Ferroic alternation in methylammonium lead triiodide perovskite

Methylammonium lead triiodide (MAPbI(3)) 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 MAPbI(3) 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 MAPbI(3). Herein, we perform a statistical synthesis on ferroelectric and anti-ferroelectric features for tetragonal MAPbI(3) 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 forMAPbI(3) perovskite.