08/2017

In this report, that brings together four research groups from the United States, Belgium and China, a novel continuous flow based C–H functionalization technology is used to prepare organic thin-film polymers for application in organic photovoltaic (OPV) devices in a reproducible and efficient fashion.

OPV devices offer great potential as renewable energy sources. There are two major challenges that hamper the implementation of polymer-based solar cells in large scale application; lack of availability of large quantities of high-quality polymer and translation of the device efficiencies seen in lab-based spin-coated devices to manufacturing scale large are printed devices.

Lab-based synthesis of these polymers is performed batch-to-batch, as such quality and performance can vary from batch-to-batch. The sensitivity of this reaction to specific reaction conditions means that reproducibility is low. This report employs continuous flow technology to overcome this hurdle, with a bespoke reactor designed and built that delivers, in a reproducible fashion, a technique to synthesize polymers in a reliable and highly controlled fashion. The observed control over the molecular weight of the flow process significantly surpasses that of the batch technique.

The results from this study provide a scalable and controlled technique for production of these valuable OPV polymers, furnishing products with properties suitable for use in roll-to-roll large area printing devices, solutions to both of the identified major challenges for this technology