Observation of intrinsic dark exciton in Janus-MoSSe heterosturcture induced by intrinsic electric field. (10th September 2018)

• Record Type: Journal Article
• Authors: Long, Chen; Gong, Zhi-Rui; Jin, Hao; Dai, Ying
• Is Part Of: Journal of physics. Volume 30:Number 39(2018)
• Publication Date: 2018-09-10
• Subjects: transition metal dichalcoginides -- exciton -- heterostructure; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aadc32
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The nature of exciton in heterostructure exhibits distinct properties, which makes heterostructure a promising candidate for valleytronic and optoelectronic applications. Therefore, understanding of exciton behaviour in heterostructure is the key approach to design novel devices. Here, we investigate the electronic properties including quasiparticle-energy calculations (on the level of the GW approximation) and optical properties (on the level of the Bethe–Salpeter equation) of Janus-MoSSe based heterostructure. Our results show that the build-in electric field caused by spontaneous polarization of Janus-MoSSe monolayer can significantly affect the interlayer interactions within the heterostructure, giving rise to a bright-to-dark exciton transition. To shed light on this phenomenon, a theoretical model is developed, which illustrates that the dark exciton can be ascribed to a coherence cancellation at the band edge positions induced by the strong interlayer coupling. Our findings may provide a new way for modulating and developing of van der Waals heterostructure that have applications in valleytronic and optoelectronic devices.