TY - JOUR

T1 - Multi-Layer Palladium Diselenide as a Contact Material for Two-Dimensional Tungsten Diselenide Field-Effect Transistors

AU - Murastov, Gennadiy

AU - Aslam, Muhammad Awais

AU - Leitner, Simon

AU - Tkachuk, Vadym

AU - Plutnarová, Iva

AU - Pavlica, Egon

AU - Rodriguez, Raul D.

AU - Sofer, Zdenek

AU - Matković, Aleksandar

PY - 2024/3/6

Y1 - 2024/3/6

N2 - Tungsten diselenide (WSe2) has emerged as a promising ambipolar semiconductor materialfor field-effect transistors (FETs) due to its unique electronic properties, including a sizeable bandgap, high carrier mobility, and remarkable on–off ratio. However, engineering the contacts to WSe2remains an issue, and high contact barriers prevent the utilization of the full performance in electronicapplications. Furthermore, it could be possible to tune the contacts to WSe2 for effective electron orhole injection and consequently pin the threshold voltage to either conduction or valence band. Thiswould be the way to achieve complementary metal–oxide–semiconductor devices without dopingof the channel material.This study investigates the behaviour of two-dimensional WSe2 field-effecttransistors with multi-layer palladium diselenide (PdSe2) as a contact material. We demonstrate thatPdSe2 contacts favour hole injection while preserving the ambipolar nature of the channel material.This consequently yields high-performance p-type WSe2 devices with PdSe2 van der Waals contacts.Further, we explore the tunability of the contact interface by selective laser alteration of the WSe2under the contacts, enabling pinning of the threshold voltage to the valence band of WSe2, yieldingpure p-type operation of the devices.

AB - Tungsten diselenide (WSe2) has emerged as a promising ambipolar semiconductor materialfor field-effect transistors (FETs) due to its unique electronic properties, including a sizeable bandgap, high carrier mobility, and remarkable on–off ratio. However, engineering the contacts to WSe2remains an issue, and high contact barriers prevent the utilization of the full performance in electronicapplications. Furthermore, it could be possible to tune the contacts to WSe2 for effective electron orhole injection and consequently pin the threshold voltage to either conduction or valence band. Thiswould be the way to achieve complementary metal–oxide–semiconductor devices without dopingof the channel material.This study investigates the behaviour of two-dimensional WSe2 field-effecttransistors with multi-layer palladium diselenide (PdSe2) as a contact material. We demonstrate thatPdSe2 contacts favour hole injection while preserving the ambipolar nature of the channel material.This consequently yields high-performance p-type WSe2 devices with PdSe2 van der Waals contacts.Further, we explore the tunability of the contact interface by selective laser alteration of the WSe2under the contacts, enabling pinning of the threshold voltage to the valence band of WSe2, yieldingpure p-type operation of the devices.

KW - palladium diselenide

KW - tungsten diselenide

KW - tungsten selenium oxide

KW - semi-metal

KW - laser treatment

KW - contact engineering

KW - field-effect transistor

KW - pMOS

KW - van der Waals electronics

KW - 2D Materials

UR - https://doi.org/10.3390/nano14050481

U2 - 10.3390/nano14050481

DO - 10.3390/nano14050481

M3 - Article

JO - Nanomaterials

JF - Nanomaterials

SN - 2079-4991

ER -