초록 |
We report a both highly efficient and mechanically robust polymer solar cells (PSCs), employing high molecular weight (MW) polymer aceptor (PA) additives into highly efficient PSC system. In the conventional ITO-based architectured PSCs, reference PSC system showed 15.4% of maximum PCE without PA additive, and the PCE maintained up to 14.0% with incorporating 30% of the additive. With further loading of the PA additive, the PCE decreases rapidly showing 8.7% at the 50% of the PA loading. Notably, the engineering crack onset strain (COS) sharply increases in proportional to the loading amount of the PA additives, from 2.3 at the 0% to 12.4% at the 30% of the additive loading. We revealed both the PCE maintanence and the skyrocketed mechanical robustness with loading of the PA additive are mainly attributed to the formation of chain entanglement and tie molecules due to long PA chains. |