Polymer design to promote low work function surfaces in organic electronics

Abstract

Organic electronics (OEs) are advantageous for their mechanical flexibility, light weight, and easy solution processability over large areas, all ideal characteristics for next generation portable, cost-effective flexible electronics. The interlayer materials present between the organic active layer and electrodes are critical elements for promoting efficient device operation. Recently, solution-processable polymers have been investigated extensively as efficient electrode interlayer materials for applications in OE devices. We begin this article by describing energy level alignment mechanisms associated with contact of the polymer interlayer and metal electrode. We then overview the latest progress where polymer interlayer materials are used in efficient OE device fabrication. We discuss critical properties of these polymer interlayers, including (1) polymer interactions with the metal surface; (2) the effect of energy levels and electronic structures of these polymers on interfacial modification; and (3) the effect of charge transport and conductivity of the polymer interlayer on device operation. Our motivation is to describe our current understanding, recent progress, and outstanding issues of polymer interlayers in OEs, and propose future potential directions and opportunities.