This work studies the open-circuit voltage (VOC) of planar and bulk heterojunction organic photovoltaic (OPV) devices by means of electroluminescent (EL) technique to resolve the charge transfer (CT) states between donor and acceptor. The OPV devices containing a small part of bulk heterojunction increases the VOC as a result of the enhanced CT process as compared with a complete planar structure. Red shift of the CT charge transfer was observed by increasing the bulk volume, which indicates the increased degree of interaction between both molecules and excitons. By characterizing the EL spectra of OPV devices and relating them to the CT absorption, the interfacial property between the donor and acceptor is shown to be crucial for determining the VOC in small-molecule OPV devices. Detailed analysis of the energetic loss was also used to interpret the VOC under the effect of CT states.
|頁（從 - 到）||1-8|
|期刊||Organic Electronics: physics, materials, applications|
|出版狀態||已發佈 - 1月 1 2015|
ASJC Scopus subject areas
- 化學 (全部)