Thick Does the Trick: Genesis of Ferroelectricity in 2D GeTe‐Rich (GeTe)<sub><i>m</i></sub>(Sb<sub>2</sub>Te<sub>3</sub>)<sub><i>n</i></sub> Lamellae

Publication date: 21 Nov 2023

JournalSource: OPENALEXOpenAlex type: articleOpen Access
Authors: Stefano Cecchi, Jamo Momand, Daniele Dragoni, Omar Abou El Kheir, Federico Fagiani, Dominik Kriegner, Christian Rinaldi, F. Arciprete, V. Holý, Bart J. Kooi, Marco Bernasconi, Raffaella Calarco

Abstract The possibility to engineer (GeTe) m (Sb 2 Te 3 ) n phase‐change materials to co‐host ferroelectricity is extremely attractive. The combination of these functionalities holds great technological impact, potentially enabling the design of novel multifunctional devices. Here an experimental and theoretical study of epitaxial (GeTe) m (Sb 2 Te 3 ) n with GeTe‐rich composition is presented. These layered films feature a tunable distribution of (GeTe) m (Sb 2 Te 3 ) 1 blocks of different sizes. Breakthrough evidence of ferroelectric displacement in thick (GeTe) m (Sb 2 Te 3 ) 1 lamellae is provided. The density functional theory calculations suggest the formation of a tilted (GeTe) m slab sandwiched in GeTe‐rich blocks. That is, the net ferroelectric polarization is confined almost in‐plane, representing an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements. The resilience of the quasi van der Waals character of the films, regardless of their composition, is also demonstrated. Hence, the material developed hereby gathers in a unique 2D platform the phase‐change and ferroelectric switching properties, paving the way for the conception of innovative device architectures.

Origin
Advanced Science
Volume
11
Issue
1
Pages
e2304785
Cited by
4
Legacy ID
6e7630ac0990cbc5f5eb6d71a65847d1
Biblio references
Volume: 11 Issue: 1 Pages: 2304785