Evidence for stabilization of ferroelectricity in WO3 thin films under anisotropic epitaxial strain
Abstract
Interest in ferroelectric materials for processing, memory, and sensing devices has been re-energized in recent years by the discovery of nanoscale ferroelectricity in insulating binary oxides based on hafnia and zirconia deposited in complementary metal-oxide-semiconductor-compatible processes. However, their large bandgap, very limited doping range, and challenges of high coercive voltage leave the search open for an industry-friendly, low-coercive-voltage, semiconducting ferroelectric for photosensitive and resistive-switching applications. Here, we report the deposition of epitaxial WO3 films at 350°C using a chemical atmospheric process. In these films, anisotropic epitaxial strain imposed by the substrate promotes the stabilization of a polar phase at room temperatures with out-of-plane polarization, evidenced by x-ray diffraction, scanning transmission electron microscopy, piezoresponse force measurements, and Raman spectroscopy. Exploring ferroelectricity in ultrathin epitaxial WO3 films could provide a platform for polarization-controlled electronic and optical applications.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (15)
Zhuotong Sun
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Nives Strkalj
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Ming Xiao
Ziyi Yuan
Sunil Taper
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Xuan Trung Nguyen
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Babak Bakhit
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Atif Jan
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
William C. Witt
Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, U.K.
Simon M. Fairclough
Caterina Ducati
Chris J. Pickard
Bartomeu Monserrat
Department of Materials Science and Metallurgy
Giuliana Di Martino
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,
Judith L. MacManus-Driscoll
Department of Materials Science and Metallurgy, University of Cambridge 1 , Cambridge CB3 0FS,