摘要
In this work, the effect of temperature on the phononic modes (E12g and A1g) of few-layered MoS2 and WS2 nanosheets and their van der Waals heterostructure has been investigated in the temperature regime: 80-600 K. The E12g and A1g modes showed a red-shift with an increase in temperature and exhibited non-linear temperature dependency above 300 K for the constituent nanosheets and their co-stacked heterostructure. A physical model comprising of both thermal and volume effects, is used to quantitatively understand the origin of non-linear temperature dependency of E12g and A1g modes. The observed non-linearities in the phononic modes is well described by the higher-order phonon scattering as a consequence of greater amount of sulphur vacancies in the nanosheets as compared to the bulk counterparts. However, the MoS2-WS2 heterostructure exhibited higher structural stability (lesser sulphur vacancies) as compared to its constituent counterparts owing to the enhanced van der Waals coupling at the hetero-interface and subsequently it decreases with rise in temperature.
源语言 | 英语 |
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页(从-至) | 4612-4618 |
页数 | 7 |
期刊 | Materials Today: Proceedings |
卷 | 45 |
DOI | |
出版状态 | 已出版 - 2021 |
活动 | 2nd International Conference on Aspects of Materials Science and Engineering, ICAMSE 2021 - Chandigarh, 印度 期限: 5 3月 2021 → 6 3月 2021 |