Interplay between organic cations and inorganic framework and incommensurability in hybrid lead-halide perovskite CH3NH3PbBr3

Abstract

Organic-inorganic coupling in the hybrid lead-halide perovskite is a central issue in rationalizing the outstanding photovoltaic performance of these emerging materials. Here we compare and contrast the evolution of structure and dynamics of the hybrid CH3NH3PbBr3 and the inorganic CsPbBr3 lead-halide perovskites with temperature, using Raman spectroscopy and single-crystal X-ray diffraction. Results reveal a stark contrast between their order-disorder transitions, abrupt for the hybrid whereas smooth for the inorganic perovskite. X-ray diffraction observes an intermediate incommensurate phase between the ordered and the disordered phases in CH3NH3PbBr3. Low-frequency Raman scattering captures the appearance of a sharp soft mode in the incommensurate phase, ascribed to the theoretically predicted amplitudon mode. Our work highlights the interaction between the structural dynamics of organic cation CH3NH3+ and the lead-halide framework, and unravels the competition between tendencies of the organic and inorganic moieties to minimize energy in the incommensurate phase of the hybrid perovskite structure.

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• Local polar fluctuations in lead halide perovskite crystals
• Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal and cubic phases of methylammonium lead iodide
• Dynamic disorder, phonon lifetimes, and the assignment of modes to the vibrational spectra of methylammonium lead halide perovskites
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• Direct Observation of Dynamic Symmetry Breaking above Room Temperature in Methylammonium Lead Iodide Perovskite
• From soft harmonic phonons to fast relaxational dynamics in CH${}_3$NH${}_3$PbBr${}_3$
• Co-existing chiral and collinear phases in a distorted triangular antiferromagnet

Cited by in corpus (15)

• Spin-split bands cause the indirect band gap of (CH${}_3$NH${}_3$)PbI${}_3$: Experimental evidence from circular photogalvanic effect
• Photoinduced phase separation in the lead halides is a polaronic effect
• Composition, Size, and Surface Functionalization dependent Optical Properties of Lead Bromide Perovskite Nanocrystals
• Anharmonic Lattice Vibrations in Small-Molecule Organic Semiconductors
• Common acoustic phonon lifetimes in inorganic and hybrid lead halide perovskites
• Static and Dynamic Disorder in Formamidinium Lead Bromide Single Crystals
• Molecular orientational melting within a lead-halide octahedra framework - the order-disorder transition in CH3NH3PbBr3
• The Effect of Ionic Composition on Acoustic Phonon Speeds in Hybrid Perovskites from Brillouin Spectroscopy and Density Functional Theory
• The Disorder Origin of Raman Scattering In Perovskites Single Crystals
• Decoupled molecular and inorganic framework dynamics in CH${}_3$NH${}_3$PbCl${}_3$
• Lifetime-shortened acoustic phonons and static order at the Brillouin zone boundary in the organic-inorganic perovskite CH${}_3$NH${}_3$PbCl${}_3$
• Halide perovskites under polarized light: Vibrational symmetry analysis using polarized Raman
• Terahertz Kerr effect in a methylammonium lead bromide perovskite crystal
• Microscopic theory of Raman scattering for the rotational organic cation in metal halide perovskites
• Strongly Anharmonic Organic Cation Vibrations in Hybrid Lead Halide Perovskite CH3NH3PbI3 on Electronic Ground State