Improvement of BCP/MoO3 Composite Cathode Buffer Layer on the Performances of Organic Photodetectors

In this paper, bulk heterojunction organic photodetectors based on P3HT: PC61 BM as the active layer were fabricated and the effects of BCP/MoO3 composite cathode buffer layers on the photoelectric properties of the devices were also investigated. The results show that the wide bandgap BCP has a good blocking effect on the holes in the BCP/MoO3 buffer layer structure, which reduces the dark current and contacts with MoO3 to produce a built-in electric field conducive to electron transport and further improve the photocurrent, thus increasing the specific detectivity. The resulting organic photodetector shows a 1.33 $\times 10^{11}$ Jones specific detectivity at a reverse bias of 0.5 V under 515 nm (3 mw/cm2) illumination.