[행사/세미나] [Colloquium] April 12(Wed.) Raman scattering studies of various condensed matter materials (Perovskite MAPbCl3 single crystals and others)
- 물리학과
- 조회수3089
- 2023-04-06
5. Abstract: In this presentation, Raman scattering spectroscopy is reviewed as a uniquely versatile research tool for studying various materials systems. As an example, I present Raman scattering studies of methylammonium (MA) lead halide perovskite materials, especially single crystalline MAPbCl3, focusing on structural phase transition behaviors. By measuring temperature-dependent Raman spectra, we observed anomalous changes in phonon frequencies and phonon linewidths across the phase transition temperatures from which we could effectively monitor phase transitions, from cubic to tetragonal and successively to orthorhombic structure. We could also study contributions from each vibration species to the phase transitions whose influence on the phase transitions differs significantly. In addition, from analyzing polarization dependence of particular phonon modes, we could get spatial orientation information of the MA ions in the material that might induce a macroscopic special texture. I will also discuss results from other materials including oxide nanofibers with oxygen defects. We claim, from our results, that Raman scattering spectroscopy is a very effective research mean that can sensitively study characteristics that are associated with local structural environment.
Reference
[1] T. T. T. Nguyen et al., J. Phys. Chem. Lett. 11, 3773 (2020).
[2] Y. Kim et al., Chem. Mater. 34, 2972 (2022).