Flexible High‐Performance and Solution‐Processed Organic Photovoltaics with Robust Mechanical Stability

다국어 초록 (Multilingual Abstract)

Among the various advantages of organic photovoltaics (OPVs), the key one is their ability to be a highly flexible renewable energy source. However, the power conversion efficiencies for flexible OPV devices still lag behind those of their rigid counterparts, and their mechanical stability cannot meet the requirements for practical applications at present. These, in particular, depend on flexible transparent electrodes (FTEs). Here, a high‐quality FTE (called FlexAgNE), with the simultaneously combined excellent characteristics, has been tested with a series of efficient active materials for flexible OPV devices, and high performance comparable with rigid counterparts has been achieved. In addition, due to the synergistic effect of FlexAgNE and the upper ZnO transport layer, including strong binding between the polyethylene terephthalate substrate and a hydrophilic polyelectrolyte (the key component of FlexAgNE), together with the capillary force effect of crossed silver nanowires and tight filling of ZnO, the flexible devices demonstrate robust mechanical stability even under extreme bending or folding conditions.
Using newly developed high‐quality FlexAgNEs, flexible OPV devices are fabricated and studied with the newly emerging star acceptor Y6 and its derivatives. Comparable performance with rigid counterparts is achieved for all the tested materials. The flexible devices display superior and robust mechanical stability under extreme bending or even folding conditions. Furthermore, the mechanism underlying the super mechanical robustness of these flexible devices is thoroughly investigated.