14:15 〜 14:30
▼ [20p-W531-6] Interface Engineering of Inverted Organic Solar Cells using V-Shaped Polyaromatic Amphiphile as Fullerene-catching Surface Modifier
キーワード：organic solar cells,surface treatment,interface
In this work, by casting a water soluble anthracene-based V-shaped polyaromatic amphiphiles on metal oxides in organic solar cells, the interface between transparent metal oxide (ITO and ZnO), and photoactive organic layer has been improved. The anthracene-based organic surface modifiers re-engineered electron extraction layer by covering up the defect sites of the metal oxides with their positively charged ends to improve charge transport. Also its apposite energy level values allowed both increase in work function of ITO while acting as a hole-blocker, which even allowed the a thin layer of modifiers to replace ZnO. Moreover, their bent polyaromatic ends could act as fullerene catchers, forming an aligned layer of fullerene electron acceptors. They formed ohmic contact with the fullerene derivatives for photogenerated charge-carrier collection and allowed optimum photon harvest in the device. Such properties have been demonstrated and explained using various analyses. These anthracene-treated ZnO-based solar cells showed an average power conversion efficiency of 3.08% while non-treated devices gave an average of 2.91%. Even solar cells without ZnO layer, in which the anthracene derivatives were applied on ITO, it produced 2.58%. By the time we present this work, anthacene application in low-band gpa polymer, PTB7 will be complete to show a power conversion efficiency above 8.00%. We are positive that these findings will open new avenues in understanding and tailoring the interfaces between organic semiconductors and transparent oxides for the advancement of surface modifiers and solar cell researches.