Synergistic dielectric and semiconducting properties in fluorescein monopotassium salt random copolymers

POLYMER

卷:114

Article

Zhao, Zhongqiang^1,2,3  Zhang, Zhongbo^3,4  Pejic, Sandra⁴  Zhang, Guoqiang³  Zhu, Yufeng³  Liu, Hewen^1,2  Litt, Morton³  Sauve, Genevieve⁴  Zhu, Lei^3,4 

[1] Univ Sci & Technol China, Chinese Acad Sci, Key Lab Soft Matter Chem, 96 Jinzhai Rd, Hefei 230026, Anhui, Peoples R China

[2] Univ Sci & Technol China, Dept Polymer Sci & Engn, 96 Jinzhai Rd, Hefei 230026, Anhui, Peoples R China

[3] Case Western Reserve Univ, Dept Macromol Sci & Engn, Cleveland, OH 44106 USA

[4] Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA

关键词: Semiconducting polymers;    Dielectric constant;    Fluorescein monopotassium salt;    Charge carrier mobility;    Optical band gap;   

DOI  :  10.1016/j.polymer.2017.02.095

来源: Elsevier

【 摘 要 】

The low dielectric constant (epsilon(r)-3-4) for semiconducting polymers has been a major cause for their poor performance compared with the inorganic semiconductors, which possess high dielectric constants above 10. This study aimed to increase the electronic/atomic dielectric constant at high frequencies (i.e., epsilon(r infinity)) for semiconducting polymers. A new design strategy was proposed based on the electric field-induced tautomeric structures in conjugated fluorescein. To achieve this goal, fluorescein monopotassium salt-containing random copolymers were synthesized with 50 and 75 mol.% functionality. To reduce the strong electrostatic attraction between the K+ cation and the phenolate anion, 18-crown-6 ether was complexed with K+ in the fluorescein copolymers. A relatively high epsilon(r infinity) of similar to 5.5 and high electron mobility of 0.153 cm(2)/(V.s) were achieved for the 75 mol.% fluorescein K+/18C6 copolymer. The high electron mobility could be attributed to the relatively high static dielectric constant (epsilon(rs) similar to 9 at 1 Hz) of the sample. The fluorescein monopotassium salt copolymers behaved as n-type semiconductors with an optical band gap around 2.26 eV. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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