Nanoscale phase separation in the bulk heterojunction structure of perylene bisimide and porphyrin by controlling intermolecular interactions

Abstract

We demonstrate the concept of controlling phase separation behavior through designing directional intermolecular interactions. The twisted molecular configuration and intermolecular hydrogen bonds result in PBI-1 self-assembly into nanofiber aggregates of the order of tens of nanometers. In the blend of Zn-mTNP and PBI-1, the charge transfer interaction was suppressed effectively due to the unfavored π–π stacking for their twisted and planar molecular configurations. The spin-coated films of Zn-mTNP, PBI-1 and their blend have been characterized by UV-vis absorption spectra, and atomic force microscopy, revealing that the preferred phase separation structures in the nano scale were obtained.