Description
Lower-dimensional chiral perovskites have emerged as promising materials for next-generation spintronic devices because of their strong excitonic and chiroptical responses. Particularly, 1D perovskites exhibit enhanced circular dichroism (CD) compared with their 2D counterparts due to the larger structural distortions induced by chiral organic cations.
In this talk, we demonstrate 1D (R/S)-TMPPbI₃ chiral perovskites as model systems to establish a direct relationship between exciton fine structure and the origin of chiroptical properties at zero and applied magnetic field. Decomposition of the excitonic transitions reveals two distinct contributions, arising from a long-range electron-hole exchange splitting between out-of-plane (X) and in-plane (Y, Z) excitons, which is enhanced by strong quantum confinement along one dimension.
Low-energy optical transitions dominate the zero-field CD response due to chiral structural distortions occurring along the exciton polarisation axis. In contrast, high-energy transitions arise from a superposition of degenerate in-plane Y and Z excitons and produces an A-term magnetic circular dichroism (MCD) response that is identical for both enantiomers and independent of the zero-field CD signal. Quantitative MCD analysis yields an excitonic Landé g-factor of approximately 2.60, significantly larger than that of the achiral reference PEPI (g⊥ = 1.24). These results establish a direct link between structural chirality, magneto-optical phenomenon, and exciton fine structure in low-dimensional chiral perovskites.
| I am the presenting author | Yes |
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