| 초록 |
Here, we develop a series of novel polymer donors (PDs), with which highly efficient PSCs having remarkable mechanical reliability are demonstrated. By interposing a controlled amount of 1,10-di(thiophen-2-yl)decane flexible spacer (FS) into a PM6 backbone, we are able to significantly enhance the intermixing of the new PDs with a small molecule acceptor (Y7), affording sufficient pathways for efficient charge percolation and mechanical stress dissipation. As a result, PSCs based on the PD containing 5 mol% FS units and Y7 exhibit a high power conversion efficiency (PCE) of 17% with a crack onset strain (COS) of 12% and a cohesive fracture energy (Gc) of 2.1 J m−2, significantly outperforming reference PM6-based devices (PCE = 15%, COS = 2% and Gc = 1.0 J m−2). Both the photovoltaic performance and mechanical robustness of these PSCs are among the best values reported to date. The rational design of the PDs demonstrated here presents a highly promising strategy to address the mechanical properties of SMA-based solar cells and their viable application in flexible/stretchable electronics. |
