Intrinsic Electron Mobility Exceeding 10³ cm²/(V s) in Multilayer InSe FETs

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, a III-VI semiconductor, not only is 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 multilayer InSe FET devices. Through back gating and Hall measurement in four-probe configuration, the device's 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 20-300 K fall in the range of 0.1-2.0 × 10(3) cm(2)/(V s), which are comparable or better than the state of the art FETs made of widely studied 2D transition metal dichalcogenides.

Atomic-scale mechanisms of defect- and light-induced oxidation and degradation of InSe

“…35 The situation was improved for the passivated InSe sheet, particularly, the electron mobility of the boron-nitride/graphene passivated InSe sheet was found to exceed 10 3 cm 2 V −1 s −1 at room temperature. 36 Previous experiments revealed that thinner InSe films tend to suffer from a more rapid degradation, largely in the form of oxidation, compared with bulk InSe. 16 Therefore, understanding the degradation mechanisms of InSe that are predominantly involved with external adsorbates, such as O2 and H2O at ambient conditions, is thus critically important for its practical applications.…”

Engineering p – n junctions and bandgap tuning of InSe nanolayers by controlled oxidation

“…Among these vdW crystals, γ-InSe, a direct-band gap semiconductor, is attracting increasing interest. Strong quantum confinement effects with decreasing layer thickness and high room temperature electron mobility (>0.1 m 2 V −1 s −1 ) have been achieved in exfoliated InSe and/or films grown by physical vapour deposition [14][15][16][17][18][19]. Although the chemical stability of InSe has been questioned [20], recent research has shown that 2D InSe can be chemically inert under ambient conditions [21].…”

Photogeneration and Mobility of Charge Carriers in Atomically Thin Colloidal InSe Nanosheets Probed by Ultrafast Terahertz Spectroscopy

“…The tunability of the optical and electronic properties by variation of material thickness and composition offers promising prospects for application in optoelectronic devices [1][2][3][4] with high charge mobilities 5 and efficient charge carrier multiplication. 6 InSe is a layered 2D van der Waals structure, which has been successfully applied as highly responsive (87 µs) photodetector 7 and in field-effect transistors (FETs) with high charge mobility (µ = 1000 cm 2 /Vs).…”