Ultraviolet-Extended Circularly Polarized Light Detection via Cooperative Chirality in Nanoscale Ternary Organic Semiconductors

Owing to their potential applications in polarized optical encryption, biomedical imaging, and quantum information processing, CPL detection has garnered increasing research attention, particularly toward the development of integrated, high-performance, and broadband CPL photodetectors. However, the detection bandwidth of CPL devices based on chiral semiconductor photoactive nanomaterials is fundamentally constrained by their intrinsic optical bandgaps, making it challenging to achieve high-sensitivity CPL detection across a broad spectral range. In this work, we propose a ternary energy-level-bridged chiral organic photodetection system to effectively broaden the spectral response of CPL detectors. By integrating a chiral nanomolecular materials (TPPS), chiral polymeric nanowires (P 3 TH), and PC 71 BM, and by leveraging the strong spin–orbit coupling induced by molecular chirality together with an optimized energy-level alignment, we realize highly efficient photogenerated charge separation and transport under CPL excitation. Consequently, the CPL detection window is extended from 400–650 nm in the binary system to 350–650 nm in the ternary chiral organic semiconductor system. The ternary chiral organic CPL photodetector achieves a responsivity of 0.09 A W –1 and a detectivity of 3.5 × 10 12 Jones, with the responsivity further enhanced to 0.14 A W –1 in the visible region while maintaining a detectivity of 3.5 × 10 12 Jones. Moreover, the device exhibits excellent operational stability, with the photocurrent remaining nearly unchanged after more than 300 on–off switching cycles. This study presents a generally applicable strategy for spectral broadening and performance enhancement of chiral semiconductor–based CPL photodetectors via energy-level engineering and chirality-induced spin–orbit coupling. The approach provides a solid foundation for advancing their practical implementation in integrated optoelectronic systems.