Ferroelectric Nanodot Formation from Spin-Coated Poly(vinylidene fluoride-co-trifluoroethylene) Films and Their Application to Organic Solar Cells

We demonstrated a facile route to the preparation of self-assembled poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] nanodots from spin-coated thin films. We found that the initial film thickness would play an important role in the formation of such P(VDF-TrFE) nanodots. Interestingly, the electric dipoles of such nanodots were self-aligned toward the bottom electrode and their ferroelectric properties were determined by using piezoresponse force microscopy. In addition, the self-polarized ferroelectric nanostructures were introduced to small molecular organic photovoltaic devices and allowed for enhancing the short circuit current density (J(sc)) from 9.4 mA/cm(2) to 10.2 mA/cm(2) and the power conversion efficiency from 2.37% to 2.65%. (C) 2014 Wiley Periodicals, Inc.