This Communication describes a new molecular design that yields ultranarrowband organic
photodetectors. The design is based on a series of helically twisted molecular ribbons as the
optoelectronic material. We fabricate charge collection narrowing photodetectors based on
four different helical ribbons that differ in the wavelength of their response. The
photodetectors made from these materials have narrow spectral response with full-width at
half maxima of< 20 nm. The devices reported here are superior by approximately a factor of …