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Updated: Aug 28, 2025

Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication
Published on: November 28, 2017
Anomalously polarised emission from a MoS2/WS2 heterostructure
P Riya Mol1, Prahalad Kanti Barman1, Prasad V Sarma1
1Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Maruthamala P. O. Vithura Kerala 695551 India rajeevkini@iisertvm.ac.in.
Abstract:
We report circularly polarised emission, with helicity opposite to the optical excitation, from a van der Waals heterostructure (HS) consisting of a monolayer MoS2 and three-layer WS2. Selective excitation of the MoS2 layer confirms that this cross-polarized emission is due to the charge transfer from the WS2 layers to the MoS2 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 WS2 to the k' valley of MoS2, which leads to the emission, counter polarized to the excitation. Simulations based on the rate equation model support this conclusion.
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