The correlation between open-circuit voltage (VOC) and built-in potential (Vbi) upon photo-irradiation in the vicinity of the donor/acceptor (D/A) interface in zinc-octaethylporphyrin [Zn(OEP)]/C 60 heterojunction photovoltaic (OPV) cells is investigated by examining the capacitance-voltage (C-V) characteristics. Charge accumulation of photogenerated carriers in the vicinity of the D/A interface is found to enlarge Vbi of both D [Zn(OEP)] and A (C60) films in the vicinity of the interface. In addition, it is noted that VOC is in good agreement with the sum of Vbi of each film in the vicinity of the D/A interface. This suggests that charge accumulation of photogenerated carriers in the vicinity of the D/A interface plays a key role in determining V OC for solar cells.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films