Realizing Ultrahigh Mechanical Flexibility and >15%  Efficiency of Flexible Organic Solar Cells via a “Welding” Flexible Transparent Electrode

Xiaobin Chen¹, Guiying Xu¹, Guang Zeng^1,2, Hongwei Gu^1*（顾宏伟）, Haiyang Chen, Haitao Xu², Huifeng Yao³, Yaowen Li^1*（李耀文）, Jianhui Hou³, and Yongfang Li^{1, 3}

¹Laboratory of Advanced Optoelectronic Materials,College of Chemistry

Chemical Engineering and Materials Science,Soochow University,Suzhou 215123, China

²College of Materials Science and Engineering,Nanchang Hangkong University,696 Fenghe Avenue, Nanchang 330063, China

³Beijing National Laboratory for Molecular Sciences Institute of Chemistry ,Chinese Academy of Sciences,Beijing 100190, China

Adv. Mater. 2020, 32, 1908478

The power conversion efficiencies (PCEs) of flexible organic solar cells (OSCs) still lag behind those of rigid devices and their mechanical stability is unable to meet the needs of flexible electronics at present due to the lack of a high‐performance flexible transparent electrode (FTE). Here, a so‐called “welding” concept is proposed to design an FTE with tight binding of the upper electrode and the underlying substrate. The upper electrode consisting of solution‐processed Al‐doped ZnO (AZO) and silver nanowire (AgNW) network is well welded by utilizing the capillary force effect and secondary growth of AZO, leading to a reduction of the AgNWs junction site resistance. Meanwhile, the poly(ethylene terephthalate) is modified by embedding the AgNWs, which are then used to link with the AgNWs in the upper hybrid electrode, thus enhancing the adhesion of the electrode to the substrate. By this welding strategy, critical bottleneck issues relating to the FTEs in terms of optoelectronic and mechanical properties are comprehensively addressed. The single‐junction flexible OSCs based on this welded FTE show a high performance, achieving a record high PCE of 15.21%. In addition, the PCEs of the flexible OSCs are less influenced by the device area and display robust bending durability even under extreme test conditions.

链接：https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201908478