Gate-Induced Trans-Dimensionality of Carrier Distribution in Bilayer Lateral Heterosheet of MoS₂ and WS₂ for Semiconductor Devices with Tunable Functionality

Abstract

Using the metal−organic chemical vapor deposition technique, we synthesized a bilayer lateral heterostucture of MoS 2 and WS 2 , each of which layers consist of alternately arranged nanostrips of MoS 2 and WS 2 . Transmission electron microscope images exhibit a checked pattern contrast, reflecting the three distinct interlayer metal arrangements of Mo/Mo, W/Mo (Mo/W), and W/W stacking. Theoretical calculations based on the density functional theory elucidated that the bilayer lateral heterostructure of MoS 2 and WS 2 exhibits complexed type-II band edge alignments depending on the interlayer metal arrangement: The conduction band edge is located at the Mo atom in a Mo/Mo sector, while the valence band edge is located at the W atom in a W/W sector. According to the complexed band edge alignment, the field-induced carrier injection behavior in the bilayer heterosheet composed of MoS 2 and WS 2 strips shows gate-induced transdimensionality, where the accumulated carrier distributions continuously vary from zero-to two-dimensional based on the applied gate voltage. Tunable carrier dimensionality can be applicable for wide areas of electronics, such as quantum dot arrays with tunable dot−dot interaction.

Trans-dimensionality of electron/hole channels in multilayer in-plane heterostructures comprising graphene and hBN superlattice

“…26) Recently, a bilayer in-plane heterostructure of WS 2 and MoS 2 has been synthesized using the metal-organic CVD technique. 33) This bilayer in-plane heterostructure has a unique electronic structure near the band gap; the bandedge alignments strongly depend on the interlayer arrangement of its transition-metal atoms. 33) However, how the electronic structure of multilayer in-plane heterostructures depends on their interlayer stacking arrangements remains uncertain.…”

“…33) This bilayer in-plane heterostructure has a unique electronic structure near the band gap; the bandedge alignments strongly depend on the interlayer arrangement of its transition-metal atoms. 33) However, how the electronic structure of multilayer in-plane heterostructures depends on their interlayer stacking arrangements remains uncertain. Therefore, in this work, the aim was to elucidate what is expected to take place in these multilayered in-plane heterostructures.…”

Energetics and electronic structure of Janus WSSe formation by continuous chalcogen substitutions

“…[30][31][32] Bilayer van der Waals complexes composed of TMDs show unusual carrier accumulation under the application of an external field because of band edge misalignment and interlayer orbital hybridization that depend on their constituent elements and stacking arrangements. [33][34][35][36] In-plane heterostructures are the other possible complexes that can be derived from atomic layer materials. Graphene can form a lateral heterostructure with h-BN by forming zigzag borders composed of B and C atoms, where an unusual border localized state emerges at and around the border atoms.…”

Energetics and electronic structure of bilayer Janus WSSe

“…27,28) Furthermore, in-plane and out-ofplane heterostructures of TMDs support trans-dimensional electron systems by controlling the heterostructures and excess carriers. 31) Owing to their three-atom thickness structures, TMDs are unique atomic-layer materials that maintain heterostructures across their layers, where the transition-metal triangular lattice is sandwiched between chalcogen triangular lattices in a prismatic arrangement. By selecting different chalcogen atoms for the top and bottom layers, we have ternary-layered compounds comprising a transition-metal layer and two different chalcogen layers, which are known as Janus TMDs.…”