Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus

Bulk black phosphorus (BP) consists of puckered layers of phosphorus atoms. Few-layer BP, obtained from bulk BP by exfoliation, is an emerging candidate as a channel material in post-silicon electronics. A deep understanding of its physical properties and its full range of applications are still bei...

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Main Authors: Luo, Xin, Lu, Xin, Koon, Gavin Kok Wai, Castro Neto, Antonio H., Özyilmaz, Barbaros, Xiong, Qihua, Quek, Su Ying
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2020
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Online Access:https://hdl.handle.net/10356/140423
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1404232023-02-28T19:49:12Z Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus Luo, Xin Lu, Xin Koon, Gavin Kok Wai Castro Neto, Antonio H. Özyilmaz, Barbaros Xiong, Qihua Quek, Su Ying School of Electrical and Electronic Engineering School of Physical and Mathematical Sciences NOVITAS, Nanoelectronics Centre of Excellence Science::Physics Few Layer Black Phosphorus Raman Spectroscopy Bulk black phosphorus (BP) consists of puckered layers of phosphorus atoms. Few-layer BP, obtained from bulk BP by exfoliation, is an emerging candidate as a channel material in post-silicon electronics. A deep understanding of its physical properties and its full range of applications are still being uncovered. In this paper, we present a theoretical and experimental investigation of phonon properties in few-layer BP, focusing on the low-frequency regime corresponding to interlayer vibrational modes. We show that the interlayer breathing mode A3g shows a large redshift with increasing thickness; the experimental and theoretical results agree well. This thickness dependence is two times larger than that in the chalcogenide materials, such as few-layer MoS2 and WSe2, because of the significantly larger interlayer force constant and smaller atomic mass in BP. The derived interlayer out-of-plane force constant is about 50% larger than that of graphene and MoS2. We show that this large interlayer force constant arises from the sizable covalent interaction between phosphorus atoms in adjacent layers and that interlayer interactions are not merely of the weak van der Waals type. These significant interlayer interactions are consistent with the known surface reactivity of BP and have been shown to be important for electric-field induced formation of Dirac cones in thin film BP. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Accepted version 2020-05-29T01:01:58Z 2020-05-29T01:01:58Z 2015 Journal Article Luo, X., Lu, X., Koon, G. K. W., Castro Neto, A. H., Özyilmaz, B., Xiong, Q., & Quek, S. Y. (2015). Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus. Nano Letters, 15(6), 3931-3938. doi:10.1021/acs.nanolett.5b00775 1530-6984 https://hdl.handle.net/10356/140423 10.1021/acs.nanolett.5b00775 25939057 2-s2.0-84935886572 6 15 3931 3938 en Nano Letters This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.5b00775 application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics
Few Layer Black Phosphorus
Raman Spectroscopy
spellingShingle Science::Physics
Few Layer Black Phosphorus
Raman Spectroscopy
Luo, Xin
Lu, Xin
Koon, Gavin Kok Wai
Castro Neto, Antonio H.
Özyilmaz, Barbaros
Xiong, Qihua
Quek, Su Ying
Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
description Bulk black phosphorus (BP) consists of puckered layers of phosphorus atoms. Few-layer BP, obtained from bulk BP by exfoliation, is an emerging candidate as a channel material in post-silicon electronics. A deep understanding of its physical properties and its full range of applications are still being uncovered. In this paper, we present a theoretical and experimental investigation of phonon properties in few-layer BP, focusing on the low-frequency regime corresponding to interlayer vibrational modes. We show that the interlayer breathing mode A3g shows a large redshift with increasing thickness; the experimental and theoretical results agree well. This thickness dependence is two times larger than that in the chalcogenide materials, such as few-layer MoS2 and WSe2, because of the significantly larger interlayer force constant and smaller atomic mass in BP. The derived interlayer out-of-plane force constant is about 50% larger than that of graphene and MoS2. We show that this large interlayer force constant arises from the sizable covalent interaction between phosphorus atoms in adjacent layers and that interlayer interactions are not merely of the weak van der Waals type. These significant interlayer interactions are consistent with the known surface reactivity of BP and have been shown to be important for electric-field induced formation of Dirac cones in thin film BP.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Luo, Xin
Lu, Xin
Koon, Gavin Kok Wai
Castro Neto, Antonio H.
Özyilmaz, Barbaros
Xiong, Qihua
Quek, Su Ying
format Article
author Luo, Xin
Lu, Xin
Koon, Gavin Kok Wai
Castro Neto, Antonio H.
Özyilmaz, Barbaros
Xiong, Qihua
Quek, Su Ying
author_sort Luo, Xin
title Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
title_short Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
title_full Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
title_fullStr Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
title_full_unstemmed Large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
title_sort large frequency change with thickness in interlayer breathing mode — significant interlayer interactions in few layer black phosphorus
publishDate 2020
url https://hdl.handle.net/10356/140423
_version_ 1759854471592017920