Jump to main content
Jump to site search

Issue 3, 2020
Previous Article Next Article

Ir6In32S21, a polar, metal-rich semiconducting subchalcogenide

Author affiliations

Abstract

Subchalcogenides are uncommon, and their chemical bonding results from an interplay between metal–metal and metal–chalcogenide interactions. Herein, we present Ir6In32S21, a novel semiconducting subchalcogenide compound that crystallizes in a new structure type in the polar P31m space group, with unit cell parameters a = 13.9378(12) Å, c = 8.2316(8) Å, α = β = 90°, γ = 120°. The compound has a large band gap of 1.48(2) eV, and photoemission and Kelvin probe measurements corroborate this semiconducting behavior with a valence band maximum (VBM) of −4.95(5) eV, conduction band minimum of −3.47(5) eV, and a photoresponse shift of the Fermi level by ∼0.2 eV in the presence of white light. X-ray absorption spectroscopy shows absorption edges for In and Ir do not indicate clear oxidation states, suggesting that the numerous coordination environments of Ir6In32S21 make such assignments ambiguous. Electronic structure calculations confirm the semiconducting character with a nearly direct band gap, and electron localization function (ELF) analysis suggests that the origin of the gap is the result of electron transfer from the In atoms to the S 3p and Ir 5d orbitals. DFT calculations indicate that the average hole effective masses near the VBM (1.19me) are substantially smaller than the average electron masses near the CBM (2.51me), an unusual feature for most semiconductors. The crystal and electronic structure of Ir6In32S21, along with spectroscopic data, suggest that it is neither a true intermetallic nor a classical semiconductor, but somewhere in between those two extremes.

Graphical abstract: Ir6In32S21, a polar, metal-rich semiconducting subchalcogenide

Back to tab navigation

Supplementary files

Article information


Submitted
06 Nov 2019
Accepted
02 Dec 2019
First published
10 Dec 2019

This article is Open Access
All publication charges for this article have been paid for by the Royal Society of Chemistry

Chem. Sci., 2020,11, 870-878
Article type
Edge Article

Ir6In32S21, a polar, metal-rich semiconducting subchalcogenide

J. F. Khoury, J. He, J. E. Pfluger, I. Hadar, M. Balasubramanian, C. C. Stoumpos, R. Zu, V. Gopalan, C. Wolverton and M. G. Kanatzidis, Chem. Sci., 2020, 11, 870
DOI: 10.1039/C9SC05609B

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

Reproduced material should be attributed as follows:

  • For reproduction of material from NJC:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
  • For reproduction of material from PCCP:
    [Original citation] - Published by the PCCP Owner Societies.
  • For reproduction of material from PPS:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
  • For reproduction of material from all other RSC journals:
    [Original citation] - Published by The Royal Society of Chemistry.

Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.


Social activity

Search articles by author

Spotlight

Advertisements