Magnetic properties of chiral 2D Lead Iodide Perovskites probed by Helicity Resolved Raman Spectroscopy
ORAL
Abstract
Two-dimensional (2D) layered perovskites are composed of inorganic layers made up of metal halide octahedra, separated by organic cation layers that act as spacers, with unique properties. In chiral 2D perovskites, the chirality that comes from the organic spacer is transferred to the band-edge excitons hosted in the inorganic layer. [1-3] Emerging interesting properties are seen in these systems such as asymmetric chemical synthesis, circular dichroism (CD), circularly polarized photoluminescence (CPPL), chirality-induced spin selectivity (CISS), ferroelectricity, and topological quantum properties. [4]
This work presents helicity-resolved Raman spectroscopy (HRRS) as a function of temperature (>2 K) and applied magnetic field (< 9 T) of 2D methylbenzylamine lead iodide [(MBA)2PbI4], with phonons observed down to 8 cm-1 (1 meV) of the inorganic Pb-I octahedra. HRRS is an effective method for assigning chiral phonons. A polarizer and quarter-wave plate control the incident circular polarization right (R) or left (L) and for the scattering, a half-wave plate and a polarizer work together to enable the four combinations: RL, RR, LR, and LL. Interestingly, a magnetic response was observed and it was studied at different temperatures under circular polarization.
1. Righetto, M.; Giovanni, D.; Lim, S. S.; Sum, T. C., The photophysics of Ruddlesden-Popper perovskites: A tale of energy, charges, and spins. Appl. Phys. Rev. 2021, 8, 1-21.
2. Lu, H.; Xiao, C.; Song, R.; Li, T.; Maughan, A. E.; Levin, A.; Brunecky, R.; Berry, J. J.; Mitzi, D. B.; Blum, V.; Beard, M. C., Highly Distorted Chiral Two-Dimensional Tin Iodide Perovskites for Spin Polarized Charge Transport. J. Am. Chem. Soc. 2020, 142, 13030-13040.
3. VanOrman, Z. A.; Kitzmann, W. R.; Reponen, A.-P. M.; Deshpande, T.; Jöbsis, H. J.; Feldmann, S., Chiral light–matter interactions in solution-processable semiconductors. Nat. Rev. Chem. 2025, 9, 208-223.
4. Mike Pols, Geert Brocks, Sofía Calero, and Shuxia Tao, Temperature-Dependent Chirality in Halide Perovskites, The Journal of Physical Chemistry Letters 2024 15 (31), 8057-8064
This work presents helicity-resolved Raman spectroscopy (HRRS) as a function of temperature (>2 K) and applied magnetic field (< 9 T) of 2D methylbenzylamine lead iodide [(MBA)2PbI4], with phonons observed down to 8 cm-1 (1 meV) of the inorganic Pb-I octahedra. HRRS is an effective method for assigning chiral phonons. A polarizer and quarter-wave plate control the incident circular polarization right (R) or left (L) and for the scattering, a half-wave plate and a polarizer work together to enable the four combinations: RL, RR, LR, and LL. Interestingly, a magnetic response was observed and it was studied at different temperatures under circular polarization.
1. Righetto, M.; Giovanni, D.; Lim, S. S.; Sum, T. C., The photophysics of Ruddlesden-Popper perovskites: A tale of energy, charges, and spins. Appl. Phys. Rev. 2021, 8, 1-21.
2. Lu, H.; Xiao, C.; Song, R.; Li, T.; Maughan, A. E.; Levin, A.; Brunecky, R.; Berry, J. J.; Mitzi, D. B.; Blum, V.; Beard, M. C., Highly Distorted Chiral Two-Dimensional Tin Iodide Perovskites for Spin Polarized Charge Transport. J. Am. Chem. Soc. 2020, 142, 13030-13040.
3. VanOrman, Z. A.; Kitzmann, W. R.; Reponen, A.-P. M.; Deshpande, T.; Jöbsis, H. J.; Feldmann, S., Chiral light–matter interactions in solution-processable semiconductors. Nat. Rev. Chem. 2025, 9, 208-223.
4. Mike Pols, Geert Brocks, Sofía Calero, and Shuxia Tao, Temperature-Dependent Chirality in Halide Perovskites, The Journal of Physical Chemistry Letters 2024 15 (31), 8057-8064
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Presenters
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Maria Fernanda Munoz
- National Institute of Standards and Technology (NIST)