Chiral light-matter interactions in molecular semiconductors

Chirality is a property which is widely observed in nature and refers to the characteristic that an object cannot be superimposed on its mirror image. Recently, chiral solution-processable semiconductors have seen a surge of interest for their potential applications in emerging photonic, optoelectronic and spintronic technologies [1]. Yet, the underlying chiral light-matter interactions, especially in the excited state, which lead to spin and light polarization remain poorly understood [2].

Here, we present our preliminary results on employing transient chiroptical spectroscopy to understand the consequences of morphological (hierarchical) chirality for charge, spin and light polarization. We compare achiral chromophores in solution and a solid-state matrix with their arrangement into chiral twisted molecular crystal films with chiral domains and discuss the complex photophysics we observe [3].

By studying chiral light-matter interactions transiently and with high sensitivity we hope to aid in understanding the microscopic origin of chiral-induced spin-selectivity (CISS) observations and other mechanistic approaches that could enable efficient spin and light polarization control using cheap solution- processable semiconductors.