Electrostatically Self-Assembled Nonconjugated Polyelectrolytes as an Ideal Interfacial Layer for Inverted Polymer Solar Cells

Abstract

Nonconjugated polyelectrolytes (NPEs) are ideal interfacial layers for high-efficiency inverted polymer solar cells (I-PSCs). The NPEs are coated on indium tin oxide (ITO) using ionic self-assembly. Due to dipole formation between the cationic amine of the NPE and the anionic oxygen of ITO, the work function of ITO is dramatically reduced from 4.8 to 4.0 eV. Using the modified ITO, UV-independent I-PSCs with high efficiencies of 6.3% are demonstrated.