Intrinsic electron mobility exceeding 1000 cm$^2$/Vs in multilayer InSe FETs

TL;DR

This study demonstrates that multilayer InSe FETs can achieve intrinsic electron mobilities exceeding 1000 cm$^2$/Vs, showing promise for high-performance ultrathin electronic devices and advancing understanding of 2D material transport properties.

Contribution

The paper reports the fabrication and characterization of multilayer InSe FETs with record-high intrinsic electron mobility over 1000 cm$^2$/Vs, surpassing previous 2D material FETs.

Findings

Intrinsic Hall mobility exceeds 1000 cm$^2$/Vs at room temperature.

Mobility values are comparable or superior to other 2D transition metal dichalcogenides.

Mobility varies with substrate and temperature, indicating intrinsic transport behavior.

Abstract

Graphene-like two-dimensional (2D) materials, not only are interesting for their exotic electronic structure and fundamental electronic transport or optical properties but also, hold promises for device miniaturization down to atomic thickness. As one material belonging to this category, InSe is not only a promising candidate for optoelectronic devices but also has potential for ultrathin field effect transistor (FET) with high mobility transport. In this work, various substrates such as PMMA, bare silicon oxide, passivated silicon oxide, and silicon nitride were used to fabricate multi-layer InSe FET devices. Through back gating and Hall measurement in four-probe configuration, the devices' field effect mobility and intrinsic Hall mobility were extracted at various temperatures to study the material's intrinsic transport behavior and the effect of dielectric substrate. The sample's field effect and Hall mobilities over the range of 77-300K fall in the range of 0.1-2.0$\times$10$^3$ cm$^2$/Vs, which are comparable or better than the state of the art FETs made of 2D transition metal-dichalcogenides.