Journal article

Photophysical Identification of Three Kinds of Low-Energy Green Band Defects in Wide-Bandgap Polyfluorenes

Yi-Fan Bo, Yu-Yu Liu, Hamid Soleimaninejad, Meng-Na Yu, Ling-Hai Xie, Trevor A Smith, Kenneth P Ghiggino, Wei Huang

JOURNAL OF PHYSICAL CHEMISTRY A | AMER CHEMICAL SOC | Published : 2019

Abstract

Blue-light-emitting semiconductors based on polyfluorenes often exhibit an undesired green emission band. In this report, three well-defined oligofluorenes corresponding to three types of "defects" attributed to aggregation, keto formation, and chain entanglement, respectively, are systemically investigated to unveil the origins of the green emission band in fluorene-based materials. First, the optical properties of defect molecules in different states are studied. The defect associated with aggregation is absent in dilute solutions and in films doped at 0.01 wt % with poly(methyl methacrylate). Second, the dependence of the emission spectra on the solvent was monitored to compare the effect..

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Grants

Awarded by National Natural Science Foundation of China


Awarded by Doctoral Fund of Ministry of Education of China


Awarded by Natural Science Foundation of Jiangsu Province of China


Awarded by Nanjing University of Post and Telecommunications


Awarded by ARC Centre of Excellence in Exciton Science


Funding Acknowledgements

The project was supported by the National Natural Science Foundation of China (2150314, 21602111, 61605090), Doctoral Fund of Ministry of Education of China (20133223110007), Natural Science Foundation of Jiangsu Province of China (BK20150832, BK20180751), the Nanjing University of Post and Telecommunications (NY217082), and Synergetic Innovation Center for Organic Electronics and Information Displays and Excellent science and technology innovation team of Jiangsu Higher Education Institutions (2013). This project was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions. We also acknowledge support of the University of Melbourne IRRTF Scheme and the ARC Centre of Excellence in Exciton Science (CE170100026) (TAS).