Structural Symmetry Impressing Carrier Dynamics of Halide Perovskite

Abstract

Metal halide perovskites (MHPs) have been one of the most promising materials for the photoelectric, electro-optical, and all-optical conversion devices, thanks to their excellent energy conversion. To investigate the energy conversion induced by structural symmetry, herein, the carrier dynamics and dielectric properties in MHPs are surveyed and reviewed as the microscopic and macroscopic bridge, respectively. The intrinsic correlations between the structural symmetry broken, carrier dynamics, and energy conversion performance are systematically analyzed by considering the energy band structures and dielectric constants. The internal energy conversion mechanisms are elucidated to pave the way for the perovskite advanced applications.

In-situ Optical Control of Local Periodical Ferroelastic Domain Evolution in CH3NH3PbI3 Perovskites

“…Thus, the dynamics in Figures 3 and 4 segregation due to the strains. 15,32,34 Since the strain orientation is determined by the crystallographic order, periodically ferroelastic domain stripes can be visible in the chemical map.…”

“…Thus, the dynamics in Figures and give us a unique insight into local nucleation and growth dynamic process of CH 3 NH 3 PbI 3 perovskites under the IR illumination. Such optical control of ferroelastic domains evolution is fundamentally related to the interaction of C–N chemical bond with 1468 cm –1 IR, which induces the CH 3 NH 3 + rotation, the crystal structure distortion, and thus the CH 3 NH 3 + segregation due to the strains. ,, Since the strain orientation is determined by the crystallographic order, periodically ferroelastic domain stripes can be visible in the chemical map.…”

“…It is well-known that the ferroic states of MAPbI 3 perovskites are closely related to the external fields driven-rotatable orientation of MA + cations due to the hydrogen bond interaction between MA + and PbI 6 in tetragonal unit cells. ,,,, The rotational flexibility of the MA + cations is fundamentally dependent on the dynamic response of C–N dipoles to the external electric, stress, light fields. ,,− To further explore the complex ferroic state, we propose performing in situ optical control of local ferroic orders of MA + cations via the pulsed IR interaction with C–N dipoles in the CH 3 –NH 3 + rock using the mid-IR illumination at 1468 cm –1 . Such 1468 cm –1 excitations for the C–N stretching vibration mode of MA + undoubtedly give rise to the CH 3 asymmetric deformation of the MA + ion, followed by deformation of the inorganic PbI 6 octahedral framework and, finally, the induction of strains within the system.…”

The effects of the lattice modulation on the intermolecular motions of the MA cations of the tetragonal MAPbI3 phase

“…Although a quite deal of physical insight into temperature‐dependent charge carrier recombination was reported based on AIMD, the nature of the lattice motions and cation motions has not been clarified. Quite recently, Guo et al [ 22 ] have reviewed the effects of the structural symmetry on carrier dynamics of halide perovskites and discussed the relationships among the structural symmetry, microscopic properties, macroscopic properties, carrier dynamics, and energy conversion of metal halide perovskites (MHPs). The roles of phonons and electron–phonon coupling were highlighted.…”

Promoting Band Splitting through Symmetry Breaking in Inorganic Halide Perovskite Single Crystals for High-Sensitivity X-ray Detection

“…Additionally, some other reported works have demonstrated that when the symmetry of the crystal structure is broken, the ion migration barrier of the inside ions could also be changed. Besides, the regulation of carrier dynamics and its intrinsic correlations in metal halide perovskites induced by structural symmetry breaking have also been demonstrated. − Benefiting from the asymmetric crystal structure and distinct band splitting, the high-quality band-split SCs grown by the low-temperature solution (85 °C) method exhibited higher resistivity (5.1 × 10 9 Ω cm), larger mobility-lifetime product (3.3 × 10 –3 cm 2 V –1 ), and higher ion migration activation energy (0.64 eV) than the pristine CsPbBr 3 SC. Therefore, X-ray detectors fabricated on the band-split SCs realized the highest sensitivity of 2.8 × 10 5 μC Gy –1 cm –2 , lowest detection limit of 18 nGy s –1 , and highest spatial resolution of 12.7 lp mm –1 in imaging.…”