High-performance flexible circularly polarized light photodetectors based on chiral n-type naphthalenediimide-bithiophene polymers

Chiral π-conjugated polymers are key for advancing flexible circularly polarized light (CPL) photodetectors due to their mechanical flexibility, high sensitivity, and compatibility with large-scale fabrication. However, achieving strong CPL detection and efficient charge transport in flexible chiral photodetectors remains challenging. Here, we present a novel n -type chiral π-conjugated polymer ( S / R )-P(NDI2MH-T2) for high-performance flexible CPL photodetectors. The polymer exhibits enhanced chiroptical activity after annealing, with significant improvement in | g abs | at 382 nm (2.34 × 10 −2 ) and at 670 nm (1.38 × 10 −2 ), which is attributed to improved polymer chain stacking and exciton coupling, as confirmed by molecular dynamics simulations. The phototransistors show high electron mobility (7.9 × 10 −2 cm 2 V −1 s −1 ), photoresponsivity (92 A W −1 ), and detectivity (1.1 × 10 12 Jones). A flexible CPL photodetector fabricated with polydimethylsiloxane and polyethylene naphthalate substrates demonstrates reliable CPL detection with | g ph | of 0.043. This work highlights the potential of chiral π-conjugated polymers for efficient flexible CPL photodetectors.