Direct observation of surface and internal phase-separated structure of the active layer buried in organic photovoltaic cells

A phase-separated structure of the active layer, of variable thickness, buried in organic thin film solar cells (OTSC) was directly observed by scanning force microscopy (SFM) with the aid of a surface and interface cutting analysis system (SAICAS). This deals with SFM observation to both the surface and the internal regions of the OTSCs, leading to discussion about the formation of the overlayer in the active layer.