Revealing the influence of edge states on the electronic properties of PtSe₂

Author(s)

Kuanysh Zhussupbekov, Lida Ansari, Kenan Elibol, Ainur Zhussupbekova, Jani Kotakoski, Igor V. Shvets, Georg S. Duesberg, Paul K. Hurley, Niall McEvoy, Cormac Ó Coileáin, Farzan Gity

Abstract

The properties and performance of 2D nanostructures are known to be critically affected by localized edge states. Here, platinum diselenide (PtSe2) films, synthesized by thermally assisted conversion, are characterized by a variety of spectroscopic and microscopic methods, including scanning tunneling microscopy and spectroscopy, and scanning transmission electron microscopy. We report the presence of distinct edge states, and use surface Green's function methodology in atomistic modeling of different edge atomic structures, together with other theoretical tools, to investigate their origin. Our results indicate that the edges, inherent and abundant in polycrystalline films, can be semiconducting or semimetallic in nature depending on the edge configuration. Experimental results in conjunction with first-principles calculations demonstrate a mapped band profile of the atomically-sharp step edges of PtSe2, which form lateral heterojunctions possessing large asymmetric band offsets in the conduction and valence bands. We further explore the viability of a single step monomaterial heterojunction based field-effect transistor, through atomistic quantum transport simulations. This reveals the critical role of the edge states in creating a wider energy band for carrier transport in the ON-state and hence enabling a remarkably large ION/IOFF ratio > 1010 and near-ideal subthreshold slope, fulfilling the requirements for low-power applications.

Organisation(s)

Physics of Nanostructured Materials

External organisation(s)

Trinity College Dublin, Kh. Dosmukhamedov Atyrau State University, University College Cork, Max-Planck-Institut für Festkörperforschung, Universität der Bundeswehr München

Journal

Applied Materials Today

Volume

35

No. of pages

11

DOI

https://doi.org/10.1016/j.apmt.2023.101926

Publication date

12-2023

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics

Keywords

ASJC Scopus subject areas

Materials Science(all)

Portal url

https://ucris.univie.ac.at/portal/en/publications/revealing-the-influence-of-edge-states-on-the-electronic-properties-of-ptse2(e7575568-96da-4a8b-8566-8f3f34d6dede).html