Room-temperature relaxor ferroelectricity and photovoltaic effects in tin titanate directly deposited on a silicon substrate

作     者：Radhe Agarwal Yogesh Sharma Siliang Chang Krishna C. Pitike Changhee Sohn Serge M. Nakhmanson Christos G. Takoudis Ho Nyung Lee Rachel Tonelli Jonathan Gardner James F. Scott Ram S. Katiyar Seungbum Hong 

作者机构：Department of Physics and Institute for Functional Nanomaterials University of Puerto Rico San Juan Puerto Rico 00931 USA Material Science Division Argonne National Laboratory Lemont Illinois 60439 USA Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Department of Chemical Engineering University of Illinois at Chicago Chicago Illinois 60607 USA Department of Materials Science and Engineering Institute of Materials Science University of Connecticut Storrs Connecticut 06269 USA Department of Bioengineering University of Illinois at Chicago Chicago Illinois 60607 USA School of Chemistry University of St. Andrews St. Andrews KY16 9ST United Kingdom School of Physics and Astronomy University of St. Andrews St. Andrews KY16 9SS United Kingdom Department of Materials Science and Engineering KAIST Daejeon 34141 Republic of Korea 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2018年第97卷第5期

页      面：054109-054109页

核心收录：

基　　金：National Research Foundation of Korea, NRF Basic Energy Sciences, BES Division of Materials Sciences and Engineering, DMSE DoD-AFOSR Oak Ridge National Laboratory, ORNL U.S. Department of Energy, USDOE Emory Eye Center, EEC Universidad de Puerto Rico, UPR Office of Science, SC NSF-IFN U.S. Department of Defense, DOD, (FA95501610295) U.S. Department of Defense, DOD NSF, (1067424, 1002410, 1062943, 1309114) NSF Ministry of Science, ICT and Future Planning, MSIP, (NRF-2017M3D1A1086861) Ministry of Science, ICT and Future Planning, MSIP Natural Environment Research Council, NERC, (smru10001) Natural Environment Research Council, NERC 

主　　题：Band gap Density of states Dielectric properties Ferroelectricity Relaxor ferroelectrics 

摘      要：Tin titanate (SnTiO3) has been notoriously impossible to prepare as a thin-film ferroelectric, probably because high-temperature annealing converts much of the Sn2+ to Sn4+. In the present paper, we show two things: first, perovskite phase SnTiO3 can be prepared by atomic-layer deposition directly onto p-type Si substrates; and second, these films exhibit ferroelectric switching at room temperature, with p-type Si acting as electrodes. X-ray diffraction measurements reveal that the film is single-phase, preferred-orientation ferroelectric perovskite SnTiO3. Our films showed well-saturated, square, and repeatable hysteresis loops of around 3μC/cm2 remnant polarization at room temperature, as detected by out-of-plane polarization versus electric field and field cycling measurements. Furthermore, photovoltaic and photoferroelectricity were found in Pt/SnTiO3/Si/SnTiO3/Pt heterostructures, the properties of which can be tuned through band-gap engineering by strain according to first-principles calculations. This is a lead-free room-temperature ferroelectric oxide of potential device application.