Current Enhancement with Contact-Area-Limited Doping for Bottom-Gate, Bottom-Contact Organic Thin-Film Transistors

• Kei Noda

• Yusuke Wakatsuki

• Yuji Yamagishi

• Yasuo Wada

• Toru Toyabe

• Kazumi Matsushige

Abstract

The current enhancement mechanism in contact-area-limited doping for bottom-gate, bottom-contact (BGBC) p-channel organic thin-film transistors (OTFTs) was investigated both by simulation and experiment. Simulation results suggest that carrier shortage and large potential drop occur in the source-electrode/channel interface region in a conventional BGBC OTFT during operation, which results in a decrease in the effective field-effect mobility. These phenomena are attributed to the low carrier concentration of active semiconductor layers in OTFTs and can be alleviated by contact-area-limited doping, where highly doped layers are prepared over source–drain electrodes. According to two-dimensional current distribution obtained from the device simulation, a current flow from the source electrode to the channel region via highly doped layers is generated in addition to the direct carrier injection from the source electrode to the channel, leading to the enhancement of the drain current and effective field-effect mobility. The expected current enhancement mechanism in contact-area-limited doping was experimentally confirmed in typical α-sexithiophene (α-6T) BGBC thin-film transistors.

Journal

• Japanese Journal of Applied Physics

  Japanese Journal of Applied Physics 52 (2R), 021602-, 2013-01-31

  IOP Publishing

Keywords

• General Physics and Astronomy
• General Engineering

Details

• CRID: 1360847874816406272
• NII Article ID: 210000141818
• DOI: 10.7567/jjap.52.021602
• ISSN: 13474065
• ISSN: 00214922
• ISSN: http://id.crossref.org/issn/13474065
• Web Site: https://iopscience.iop.org/article/10.7567/JJAP.52.021602
• Web Site: https://iopscience.iop.org/article/10.7567/JJAP.52.021602/pdf
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