Block Copolymers for Organic Optoelectronics

Abstract

While polymers hold significant potential as low cost, mechanically flexible, lightweight large area photovoltaics and light emitting devices (OLEDs), their performance relies crucially on understanding and controlling the morphology on the nanometer scale. The ca. 10 nm length scale of exciton diffusion sets the patterning length scale necessary to affect charge separation and overall efficiency in photovoltaics. Moreover, the imbalance of electron and hole mobilities in most organic materials necessitates the use of multiple components in many device architectures. These requirements for 10 nm length scale patterning in large area, solution processed devices suggest that block copolymer strategies previously employed for more classical, insulating polymer systems may be very useful in organic electronics. This Perspective seeks to describe both the synthesis and self-assembly of block copolymers for organic optoelectronics. Device characterization of these inherently complex active layers remains a significant challenge and is also discussed.