Ablation enhancement of polymer-fullerene blend films under temporally-shaped femtosecond laser processing

As a very promising method for improving the performance of organic photovoltaic (OPV) devices, femtosecond laser processing is advantaged at high processing precision, small heat-affected zone and can achieve selective morphology control of the active layer. However, almost current studies focused on single pulse processing. In this work, the single and double pulse processing laws of poly(3-hexyl-thiophene) (P3HT): phenyl-C61-butyricacid methyl ester (PCBM) blend films were explored by using temporally-shaped femtosecond laser processing system. When single pulse processing is used, it indicated a structural transformation process from bump to ablation crater. The temporally-shaped double pulse femtosecond laser processing results showed the effect of ablation enhancement compared with the single pulse, and the ablation depth and the ablation area increased. (For bumps, it facilitated further fragmentation). When the double pulse delay is 0.5ps, the effect of ablation enhancement (bump fragmentation) was the strongest. This letter proposed an ablation enhancement approach based on temporally-shaped femtosecond laser processing, which can further control the morphology of the active layer for promoted performance of OPV devices.