Stable perovskite solar cells with efficiency exceeding 24.8% and 0.3-V voltage loss
Mingyu Jeong, In Woo Choi, Eun Min Go, Yongjoon Cho, Minjin Kim, Byongkyu Lee, Seonghun Jeong, Yimhyun Jo, Hyewon Choi, Jiyun Lee, Jin‐Hyuk Bae, Sang Kyu Kwak, Dong Suk Kim, Changduk Yang
Abstract
Further improvement and stabilization of perovskite solar cell (PSC) performance are essential to achieve the commercial viability of next-generation photovoltaics. Considering the benefits of fluorination to conjugated materials for energy levels, hydrophobicity, and noncovalent interactions, two fluorinated isomeric analogs of the well-known hole-transporting material (HTM) Spiro-OMeTAD are developed and used as HTMs in PSCs. The structure-property relationship induced by constitutional isomerism is investigated through experimental, atomistic, and theoretical analyses, and the fabricated PSCs feature high efficiency up to 24.82% (certified at 24.64% with 0.3-volt voltage loss), along with long-term stability in wet conditions without encapsulation (87% efficiency retention after 500 hours). We also achieve an efficiency of 22.31% in the large-area cell.