Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2
Band structures are vital in determining the electronic properties of materials. Recently, the two-dimensional (2D) semimetallic transition metal tellurides (WTe2 and MoTe2) have sparked broad research interest because of their elliptical or open Fermi surface, making distinct from the conventional...
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Online Access: | https://hdl.handle.net/10356/143605 |
| _version_ | 1826111416541642752 |
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| author | Wang, Qisheng Yesilyurt, Can Liu, Fucai Siu, Zhuo Bin Cai, Kaiming Kumar, Dushyant Liu, Zheng Jalil, Mansoor B. A. Yang, Hyunsoo |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering Wang, Qisheng Yesilyurt, Can Liu, Fucai Siu, Zhuo Bin Cai, Kaiming Kumar, Dushyant Liu, Zheng Jalil, Mansoor B. A. Yang, Hyunsoo |
| author_sort | Wang, Qisheng |
| collection | NTU |
| description | Band structures are vital in determining the electronic properties of materials. Recently, the two-dimensional (2D) semimetallic transition metal tellurides (WTe2 and MoTe2) have sparked broad research interest because of their elliptical or open Fermi surface, making distinct from the conventional 2D materials. In this study, we demonstrate a centrosymmetric photothermoelectric voltage distribution in WTe2 nanoflakes, which has not been observed in common 2D materials such as graphene and MoS2. Our theoretical model shows the anomalous photothermoelectric effect arises from an anisotropic energy dispersion and micrometer-scale hot carrier diffusion length of WTe2. Further, our results are more consistent with the anisotropic tilt direction of energy dispersion being aligned to the b-axis rather than the a-axis of the WTe2 crystal, which is consistent with the previous first-principle calculations as well as magneto-transport experiments. Our work shows the photothermoelectric current is strongly confined to the anisotropic direction of the energy dispersion in WTe2, which opens an avenue for interesting electro-optic applications such as electron beam collimation and electron lenses. |
| first_indexed | 2024-10-01T02:50:21Z |
| format | Journal Article |
| id | ntu-10356/143605 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:50:21Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1436052020-09-14T02:49:37Z Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 Wang, Qisheng Yesilyurt, Can Liu, Fucai Siu, Zhuo Bin Cai, Kaiming Kumar, Dushyant Liu, Zheng Jalil, Mansoor B. A. Yang, Hyunsoo School of Electrical and Electronic Engineering Center for Programmable Materials Engineering::Electrical and electronic engineering 2D Materials Photothermoelectric Effect Band structures are vital in determining the electronic properties of materials. Recently, the two-dimensional (2D) semimetallic transition metal tellurides (WTe2 and MoTe2) have sparked broad research interest because of their elliptical or open Fermi surface, making distinct from the conventional 2D materials. In this study, we demonstrate a centrosymmetric photothermoelectric voltage distribution in WTe2 nanoflakes, which has not been observed in common 2D materials such as graphene and MoS2. Our theoretical model shows the anomalous photothermoelectric effect arises from an anisotropic energy dispersion and micrometer-scale hot carrier diffusion length of WTe2. Further, our results are more consistent with the anisotropic tilt direction of energy dispersion being aligned to the b-axis rather than the a-axis of the WTe2 crystal, which is consistent with the previous first-principle calculations as well as magneto-transport experiments. Our work shows the photothermoelectric current is strongly confined to the anisotropic direction of the energy dispersion in WTe2, which opens an avenue for interesting electro-optic applications such as electron beam collimation and electron lenses. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version The work is partially supported by the RIE2020 AME programmatic grant: Spin–Orbit Technologies for Intelligence at the Edge. Z.L. acknowledges support by the National Research Foundation Singapore under NRF RF award no. NRF-RF2013-08 and MOE Tier 2 grants MOE2016-T2-2-153 and MOE2015-T2-2-007. M. B. A. J. acknowledges support by MOE2015-T2-1-099. 2020-09-14T02:49:37Z 2020-09-14T02:49:37Z 2019 Journal Article Wang, Q., Yesilyurt, C., Liu, F., Siu, Z. B., Cai, K., Kumar, D., . . . Yang, H. (2019). Anomalous Photothermoelectric Transport Due to Anisotropic Energy Dispersion in WTe2. Nano Letters, 19(4), 2647–2652. doi:10.1021/acs.nanolett.9b00513 1530-6984 https://hdl.handle.net/10356/143605 10.1021/acs.nanolett.9b00513 30859825 4 19 2647 2652 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.9b00513. application/pdf |
| spellingShingle | Engineering::Electrical and electronic engineering 2D Materials Photothermoelectric Effect Wang, Qisheng Yesilyurt, Can Liu, Fucai Siu, Zhuo Bin Cai, Kaiming Kumar, Dushyant Liu, Zheng Jalil, Mansoor B. A. Yang, Hyunsoo Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title | Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title_full | Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title_fullStr | Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title_full_unstemmed | Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title_short | Anomalous photothermoelectric transport due to anisotropic energy dispersion in WTe2 |
| title_sort | anomalous photothermoelectric transport due to anisotropic energy dispersion in wte2 |
| topic | Engineering::Electrical and electronic engineering 2D Materials Photothermoelectric Effect |
| url | https://hdl.handle.net/10356/143605 |
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