Giant spin-splitting and gap renormalization driven by trions in single-layer WS${}_2$/h-BN heterostructures

Abstract

In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable band gaps and strongly bound excitons and trions emerge from strong many-body effects, beyond spin-orbit coupling- and lattice symmetry-induced spin and valley degrees of freedom. Combining single-layer (SL) TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects via engineered interlayer interactions. Here, we employ micro-focused angle-resolved photoemission spectroscopy (microARPES) and in-situ surface doping to manipulate the electronic structure of SL WS${}_2$ on hexagonal boron nitride (WS${}_2$/h-BN). Upon electron doping, we observe an unexpected giant renormalization of the SL WS${}_2$ valence band (VB) spin-orbit splitting from 430~meV to 660~meV, together with a band gap reduction of at least 325~meV, attributed to the formation of trionic quasiparticles. These findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials.

14 pages, 4 figures. Address correspondence to [email protected] or [email protected]

References in corpus (12)

• Boron nitride substrates for high-quality graphene electronics
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Exciton Binding Energy of Monolayer WS2
• Many-Body Theory of Trion Absorption Features in Two-Dimensional Semiconductors
• Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides
• Second generation Dirac cones and inversion symmetry breaking induced gaps in graphene/hexagonal boron nitride
• Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe2 Thin Films
• Electronic Structure of Epitaxial Single-Layer MoS${}_2$
• Carrier Plasmon Induced Nonlinear Band Gap Renormalization in Two-Dimensional Semiconductors
• Growth and electronic structure of epitaxial single-layer WS${}_2$ on Au(111)
• Spatially Resolved Electronic Properties of Single-Layer WS${}_2$ on Transition Metal Oxides
• Large conduction band and Fermi velocity spin splittings due to Coulomb interactions in single-layer MoS_{2}

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