Organic Thin-Film Red-Light Photodiodes with Tunable Spectral Response Via Selective Exciton Activation.

Red and near-infrared light detection is vital for numerous applications, including full-color imaging, optical communication, and machine vision. However, this development is hindered by a limited choice of small band gap and narrow-bandwidth materials. Here, we report a device principle with a simple organic planar heterojunction architecture that enables a selective activation of excitons for tuning the photoresponse spectra to fabricate thin-film, filterless, red-light organic photodiodes. A sequential solution-processed active layer is formed by depositing the top layer of PC