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Vertical, electrolyte-gated organic transistors show continuous operation in the MA cm−2 regime and artificial synaptic behaviour

Nature Nanotechnology volume 14, pages 579–585 (2019)Cite this article

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Abstract

Until now, organic semiconductors have failed to achieve high performance in highly integrated, sub-100 nm transistors. Consequently, single-crystalline materials such as single-walled carbon nanotubes, MoS2 or inorganic semiconductors are the materials of choice at the nanoscale. Here we show, using a vertical field-effect transistor design with a channel length of only 40 nm and a footprint of 2 × 80 × 80 nm2, that high electrical performance with organic polymers can be realized when using electrolyte gating. Our organic transistors combine high on-state current densities of above 3 MA cm−2, on/off current modulation ratios of up to 108 and large transconductances of up to 5,000 S m−1. Given the high on-state currents at such large on/off ratios, our novel structures also show promise for use in artificial neural networks, where they could operate as memristive devices with sub-100 fJ energy usage.

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Fig. 1: Planar, electrolyte-gated nanoscopic PDPP OFETs.
Fig. 2: Device fabrication process of electrolyte gated VOFETs.
Fig. 3: Electrical characteristics of electrolyte-gated PDPP VOFET measured in ambient atmosphere.
Fig. 4: Nanoscopic electrolyte-gated PDPP VOFET measured in ambient atmosphere and comparison to state-of-the-art transistors.
Fig. 5: Short- and long-term synaptic plasticity of electrolyte-gated PDPP VOFETs measured in ambient atmosphere.

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The raw data that support the plots within this paper and other findings of this study are provided in the Supplementary Information and are available from the authors upon reasonable request.

References

  1. Cao, Q., Tersoff, J., Farmer, D. B., Zhu, Y. & Han, S.-J. Carbon nanotube transistors scaled to a 40-nanometer footprint. Science 356, 1369–1372 (2017).

    Article  CAS  Google Scholar 

  2. Si, M. et al. Steep-slope hysteresis-free negative capacitance MoS2 transistors. Nat. Nanotechnol. 13, 24–28 (2018).

    Article  CAS  Google Scholar 

  3. Cao, Q. et al. Arrays of single-walled carbon nanotubes with full surface coverage for high-performance electronics. Nat. Nanotechnol. 8, 180–186 (2013).

    Article  CAS  Google Scholar 

  4. Zschieschang, U., Letzkus, F., Burghartz, J. N. & Klauk, H. Parameter uniformity of submicron-channel-length organic thin-film transistors fabricated by stencil lithography. IEEE Trans. Nanotechnol. 16, 837–841 (2017).

    Article  CAS  Google Scholar 

  5. Klinger, M. P. et al. Organic power electronics: transistor operation in the kA/cm2 regime. Sci. Rep. 7, 44713 (2017).

    Article  CAS  Google Scholar 

  6. Bijleveld, J. C. et al. Poly(diketopyrrolopyrrole-terthiophene) for ambipolar logic and photovoltaics. J. Am. Chem. Soc. 131, 16616–16617 (2009).

    Article  CAS  Google Scholar 

  7. Ono, S., Seki, S., Hirahara, R., Tominari, Y. & Takeya, J. High-mobility, low-power, and fast-switching organic field-effect transistors with ionic liquids. Appl. Phys. Lett. 92, 103313 (2008).

    Article  Google Scholar 

  8. Cho, J. H. et al. High-capacitance ion gel gate dielectrics with faster polarization response times for organic thin film transistors. Adv. Mater. 20, 686–690 (2008).

    Article  CAS  Google Scholar 

  9. Kettner, M., Vladimirov, I., Strudwick, A. J., Schwab, M. G. & Weitz, R. T. Ionic gel as gate dielectric for the easy characterization of graphene and polymer field-effect transistors and electrochemical resistance modification of graphene. J. Appl. Phys. 118, 25501 (2015).

    Article  Google Scholar 

  10. Panzer, M. J. & Frisbie, C. D. Polymer electrolyte-gated organic field-effect transistors: low-voltage, high-current switches for organic electronics and testbeds for probing electrical transport at high charge carrier density. J. Am. Chem. Soc. 129, 6599–6607 (2007).

