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Anomalously polarised emission from a MoS(2)/WS(2) heterostructure

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 trans...

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Detalles Bibliográficos
Autores principales: Mol, P. Riya, Barman, Prahalad Kanti, Sarma, Prasad V., Kumar, Abhishek S., Sahu, Satyam, Shaijumon, Manikoth M., Kini, Rajeev N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: RSC 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9417150/
https://www.ncbi.nlm.nih.gov/pubmed/36133269
http://dx.doi.org/10.1039/d1na00462j
Descripción
Sumario: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.