초록 |
In fabrication procedure of all-polymer solar cells (APSCs), various solvent additives such as 1-chloronaphthalene (CN), 1,8-diiodooctane (DIO), and diphenylether (DPE) must be used to optimized the morphology of photoactive layer. In general, CN is non-aggregated good solvent for both PTB7-Th and P(NDI2OD-T2) polymers. DIO and DPE, on the other hand, are known as a marginal solvent for polymers. Despite such difference between solvent additives, there is no systematic study on the effect of solvent additives. In this work, we investigated the effect of various solvent additives on the performance of all-polymer solar cells based on the blend of PTB7-Th donor and P(NDI2OD-T2) acceptor. By using DIO or DPE additive, the power conversion efficiency (PCE) was slightly increased from 3.5% to 4.2% and 4.4%, respectively. Interestingly, when a very small amount of CN (0.1 vol %) was added into all-polymer blend, the PCE value was also enhanced marginally from 3.5% to 4%. |