Effective Strategy for High‐Performance Organic Photodetectors with Significantly Suppressed Dark Current and Improved Responsivity

Abstract

Organic photodetectors (OPDs) have attracted immense interest as solution‐processable optical signal‐capturing devices due to their various advantages, such as adjustable response range, excellent weak light response, lightweight, flexibility, and ease of processing on diverse substrates. Low dark current density (Jd) and high responsivity (R) are key requirements necessary for achieving a high specific detectivity (D*). Here, an effective strategy for preparing high‐performance OPDs with potential micro p‐i‐n structure by introducing insulating poly(aryl ether) (PAEN) into the organic photosensitive layer is reported. The PM6:PC71BM‐based OPDs are capable of significantly suppressing Jd while increasing R, which can be attributed to the multiple optimizations of morphology and charge transport caused by the addition of PAEN. As a result, the value of Jd (3.63 × 10−10 A cm−2) is two orders of magnitude lower than that of the device without PAEN (1.00 × 10−8 A cm−2) at −1 V bias. Combined with the increased R of 0.376 A W−1, the optimized device achieves a high D*of 3.45 × 1013 Jones (−1 V at 620 nm). The optimized OPDs demonstrate high performance that is comparable to commercial Si photodetectors (Hamamatsu S1133), paving the way for the direct market development of this cost‐effective organic photodetection technology.