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Exploring Anomalous Polarization Dynamics in Organometallic Halide Perovskites
Author(s) -
Ahmadi Mahshid,
Collins Liam,
Puretzky Alexander,
Zhang Jia,
Keum Jong Kahk,
Lu Wei,
Ivanov Ilia,
Kalinin Sergei V.,
Hu Bin
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201705298
Subject(s) - ferroelectricity , materials science , piezoresponse force microscopy , polarization (electrochemistry) , dipole , ionic bonding , chemical physics , condensed matter physics , kelvin probe force microscope , optoelectronics , nanotechnology , ion , dielectric , physics , atomic force microscopy , chemistry , quantum mechanics
Organometallic halide perovskites (OMHPs) have attracted broad attention as prospective materials for optoelectronic applications. Among the many anomalous properties of these materials, of special interest are the ferroelectric properties including both classical and relaxor‐like components, as a potential origin of slow dynamics, field enhancement, and anomalous mobilities. Here, ferroelectric properties of the three representative OMHPs are explored, including FAPb x Sn 1– x I 3 ( x = 0, x = 0.85) and FA 0.85 MA 0.15 PbI 3 using band excitation piezoresponse force microscopy and contact mode Kelvin probe force microscopy, providing insight into long‐ and short‐range dipole and charge dynamics in these materials and probing ferroelectric density of states. Furthermore, second‐harmonic generation in thin films of OMHPs is observed, providing a direct information on the noncentrosymmetric polarization in such materials. Overall, the data provide strong evidence for the presence of ferroelectric domains in these systems; however, the domain dynamics is suppressed by fast ion dynamics. These materials hence present the limit of ferroelectric materials with spontaneous polarization dynamically screened by ionic and electronic carriers.