Band Gap Temperature-Dependence and Exciton-Like State in Copper Antimony Sulphide, CuSbS2

Andriy Zakutayev; Adam Welch; Max Birkett; Christopher Savory; Mohana Rajpalke; Wojciech Linhart; Thomas Whittles; James Gibbon; Ivona Mitrovic; David Scanlon; Tim Veal

doi:10.1063/1.5030207

Band Gap Temperature-Dependence and Exciton-Like State in Copper Antimony Sulphide, CuSbS2

Andriy Zakutayev, Adam Welch, Max Birkett, Christopher Savory, Mohana Rajpalke, Wojciech Linhart, Thomas Whittles, James Gibbon, Ivona Mitrovic, David Scanlon, Tim Veal

Materials Science

Research output: Contribution to journal › Article › peer-review

15 Scopus Citations

Abstract

The temperature-dependence of the band gap of the proposed photovoltaic absorber copper antimony sulphide (CuSbS₂) has been studied by Fourier-transform infrared spectroscopy. The direct gap rises from 1.608 to 1.694 eV between 300 and 4.2 K. Below 200 K an exciton-like feature develops above the absorption edge at 1.82 eV. First-principles calculations evaluate band structure, band symmetries, and dipole selection rules, suggesting distinctly enhanced absorption for certain excitonic optical transitions. Striking consistency is seen between predicted dielectric and absorption spectra and those determined by ellipsometry, which reveal rapidly strengthening absorption passing 10⁵ cm^-1 at 2.2 eV. These results suggest beneficial photovoltaic performance due to strong optical absorption arising from unusually strong electron-hole interactions in polycrystalline CuSbS₂ material.

Original language	American English
Article number	084904
Number of pages	9
Journal	APL Materials
Volume	6
Issue number	8
DOIs	https://doi.org/10.1063/1.5030207 https://doi.org/10.1063/1.5030207
State	Published - 2018

Bibliographical note

Publisher Copyright:
© 2018 Author(s).

NREL Publication Number

NREL/JA-5K00-71226

Keywords

absorption spectroscopy
band gap
band structure
dielectrics
electromagnetic transitions
excitons
optical absorption
solar energy

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https://www.nrel.gov/docs/fy18osti/71226.pdf

Cite this

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title = "Band Gap Temperature-Dependence and Exciton-Like State in Copper Antimony Sulphide, CuSbS2",

abstract = "The temperature-dependence of the band gap of the proposed photovoltaic absorber copper antimony sulphide (CuSbS2) has been studied by Fourier-transform infrared spectroscopy. The direct gap rises from 1.608 to 1.694 eV between 300 and 4.2 K. Below 200 K an exciton-like feature develops above the absorption edge at 1.82 eV. First-principles calculations evaluate band structure, band symmetries, and dipole selection rules, suggesting distinctly enhanced absorption for certain excitonic optical transitions. Striking consistency is seen between predicted dielectric and absorption spectra and those determined by ellipsometry, which reveal rapidly strengthening absorption passing 105 cm-1 at 2.2 eV. These results suggest beneficial photovoltaic performance due to strong optical absorption arising from unusually strong electron-hole interactions in polycrystalline CuSbS2 material.",

keywords = "absorption spectroscopy, band gap, band structure, dielectrics, electromagnetic transitions, excitons, optical absorption, solar energy",

author = "Andriy Zakutayev and Adam Welch and Max Birkett and Christopher Savory and Mohana Rajpalke and Wojciech Linhart and Thomas Whittles and James Gibbon and Ivona Mitrovic and David Scanlon and Tim Veal",

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year = "2018",

doi = "10.1063/1.5030207",

language = "American English",

volume = "6",

journal = "APL Materials",

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T1 - Band Gap Temperature-Dependence and Exciton-Like State in Copper Antimony Sulphide, CuSbS2

AU - Zakutayev, Andriy

AU - Welch, Adam

AU - Birkett, Max

AU - Savory, Christopher

AU - Rajpalke, Mohana

AU - Linhart, Wojciech

AU - Whittles, Thomas

AU - Gibbon, James

AU - Mitrovic, Ivona

AU - Scanlon, David

AU - Veal, Tim

PY - 2018

Y1 - 2018

N2 - The temperature-dependence of the band gap of the proposed photovoltaic absorber copper antimony sulphide (CuSbS2) has been studied by Fourier-transform infrared spectroscopy. The direct gap rises from 1.608 to 1.694 eV between 300 and 4.2 K. Below 200 K an exciton-like feature develops above the absorption edge at 1.82 eV. First-principles calculations evaluate band structure, band symmetries, and dipole selection rules, suggesting distinctly enhanced absorption for certain excitonic optical transitions. Striking consistency is seen between predicted dielectric and absorption spectra and those determined by ellipsometry, which reveal rapidly strengthening absorption passing 105 cm-1 at 2.2 eV. These results suggest beneficial photovoltaic performance due to strong optical absorption arising from unusually strong electron-hole interactions in polycrystalline CuSbS2 material.

AB - The temperature-dependence of the band gap of the proposed photovoltaic absorber copper antimony sulphide (CuSbS2) has been studied by Fourier-transform infrared spectroscopy. The direct gap rises from 1.608 to 1.694 eV between 300 and 4.2 K. Below 200 K an exciton-like feature develops above the absorption edge at 1.82 eV. First-principles calculations evaluate band structure, band symmetries, and dipole selection rules, suggesting distinctly enhanced absorption for certain excitonic optical transitions. Striking consistency is seen between predicted dielectric and absorption spectra and those determined by ellipsometry, which reveal rapidly strengthening absorption passing 105 cm-1 at 2.2 eV. These results suggest beneficial photovoltaic performance due to strong optical absorption arising from unusually strong electron-hole interactions in polycrystalline CuSbS2 material.

KW - absorption spectroscopy

KW - band gap

KW - band structure

KW - dielectrics

KW - electromagnetic transitions

KW - excitons

KW - optical absorption

KW - solar energy

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U2 - 10.1063/1.5030207

DO - 10.1063/1.5030207

M3 - Article

AN - SCOPUS:85048326270

SN - 2166-532X

VL - 6

JO - APL Materials

JF - APL Materials

IS - 8

M1 - 084904

ER -

Band Gap Temperature-Dependence and Exciton-Like State in Copper Antimony Sulphide, CuSbS2

Abstract

Bibliographical note

NREL Publication Number

Keywords

Access to Document

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