Physicists discovered that trap states rule the performance of organic photodetectors, ultimately limiting their detectivity. Organic photodetectors (OPDs) have a huge potential for applications in low-cost imaging, health monitoring, and near-infrared sensing. Yet, before industrially realizing these applications, the performance of these devices still needs to be improved.
Recent research on organic photodetectors based on donor-acceptor systems has resulted in narrow-band, flexible and biocompatible devices, of which the best reach external photovoltaic quantum efficiencies of close to 100%. However, the high noise in the off state produced by these devices limits their specific detectivity, severely reducing the performance, for example measuring faint light.
The newly discovered relation does not only clarify the operation of OPDs but gives guidance for further research in the field. The results can refocus the attention into understanding the origin of the limited performance of OPDs, which was so far unknown.