---
OA_type: closed access
_id: '21001'
abstract:
- lang: eng
  text: Copper chalcogenides offer high charge mobility and low lattice thermal conductivity
    but suffer from structural instability due to dynamic Cu+ migration. Here, we
    report a colloidal hot-injection synthesis of ternary cesium copper selenide (CsCu5Se3)
    nanocrystals (NCs), achieving precise control over phase, size, and morphology
    through tailored precursor-ligand modulation. This strategy enabled systematic
    exploration of stable and metastable Cs–Cu–Se phases and mechanistic investigation
    of nucleation and growth, providing insight into phase modulation and dimensional
    control at the nanoscale. CsCu5Se3 NCs exhibit low lattice thermal conductivity
    (∼0.5 Wm–1K–1) and an experimental zT of 0.27 at 718 K. Complementary first-principles
    calculations, consistent with experimental electronic and optical responses, predict
    a zT of 1.05 at 1000 K. These findings elucidate the formation dynamics of CsCu5Se3
    and establish ABZ (A = alkali, B = metal, Z = chalcogen) NCs as tunable platforms
    for advanced functional applications.
acknowledgement: This publication has emanated from research conducted with the financial
  support of Taighde Éireann-Research Ireland under Grant number 22/FFP-P/11591. C.F.
  and M.I. would like to acknowledge the financial support of ISTA and the Werner
  Siemens Foundation. N.N.P. acknowledges the financial support of AMBER under grant
  number 12/rc/2278_p2.
article_processing_charge: No
article_type: letter_note
author:
- first_name: Niraj Nitish
  full_name: Patil, Niraj Nitish
  last_name: Patil
- first_name: Ruiqi
  full_name: Wu, Ruiqi
  last_name: Wu
- first_name: Christine
  full_name: Fiedler, Christine
  id: bd3fceba-dc74-11ea-a0a7-c17f71817366
  last_name: Fiedler
- first_name: Nilotpal
  full_name: Kapuria, Nilotpal
  last_name: Kapuria
- first_name: Bingfei
  full_name: Nan, Bingfei
  last_name: 'Nan'
- first_name: Navita
  full_name: Navita, Navita
  id: 6ebe278d-ba0b-11ee-8184-f34cdc671de4
  last_name: Navita
  orcid: 0000-0001-7408-8197
- first_name: Andreu
  full_name: Cabot, Andreu
  last_name: Cabot
- first_name: Maria
  full_name: Ibáñez, Maria
  id: 43C61214-F248-11E8-B48F-1D18A9856A87
  last_name: Ibáñez
  orcid: 0000-0001-5013-2843
- first_name: Kevin M.
  full_name: Ryan, Kevin M.
  last_name: Ryan
- first_name: Alex M.
  full_name: Ganose, Alex M.
  last_name: Ganose
- first_name: Shalini
  full_name: Singh, Shalini
  last_name: Singh
citation:
  ama: 'Patil NN, Wu R, Fiedler C, et al. Layered alkali-copper selenides: Deciphering
    thermoelectric properties and reaction pathways for nanostructuring β-CsCu5Se3.
    <i>ACS Energy Letters</i>. 2026;11(1):481-488. doi:<a href="https://doi.org/10.1021/acsenergylett.5c02909">10.1021/acsenergylett.5c02909</a>'
  apa: 'Patil, N. N., Wu, R., Fiedler, C., Kapuria, N., Nan, B., Jakhar, N., … Singh,
    S. (2026). Layered alkali-copper selenides: Deciphering thermoelectric properties
    and reaction pathways for nanostructuring β-CsCu5Se3. <i>ACS Energy Letters</i>.
    American Chemical Society. <a href="https://doi.org/10.1021/acsenergylett.5c02909">https://doi.org/10.1021/acsenergylett.5c02909</a>'
  chicago: 'Patil, Niraj Nitish, Ruiqi Wu, Christine Fiedler, Nilotpal Kapuria, Bingfei
    Nan, Navita Jakhar, Andreu Cabot, et al. “Layered Alkali-Copper Selenides: Deciphering
    Thermoelectric Properties and Reaction Pathways for Nanostructuring β-CsCu5Se3.”
    <i>ACS Energy Letters</i>. American Chemical Society, 2026. <a href="https://doi.org/10.1021/acsenergylett.5c02909">https://doi.org/10.1021/acsenergylett.5c02909</a>.'
  ieee: 'N. N. Patil <i>et al.</i>, “Layered alkali-copper selenides: Deciphering
    thermoelectric properties and reaction pathways for nanostructuring β-CsCu5Se3,”
    <i>ACS Energy Letters</i>, vol. 11, no. 1. American Chemical Society, pp. 481–488,
    2026.'
  ista: 'Patil NN, Wu R, Fiedler C, Kapuria N, Nan B, Jakhar N, Cabot A, Ibáñez M,
    Ryan KM, Ganose AM, Singh S. 2026. Layered alkali-copper selenides: Deciphering
    thermoelectric properties and reaction pathways for nanostructuring β-CsCu5Se3.
    ACS Energy Letters. 11(1), 481–488.'
  mla: 'Patil, Niraj Nitish, et al. “Layered Alkali-Copper Selenides: Deciphering
    Thermoelectric Properties and Reaction Pathways for Nanostructuring β-CsCu5Se3.”
    <i>ACS Energy Letters</i>, vol. 11, no. 1, American Chemical Society, 2026, pp.
    481–88, doi:<a href="https://doi.org/10.1021/acsenergylett.5c02909">10.1021/acsenergylett.5c02909</a>.'
  short: N.N. Patil, R. Wu, C. Fiedler, N. Kapuria, B. Nan, N. Jakhar, A. Cabot, M.
    Ibáñez, K.M. Ryan, A.M. Ganose, S. Singh, ACS Energy Letters 11 (2026) 481–488.
date_created: 2026-01-18T23:02:43Z
date_published: 2026-01-09T00:00:00Z
date_updated: 2026-01-19T08:43:21Z
day: '09'
department:
- _id: MaIb
- _id: GradSch
doi: 10.1021/acsenergylett.5c02909
intvolume: '        11'
issue: '1'
language:
- iso: eng
month: '01'
oa_version: None
page: 481-488
project:
- _id: 9B8F7476-BA93-11EA-9121-9846C619BF3A
  name: 'HighTE: The Werner Siemens Laboratory for the High Throughput Discovery of
    Semiconductors for Waste Heat Recovery'
publication: ACS Energy Letters
publication_identifier:
  eissn:
  - 2380-8195
publication_status: published
publisher: American Chemical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Layered alkali-copper selenides: Deciphering thermoelectric properties and
  reaction pathways for nanostructuring β-CsCu5Se3'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 11
year: '2026'
...