An Organic Borate Salt with Superior p‐Doping Capability for Organic Semiconductors

Advanced Science

Jan Behrends¹  Claudia E. Tait¹  Andreas Opitz²  Berthold Wegner²  Emil J. W. List‐Kratochvil²  Norbert Koch²  Dominique Lungwitz²  Ahmed E. Mansour²  Tianshu Zhai³  Steffen Duhm³  Naoki Tanaka⁴  Yoshiaki Shoji⁴  Takanori Fukushima⁴  Michael Forster⁵  Ullrich Scherf⁵ 

[1] Berlin Joint EPR Lab Fachbereich Physik Freie Universität Berlin Berlin D‐14195 Germany;Institut für Physik and IRIS Adlershof Humboldt‐Universität zu Berlin Berlin D‐12489 Germany;Institute of Functional Nano and Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon‐Based Functional Materials and Devices and Joint International Research Laboratory of Carbon‐Based Functional Materials and Devices Soochow University Suzhou 215123 P. R. China;Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226‐8503 Japan;Makromolekulare Chemie and Institut für Polymertechnologie Bergische Universität Wuppertal Wuppertal D‐42097 Germany;

关键词: bipolarons;    borate salt;    doping;    organic semiconductors;    polarons;   

DOI  :  10.1002/advs.202001322

来源: DOAJ

【 摘 要 】

Abstract Molecular doping allows enhancement and precise control of electrical properties of organic semiconductors, and is thus of central technological relevance for organic (opto‐) electronics. Beyond single‐component molecular electron acceptors and donors, organic salts have recently emerged as a promising class of dopants. However, the pertinent fundamental understanding of doping mechanisms and doping capabilities is limited. Here, the unique capabilities of the salt consisting of a borinium cation (Mes2B+; Mes: mesitylene) and the tetrakis(penta‐fluorophenyl)borate anion [B(C6F5)4]− is demonstrated as p‐type dopant for polymer semiconductors. With a range of experimental methods, the doping mechanism is identified to comprise electron transfer from the polymer to Mes2B+, and the positive charge on the polymer is stabilized by [B(C6F5)4]−. Notably, the former salt cation leaves during processing and is not present in films. The anion [B(C6F5)4]− even enables the stabilization of polarons and bipolarons in poly(3‐hexylthiophene), not yet achieved with other molecular dopants. From doping studies with high ionization energy polymer semiconductors, the effective electron affinity of Mes2B+[B(C6F5)4]− is estimated to be an impressive 5.9 eV. This significantly extends the parameter space for doping of polymer semiconductors.

【 授权许可】

Unknown