Tandem organic photodetectors with tunable, broadband response

Broadband photodetection is achieved by integrating three electron donor materials with complementary absorption into an organic photodetector (OPD). While a single donor-acceptor heterojunction can show broadband response, the spectral tunability is intrinsically limited to the absorption profiles of the active materials. Here, we demonstrate broadband OPDs consisting of multiple bulk heterojunctions arranged in tandem. These OPDs show high responsivity under moderate reverse bias from the ultraviolet to the near-infrared. By combining materials with complementary absorption in a tandem OPD, we demonstrate that the response from each band can be separately tuned with manipulation of the heterojunction thicknesses or composition.