| 초록 |
A simple method was developed to tune the work function (WF) of indium tin oxide (ITO) cathode in inverted polymer solar cells (PSCs) by inserting a poly(diallyldimethylammonium chloride) (PDDAC) nanolayer as an electron collecting layer (ECL). The WF of ITO is dramatically reduced by dipole formation between the cationic amine of the PDDAC and the anionic oxygen of ITO. A reduction of ITO WF leads to improved electron selectivity. As a result, all solar cell parameters including short circuit current density, open circuit voltage and fill factor are improved, leading to the power conversion efficiency of 2.64% for P3HT:PC71BM active systems under AM1.5G illumination, which is significantly higher than that of the control inverted PSC with blank ITO and comparable to that of the control inverted PSC with ZnO ECL. The results provide an efficient method for interface engineering in organic-based optoelectronic devices. |
