Versatile Sequential Casting Processing for Highly Efficient and Stable Binary Organic Photovoltaics

• DOI: 10.1002/adma.202203379
• Publication Date: 2022-06-29T08:04:00Z
• Authors: Chengliang He; Youwen Pan; Guanghao Lu; Baohua Wu; Xinxin Xia; Chang‐Qi Ma; Zeng Chen; Haiming Zhu; Xinhui Lu; Wei Ma; Lijian Zuo; Hongzheng Chen
• Keywords: Acceptor

Forming an ideal bulk heterojunction (BHJ) morphology is a critical issue governing the photon to electron process in organic solar cells (OSCs). Complementary widely-used blend casting (BC) method for BHJ construction, sequential (SC) can also enable similar or even better and device performance OSCs. Here, BC SC methods on three representative donor:acceptor (D:A) blends are utilized, that is, PM6:PC71 BM, PM6:IT-4F PM6:L8-BO. Higher power conversion efficiencies (PCEs) all cases by taking advantage of beneficial from processing achieved, champion PCE 18.86% (certified as 18.44%) based PM6:L8-BO reached, representing record value among binary The observations phase separation vertical distribution inspire proposal swelling-intercalation phase-separation model interpret evolution during processing. Further, segregation found deliver improvement via affecting charge transport collection processes, evidenced D:A-ratio-dependent photovoltaic properties. Besides, OSCs show advantages photostability upscale fabrication. This work demonstrates versatility efficacy BHJ-based