Halide perovskites under polarized light: Vibrational symmetry analysis using polarized Raman

Abstract

In the last decade, hybrid organic-inorganic halide perovskites have emerged as a new type of semiconductor for photovoltaics and other optoelectronic applications. Unlike standard, tetrahedrally bonded semiconductors (e.g. Si and GaAs), the ionic thermal fluctuations in the halide perovskites (i.e. structural dynamics) are strongly coupled to the electronic dynamics. Therefore, it is crucial to obtain accurate and detailed knowledge about the nature of atomic motions within the crystal. This has proved to be challenging due to low thermal stability and the complex, temperature dependent structural phase sequence of the halide perovskites. Here, these challenges are overcome and a detailed analysis of the mode symmetries is provided in the low-temperature orthorhombic phase of methylammonium-lead iodide. Raman measurements using linearly- and circularly- polarized light at 1.16 eV excitation are combined with density functional perturbation theory (DFPT). By performing an iterative analysis of Raman polarization-orientation dependence and DFPT mode analysis, the crystal orientation is determined. Subsequently, accounting for birefringence effects detected using circularly polarized light excitation, the symmetries of all the observed Raman-active modes at 10 K are assigned.

References in corpus (10)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• 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
• Optical Phonons in Methylammonium Lead Halide Perovskites and Implications for Charge Transport
• Phonon anharmonicity, lifetimes and thermal transport in CH${}_3$NH${}_3$PbI${}_3$ from many-body perturbation theory
• How Lattice and Charge Fluctuations Control Carrier Dynamics in Halide Perovskites
• From soft harmonic phonons to fast relaxational dynamics in CH${}_3$NH${}_3$PbBr${}_3$
• Interplay between organic cations and inorganic framework and incommensurability in hybrid lead-halide perovskite CH3NH3PbBr3
• Infrared Spectroscopic Study of Vibrational Modes across the Orthorhombic-Tetragonal Phase Transition in Methylammonium Lead Halide Single Crystals

Cited by in corpus (1)

• The tetragonal phase of CH${}_3$NH${}_3$PbI${}_3$ is strongly anharmonic