title: Photovoltaics with Ferroelectrics: Current Status and Beyond.
abstract: Ferroelectrics carry a switchable spontaneous electric polarization. This polarization is usually coupled to strain, making ferroelectrics good piezoelectrics. When coupled to magnetism, they become so-called multiferroic systems, a field that has been widely investigated since 2003. While ferroelectrics are birefringent and non-linear optically transparent materials, the coupling of polarization with optical properties has received, since 2009, renewed attention, triggered notably by low-bandgap ferroelectrics suitable for sunlight spectrum absorption and original photovoltaic effects. Consequently, power conversion efficiencies up to 8.1% were recently achieved and values of 19.5% were predicted, making photoferroelectrics promising photovoltaic alternatives. This article aims at providing an up-to-date review on this emerging and rapidly progressing field by highlighting several important issues and parameters, such as the role of domain walls, ways to tune the bandgap, consequences arising from the polarization switchability, and the role of defects and contact electrodes, as well as the downscaling effects. Beyond photovoltaicity, other polarization-related processes are also described, like light-induced deformation (photostriction) or light-assisted chemical reaction (photostriction). It is hoped that this overview will encourage further avenues to be explored and challenged and, as a byproduct, will inspire other research communities in material science, e.g., so-called hybrid halide perovskites.
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Paillard
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Bai
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France.|Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg.
authors.forename: Ingrid C
authors.initials: IC
authors.lastname: Infante
authors.affiliation: Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg.
authors.forename: Maël
authors.initials: M
authors.lastname: Guennou
authors.affiliation: DAM, DIF, CEA, F-91297, Arpajon, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Geneste
authors.affiliation: Department of Physics, University of Warwick, Coventry, CV, 47AL, UK.
authors.forename: Marin
authors.initials: M
authors.lastname: Alexe
authors.affiliation: Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg.|Physics and Materials Science Research Unit, University of Luxembourg, 41 Rue du Brill, L-4422, Belvaux, Luxembourg.
authors.forename: Jens
authors.initials: J
authors.lastname: Kreisel
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France.
authors.forename: Brahim
authors.initials: B
authors.lastname: Dkhil
keywords: multiferroics; photocatalysis; photostriction; photovoltaics