Nanoassembly of Dipolar Imidazoanthraquinone Derivatives Leading to Enhanced Hole Mobility

Abstract

Imidazoanthraquinone-based high dipolar molecules (AQ01 and AQ02) were synthesized and characterized. Photophysical properties in various solvents suggested the polar nature of the ground state for these materials. In addition, fluorescence quenching experiments with the commonly used electron donor poly-3-hexylthiophene (P3HT) in bulk heterojunction (BHJ) solar cells ascertained the electron acceptor properties of these molecules. Theoretical calculations based on density functional theory (DFT) gave insight on the dipolar nature, H-bonding, and π–π interaction in different types of supramolecular assemblies of AQ01 and AQ02. Calculations predicted that the π–π interaction via antiparallel orientation and H-bonding with the OH···OH interaction is favored energetically in AQ01. Morphological studies on thermally evaporated thin films indicated interconnected nanoassemblies in AQ01 while random aggregates in AQ02. Charge transport properties of these molecules were estimated for AQ01/AQ02 and their blends ...