# Lattice Softening and Band Convergence in GeTe-Based Alloys for High Thermoelectric Performance

https://mdr.nims.go.jp/datasets/925fd3a9-5824-4448-91f2-d184a97005c1

## File

- [GeTe_SONGYI_final-Sb-doped GeTe0.9I0.1.docx](https://mdr.nims.go.jp/filesets/863781d0-3c90-4735-8697-9ce750e4ad23/download) ([Detail](https://mdr.nims.go.jp/filesets/863781d0-3c90-4735-8697-9ce750e4ad23.md))

## Id

925fd3a9-5824-4448-91f2-d184a97005c1

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2024-10-05T11:11:35.966753Z

## Updated at

2024-10-07T05:41:35.656290Z

## Published at

2024-10-07T05:41:35.760113Z

## Doi

https://doi.org/10.48505/nims.4801

## First published url

https://doi.org/10.1021/acsami.4c09683

## Date published

2024-09-04

## Recorded date published

2024-9-4

## Resource type

journal_article

## Manuscript type

authors_original

## Collection



## Title

- title: Lattice Softening and Band Convergence in GeTe-Based Alloys for High Thermoelectric
    Performance
  title_type: original
  lang: en

## Description

- description: "GeTe-based alloys have been studied as promising TE materials in the
    mid-temperature range, as a lead-free alternate to PbTe due to their non-toxicity.
    Our previous study on GeTe1-xIx revealed that I-doping increases lattice anharmonicity
    and decreases the structural phase transition temperature, consequently enhancing
    thermoelectric performance. Our current work elucidates the synergistic interplay
    between band convergence and lattice softening, resulting in an enhanced thermoelectric
    performance for Ge1-ySbyTe0.9I0.1 (y=0.10, 0.12, 0.14, and 0.16). Sb doping in
    GeTe0.9I0.1 serves a double role: firstly, it leads to lattice softening, thereby
    reducing lattice thermal conductivity; secondly, it promotes a band convergence,
    thus a higher valley degeneracy. The presence of lattice softening is corroborated
    by an increase in the internal strain ratio observed in XRD patterns. Doping also
    introduces phonon scattering centers, further diminishing lattice thermal conductivity.
    Additionally, variations in the electronic band structure are indicated by an
    increase in density of state effective mass and a decrease in carrier mobility
    with Sb concentration. Besides, Sb doping\r\noptimizes the carrier concentration
    efficiently. Through a two-band modeling and electronic band structure calculations,
    the valence band convergence due to Sb doping can be confirmed. Specifically,
    the energy difference between valence bands progressively narrows upon Sb doping
    in Ge1-ySbyTe0.9I0.1 (y=0, 0.02, 0.05, 0.10, 0.12, 0.14, and 0.16). As a culmination
    of these effects, we have achieved a significant enhancement in \U0001D467\U0001D447
    for Ge1-ySbyTe0.9I0.1 (y=0.10, 0.12, 0.14, and 0.16) across the entire range of
    measured temperatures. Notably, the sample with y=0.12 exhibits the highest \U0001D467\U0001D447
    value of 1.70 at 723K."
  description_type: abstract
  lang: und

## Creator

- name: Song Yi Back
  role: author
  orcid: https://orcid.org/0009-0000-8890-1484
  organization: National Institute for Materials Science
- name: Hyunyong Cho
  role: author
  organization: National Institute for Materials Science
- name: Wenhao Zhang
  role: author
  organization: National Institute for Materials Science
- name: Takao Mori
  role: author
  orcid: https://orcid.org/0000-0003-2682-1846
  organization: National Institute for Materials Science
- name: Jong-Soo Rhyee
  role: author

## Contact agent



## Publisher

organization: American Chemical Society (ACS)

## Managing organization



## Keyword

- subject: thermoelectric
  schema: not_defined

## Rights

- description: This document is the unedited Author’s version of a Submitted Work
    that was subsequently accepted for publication in ACS Applied Materials & Interfaces,
    copyright © 2024 American Chemical Society after peer review. To access the final
    edited and published work see https://doi.org/10.1021/acsami.4c09683
  identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: ACS Applied Materials & Interfaces
  issn: '19448252'
  volume: '16'
  issue: '35'
  start_page: 46363
  end_page: 46373

## Conference



## Related item



## Funding

- identifier: JPMJMI19A1
  funder_name: JST-Mirai Program
- identifier: NRF-2022M3C1A3091988
  funder_name: National Research Foundation of Korea

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



## Software



## Custom property



## Fileset

- id: 863781d0-3c90-4735-8697-9ce750e4ad23
  filename: GeTe_SONGYI_final-Sb-doped GeTe0.9I0.1.docx
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  size: 2246862
  md5: f14224716bf7442a7e02da84c7d6fbdb

## Thumbnail

fileset_id: 863781d0-3c90-4735-8697-9ce750e4ad23
filename: GeTe_SONGYI_final-Sb-doped GeTe0.9I0.1.docx