The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals

The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to th...

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Main Authors: Mudd, G.W., Molas, M.R., Chen, X., Zólyomi, V., Nogajewski, K., Kudrynskyi, Zakhar R., Kovalyuk, Zakhar D., Yusa, G., Makarovsky, Oleg, Eaves, Laurence, Potemski, M., Fal'ko, V.I., Patanè, Amalia
Format: Article
Published: Nature Publishing Group 2016
Online Access:https://eprints.nottingham.ac.uk/38958/
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author Mudd, G.W.
Molas, M.R.
Chen, X.
Zólyomi, V.
Nogajewski, K.
Kudrynskyi, Zakhar R.
Kovalyuk, Zakhar D.
Yusa, G.
Makarovsky, Oleg
Eaves, Laurence
Potemski, M.
Fal'ko, V.I.
Patanè, Amalia
author_facet Mudd, G.W.
Molas, M.R.
Chen, X.
Zólyomi, V.
Nogajewski, K.
Kudrynskyi, Zakhar R.
Kovalyuk, Zakhar D.
Yusa, G.
Makarovsky, Oleg
Eaves, Laurence
Potemski, M.
Fal'ko, V.I.
Patanè, Amalia
author_sort Mudd, G.W.
building Nottingham Research Data Repository
collection Online Access
description The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to the family of vdW layered crystals, which transforms from a direct to an indirect band gap semiconductor as the number of layers is reduced. We investigate this direct-to-indirect bandgap crossover, demonstrate a highly tuneable optical response from the near infrared to the visible spectrum with decreasing layer thickness down to 2 layers, and report quantum dot-like optical emissions distributed over a wide range of energy. Our analysis also indicates that electron and exciton effective masses are weakly dependent on the layer thickness and are significantly smaller than in other vdW crystals. These properties are unprecedented within the large family of vdW crystals and demonstrates the potential of InSe for electronic and photonic technologies.
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spelling nottingham-389582020-05-04T18:24:37Z https://eprints.nottingham.ac.uk/38958/ The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals Mudd, G.W. Molas, M.R. Chen, X. Zólyomi, V. Nogajewski, K. Kudrynskyi, Zakhar R. Kovalyuk, Zakhar D. Yusa, G. Makarovsky, Oleg Eaves, Laurence Potemski, M. Fal'ko, V.I. Patanè, Amalia The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to the family of vdW layered crystals, which transforms from a direct to an indirect band gap semiconductor as the number of layers is reduced. We investigate this direct-to-indirect bandgap crossover, demonstrate a highly tuneable optical response from the near infrared to the visible spectrum with decreasing layer thickness down to 2 layers, and report quantum dot-like optical emissions distributed over a wide range of energy. Our analysis also indicates that electron and exciton effective masses are weakly dependent on the layer thickness and are significantly smaller than in other vdW crystals. These properties are unprecedented within the large family of vdW crystals and demonstrates the potential of InSe for electronic and photonic technologies. Nature Publishing Group 2016-12-23 Article PeerReviewed Mudd, G.W., Molas, M.R., Chen, X., Zólyomi, V., Nogajewski, K., Kudrynskyi, Zakhar R., Kovalyuk, Zakhar D., Yusa, G., Makarovsky, Oleg, Eaves, Laurence, Potemski, M., Fal'ko, V.I. and Patanè, Amalia (2016) The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals. Scientific Reports, 6 (39619). pp. 1-10. ISSN 2045-2322 http://www.nature.com/articles/srep39619 doi:10.1038/srep39619 doi:10.1038/srep39619
spellingShingle Mudd, G.W.
Molas, M.R.
Chen, X.
Zólyomi, V.
Nogajewski, K.
Kudrynskyi, Zakhar R.
Kovalyuk, Zakhar D.
Yusa, G.
Makarovsky, Oleg
Eaves, Laurence
Potemski, M.
Fal'ko, V.I.
Patanè, Amalia
The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title_full The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title_fullStr The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title_full_unstemmed The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title_short The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals
title_sort direct-to-indirect band gap crossover in two-dimensional van der waals indium selenide crystals
url https://eprints.nottingham.ac.uk/38958/
https://eprints.nottingham.ac.uk/38958/
https://eprints.nottingham.ac.uk/38958/