Improved zT in Nb5Ge3–GeTe thermoelectric nanocomposite. Issue 2 (20th December 2021)

• Record Type: Journal Article
• Authors: Cao, Jing; Tan, Xian Yi; Jia, Ning; Lan, Da; Solco, Samantha Faye Duran; Chen, Kewei; Chien, Sheau Wei; Liu, Hongfei; Tan, Chee Kiang Ivan; Zhu, Qiang; Xu, Jianwei; Yan, Qingyu; Suwardi, Ady
• Is Part Of: Nanoscale. Volume 14:Issue 2(2022)
• Page Start: 410
• Page End: 418
• Publication Date: 2021-12-20
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d1nr06962d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Doping high electrical conductivity Nb5 Ge3 precipitates into GeTe results in nanoprecipitates phonon scattering, while retaining electrical mobility. As a result, thermoelectric zT of GeTe is drastically enhanced to 2.0 at 723 K. Abstract : Robust electronic transport properties is a crucial in designing high performance thermoelectrics. A key similarity between superconductor and thermoelectric lies in their generally high electrical conductivity, even at above its superconducting temperature. In this work, we design a nanocomposite between Nb5 Ge3 and GeTe-based thermoelectric to improve its thermoelectric figure of merit zT . Phase and microstructural characterization shows distinct Nb5 Ge3 precipitates embed in Ge0.9 Sb0.1 Te matrix. In addition, experimental electronic and thermal transport analysis, together with density functional theory calculation were employed to show the synergistic effect of doping Sb and Nb5 Ge3 nanocomposite approach. 10% Sb doping was found to optimize the electronic properties of the GeTe-based matrix. Further addition of 2 wt% Nb5 Ge3 nanocomposite to the matrix enhances the phonon scattering, which consequently lowers the lattice thermal conductivity, which results in zT of up to 2.0 at 723 K. Such superconductor nanocomposite approach shown in this work can be employed to enhance the properties of other thermoelectric materials.