    Article  CAS  Google Scholar 

  11. Panzer, M. J., Newman, C. R. & Frisbie, C. D. Low-voltage operation of a pentacene field-effect transistor with a polymer electrolyte gate dielectric. Appl. Phys. Lett. 86, 103503 (2005).

    Article  Google Scholar 

  12. Herlogsson, L. et al. Downscaling of organic field-effect transistors with a polyelectrolyte gate insulator. Adv. Mater. 20, 4708–4713 (2008).

    Article  CAS  Google Scholar 

  13. Klauk, H. Will we see gigahertz organic transistors? Adv. Electron. Mater. 4, 1700474 (2018).

    Article  Google Scholar 

  14. Braga, D., Ha, M., Xie, W. & Frisbie, C. D. Ultralow contact resistance in electrolyte-gated organic thin film transistors. Appl. Phys. Lett. 97, 193311 (2010).

    Article  Google Scholar 

  15. Khodagholy, D. et al. High transconductance organic electrochemical transistors. Nat. Commun. 4, 2133 (2013).

    Article  Google Scholar 

  16. Bucella, S. G. et al. Macroscopic and high-throughput printing of aligned nanostructured polymer semiconductors for MHz large-area electronics. Nat. Commun. 6, 8394 (2015).

    Article  CAS  Google Scholar 

  17. Lüssem, B., Günther, A., Fischer, A., Kasemann, D. & Leo, K. Vertical organic transistors. J. Phys. Condens. Matter 27, 443003 (2015).

    Article  Google Scholar 

  18. Li, S.-H., Xu, Z., Yang, G., Ma, L. & Yang, Y. Solution-processed poly(3-hexylthiophene) vertical organic transistor. Appl. Phys. Lett. 93, 213301 (2008).

    Article  Google Scholar 

  19. Stutzmann, N., Friend, R. H. & Sirringhaus, H. Self-aligned, vertical-channel, polymer field-effect transistors. Science 299, 1881–1884 (2003).

    Article  CAS  Google Scholar 

  20. Rother, M. et al. Vertical electrolyte-gated transistors based on printed single-walled carbon nanotubes. ACS Appl. Nano Mater. 1, 3616–3624 (2018).

    Article  CAS  Google Scholar 

  21. Huang, K.-M. et al. 2-V operated flexible vertical organic transistor with good air stability and bias stress reliability. Org. Electron. 50, 325–330 (2017).

    Article  CAS  Google Scholar 

  22. Johnston, D. E., Yager, K. G., Nam, C.-Y., Ocko, B. M. & Black, C. T. One-volt operation of high-current vertical channel polymer semiconductor field-effect transistors. Nano Lett. 12, 4181–4186 (2012).

    Article  CAS  Google Scholar 

  23. Liu, Y. et al. High-current-density vertical-tunneling transistors from graphene/highly doped silicon heterostructures. Adv. Mater. 28, 4120–4125 (2016).

    Article  CAS  Google Scholar 

  24. Wilbers, J. G. E., Xu, B., Bobbert, P. A., Jong, M. P. de & van der Wiel. Wilfred G. Charge transport in nanoscale vertical organic semiconductor pillar devices. Sci. Rep. 7, 41171 (2017).

  25. Greenman, M. et al. Reaching saturation in patterned source vertical organic field effect transistors. J. Appl. Phys. 121, 204503 (2017).

    Article  Google Scholar 

  26. Mo, Y. G. et al. Amorphous-oxide TFT backplane for large-sized AMOLED TVs. J. Soc. Inf. Display 19, 16 (2011).

    Article  CAS  Google Scholar 

  27. Roy, K., Mukhopadhyay, S. & Mahmoodi-Meimand, H. Leakage current mechanisms and leakage reduction techniques in deep-submicrometer CMOS circuits. Proc. IEEE 91, 305–327 (2003).

