High-detectivity organic photodetectors with double bulk heterojunction enabled by water transfer printing

Suppressing the dark current is an effective strategy to boost the detection capability of organic photodetectors (OPDs). In this Letter, the water transfer printing method is demonstrated in double bulk heterojunction (BHJ) OPDs, which is solvent-independent rather than the traditional sequential spin-coating method, enabling the elimination of the negative effects of solvents on the underlying film and the suppressing of the dark current. As a result, a photo detectivity up to 10¹² Jones was obtained in the wide spectral range of 400-900 nm with a small working area of 3 mm².