Abstract

Carrier mobilities of organic single crystals reached greater than 10 cm² V^-1s^-1 [1,2]. Such high mobility was observed for carriers moving laterally through the material due to π-π stacking parallel to the crystal surface. Conventional organic solar cells are built vertically on indium tin oxide (ITO) glass substrates with a sandwich-type structure [3-6]. However, the thickness of such solar cells with blended layers of donor (D) and acceptor (A) molecules, which are indispensable to dissociate excitons, is limited to just around 100nm due to the problem of carrier collection arising from imperfections in the electron and hole transport routes in the blended layer. If the photogenerated electrons and holes can be transported laterally and collected, we can be freed from the vertical transport of carriers and freed from the limitation to the vertical thickness of the cell.

Abbreviations: Indium tin oxide; Donor; Acceptor; DBP; NTCDA