Doping organic semiconductors has become a key technology for highly efficient organic LEDs and solar cells1. For organic transistors, the benefits of doping are increasingly acknowledged as well. For example, it has been shown that doping increases the reliability and reproducibility of organic transistors2; it allows to design and study new flexible transistor concepts3,4; and it minimizes injection losses at the contacts5.
The organic electrochemical transistor (OECT) is one of the most promising doped organic transistors. It has been used to detect various biomolecules6 and pathogens7, for electrocardiographic recordings8, or for in-vivo recording of brain activity9.
In this presentation, our current understanding of the influence of doping on organic transistors will be discussed. The theory of doped organic transistors will be presented and used to discuss the working mechanism of organic electrochemical transistors10. Strategies to optimize the performance of OECTs will be proposed11. Finally, limits of the current model of OECTs will be presented and it will be discussed how the model can be refined to further our understanding of the working mechanisms of OECTs.
1. Lüssem, B., Riede, M. & Leo, K. Phys. Status Solidi Appl. Mater. Sci. 210, (2013).
2. Hein, M. P., Zakhidov, A. a., Lüssem, B., Jankowski, J., Tietze, M. L., Riede, M. K. & Leo, K. Appl. Phys. Lett. 104, 13507 (2014).
3. Lüssem, B., Tietze, M. L., Kleemann, H., Hoßbach, C., Bartha, J. W., Zakhidov, A. & Leo, K. Nat. Commun. 4, 2775 (2013).
4. Lüssem, B., Keum, C.-M., Kasemann, D., Naab, B., Bao, Z. & Leo, K. Chem. Rev. 116, (2016).
5. Ante, F., Kälblein, et al. Small 7, 1186 (2011).
6. Kergoat, L., Piro, B., Simon, D. T., Pham, M. C., Noël, V. & Berggren, M. Adv. Mater. 26, 5658–5664 (2014).
7. He, R.-X., Zhang, M., Tan, F., Leung, P. H. M., Zhao, X.-Z., Chan, H. L. W., Yang, M. & Yan, F. J. Mater. Chem. 22, 22072 (2012).
8. Campana, A., Cramer, T., Simon, D. T., Berggren, M. & Biscarini, F. Adv. Mater. 26, 3874–3878 (2014).
9. Khodagholy, D., et al. Nat. Commun. 4, 1575 (2013).
10. Bernards, D. A. & Malliaras, G. G. Adv. Funct. Mater. 17, 3538–3544 (2007).
11. Kaphle, V., Liu, S., Al-Shadeedi, A., Keum, C.-M. & Lüssem, B. Adv. Mater. 28, (2016).