title: Dual-gated MoS2/WSe2 van der Waals tunnel diodes and transistors.
abstract: Two-dimensional layered semiconductors present a promising material platform for band-to-band-tunneling devices given their homogeneous band edge steepness due to their atomically flat thickness. Here, we experimentally demonstrate interlayer band-to-band tunneling in vertical MoS2/WSe2 van der Waals (vdW) heterostructures using a dual-gate device architecture. The electric potential and carrier concentration of MoS2 and WSe2 layers are independently controlled by the two symmetric gates. The same device can be gate modulated to behave as either an Esaki diode with negative differential resistance, a backward diode with large reverse bias tunneling current, or a forward rectifying diode with low reverse bias current. Notably, a high gate coupling efficiency of ∼80% is obtained for tuning the interlayer band alignments, arising from weak electrostatic screening by the atomically thin layers. This work presents an advance in the fundamental understanding of the interlayer coupling and electron tunneling in semiconductor vdW heterostructures with important implications toward the design of atomically thin tunnel transistors.
authors.affiliation: Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.
authors.forename: Tania
authors.initials: T
authors.lastname: Roy
authors.forename: Mahmut
authors.initials: M
authors.lastname: Tosun
authors.forename: Xi
authors.initials: X
authors.lastname: Cao
authors.forename: Hui
authors.initials: H
authors.lastname: Fang
authors.forename: Der-Hsien
authors.initials: DH
authors.lastname: Lien
authors.forename: Peida
authors.initials: P
authors.lastname: Zhao
authors.forename: Yu-Ze
authors.initials: YZ
authors.lastname: Chen
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Chueh
authors.forename: Jing
authors.initials: J
authors.lastname: Guo
authors.forename: Ali
authors.initials: A
authors.lastname: Javey
keywords: 2D; TFET; electron tunneling; negative differential resistance; steep; transition metal dichalcogenide