Enhanced Charge Injection Properties of Organic Field-Effect Transistor by Molecular Implantation Doping

Youngrok Kim, Seungjun Chung, Kyungjune Cho, David Harkin, Wang Taek Hwang, Daekyoung Yoo, Jae Keun Kim, Woocheol Lee, Younggul Song, Heebeom Ahn, Yongtaek Hong, Henning Sirringhaus, Keehoon Kang, Takhee Lee

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


Organic semiconductors (OSCs) have been widely studied due to their merits such as mechanical flexibility, solution processability, and large-area fabrication. However, OSC devices still have to overcome contact resistance issues for better performances. Because of the Schottky contact at the metal–OSC interfaces, a non-ideal transfer curve feature often appears in the low-drain voltage region. To improve the contact properties of OSCs, there have been several methods reported, including interface treatment by self-assembled monolayers and introducing charge injection layers. Here, a selective contact doping of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) by solid-state diffusion in poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) to enhance carrier injection in bottom-gate PBTTT organic field-effect transistors (OFETs) is demonstrated. Furthermore, the effect of post-doping treatment on diffusion of F4-TCNQ molecules in order to improve the device stability is investigated. In addition, the application of the doping technique to the low-voltage operation of PBTTT OFETs with high-k gate dielectrics demonstrated a potential for designing scalable and low-power organic devices by utilizing doping of conjugated polymers.

Original languageEnglish
Article number1806697
JournalAdvanced Materials
Issue number10
Publication statusPublished - 2019 Mar 8

Bibliographical note

Funding Information:
This work was supported by the National Creative Research Laboratory Program (grant No. 2012026372) through the National Research Foundation of Korea funded by the Korean Ministry of Science and ICT. S.C. appreciates the financial support from the Korean Ministry of Trade, Industry & Energy and Korea Display Research Consortium support program (10051541). Y.H. appreciates the financial support from the R&D Convergence Program of NST (National Research Council of Science & Technology) of Korea (CAP-15-04-KITECH). D.H. would like to thank the Doctoral Training Centre in Plastic Electronics EP/G037515/1. H.S. acknowledges funding from the European Research Council (ERC) through a Synergy Grant (Grant No. 610116). The authors thank R. D. Pietro for valuable discussions.

Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering


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