    Article  CAS  Google Scholar 

  28. Kim, S. H., Hong, K., Lee, K. H. & Frisbie, C. D. Performance and stability of aerosol-jet-printed electrolyte-gated transistors based on poly(3-hexylthiophene). ACS Appl. Mater. Interfaces 5, 6580–6585 (2013).

    Article  CAS  Google Scholar 

  29. van de Burgt, Y., Melianas, A., Keene, S. T., Malliaras, G. & Salleo, A. Organic electronics for neuromorphic computing. Nat. Electron. 1, 386–397 (2018).

    Article  Google Scholar 

  30. Weitz, R. T., Walter, A., Engl, R., Sezi, R. & Dehm, C. New charge-transfer salts for reversible resistive memory switching. Nano Lett. 6, 2810–2813 (2006).

    Article  CAS  Google Scholar 

  31. Gkoupidenis, P., Schaefer, N., Garlan, B. & Malliaras, G. G. Neuromorphic functions in PEDOT:PSS organic electrochemical transistors. Adv. Mater. 27, 7176–7180 (2015).

    Article  CAS  Google Scholar 

  32. Yang, Y. et al. Long-term synaptic plasticity emulated in modified graphene oxide electrolyte gated IZO-based thin-film transistors. ACS Appl. Mater. Interfaces 8, 30281–30286 (2016).

    Article  CAS  Google Scholar 

  33. van de Burgt, Y. et al. A non-volatile organic electrochemical device as a low-voltage artificial synapse for neuromorphic computing. Nat. Mater. 16, 414–418 (2017).

    Article  Google Scholar 

  34. Peng, Y., Cullis, T. & Inkson, B. Accurate electrical testing of individual gold nanowires by in situ scanning electron microscope nanomanipulators. Appl. Phys. Lett. 93, 183112 (2008).

    Article  Google Scholar 

  35. Hayyan, M., Mjalli, F. S., Hashim, M. A., AlNashef, I. M. & Mei, T. X. Investigating the electrochemical windows of ionic liquids. J. Ind. Eng. Chem. 19, 106–112 (2013).

    Article  CAS  Google Scholar 

  36. Gao, G. B., Fan, Z. F. & Morkoç, H. Negative output differential resistance in AlGaAs/GaAs heterojunction bipolar transistors. Appl. Phys. Lett. 61, 198–200 (1992).

    Article  CAS  Google Scholar 

  37. Klinger, M. P., Fischer, A., Kleemann, H. & Leo, K. Non-linear self-heating in organic transistors reaching high power densities. Sci. Rep. 8, 9806 (2018).

    Article  Google Scholar 

  38. Yu, F. et al. Vertical architecture for enhancement mode power transistors based on GaN nanowires. Appl. Phys. Lett. 108, 213503 (2016).

    Article  Google Scholar 

  39. Yu, W. J. et al. Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters. Nat. Mater. 12, 246–252 (2013).

    Article  CAS  Google Scholar 

  40. Seo, K.-I. et al. A 10 nm platform technology for low power and high performance application featuring FINFET devices with multi workfunction gate stack on bulk and SOI. Proc. 2014 Symposium on VLSI Technology 1–2 (2014).

  41. Donahue, M. J. et al. High-performance vertical organic electrochemical transistors. Adv. Mater. 30, 1705031 (2018).

    Article  Google Scholar 

  42. Wu, G. et al. Artificial synaptic devices based on natural chicken albumen coupled electric-double-layer transistors. Sci. Rep. 6, 23578 (2016).

    Article  CAS  Google Scholar 

  43. Xu, W., Min, S.-Y., Hwang, H. & Lee, T.-W. Organic core–sheath nanowire artificial synapses with femtojoule energy consumption. Sci. Adv. 2, e1501326 (2016).

    Article  Google Scholar 

  44. Samuel, I. D. W. & Turnbull, G. A. Organic semiconductor lasers. Chem. Rev. 107, 1272–1295 (2007).

    Article  CAS  Google Scholar 

  45. Hayashi, K. et al. Suppression of roll-off characteristics of organic light-emitting diodes by narrowing current injection/transport area to 50 nm. Appl. Phys. Lett. 106, 93301 (2015).

