Does P-type Ohmic Contact Exist in WSe2-metal Interfaces?

Abstract

Formation of low-resistance metal contacts is the biggest challenge that masks the intrinsic exceptional electronic properties of 2D WSe2 devices. We present the first comparative study of the interfacial properties between ML/BL WSe2 and Sc, Al, Ag, Au, Pd, and Pt contacts by using ab initio energy band calculations with inclusion of the spin-orbital coupling (SOC) effects and quantum transport simulations. The interlayer coupling tends to reduce both the electron and hole Schottky barrier heights (SBHs) and alters the polarity for WSe2-Au contact, while the SOC chiefly reduces the hole SBH. In the absence of the SOC, Pd contact has the smallest hole SBH with a value no less than 0.22 eV. Dramatically, Pt contact surpasses Pd contact and becomes p-type Ohmic or quasi-Ohmic contact with inclusion of the SOC. Our study provides a theoretical foundation for the selection of favorable metal electrodes in ML/BL WSe2 devices.

References in corpus (17)

• Phosphorene: A New 2D Material with High Carrier Mobility
• High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus
• Tunable Band Gap and Anisotropic Optical Response in Few-layer Black Phosphorus
• Atomically thin p-n junctions with van der Waals heterointerfaces
• The Valley Hall Effect in MoS2 Transistors
• High Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts
• Electroluminescence and photocurrent generation from atomically sharp WSe2/MoS2 heterojunction p-n diodes
• Strain engineered direct-indirect band gap transition and its mechanism in 2D phosphorene
• Layer-dependent Band Alignment and Work Function of Few-Layer Phosphorene
• Valley-selective optical Stark effect in monolayer WS2
• MoS2/MX2 heterobilayers: Bandgap engineering via tensile strain or external electrical field
• Van der Waals trilayers and superlattices: Modification of electronic structures of MoS2 by intercalation
• Ultrafast Generation of Pseudo-magnetic Field for Valley Excitons in WSe2 Monolayers
• High-Mobility Holes in Dual-Gated WSe${}_2$ Field-Effect Transistors
• Controlling the Schottky barrier at MoS2|metal contacts by inserting a BN monolayer
• Low Resistance Metal Contacts to MoS2 Devices with Nickel-Etched-Graphene Electrodes
• Graphdiyne-metal contacts and graphdiyne transistors

Cited by in corpus (8)

• Promising Properties of Sub-5 nm Monolayer MoSi2N4 Transistor
• N- and p-type carrier injections into WSe2 with van der Waals contacts of two-dimensional materials
• Contact resistance and interfacial engineering: Advances in high-performance 2D-TMD based devices
• Contact-Induced Semiconductor-to-Metal Transition in Single-Layer WS${}_2$
• Interfacial properties of black phosphorus/transition metal carbide van der Waals heterostructures
• Experimental observation of spin-split energy dispersion in high-mobility single-layer graphene/WSe2 heterostructures
• Growth and applications of two-dimensional single crystals
• Fermi level depinning via insertion of a graphene buffer layer at the gold-2D tin monoxide contact