Change in electronic states before and after photo-irradiation at a Donor/Accepter (D/A) interface in organic solar cells consisting of Zinc-porphyrin and fullerene films has been examined using in situ impedance spectroscopy (IS), which makes it possible to non-destructively measure a built-in potential (Vbi) of both D and A films at the D/A interface. Charge accumulation of photo-generated carriers in the vicinity of the D/A interface was found to enlarge the Vbi of both D [Zn(OEP)] and A [C60] films at the interface. In addition, it was noted that the sum of Vbi upon photo-irradiation was in good agreement with the open-circuit voltage (VOC), the origin of which has still remained unsolved for organic solar cells. It was thus found that charge accumulation of photo-generated carriers in the vicinity of the D/A interface plays a key role in determining VOC.
|Number of pages||6|
|Journal||IEEJ Transactions on Electronics, Information and Systems|
|Publication status||Published - 2012|
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering