High Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts

TL;DR

This paper demonstrates high-performance p-type monolayer WSe2 transistors with chemically doped contacts, achieving high mobility, low subthreshold swing, and high on/off ratio, advancing 2D material-based electronics.

Contribution

It introduces a novel device architecture with chemically doped contacts and high-κ dielectrics, significantly improving contact resistance and device performance in monolayer WSe2 transistors.

Findings

Effective hole mobility of ~250 cm2/Vs

Subthreshold swing of ~60 mV/dec

On/off ratio >10^6

Abstract

We report high performance p-type field-effect transistors based on single layered (thickness, ~0.7 nm) WSe2 as the active channel with chemically doped source/drain contacts and high-{\kappa} gate dielectrics. The top-gated monolayer transistors exhibit a high effective hole mobility of ~250 cm2/Vs, perfect subthreshold swing of ~60 mV/dec, and ION/IOFF of >10^6 at room temperature. Special attention is given to lowering the contact resistance for hole injection by using high work function Pd contacts along with degenerate surface doping of the contacts by patterned NO2 chemisorption on WSe2. The results here present a promising material system and device architecture for p-type monolayer transistors with excellent characteristics.