High-Performance Organic Photodetectors by Introducing a Non-Fullerene Acceptor to Broaden Long Wavelength Detective Spectrum

We demonstrate the broadband visible organic photodetectors (OPDs) by introducing a non-fullerene acceptor of 3,9-bis(2-methylene-(3-(1,1dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3d:2,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) into the bulk heterojunction (BHJ) based on a conventional system of poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl C71-butyric acid methyl ester (PC 71 BM) .The resultant OPDs exhibit a specific detectivity beyond 10 12 Jones in the whole visible region ranged from 380 nm to 760 nm, and the highest detectivity reaches 2.67 × 10 12 Jones at 710 nm. UV-Vis absorption spectrum, steady-state photoluminescence, atomic force microscopy, and space-charge-limited current property were applied to analyze the film characteristics of obtained OPDs. Owing to the long-wavelength absorption band of ITIC, the spectral photodetection range has been broadened effectively, and better film morphology, more effective energy transfer, and the reduced electron mobility in the active layer are responsible for the excellent photodetection capability. The proposed scheme provides a reliable strategy for implementing high-performance broadband visible OPDs.