Enhanced Ultraviolet Circularly Polarized Light Detection through Tuning Constitutional Isomers in Chiral Benzo[ ghi ]perylenetriimides

Abstract

ABSTRACT Chiral perylene diimides (PDIs) are promising candidates for circularly polarized light (CPL) detection due to their intrinsic chirality, outstanding photothermal stability and tunable molecular structures. However, the photocurrent dissymmetry factor ( g ph ) of CPL photodetectors based on chiral PDIs remains relatively low, limiting their applications in advanced chiral optoelectronics. In this work, two constitutional isomers of PDIs, ( S,S )‐BPTI‐ L ‐Ile and ( S,S )‐BPTI‐ L ‐Leu, were synthesized and self‐assembled into microcrystal arrays. ( S,S )‐BPTI‐ L ‐Ile microcrystal arrays had 7.1 × 10 −3 absorption dissymmetry factor ( g abs ), 2.4 times that of ( S,S )‐BPTI‐ L ‐Leu microcrystal arrays ( g abs = 2.9 × 10 −3 ). Theoretical calculations indicated that this difference originated from the distinct angle between the electric and magnetic transition dipole moments in the two microcrystal arrays. Meanwhile, the corresponding ( S,S )‐BPTI‐ L ‐Ile microcrystal arrays achieved record‐high g ph of 0.84 among chiral PDIs, which is consistent with higher spin polarization of 61%, nearly twice that of the ( S,S )‐BPTI‐ L ‐Leu microcrystal arrays (31%). Benefiting from its outstanding CPL detection capability and intrinsic device‐to‐device variability, ( S,S )‐BPTI‐ L ‐Ile microcrystal arrays were further applied to construct physical unclonable functions (PUFs) for secure information encryption. This work demonstrates the crucial role of constitutional isomers in regulating molecular packing, enhancing the detection capability of CPL, and highlights their potential for information security applications.