Optimization of the response spectra of organic photodetectors based on P3HT:PC 61 BM using PCPDTBT as the third component

In this work, we report a new method for extending the response spectra of organic photodetectors (OPDs) by incorporating PCPDTBT in the P3HT:PC 61 BM. The effects of PCPDTBT incorporation on the optical and electrical properties of OPDs were investigated, It was found that when the mass ratio of P3HT:PCPDTBT:PC 61 BM was 8:2:10, the response spectrum of the active layer was extended to 840 nm. The responsivity (R) and external quantum efficiency of the OPDs reached 229, 278, 249 mA/W and 48%, 65%, 68% under 630, 530, and 460 nm illumination and − 1 V bias, respectively, and the detectivity (D * ) reached 10 12 Jones. The results show that highly ordered polymer PCPDTBT with appropriate mass ratio can increases the exciton generation in P3HT:PC 61 BM, which increases the photocurrent of the device. In addition, the addition of PCPDTBT promotes the crystallization of the film, reduces the density of trap defects in the film, and reduces the dark current of the device. Graphic abstract