Thermoplastic elastomer enhanced interface adhesion and bending durability for flexible organic solar cells
Zihan Xu, Yunfei Han, Yuanyuan Bai, Xingze Chen, Jingbo Guo, Lianping Zhang, Chao Gong, Qun Luo, Ting Zhang, Chang‐Qi Ma
Abstract
Abstract Stable interface adhesion and bending durability of flexible organic solar cells (FOSCs) is a basic requirement for its real application in wearable electronics. Unfortunately, the device performance always degraded during continuous bending. Here, we revealed the weak interface adhesion force between MoO 3 hole transporting layer (HTL) and the organic photoactive layer was the main reason of poor bending durability. The insertion of an interface bonding layer with a thermoplastic elastomer, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) effectively improved the interface adhesion force of MoO 3 HTL and the active layer and decreased the modulus, which ensured higher than 90% of the initial efficiency remaining after 10000 bending. Meanwhile, the FOSCs gave an efficiency of 14.18% and 16.15% for the PM6:Y6 and PM6:L8-BO devices, which was among the highest performance of FOSCs. These results demonstrated the potential of improving the mechanical durability of FOSCs through thermoplastic elastomer interface modification.