The narrow-band organic photodetectors based on organic photo-filtering layers using a transfer printing technology
摘要
Aiming at the response spectral of organic photodetectors (OPDs), we investigate a method of preparing the narrow-band near-infrared (NIR) OPDs by using thin film transfer print technology (TFTPT) to prepare the active layer of bulk heterojunction on the organic photo-filtering layer—a functional layer which can block some specific wavelengths of light and prevent these photons from reaching the next functional layer. Herein, short-wavelength photons are absorbed by the photo-filtering layer to form excitons, but they cannot be successfully dissociated due to the lack of a dissociation interface to the acceptor for eventual composite annihilation. While long-wavelength photons can effectively pass through the photo-filtering layer to reach the active layer and be absorbed and dissociated into free electrons and holes and eventually realize the narrow-band optical response. A narrow-band NIR OPD is prepared with a response peak of 790 nm and a full width at half maximum of 62 nm. Under the bias voltage of -5 V, the responsivity and specific detectivity of the device at 790 nm are 0.24 A/W and 1.39 × 1012 Jones, respectively. The responsivity and specific detectivity of OPDs prepared based on our method can be flexibly adjusted by the combination of different photo-filtering and active layers, and the universality of our method is also proved.