Optical activity of chiral excitons

作     者：Sercel, Peter C. Hautzinger, Matthew P. Song, Ruyi Blum, Volker Beard, Matthew C. 

作者机构：Center for Hybrid Organic–Inorganic Semiconductors for Energy GoldenCO80401 United States National Renewable Energy Laboratory GoldenCO80401 United States Dept. of Chemistry Duke University DurhamNC27708 United States Dept. of Mechanical Engineering and Materials Science Duke University DurhamNC27708 United States 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Dichroism 

摘      要：Recent activity in the area of chiroptical phenomena has been focused on the connection between structural asymmetry, electron spin configuration and light matter interactions in chiral semiconductors. In these systems, spin-splitting phenomena emerge due to inversion symmetry breaking and the presence of extended electronic states, yet the connection to chiroptical phenomena is lacking. Here, we develop an analytical effective mass model of chiral excitons, parameterized by density functional theory. The model accounts for parity mixing of the band edge Bloch functions resulting from polar distortions, resulting in magnetic dipole allowed transitions. Through the study of a prototypical chiral 2D hybrid perovskite semiconductor, we show that circular dichroism of the chiral exciton and its interband continuum emerges from spin-splitting via cross coupling of Rashba-like and chiral/helical spin-texture components. As a counterpoint, we apply our model to describe chiroptical properties of excitons in perovskite nanocrystals that occur without chiral lattice distortions. Copyright © 2024, The Authors. All rights reserved.