Organic Polaritons for Angle-Independent Narrowband Microcavity Photodiodes

Microcavities have become a widely adopted strategy for achieving narrowband spectral responses in optoelectronic devices. For instance, they serve as an excellent platform for spectrally selective light detection in organic photodiodes. However, microcavities suffer from significant angular dispersion—up to 50 nm at a 45° tilt—which limits their applicability. Engineering microcavities to strongly couple their photonic resonance to molecular transitions of the active absorbing or electronic device materials creates hybrid light-matter states known as polaritons. These polaritons show reduced angular dispersion due to their matter component, together have emerged as a technology to enhance several performance merits of optoelectronic devices.

Here, we present a novel device architecture leveraging the strong coupling of non-fullerene acceptors to achieve a highly efficient polaritonic narrowband infrared organic photodiode. The optimized devices exhibit high responsivity at the lower polariton branch, achieving ~0.23 A/W (EQE of 30%) and ~0.24 A/W (EQE of 30.5%) under -2V bias at 945 nm and 965 nm, respectively, with a full-width at half-maximum of less than 50 nm. Furthermore, they demonstrate ultra-low angular dispersion of less than 15 nm at a 45° tilt.