A Universal Method to Produce Low–Work Function Electrodes for Organic Electronics

TLDR

Organic and printed electronics require conductors with a sufficiently low work function to enable efficient electron transport in optoelectronic devices. The authors propose that polymer surface modifiers can simplify manufacturing of low‑cost, large‑area organic electronics. The neutral polymer physisorbs onto conductors, lowering their work function and rendering them electron‑selective, and can be applied from solution in air as a non‑reactive alternative to low‑work‑function metals. Polymers with simple aliphatic amine groups were shown to reduce the work function of metals, transparent conductive oxides, conducting polymers, and graphene.

Abstract

Organic and printed electronics technologies require conductors with a work function that is sufficiently low to facilitate the transport of electrons in and out of various optoelectronic devices. We show that surface modifiers based on polymers containing simple aliphatic amine groups substantially reduce the work function of conductors including metals, transparent conductive metal oxides, conducting polymers, and graphene. The reduction arises from physisorption of the neutral polymer, which turns the modified conductors into efficient electron-selective electrodes in organic optoelectronic devices. These polymer surface modifiers are processed in air from solution, providing an appealing alternative to chemically reactive low-work function metals. Their use can pave the way to simplified manufacturing of low-cost and large-area organic electronic technologies.