| 초록 |
The mechanical robustness of the polymer solar cells (PSCs) is importance to ensure the long-term stability for applications in flexible electronics. Here, we compare the mechanical properties of non-fullerene small molecule acceptor (SMA)-based, polymer acceptor (PA)-based, and fullerene-based PSCs. We chose ITIC as SMA, P(NDI2OD-T2) as PA, and PCBM as the fullerene derivative as three representative acceptors. And, we apply the P(NDI2OD-T2) PA with different number-average molecular weight (Mn) from 15 to 163 kg mol-1 in all-PSCs. The all-PSCs based high Mn PA exhibit higher cohesion energy (4.03 J m-2) than SMA-PSCs (1.19 J m-2) and PCBM-PSCs (0.29 J m-2). Notably, the all-PSCs exhibited a much higher strain at fracture of 31.1%, which is 9- and 28-fold higher than those of SMA-PSCs and PCBM-PSCs, respectively. The superior mechanical robustness of all-PSCs is attributed to the use of high Mn PA above the critical molecular weight producing tie molecules and chain entanglements. |
