In:
npj 2D Materials and Applications, Springer Science and Business Media LLC, Vol. 3, No. 1 ( 2019-12-13)
Abstract:
In two-dimensional (2D)-semiconductor-based field-effect transistors and optoelectronic devices, metal–semiconductor junctions are one of the crucial factors determining device performance. The Fermi-level (FL) pinning effect, which commonly caused by interfacial gap states, severely limits the tunability of junction characteristics, including barrier height and contact resistance. A tunneling contact scheme has been suggested to address the FL pinning issue in metal–2D-semiconductor junctions, whereas the experimental realization is still elusive. Here, we show that an oxidized-monolayer-enabled tunneling barrier can realize a pronounced FL depinning in indium selenide (InSe) transistors, exhibiting a large pinning factor of 0.5 and a highly modulated Schottky barrier height. The FL depinning can be attributed to the suppression of metal- and disorder-induced gap states as a result of the high-quality tunneling contacts. Structural characterizations indicate uniform and atomically thin-surface oxidation layer inherent from nature of van der Waals materials and atomically sharp oxide–2D-semiconductor interfaces. Moreover, by effectively lowering the Schottky barrier height, we achieve an electron mobility of 2160 cm 2 /Vs and a contact barrier of 65 meV in two-terminal InSe transistors. The realization of strong FL depinning in high-mobility InSe transistors with the oxidized-monolayer presents a viable strategy to exploit layered semiconductors in contact engineering for advanced electronics and optoelectronics.
Type of Medium:
Online Resource
ISSN:
2397-7132
DOI:
10.1038/s41699-019-0133-3
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2019
detail.hit.zdb_id:
2893016-2
