Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures
Monolayer transition metal dichalcogenide (TMD) alloys have emerged as a unique material system for promising applications in electronics, optoelectronics, and spintronics due to their tunable electronic structures, effective masses of carriers, and valley polarization with various alloy composition...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/160131 |
| _version_ | 1811686256113876992 |
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| author | Wu, Lishu Cong, Chunxiao Yang, Weihuang Chen, Yu Shao, Yan Do, Thi Thu Ha Wen, Wen Feng, Shun Zou, Chenji Zhang, Hongbo Du, Bowen Cao, Bingchen Shang, Jingzhi Xiong, Qihua Loh, Kian Ping Yu, Ting |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Wu, Lishu Cong, Chunxiao Yang, Weihuang Chen, Yu Shao, Yan Do, Thi Thu Ha Wen, Wen Feng, Shun Zou, Chenji Zhang, Hongbo Du, Bowen Cao, Bingchen Shang, Jingzhi Xiong, Qihua Loh, Kian Ping Yu, Ting |
| author_sort | Wu, Lishu |
| collection | NTU |
| description | Monolayer transition metal dichalcogenide (TMD) alloys have emerged as a unique material system for promising applications in electronics, optoelectronics, and spintronics due to their tunable electronic structures, effective masses of carriers, and valley polarization with various alloy compositions. Although spin-orbit engineering has been extensively studied in monolayer TMD alloys, the valley Zeeman effect in these alloys still remains largely unexplored. Here we demonstrate the enhanced valley magnetic response in Mo0.5W0.5Se2 alloy monolayers and Mo0.5W0.5Se2/WS2 heterostructures probed by magneto-photoluminescence spectroscopy. The large g factors of negatively charged excitons (trions) of Mo0.5W0.5Se2 have been extracted for both pure Mo0.5W0.5Se2 monolayers and Mo0.5W0.5Se2/WS2 heterostructures, which are attributed to the significant impact of doping-induced strong many-body Coulomb interactions on trion emissions under an out-of-plane magnetic field. Moreover, compared with the monolayer Mo0.5W0.5Se2, the slightly reduced valley Zeeman splitting in Mo0.5W0.5Se2/WS2 is a consequence of the weakened exchange interaction arising from p-doping in Mo0.5W0.5Se2 via interlayer charge transfer between Mo0.5W0.5Se2 and WS2. Such interlayer charge transfer further evidences the formation of type-II band alignment, in agreement with the density functional theory calculations. Our findings give insights into the spin-valley and interlayer coupling effects in monolayer TMD alloys and their heterostructures, which are essential to develop valleytronic applications based on the emerging family of TMD alloys. |
| first_indexed | 2024-10-01T04:57:31Z |
| format | Journal Article |
| id | ntu-10356/160131 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:57:31Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1601312022-07-13T04:29:27Z Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures Wu, Lishu Cong, Chunxiao Yang, Weihuang Chen, Yu Shao, Yan Do, Thi Thu Ha Wen, Wen Feng, Shun Zou, Chenji Zhang, Hongbo Du, Bowen Cao, Bingchen Shang, Jingzhi Xiong, Qihua Loh, Kian Ping Yu, Ting School of Physical and Mathematical Sciences Engineering::Materials Interlayer Coupling Valley Zeeman Splitting Monolayer transition metal dichalcogenide (TMD) alloys have emerged as a unique material system for promising applications in electronics, optoelectronics, and spintronics due to their tunable electronic structures, effective masses of carriers, and valley polarization with various alloy compositions. Although spin-orbit engineering has been extensively studied in monolayer TMD alloys, the valley Zeeman effect in these alloys still remains largely unexplored. Here we demonstrate the enhanced valley magnetic response in Mo0.5W0.5Se2 alloy monolayers and Mo0.5W0.5Se2/WS2 heterostructures probed by magneto-photoluminescence spectroscopy. The large g factors of negatively charged excitons (trions) of Mo0.5W0.5Se2 have been extracted for both pure Mo0.5W0.5Se2 monolayers and