Doping of Fullerenes via Anion‐Induced Electron Transfer and Its Implication for Surfactant Facilitated High Performance Polymer Solar Cells

Abstract
Simple and solution‐processible tetrabutyl‐ammonium salts (TBAX) can dope fullerene and its derivatives to achieve conductive thin films (σ as high as 0.56 S/m). The electron transfer between the anions of TBAXs and n‐type semiconductors induces doping without encountering any harsh activation. These provide valid support for the surfactant interfacial doping of fullerene in polymer solar cells for enhanced device performance.