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 (g_abs) 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 g_abs 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 (g_ph) 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.