Quantum Confinement and Electronic Structure at the Surface of van der Waals Ferroelectric α-In2Se3 - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue ACS Nano Année : 2023

Quantum Confinement and Electronic Structure at the Surface of van der Waals Ferroelectric α-In2Se3

Patrick Le Fèvre
Franco̧is Bertran
Marco Pala
Julien Chaste

Résumé

Two-dimensional (2D) ferroelectric (FE) materials are promising compounds for next-generation nonvolatile memories, due to their low energy consumption and high endurance. Among them, α-In2Se3 has drawn particular attention due to its in-and out-of-plane ferroelectricity, whose robustness has been demonstrated down to the monolayer limit. This is a relatively uncommon behavior since most bulk FE materials lose their ferroelectric character at the 2D limit due to depolarization field. Using angle resolved photoemission spectroscopy (ARPES), we unveil another unusual 2D phenomena appearing in 2H α-In2Se3 single crystals, the occurrence of a highly metallic two-dimensional electron gas (2DEG) at the surface of vacuum-cleaved crystals. This 2DEG exhibits two confined states which correspond to an electron density of approximatively 10 13 electrons/cm², also confirmed by thermoelectric measurements. Combination of ARPES and density functional theory (DFT) calculations reveals a direct band gap of energy equal to 1.3 +/-0.1 eV, with the bottom of the conduction band localized at the center of the Brillouin zone, just below the Fermi level. Such strong n-type doping further supports the quantum confinement of electrons and the formation of the 2DEG.
Fichier principal
Vignette du fichier
2308.04864.pdf (2.03 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04179830 , version 1 (10-08-2023)

Identifiants

Citer

Geoffroy Kremer, Aymen Mahmoudi, A. M'Foukh, Meryem Bouaziz, Mehrdad Rahimi, et al.. Quantum Confinement and Electronic Structure at the Surface of van der Waals Ferroelectric α-In2Se3. ACS Nano, 2023, ⟨10.1021/acsnano.3c04186⟩. ⟨hal-04179830⟩
97 Consultations
10 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More