High‐Performance Linear‐Polarization‐Sensitive Organic Photodetectors from Liquid‐Crystal Small Molecules

Abstract Novel polarization‐sensitive photodetectors utilizing intrinsic optically anisotropic materials have attracted significant attention, as they offer potential to revolutionize traditional polarization imaging systems and advance polarization detection technology. However, achieving both high polarization sensitivity and robust specific detectivity (D*) remains challenging due to their often‐conflicting requirements. Here, a facile strategy utilizing a liquid‐crystal small‐molecule (LCSM) as a dual‐function agent is presented to simultaneously promote molecular alignment and optimize energy‐level alignment, enhancing polarization sensitivity and D* in linear‐polarization‐sensitive organic photodetectors (LPS‐OPDs). The LCSM, BTR, markedly amplifies the linear dichroism in P3HT: Y6‐based systems, doubling the dichroic ratio (DR) to an impressive peak value of 30.2 and achieving a responsivity anisotropy ratio of 9.5. BTR preferentially accumulates at the P3HT/Y6 interface, effectively mitigating charge recombination induced by the close alignment of the HOMO of P3HT and the LUMO of Y6. This interfacial modulation, together with improved crystallinity, significantly suppresses carrier recombination, resulting in an exceptional D*exceeding 10 14 Jones and a responsivity of 93 mA W −1 at 550 nm under zero bias. Finally, integrated into a single‐pixel imaging system, these devices demonstrate superior polarization capture. This work underscores the transformative potential of organic semiconductors for polarization detection and offers valuable insights into optimizing LPS‐OPDs.