Anomalously polarised emission from a MoS 2 /WS 2 heterostructure.

Autor: Mol PR; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Barman PK; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Sarma PV; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Kumar AS; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Sahu S; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Shaijumon MM; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in., Kini RN; Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in.
Jazyk: angličtina
Zdroj: Nanoscale advances [Nanoscale Adv] 2021 Aug 17; Vol. 3 (19), pp. 5676-5682. Date of Electronic Publication: 2021 Aug 17 (Print Publication: 2021).
DOI: 10.1039/d1na00462j
Abstrakt: We report circularly polarised emission, with helicity opposite to the optical excitation, from a van der Waals heterostructure (HS) consisting of a monolayer MoS 2 and three-layer WS 2 . Selective excitation of the MoS 2 layer confirms that this cross-polarized emission is due to the charge transfer from the WS 2 layers to the MoS 2 layer. We propose that the high levels of n-doping in the constituent layers due to sulphur vacancies and defects give rise to an enhanced transition rate of electrons from the k valley of WS 2 to the k ' valley of MoS 2 , which leads to the emission, counter polarized to the excitation. Simulations based on the rate equation model support this conclusion.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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