Improving performance of polymer solar cell by adjusting crystallinity and nanoscale phase separation

In this paper, we report a high-performance P3HT/PCBM bulk-heterojunction solar cell with a power conversion efficiency of 4.85% fabricated by adjusting polymer crystallinity and nanoscale phase separation using an ultrasonic irradiation mixing approach of the polymer. The results of grazing incidence X-ray diffraction, UV/Vis spectroscopic, and atomic force microscopic measurements of the P3HT/PCBM blend films reveal that the P3HT/PCBM film fabricated by ultrasonic irradiation mixing P3HT and PCBM solutions for 10 min has higher degree of crystallinity, higher absorption efficiency, and better phase separation, which altogether account for the higher charge transport properties and photovoltaic cell performance.