Preparation And Performance Study Of Two-dimensional Ruddlesden-Popper Organic-inorganic Hybrid Perovskite

Organic-inorganic hybrid perovskite has become a star material for emerging semiconductor materials.The past decade has witnessed the successful application of this material,especially the three-dimensional hybrid perovskite CH₃NH₃PbI in high-performance photovoltaics.However,the three-dimensional hybrid perovskite is limited by the size of the cations,and only small organic amine ions can penetrate the voids stacked in the inorganic layer.Therefore,dimensional reduction has become a bright direction for this field.The two-dimensional Ruddlesden-Popper organic-inorganic hybrid perovskite combines the characteristics of organic components and inorganic parts,so as to obtain both structural variability,greater polarity and ease of processing,as well as electronic properties,optical performance materials.In particular,electrons and holes are confined within the well,leading to an enhancement of the radiative recombination and stronger binding energies for the exciton than in a 3D material.In this paper,fluorophenethylamine and isoamylamine were used to transform three-dimensional hybrid perovskites,and four cases of two-dimensional Ruddlesden-Popper type hybrid perovskites were synthesized.?1?A large-size crystal of a was synthesized in a short time by a rapid crystallization engineering.Based on its intrinsic quantum well structure,the crystal shows excellent advantages such as superior carrier transport and lower defect density.In addition,a large optical dichroism ratio?_c/?_a?2.05 caused by its unique quantum confined effect.In addition,crystal-based photodetectors show excellent polarization detection behavior,showing their great potential in polarized light detection.?2?By cutting out the three-dimensional perovskite structure,a new method for constructing a two-dimensional three-layer hybrid perovskite ferroelectric was studied.Based on the quantum well structure of compound b,the five-photon absorption performance was achieved with a femtosecond laser test system.The absorption cross-section?5 reaches 1.2×10^-132 cm¹⁰?s⁴?photon^-4.As a new candidate material for multiphoton absorption,it further promotes the application of hybrid perovskite ferroelectrics in the field of photonics.The photodetector made of single crystal flakes based on compound c exhibits excellent detection behavior including extremely low dark current(10^-12A),large dark-on/off ratio?2.5×10³?and fast response time?150?s?And excellent selective wavelength detection capability.Based on these advantages,the fabricated 2D perovskite photodetector is comparable to the MAPbI₃ photodetector.?3?A new two-dimensional RP hybrid perovskite antiferroelectric compound d was synthesized by the modification of three-dimensional hybrid perovskite CsPbBr₃.The order and disorder of organic cations and inorganic frameworks plays a major role in the electric-antiferroelectric-paraelectric phase transition.Measurements of ferroelectric hysteresis loops and antiferroelectric hysteresis loops have proven their ferroelectric-antiferroelectric phase transitions.By measuring the current peak,we proved that the coerce field of the compound increased with the increase of temperature in the antiferroelectric phase.This discovery expands the application of ferroelectric/antiferroelectric multifunctional materials in the fields of refrigeration and energy storage.