seebeck coefficient. This work will enable the optimal and novel design of heterostructures for thermoelectric materials with further improved performance.

Keywords: Bi2Te3; heterostructure; interface; metal; oxide; thermoelectric.

Grants and funding

51776126/National Natural Science Foundation of China