Diketopyrrolopyrrole-Based Conjugated Polymer Entailing Triethylene Glycols as Side Chains with High Thin-Film Charge Mobility without Post-Treatments.

Si‐Fen Yang,De‐Qing Zhang,Hua‐Jun Ju,Guan‐Xin Zhang,Zheng‐Xu Cai,Zi‐Tong Liu,Natalie Stingelin,Matthew J Dyson,Wei Chen

doi:10.1002/advs.201700048

Abstract

Side chain engineering of conjugated donor–acceptor polymers is a new way to manipulate their optoelectronic properties. Two new diketopyrrolopyrrole (DPP)‐terthiophene‐based conjugated polymers PDPP3T‐1 and PDPP3T‐2, with both hydrophilic triethylene glycol (TEG) and hydrophobic alkyl chains, are reported. It is demonstrated that the incorporation of TEG chains has a significant effect on the interchain packing and thin‐film morphology with noticeable effect on charge transport. Polymer chains of PDPP3T‐1 in which TEG chains are uniformly distributed can self‐assemble spontaneously into a more ordered thin film. As a result, the thin film of PDPP3T‐1 exhibits high saturated hole mobility up to 2.6 cm2 V−1 s−1 without any post‐treatment. This is superior to those of PDPP3T with just alkyl chains and PDPP3T‐2. Moreover, the respective field effect transistors made of PDPP3T‐1 can be utilized for sensing ethanol vapor with high sensitivity (down to 100 ppb) and good selectivity.

Highlights

Introduction to manipulate their optoelectronic propertiesTwo new diketopyrrolopyrrole (DPP)-terthiophene-based conjugated polymers PDPP3T-1 and PDPP3T-2, with both hydrophilic triethylene glycol (TEG) and hydrophobic alkyl chains, are reported
The results reveal that attaching TEG chains in a regular fashion as in PDPP3T-1 is more favorable for improving molecular order than the random arrangement in PDPP3T-2
Thin films of PDPP3T-1 show better molecular order and a beneficial edge-on chain orientation compared to films of the PDPP3T polymer without TEG chains

Summary

FULL PAPER

Zhang Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids In this respect, various electron acceptors and donors have been devised and incorporated into the polymer backbones to tune their highest occupied molecular orbital (HOMO)/ lowest unoccupied molecular orbital (LUMO) levels and back-. Chen Materials Science Division Argonne National Laboratory acceptors.[19,20,21,22,23,24,25,26,27] Recent studies demonstrate that the alkyl side chains in conjugated D-A polymers improve solubility and influence interchain packing and affect their semiconducting properties. Field-effect transistors with thin films of PDPP3T-1 show sensitive and selective response to alcohol vapors by taking advantage of the presence of TEG chains in PDPP3T-1

Results and Discussion

Conclusion

Conflict of Interest