Electrical properties of the interfaces in bulk heterojunction organic solar cells investigated by electrochemical impedance spectroscopy

- Organic photovoltaic cells based on P3HT:PCBM were fabricated with different drying durations of 0, 30, 60, and 80 min before annealing.
- The power conversion efficiency of the device with optimal 60 min drying increased by 10.3% compared with the device without drying.
- AC impedance analysis indicated that the optimal drying duration of P3HT:PCBM blend film facilitated the formation of the electrically perfect interface between P3HT and PCBM.