title: Modulating charge recombination and structural dynamics in isolated organometal halide perovskite crystals by external electric fields.
abstract: Time-resolved photoluminescence (PL) of isolated methylammonium lead tribromide (MAPbBr3) perovskite crystalline platelets is studied under applied electric fields to understand the influence of ion conformational and translational dynamics on charge recombination dynamics. MAPbBr3 PL decays and intensity transients over ∼100 ps to 10 s time scales show large modulation upon application of electric fields up to ∼ ±10(7) V/m that we attribute primarily to reorientation of the methylammonium cation (MA(+)) dipole moments. On longer time scales, a large fraction of electric field-dependent PL intensity transients exhibit oscillatory behavior and undergo spontaneous switching on time scales comparable to ion drift (∼1-10 s). PL modulation behavior decreases significantly with aging, suggesting diminished reorientational susceptibility (conformational flexibility) of MA(+) groups to applied electric fields.
authors.affiliation: Department of Chemistry, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Chao
authors.initials: C
authors.lastname: Qiu
authors.affiliation: Department of Chemistry, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: John K
authors.initials: JK
authors.lastname: Grey
keywords: electric field; organometal halide perovskites; photoluminescence modulation; polarization