Highly Selective High‐Speed Circularly Polarized Photodiodes Based on π‐Conjugated Polymers

Chiral π-conjugated molecular systems that are intrinsically sensitive to the handedness of circularly polarized (CP) light potentially allow for miniaturized, low-cost CP detection devices. Such devices promise transform several technologies, including biosensing, quantum optics, and communication data encrypted by exploiting spin angular momentum light. Here a simple, bilayer organic photodiode (CP OPD) comprising an achiral polymer–chiral additive blend as electron donor layer C60 acceptor is realized. These exhibit considerable photocurrent dissymmetry gph, with absolute values high 0.85 dark currents low 10 pA. Impressively, they showcase linear dynamic range 80 dB, rise fall times ≈7 µs, which significantly outperforms all previously reported selective photodetectors. Mechanistically, it shown gph thickness both chiral layers trade-off exists between external efficiency gph. The fast-switching speeds these devices, coupled their large highly response light, opens up possibility direct application in sensing optical communications.