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Download fileObservation of Stepwise Ultrafast Crystallization Kinetics of Donor–Acceptor Conjugated Polymers and Correlation with Field Effect Mobility
journal contribution
posted on 15.02.2021, 17:35 authored by Shaochuan Luo, Nan Li, Song Zhang, Chen Zhang, Tengfei Qu, Michael U. Ocheje, Gi Xue, Xiaodan Gu, Simon Rondeau-Gagné, Wenbing Hu, Sihong Wang, Chao Teng, Dongshan Zhou, Jie XuThe semicrystalline microstructures
of donor–acceptor conjugated
polymers strongly impact their optoelectronic properties. The control
of the microstructure relies on the understandings of the crystallization
processes in these polymers, from packing structures to crystallization
kinetics. How fast these conjugated polymer chains crystallize and
how their chemical structures and pre-existing microstructure history
influence their crystallization have so far remained unclear, due
to the fast crystallization rate caused by chain rigid structures
and strong interactions. Here, ultrafast scanning calorimetry (FSC)
is employed to reveal the crystallization behaviors of high performance
diketopyrrolopyrrole (DPP)-based conjugated polymers with scanning
rates up to 500 000 K/s. Through elaborately designed nonisothermal
and isothermal crystallization studies, we probed the fast crystallization
kinetics and extracted the two-step crystallization process of these
polymers quantitatively. We found that both the rigidity of the chain
backbones and the preinduced crystalline microstructures can influence
the crystallization rate over an order of magnitude at the same degree
of undercooling. We further demonstrated the manipulated crystallization
kinetics in the DPP-based polymer films with different amounts of
preinduced crystallites and correlate it to the polymers’ charge
transport mobility.