Structural Phase Transitions and Thermal Degradation Process of MAPbCl3 Single Crystals Studied by Raman and Brillouin Scattering

Raman spectroscopy was applied to MAPbCl3 single crystals in a wide frequency range from 10 to 3500 cm−1 over a broad temperature range from −196 °C to 200 °C including both two structural phase transitions and a thermal degradation range. Low-frequency lattice modes of MAPbCl3 were revealed for the...

Full description

Saved in:
Bibliographic Details
Published in:Materials 2022-11, Vol.15 (22), p.8151
Main Authors: Naqvi, Furqanul Hassan, Ko, Jae-Hyeon
Format: Article
Language:English
Subjects:
Anharmonicity
Anomalies
Cations
Crystallization
Diodes
Frequency ranges
Geometry
High temperature
Investigations
Lattice vibration
Lead chlorides
NMR
Nuclear magnetic resonance
Perovskites
Phase transitions
Raman spectroscopy
Scattering
Single crystals
Spectrum analysis
Temperature
Thermal decomposition
Thermal degradation
Transition points
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Raman spectroscopy was applied to MAPbCl3 single crystals in a wide frequency range from 10 to 3500 cm−1 over a broad temperature range from −196 °C to 200 °C including both two structural phase transitions and a thermal degradation range. Low-frequency lattice modes of MAPbCl3 were revealed for the first time, which showed discontinuous anomalies along with the change in the number of Raman modes at the transition points of −114 °C and −110 °C. Several Raman modes related to the C–N stretching and MA rocking modes in addition to the lattice modes displayed temperature dependences similar to those of MAPbBr3 in both Raman shifts and half widths, indicating that the MA cation arrangement and H–halide bond interactions behave similarly in both systems during the phase transition. The substantial increase in the half widths of nearly all Raman modes especially suggests that the dynamic disorder caused by the free rotational motions of MA cations induces significant anharmonicity in the lattice and thus, reduces the phonon lifetimes. High-temperature Raman and Brillouin scattering measurements showed that the spectral features changed drastically at ~200 °C where the thermal decomposition of MAPbCl3 into PbCl2 began. This result exhibits that combined Raman and Brillouin spectroscopic techniques can be a useful tool in monitoring temperature-induced or temporal changes in lead-based halide perovskite materials.
ISSN:1996-1944
1996-1944
DOI:10.3390/ma15228151