Ultrafast formation of high quality polymer films on a liquid substrate and fabrication of organic solar cells

Abstract

We introduce an ultrafast, scalable, and versatile process to form high quality organic films on a liquid substrate utilizing spontaneously spreading phenomenon of the films. This ap-proach has an easy control over the thickness of the films by tuning spreading conditions, and the films can be transferred to the various substrates. Moreover, the amphiphilicity of polymer molecule and the Marangoni flow by 1,8-diioodoctane (DIO) assist the films to have uniform and high quality of nanomorphology with finely phase-separated domains. Polymer solar cells were fabricated based on the high quality films, and the device showed excellent power con-version efficiency of 6.27 %. Furthermore, R2R system using this new process was suggested the potential for a scalable process in organic devices.