Ferroic alternation in methylammonium lead triiodide perovskite. Issue 5 (11th August 2021) - Qin, Shengjian
Abstract: Methylammonium lead triiodide (MAPbI3 ) perovskite has attracted broad interest for solar cells, light‐emitting diodes, and so forth. Experiments have captured that the alternative coexistence of polar and nonpolar domains in MAPbI3 can be switched by photons and phonons. Therefore, it is urgent to clarify the interplay among the crystal space group, polarity, ferroic properties, and switching mechanisms for MAPbI3 . Herein, we perform a statistical synthesis on ferroelectric and anti‐ferroelectric features for tetragonal MAPbI3 perovskite. The polar and nonpolar domains are ferroelectric with the I4cm space group and anti‐ferroelectric with the I4/mcm space group, respectively. The domain wall (DW) separating nonpolar and polar regions is charged. Combining the effects of the electric properties of ferroic domains and the charged DWs, novel switching mechanisms are proposed in which photons and phonons drive alternations between ferroelectric and anti‐ferroelectric domains, which provide a reasonable approach to clarify the ambiguous understanding of ferroic behavior for MAPbI3 perovskite. Abstract : This review establishes the inherent relation among space group, polarity, ferroic properties, and switching mechanisms in tetragonal MAPbI3 perovskite. More important from this review is that, ferroic domain wall engineering including electric potential, organic orientation, and so forth, would be an efficient way to tune photoelectric and thermomechanical performances of MAPbI3 perovskite.