[25a-E206-1~9] 12.5 Organic solar cells

▲ [25a-E206-1] Lateral Tandem Organic Photovoltaic cells with carrier transport and generation layers

〇(D)Jaseela Palasheriithikkal^1,2, Yusuke Yabara¹, Shoko Uto¹, Seiichiro Izawa^1,2, Masahiro Hiramoto^1,2 (1.Institute for Molecular Science, Japan, 2.The Graduate University for Advanced Studies (SOKENDAI), Japan)

Keywords:Lateral tandem cell, organic solar cells

We report the fabrication and operation of organic photovoltaic cells with lateral junctions and separated carrier-generating and carrier-transporting layers. We operated function separated lateral cells with C8-BTBT and PTCDI-C8 as charge transporting layers and highly efficient light absorbing films of DBP and C60 as the charge generating layers (Fig 1(b)). A lateral cell having only a carrier generation layer (DBP/C60) showed no photocurrent (Fig. 1(d), orange curve). A lateral cell having only carrier transporting layer (C8-BTBT/PTCDI-C8, Fig 1(a)) showed a very small short-circuit photocurrent density (J_sc) of 0.005 mAcm^-2 (Fig. 1(d), blue curve). Significant photocurrent increase was observed by inserting carrier generating layer having strong visible absorption (Fig. 1(d), red curve). This justifies our hypothesis that the carriers are generated in DBP/C60 films and are transported laterally by C8-BTBT and PTCDI-C8 films. A lateral cell having a 2-unit cell (Fig. 1(c)) doubled the J_sc of one unit cell (Fig. 1(d), green curve). In this way, the lateral tandem cells can be successfully operated. For the lateral tandem cells, an increase in the number of unit cells increased the photocurrent while keeping the photovoltage constant.