[10p-Z25-1~17] 12.2 Characterization and Materials Physics

▲ [10p-Z25-8] Lateral Junctions Reaching 1.8 cm for Organic Solar Cells

〇Jaseela Palasheriithikkal^1,2, A. Girault^1,3, Yusuke Yabara¹, Seiichiro Izawa^1,2, Masahiro Hiramoto^1,2 (1.Institute for Molecular Science, 2.SOKENDAI, 3.Chimie ParisTech Ecole nationale superieure de chimie de Paris)

Keywords:organic solar cells, long length carrier transport, mobility

Recently, we reported a lateral alternating multilayered junction using a high mobility organic semiconductor. In this study, we fabricated lateral junction cells having distance reaching cm order (Fig. 1). A donor [C8-BTBT (u_h = 43 cm²V^-1s^-1)] – acceptor [PTCDI-C8 (u_e = 1.7 cm²V^-1s^-1)] combination was used. Buffer layers of BCP and MoO₃ were used for the selective carrier collection of electrons and holes, respectively (Fig. 1). It is surprising that even lateral cells with L=1.8 cm showed clear photovoltaic behavior (Fig. 2, red curve) although the photocurrent of lateral cell decreased with L. Slopes of light intensity vs. photocurrent (J_sc) plots are close to unity even at L = 1.8 cm (Fig. 3). This means that little bimolecular recombination occurs in the cells. We assume that trap-assisted recombination is the main reason for photocurrent decrease (Fig. 4) . Hence, identifying and removing the defects acting as traps would improve the cell performance.