“...our paper provides insights into how to combine different polymers to form multicomponent organic semiconductors and control their ability to transport both electrons and holes”

One of the key challenges of developing plastic electronics based on polymer (or organic) semiconductors is that, unlike inorganic semiconductors such as silicon, current polymer semiconductors do not have the ability to accept and transport both electrons and holes. Typical electroluminescent polymer semiconductors either have good hole accepting and transport (p-type) characteristics, as exemplified by poly(p-phenylene vinylene) (PPV), or good electron accepting and transport (n-type) characteristics, as seen in poly(phenylquinoline) (PPQ). To make efficient, high-performance, polymer semiconductor devices like light-emitting diodes (LEDs) requires the combination of a p-type polymer with an n-type polymer into a multicomponent system in the form of multilayered thin films or physical blends. Our paper showed that well-defined two-layer heterojunctions can be prepared from a p-type conjugated polymer such as PPV and a series of n-type conjugated polymers with different electronic structures, paving the way for both fundamental insights into the roles of the electronic structure of the polymer/polymer interface and for device applications. Two-layer heterojunction thin films represent excellent model systems for understanding many multicomponent conjugated polymers, including multilayer thin films, phase-separated blends and block copolymers. Such multicomponent conjugated polymers are of growing interest in LEDs, solar cells, and other applications.

Samson A. Jenekhe
Boeing-Martin Professor of Chemical Engineering
Professor of Chemistry
University of Washington
Seattle, Washington, USA