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Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers

Abstract

Self-assembled monolayers (SAMs) are widely used in a variety of emerging applications for surface modification of metals and oxides. Here, we demonstrate a new type of molecular self-assembly: the growth of organosilane SAMs at the surface of organic semiconductors. Remarkably, SAM growth results in a pronounced increase of the surface conductivity of organic materials, which can be very large for SAMs with a strong electron-withdrawing ability. For example, the conductivity induced by perfluorinated alkyl silanes in organic molecular crystals approaches 10−5 S per square, two orders of magnitude greater than the maximum conductivity typically achieved in organic field-effect transistors. The observed large electronic effect opens new opportunities for nanoscale surface functionalization of organic semiconductors with molecular self-assembly. In particular, SAM-induced conductivity shows sensitivity to different molecular species present in the environment, which makes this system very attractive for chemical sensing applications.

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Figure 1: Effect of SAM formation on conductivity of organic single crystals.
Figure 2: Scanning electron microscope images of SAMs at the surface of rubrene.
Figure 3: Atomic force microscope images of the surface of a rubrene single crystal partially coated with a (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane SAM.
Figure 4: ESR spectra of rubrene functionalized with SAMs.
Figure 5: Measurements of the anisotropy of SAM-induced conductivity and the density of SAM-induced holes at the surface of rubrene.
Figure 6: Sensing of polar-solvent fumes with SAM-functionalized rubrene.

References

  1. 1

    Love, J. C., Estroff, L. A., Kriebel, J. K., Nuzzo, R. G. & Whitesides, G. M. Self-assembled monolayers of thiolates on metals as a form of nanotechnology. Chem. Rev. 105, 1103–1170 (2005).

    CAS  Article  Google Scholar 

  2. 2

    Campbell, I. H. et al. Controlling charge injection in organic electronic devices using self-assembled monolayers. Appl. Phys. Lett. 71, 3528–3530 (1997).

    CAS  Article  Google Scholar 

  3. 3

    Gundlach, D. J., Jia, L. & Jackson, T. N. Pentacene TFT with improved linear region characteristics using chemically modified source and drain electrodes. IEEE Electron. Dev. Lett. 22, 571–573 (2001).

    CAS  Article  Google Scholar 

  4. 4

    Akkerman, H. B., Blom, P. W. M., de Leeuw, D. M. & de Boer, B. Towards molecular electronics with large-area molecular junctions. Nature 441, 69–72 (2006).

    CAS  Article  Google Scholar 

  5. 5

    Heimel, G., Romaner, L., Brédas, J.-L. & Zojer, E. Interface energetics and level alignment at covalent metal–molecule junctions: π-conjugated thiols on gold. Phys. Rev. Lett. 96, 196806 (2006).

    Article  Google Scholar 

  6. 6

    Briseno, A. L. et al. Patterning organic single-crystal transistor arrays. Nature 444, 913–917 (2006).

    CAS  Article  Google Scholar 

  7. 7

    Kobayashi, S. et al. Control of carrier density by self-assembled monolayers in organic field-effect transistors. Nature Mater. 3, 317–322 (2004).

    CAS  Article  Google Scholar 

  8. 8

    Takeya, J. et al. Effect of polarized organosilane self-assembled monolayers on organic single-crystal field-effect transistors. Appl. Phys. Lett. 85, 5078–5080 (2004).

    CAS  Article  Google Scholar 

  9. 9

    Pernstich, K. P. et al. Threshold voltage shift in organic field effect transistors by dipole monolayers on the gate insulator. J. Appl. Phys. 96, 6431–6438 (2004).

    CAS  Article  Google Scholar 

  10. 10

    Facchetti, A., Yoon, M.-H. & Marks, T. J. Gate dielectrics for organic field-effect transistors: new opportunities for organic electronics. Adv. Mater. 17, 1705–1725 (2005).

    CAS  Article  Google Scholar 

  11. 11

    Chua, L. L. et al. General observation of n-type field-effect behaviour in organic semiconductors. Nature 434, 194–199 (2005).

    CAS  Article  Google Scholar 

  12. 12

    Ong, B. S., Wu, Y., Liu, P. & Gardner, S. High-performance semiconducting polythiophenes for organic thin-film transistors. J. Am. Chem. Soc. 126, 3378–3379 (2004).

    CAS  Article  Google Scholar 

  13. 13

    McCulloch, I. et al. Liquid-crystalline semiconducting polymers with high charge-carrier mobility. Nature Mater. 5, 328–333 (2006).

    CAS  Article  Google Scholar 

  14. 14

    Payne, M. M. et al. Organic field-effect transistors from solution-deposited functionalized acenes with mobilities as high as 1 cm2/Vs. J. Am. Chem. Soc. 127, 4986–4987 (2005).

