Development of Nanostructured Bi2Te3 with High Thermoelectric Performance by Scalable Synthesis and Microstructure Manipulations

Chhatrasal Gayner; Luke T Menezes; Yuriy Natanzon; Yaron Kauffmann; Holger Kleinke; Yaron Amouyal

doi:10.1021/acsami.2c21561

Development of Nanostructured Bi₂Te₃ with High Thermoelectric Performance by Scalable Synthesis and Microstructure Manipulations

ACS Appl Mater Interfaces. 2023 Mar 15;15(10):13012-13024. doi: 10.1021/acsami.2c21561. Epub 2023 Mar 6.

Authors

Chhatrasal Gayner¹, Luke T Menezes², Yuriy Natanzon¹, Yaron Kauffmann¹, Holger Kleinke², Yaron Amouyal¹

Affiliations

¹ Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
² Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.

PMID: 36877663
DOI: 10.1021/acsami.2c21561

Abstract

Nanostructuring of thermoelectric (TE) materials leads to improved energy conversion performance; however, it requires a perfect fit between the nanoprecipitates' chemistry and crystal structure and those of the matrix. We synthesize bulk Bi₂Te₃ from molecular precursors and characterize their structure and chemistry using electron microscopy and analyze their TE transport properties in the range of 300-500 K. We find that synthesis from Bi₂O₃ + Na₂TeO₃ precursors results in n-type Bi₂Te₃ containing a high number density (N_v ∼ 2.45 × 10²³ m^-3) of Te-nanoprecipitates decorating the Bi₂Te₃ grain boundaries (GBs), which yield enhanced TE performance with a power factor (PF) of ∼19 μW cm^-1 K^-2 at 300 K. First-principles calculations validate the role of Te/Bi₂Te₃ interfaces in increasing the charge carrier concentration, density of states, and electrical conductivity. These optimized TE coefficients yield a promising TE figure of merit (zT) peak value of 1.30 at 450 K and an average zT of 1.14 from 300 to 500 K. This is one of the cutting-edge zT values recorded for n-type Bi₂Te₃ produced by chemical routes. We believe that this chemical synthesis strategy will be beneficial for future development of scalable n-type Bi₂Te₃ based devices.

Keywords: bismuth-telluride; density functional theory; electronic and thermal transport; nanostructuring; thermoelectric materials.