Highly Luminescent Encapsulated Narrow Bandgap Polymers Based on Diketopyrrolopyrrole

We present the synthesis and characterisation of a series of encap-sulated diketopyrrolopyrrole red-emitting conjugated polymers. The novel materials display extremely high fluorescence quantum yields in both solution (>70%) and thin film (>20%). Both the absorption and emission spectra show clearer, more defined features compared to their naked counterparts demonstrating the suppression of inter and intra-molecular aggregation. We find that the encapsulation results in decreased energetic disorder and a dramatic increase in backbone co-linearity as evidenced by STM. This study paves the way for DPP to be used in emissive solid state applications and demonstrates a novel method to reduce structural disorder in conju-gated polymers

Effect of Alkyl Chain Branching Point on 3D Crystallinity in High N-Type Mobility Indolonaphthyridine Polymers

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Herein, this study investigates the impact of branching-point-extended alkyl chains on the charge transport properties of three ultrahigh n-type mobility conjugated polymers. Using grazing incidence wide-angle X-ray scattering, analysis of the crystallinity of the series shows that while π–π interactions are increased for all three polymers as expected, the impact of the side-chain engineering on polymer backbone crystallinity is unique to each polymer and correlates to the observed changes in charge transport. With the three polymers exhibiting n-type mobilities between 0.63 and 1.04 cm2 V−1 s−1, these results ratify that the indolonaphthyridine building block has an unprecedented intrinsic ability to furnish high-performance n-type organic semiconductors