    CAS  Article  Google Scholar 

  15. 15

    de Boer, R. W. I., Gershenson, M. E., Morpurgo, A. F. & Podzorov, V. Organic single-crystal field-effect transistors. Phys. Status Solidi 201, 1302–1331 (2004).

    CAS  Article  Google Scholar 

  16. 16

    Gershenson, M. E., Podzorov, V. & Morpurgo, A. F. Colloquium: Electronic transport in single-crystal organic transistors. Rev. Mod. Phys. 78, 973–989 (2006).

    CAS  Article  Google Scholar 

  17. 17

    de Boer, R. W. I., Iosad, N. N., Stassen, A. F., Klapwijk, T. M. & Morpurgo, A. F. Influence of the gate leakage current on the stability of organic single-crystal field-effect transistors. Appl. Phys. Lett. 86, 032103 (2005).

    Article  Google Scholar 

  18. 18

    Hulea, I. N. et al. Tunable Fröhlich polarons in organic single-crystal transistors. Nature Mater. 5, 982–986 (2006).

    CAS  Article  Google Scholar 

  19. 19

    Panzer, M. J. & Frisbie, C. D. High charge carrier densities and conductance maxima in single-crystal organic field-effect transistors with a polymer electrolyte gate dielectric. Appl. Phys. Lett. 88, 203504 (2006).

    Article  Google Scholar 

  20. 20

    Lin, C.-H. & Radhakrishnan, K. Synthesis of anthracene ethers from anthracene methyl ethers via an acid-catalyzed exchange reaction. Chem. Commun. 4, 504–506 (2005).

    Article  Google Scholar 

  21. 21

    Abe, Y. et al. Control of threshold voltage in pentacene thin-film transistors using carrier doping at the charge-transfer interface with organic acceptors. Appl. Phys. Lett. 87, 153506 (2005).

    Article  Google Scholar 

  22. 22

    Maenning, B. et al. Controlled p-type doping of polycrystalline and amorphous organic layers: Self-consistent description of conductivity and field-effect mobility by a microscopic percolation model. Phys. Rev. B 64, 195208 (2001).

    Article  Google Scholar 

  23. 23

    Nollau, A. Investigation of the Doping Process in Organic Molecular Thin Films. Thesis, Dresden Technical Univ. (2002).

  24. 24

    Podzorov, V. et al. Interaction of organic surfaces with active species in the high-vacuum environment. Appl. Phys. Lett. 87, 093505 (2005).

    Article  Google Scholar 

  25. 25

    Sugimura, H., Hayashi, K., Saito, N., Nakagiri, N. & Takai, O. Surface potential microscopy for organized molecular systems. Appl. Surf. Sci. 188, 403–410 (2002).

    CAS  Article  Google Scholar 

  26. 26

    Sariciftci, N. S., Smilowitz, L., Heeger, A. J. & Wudl, F. Photoinduced electron transfer from a conducting polymer to buckminsterfullerene. Science 258, 1474–1476 (1992).

    CAS  Article  Google Scholar 

  27. 27

    Lee, S. B. et al. Ground state charge transfer in fullerene–polyalkylthiophene composites: ESR and iodine doping effect. Synth. Met. 77, 155–159 (1996).

    CAS  Article  Google Scholar 

  28. 28

    Marumoto, K., Kuroda, S., Takenobu, T. & Iwasa, Y. Spatial extent of wave functions of gate-induced hole carriers in pentacene field-effect devices as investigated by electron spin resonance. Phys. Rev. Lett. 97, 256603 (2006).

    Article  Google Scholar 

  29. 29

    Sundar, V. C. et al. Elastomeric transistor stamps: Reversible probing of charge transport in organic crystals. Science 303, 1644–1646 (2004).

    CAS  Article  Google Scholar 

  30. 30

    Podzorov, V. et al. Intrinsic charge transport on the surface of organic semiconductors. Phys. Rev. Lett. 93, 086602 (2004).

    CAS  Article  Google Scholar 

  31. 31

    Podzorov, V., Pudalov, V. M. & Gershenson, M. E. Field-effect transistors on rubrene single crystals with parylene gate insulator. Appl. Phys. Lett. 82, 1739–1741 (2003).

    CAS  Article  Google Scholar 

  32. 32

    Crone, B. et al. Electronic sensing of vapors with organic transistors. Appl. Phys. Lett. 78, 2229–2231 (2001).

    CAS  Article  Google Scholar 

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Acknowledgements

We thank A. Zakhidov, J. E. Anthony, E. Garfunkel and Y. Chabal for helpful discussions and S.-W. Cheong and S. Park for technical assistance with AFM. This work has been supported by the NSF grants DMR-0405208 and ECS-0437932.

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Correspondence to V. Podzorov.

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Supplementary information, supplementary table 1, supplementary figures 1-4 (PDF 861 kb)

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Calhoun, M., Sanchez, J., Olaya, D. et al. Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers. Nature Mater 7, 84–89 (2008). https://doi.org/10.1038/nmat2059

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