Efficiency improvement of blended poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 solar cells by nanoimprinting

This work demonstrates the effects of nanoimprinting on poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 (P3HT:PCBM)-blended organic solar cells at room temperature. Textured Si wafer was used as a stamp. Nanoimprinting significantly increased the open-circuit voltage, the short-circuit current, and the fill factor, increasing the power conversion efficiency by ∼50%. The fill factor contributed most to the cell efficiency. Upon nanoimprinting, not only the surface structure but also the applied pressure contributed to the performance of the device. The origin of the hydrostatic pressure-induced efficiency improvement was also investigated. The proposed approach has potential to be applied in the future to improve the efficiency of various organic solar cells.