标题：Observation of intrinsic dark exciton in Janus-MoSSe heterosturcture induced by intrinsic electric field
作者：Long, Chen; Gong, Zhi-Rui; Jin, Hao; Dai, Ying
作者机构：[Long, Chen; Dai, Ying] Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.; [Gong, Zhi-Rui; Jin, Hao] Shen 更多
通讯作者地址：[Jin, H]Shenzhen Univ, Coll Phys & Energy, Shenzhen Key Lab Adv Thin Films & Applicat, Shenzhen 518060, Peoples R China.
来源：JOURNAL OF PHYSICS-CONDENSED MATTER
关键词：transition metal dichalcoginides; exciton; heterostructure
摘要：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 brightto-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.