Here, we introduce a method of tuning the high-detectivity spectra of the organic photodiode (OPD) to fabricate a thin-film filter-less full-color image sensor. The strategically introduced PIN junction enables a selective activation of excitons generated from the photons with low extinction coefficient in the active layer such that the separated holes/electrons can contribute to the external current. In addition, we show that a well-defined PIN junction blocks the injection of nonallowed charge carriers, leading to very low dark current and near-ideal diode characteristics. Consequently, the high specific detectivity over 1.0 × 1012 Jones are observed from R/G/B-selective thin-film OPDs.
Keywords: barrier height; full-color image sensor; organic semiconductor; photodetector; photodiode.