    Article  Google Scholar 

  46. Kim, S. H. et al. Electrolyte-gated transistors for organic and printed electronics. Adv. Mater. 25, 1822–1846 (2013).

    Article  CAS  Google Scholar 

  47. Choi, J.-H. et al. High capacitance, photo-patternable ion gel gate insulators compatible with vapor deposition of metal gate electrodes. ACS Appl. Mater. Interfaces 6, 19275–19281 (2014).

    Article  CAS  Google Scholar 

  48. McCarthy, M. A., Liu, B. & Rinzler, A. G. High current, low voltage carbon nanotube enabled vertical organic field effect transistors. Nano Lett. 10, 3467–3472 (2010).

    Article  CAS  Google Scholar 

  49. Kleemann, H., Günther, A. A., Leo, K. & Lüssem, B. High-performance vertical organic transistors. Small 9, 3670–3677 (2013).

    Article  CAS  Google Scholar 

  50. Fischer, A., Scholz, R., Leo, K. & Lüssem, B. An all C60vertical transistor for high frequency and high current density applications. Appl. Phys. Lett. 101, 213303 (2012).

    Article  Google Scholar 

  51. Yang, C.-Y. et al. Vertical organic triodes with a high current gain operated in saturation region. Appl. Phys. Lett. 89, 183511 (2006).

    Article  Google Scholar 

  52. Fukagawa, H. et al. High-current operation of vertical-type organic transistor with preferentially oriented molecular film. AIP Adv. 6, 45010 (2016).

    Article  Google Scholar 

  53. Watanabe, Y., Iechi, H. & Kudo, K. Improvement in on/off ratio of pentacene static induction transistors with ultrathin CuPc layer. Jpn J. Appl. Phys. 45, 3698–3703 (2006).

    Article  CAS  Google Scholar 

  54. Chao, Y.-C. et al. Polymer space-charge-limited transistor as a solid-state vacuum tube triode. Appl. Phys. Lett. 97, 223307 (2010).

    Article  Google Scholar 

  55. Qiu, C. et al. Dirac-source field-effect transistors as energy-efficient, high-performance electronic switches. Science 361, 387–392 (2018).

    Article  CAS  Google Scholar 

  56. Zan, H.-W. et al. High output current in vertical polymer space-charge-limited transistor induced by self-assembled monolayer. Appl. Phys. Lett. 101, 93307 (2012).

    Article  Google Scholar 

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Acknowledgements

The authors thank BASF SE for supplying the organic semiconductors and liquid electrolytes. The authors acknowledge partial support by the ‘Solar Technologies go Hybrid’ (SolTech) initiative, the Center for Nanoscience (CeNS) and the Nanosystems Initiative Munich (NIM).

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Author notes

  1. Fabio del Giudice

    Present address: Walter-Schottky Institute, Technical University Munich, Garching, Germany

Authors and Affiliations

  1. Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany

    Jakob Lenz, Fabio del Giudice, Fabian R. Geisenhof, Felix Winterer & R. Thomas Weitz

  2. Nanosystems Initiative Munich (NIM), Munich, Germany

    R. Thomas Weitz

  3. Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany

    R. Thomas Weitz

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Contributions

J.L. and R.T.W conceived the project. J.L. prepared the VOFET samples and conducted the measurements and data analysis. F.d.G prepared the lateral transistor samples and conducted the measurements and data analysis. All authors discussed the data. J.L. and R.T.W. wrote the manuscript with input from all authors. R.T.W. supervised the project.

Corresponding author

Correspondence to R. Thomas Weitz.

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Competing interests

J.L. and R.T.W. have submitted a patent application to the German patent office (no. 10 2018 221 361.5) covering the structure of the VOFET and the applications discussed in this manuscript.

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Journal peer review information Nature Nanotechnology thanks Bjorn Lussem and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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Lenz, J., del Giudice, F., Geisenhof, F.R. et al. Vertical, electrolyte-gated organic transistors show continuous operation in the MA cm−2 regime and artificial synaptic behaviour. Nat. Nanotechnol. 14, 579–585 (2019). https://doi.org/10.1038/s41565-019-0407-0

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