Hard Materials Seminar - "Chirality-Induced Spin Selectivity in Conjugated Polymers"

Chirality-induced spin selectivity, CISS, has attracted broad interest as a route to generating angular-momentum-dependent charge transport in molecular and soft materials without conventional magnets and heavy metals. While CISS has been widely studied in biomolecules and inorganic chiral systems, its manifestation in conjugated polymers remains poorly understood. Structurally chiral conjugated polymers are particularly attractive because their chiral organization, electrical conductivity, and in-plane alignment can be tuned through molecular design and processing. Here, we investigate chirality-dependent angular-momentum-selective transport in printed films of the conjugated polymer p(g4₂T-TT) using a lateral device geometry with metallic detectors. We prepare left-handed and right-handed polymer films and measure the transverse voltage generated in the detector under applied longitudinal current in the polymer film. In the devices, the transverse response varies linearly with current and reverses sign with polymer handedness, while racemic control films exhibit strongly suppressed signals. These observations establish a robust chirality-dependent lateral electrical response in chiral conjugated polymer films. To further probe the origin of the response, we compare devices incorporating detector metals with distinct angular-momentum-to-charge conversion characteristics. These results identify chiral conjugated polymers as a versatile platform for studying chirality-driven angular-momentum transport in soft electronic materials and suggest new opportunities for flexible spintronic and orbitronic functionalities.