Mo0.5W0.5Se2/WS2 heterostructures, which are attributed to the significant impact of doping-induced strong many-body Coulomb interactions on trion emissions under an out-of-plane magnetic field. Moreover, compared with the monolayer Mo0.5W0.5Se2, the slightly reduced valley Zeeman splitting in Mo0.5W0.5Se2/WS2 is a consequence of the weakened exchange interaction arising from p-doping in Mo0.5W0.5Se2 via interlayer charge transfer between Mo0.5W0.5Se2 and WS2. Such interlayer charge transfer further evidences the formation of type-II band alignment, in agreement with the density functional theory calculations. Our findings give insights into the spin-valley and interlayer coupling effects in monolayer TMD alloys and their heterostructures, which are essential to develop valleytronic applications based on the emerging family of TMD alloys. Ministry of Education (MOE) National Research Foundation (NRF) This project is mainly supported by the Academic Research Fund Tier 1 (RG93/19), the Ministry of Education of Singapore Tier 2 (MOE2019-T2-1-044 and MOE2018-T2-2- 072), and the Singapore National Research Foundation (NRF) under the Competitive Research Programs (NRF-CRP-21- 2018-0007). C.C. acknowledges the support of the Shanghai Municipal Natural Science Foundation (no. 16ZR1402500), the Shanghai Municipal Science and Technology Commission (no. 18JC1410300), the National Young 1000 Talent Plan of China, and the National Natural Science Foundation of China (no. 61774040). This project is also supported by National Natural Science Foundation of China (no. 11774170). W.Y. acknowledges the support of the National Natural Science Foundation of China (no. 61704040) and the Zhejiang Provincial Natural Science Foundation of China (no. LGG19F040003). J.S. appreciates the support of the Fundamental Research Funds for the Central Universities of China, National Natural Science Foundation of China (no. 61904151), the Natural Science Foundation of Shaanxi (no. 2020JM-108), and the Joint Research Funds of Department of Science & Technology of Shaanxi Province and Northwestern Polytechnical University (no. 2020GXLH-Z-020). K.P.L. acknowledges the National Research Foundation grant NRFCRP22-2019-0006, Prime Minister’s Office, Singapore. S.F. acknowledges the support by the H2020-MSCA-IF-2020 project SingExTr (no. 101031596). 2022-07-13T04:29:27Z 2022-07-13T04:29:27Z 2021 Journal Article Wu, L., Cong, C., Yang, W., Chen, Y., Shao, Y., Do, T. T. H., Wen, W., Feng, S., Zou, C., Zhang, H., Du, B., Cao, B., Shang, J., Xiong, Q., Loh, K. P. & Yu, T. (2021). Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures. ACS Nano, 15(5), 8397-8406. https://dx.doi.org/10.1021/acsnano.0c10478 1936-0851 https://hdl.handle.net/10356/160131 10.1021/acsnano.0c10478 33881826 2-s2.0-85106421282 5 15 8397 8406 en RG93/19 MOE2019-T2-1-044 MOE2018-T2-2-072 NRF-CRP-21-2018-0007 NRFCRP22-2019-0006 ACS Nano © 2021 American Chemical Society. All rights reserved. |
| spellingShingle | Engineering::Materials Interlayer Coupling Valley Zeeman Splitting Wu, Lishu Cong, Chunxiao Yang, Weihuang Chen, Yu Shao, Yan Do, Thi Thu Ha Wen, Wen Feng, Shun Zou, Chenji Zhang, Hongbo Du, Bowen Cao, Bingchen Shang, Jingzhi Xiong, Qihua Loh, Kian Ping Yu, Ting Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title | Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title_full | Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title_fullStr | Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title_full_unstemmed | Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title_short | Observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of Mo₀.₅W₀.₅Se₂ and Mo₀.₅W₀.₅Se₂/WS₂ heterostructures |
| title_sort | observation of strong valley magnetic response in monolayer transition metal dichalcogenide alloys of mo₀ ₅w₀ ₅se₂ and mo₀ ₅w₀ ₅se₂ ws₂ heterostructures |
| topic | Engineering::Materials Interlayer Coupling Valley Zeeman Splitting |
| url | https://hdl.handle.net/10356/160131 |
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