Group theory-guided materials design of chiral organic semiconductors for high-performance circularly polarized light detection

Summary Chiral organic small molecules, recognized for their intrinsic chirality and tunable chiroptical properties, present a promising candidate for circularly polarized light (CPL) detection. However, they often exhibit low CPL absorption asymmetry factor (gabs) due to the lack of effective material design principles. Here, we conceptualize the group theory-guided material design principle and demonstrate high-performance CPL detection using doubly bridged naphthalene-1,8:4,5-bis(dicarboximide) cyclophanes ((+)/(−)-2NDI) as an example. The D2 point group endows (+)/(−)-2NDI with optimal angles—either 180° or 0°—between the magnetic and electric transition dipole moments, achieving a gabs of up to ±0.06, one of the highest values reported for chiral organic semiconductors. This strategy has facilitated CPL photodetectors with a photocurrent asymmetry factor (gph) of 1.67, far surpassing most of the current CPL photodetectors. Our group theory-guided material design principle offers a robust framework for designing polarization-sensitive materials, heralding new possibilities for integrated chiroptical devices.