Charge Transfer-Driven Modulation of Induced Chirality in Hybrid Perovskite Nanocrystals

The design and control of chirality in perovskite nanocrystals (NCs) offer exciting opportunities for spintronic, optoelectronic, and chiral photonic applications. Here, we have induced chirality in pristine organic-inorganic hybrid halide perovskite (MAPbBr₃) NCs using chiral phenylethylamine (S/R-PEA) molecules. Circular dichroism (CD) spectroscopy reveals a dissymmetry factor (g_CD) of 9.3 × 10^-4 for the chiral MAPbBr₃ NCs. To understand the influence of charge transfer on the induced chirality of MAPbBr₃ NCs, an electron acceptor, Benzoquinone (BQ), and a hole acceptor, Phenothiazine (PTZ), are introduced into the system. Femtosecond transient absorption spectroscopic investigation shows that hole transfer has a more pronounced effect than electron transfer. CD analysis reveals a more pronounced decrease in g_CD during hole transfer (2.12 × 10^-4) compared to electron transfer (5.27 × 10^-4). These findings highlight the critical role of charge transfer in modulating chiroptical properties, offering insight into designing spin-selective hybrid materials for optoelectronic applications.