Multilayers based on quantum materials (complex oxides, topological insulators, transition-metal dichalcogenides, etc) have enabled the design of devices that could revolutionize microelectronics and optoelectronics. However, heterostructures incorporating quantum materials from different families remain scarce, while they would immensely broaden the range of possible applications. Here we demonstrate the large-scale integration of compounds from two highly-multifunctional families: perovskite oxides and transition-metal dichalcogenides (TMDs). We couple BiFeO3, a room-temperature multiferroic oxide, and WSe2, a semiconducting two-dimensional material with potential for photovoltaics and photonics. WSe2 is grown by molecular beam epitaxy and transferred on a centimeter-scale onto BiFeO3 films. Using angle-resolved photoemission spectroscopy, we visualize the electronic structure of 1 to 3 monolayers of WSe2 and evidence a giant energy shift as large as 0.75 eV induced by the ferroelectric polarization direction in the underlying BiFeO3. Such a strong shift opens new perspectives in the efficient manipulation of TMDs properties by proximity effects.
@article{arxiv.2210.14786,
title = {Visualizing giant ferroelectric gating effects in large-scale WSe$_2$/BiFeO$_3$ heterostructures},
author = {Raphaël Salazar and Sara Varotto and Céline Vergnaud and Vincent Garcia and Stéphane Fusil and Julien Chaste and Thomas Maroutian and Alain Marty and Frédéric Bonell and Debora Pierucci and Abdelkarim Ouerghi and François Bertran and Patrick Le Fèvre and Matthieu Jamet and Manuel Bibes and Julien Rault},
journal= {arXiv preprint arXiv:2210.14786},
year = {2022}
}