Atomically precise graphene nanoribbon heterojunctions from a single molecular precursor


The rational bottom-up synthesis of atomically defined graphene nanoribbon (GNR) heterojunctions represents an enabling technology for the design of nanoscale electronic devices. Synthetic strategies used thus far have relied on the random copolymerization of two electronically distinct molecular precursors to yield GNR heterojunctions. Here we report the fabrication and electronic characterization of atomically precise GNR heterojunctions prepared through late-stage functionalization of chevron GNRs obtained from a single precursor. Post-growth excitation of fully cyclized GNRs induces cleavage of sacrificial carbonyl groups, resulting in atomically well-defined heterojunctions within a single GNR. The GNR heterojunction structure was characterized using bond-resolved scanning tunnelling microscopy, which enables chemical bond imaging at T = 4.5 K. Scanning tunnelling spectroscopy reveals that band alignment across the heterojunction interface yields a type II heterojunction, in agreement with first-principles calculations. GNR heterojunction band realignment proceeds over a distance less than 1 nm, leading to extremely large effective fields.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Bottom-up fabrication of fluorenone GNRs.
Figure 2: Electronic structure of fluorenone and unfunctionalized chevron GNRs.
Figure 3: Electronic structure of a fluorenone/unfunctionalized chevron GNR heterojunction.
Figure 4: Band alignment across the fluorenone/unfunctionalized chevron GNR heterojunction interface.
Figure 5: Comparison of experimental dI/dV maps and theoretical LDOS for a fluorenone/unfunctionalized chevron GNR heterojunction.


  1. 1

    Son, Y.-W., Cohen, M. L. & Louie, S. G. Half-metallic graphene nanoribbons. Nature 444, 347–349 (2006).

    CAS  Article  Google Scholar 

  2. 2

    Shen, Y. T. et al. Switchable ternary nanoporous supramolecular network on photo-regulation. Nano Lett. 11, 3245–3250 (2011).

    CAS  Article  Google Scholar 

  3. 3

    Cai, J. et al. Atomically precise bottom-up fabrication of graphene nanoribbons. Nature 466, 470–473 (2010).

    CAS  Article  Google Scholar 

  4. 4

    Bennett, P. B. et al. Bottom-up graphene nanoribbon field-effect transistors. Appl. Phys. Lett. 103, 253114 (2013).

    Article  Google Scholar 

  5. 5

    Chen, Y. C. et al. Tuning the band gap of graphene nanoribbons synthesized from molecular precursors. ACS Nano 7, 6123–6128 (2013).

    CAS  Article  Google Scholar 

  6. 6

    Bronner, C. et al. Aligning the band gap of graphene nanoribbons by monomer doping. Angew. Chem. Int. Ed. 52, 4422–4425 (2013).

    CAS  Article  Google Scholar 

  7. 7

    Nguyen, G. D. et al. Bottom-up synthesis of N = 13 sulfur-doped graphene nanoribbons. J. Phys. Chem. C 120, 2684–2687 (2016).

    CAS  Article  Google Scholar 

  8. 8

    Cloke, R. R. et al. Site-specific substitutional boron doping of semiconducting armchair graphene nanoribbons. J. Am. Chem. Soc. 137, 8872–8875 (2015).

    CAS  Article  Google Scholar 

  9. 9

    Kawai, S. et al. Atomically controlled substitutional boron-doping of graphene nanoribbons. Nature Commun. 6, 8098 (2015).

    CAS  Article  Google Scholar 

  10. 10

    Marangoni, T., Haberer, D., Rizzo, D. J., Cloke, R. R. & Fischer, F. R. Heterostructures through divergent edge reconstruction in nitrogen-doped segmented graphene nanoribbons. Eur. J. Chem. A 22, 13037–13040 (2016).

    CAS  Article  Google Scholar 

  11. 11

    Yoon, Y. & Salahuddin, S. Barrier-free tunneling in a carbon heterojunction transistor. Appl. Phys. Lett. 97, 33102 (2010).

    Article  Google Scholar 

  12. 12

    Ghoreishi, S. S., Saghafi, K., Yousefi, R. & Moravvej-Farshi, M. K. Graphene nanoribbon tunnel field effect transistor with lightly doped drain: numerical simulations. Superlattices Microstruct. 75, 245–256 (2014).

    CAS  Article  Google Scholar 

  13. 13

    Neamen, D. A. Semiconductor Physics and Devices: Basic Principles (McGraw-Hill, 2003).

    Google Scholar 

  14. 14

    Joachim, C., Gimzewski, J. K. & Aviram, A. Electronics using hybrid-molecular and mono-molecular devices. Nature 408, 541–548 (2000).

    CAS  Article  Google Scholar 

  15. 15

    Imada, H. et al. Real-space investigation of energy transfer in heterogeneous molecular dimers. Nature 538, 364–367 (2016).

    CAS  Article  Google Scholar 

  16. 16

    Tao, C. et al. Spatial resolution of a type II heterojunction in a single bipolar molecule. Nano Lett. 9, 3963–3967 (2009).

    CAS  Article  Google Scholar 

  17. 17

    Smerdon, J. A., Giebink, N. C., Guisinger, N. P., Darancet, P. & Guest, J. R. Large spatially resolved rectification in a donor–acceptor molecular heterojunction. Nano Lett. 16, 2603–2607 (2016).

    CAS  Article  Google Scholar 

  18. 18

    Cai, J. et al. Graphene nanoribbon heterojunctions. Nature Nanotech. 9, 896–900 (2014).

    CAS  Article  Google Scholar 

  19. 19

    Chen, Y.-C. et al. Molecular bandgap engineering of bottom-up synthesized graphene nanoribbon heterojunctions. Nature Nanotech. 10, 156–160 (2015).

    CAS  Article  Google Scholar 

  20. 20

    Vo, T. H. et al. Nitrogen-doping induced self-assembly of graphene nanoribbon-based two-dimensional and three-dimensional metamaterials. Nano Lett. 15, 5770–5777 (2015).

    CAS  Article  Google Scholar 

  21. 21

    Hapala, P. et al. Mechanism of high-resolution STM/AFM imaging with functionalized tips. Phys. Rev. B 90, 85421 (2014).

    Article  Google Scholar 

  22. 22

    Gross, L., Mohn, F., Moll, N., Liljeroth, P. & Meyer, G. The chemical structure of a molecule resolved by atomic force microscopy. Science 325, 1110–1114 (2009).

    CAS  Article  Google Scholar 

  23. 23

    Chiang, C., Xu, C., Han, Z. & Ho, W. Real-space imaging of molecular structure and chemical bonding by single-molecule inelastic tunneling probe. Science 344, 885–888 (2014).

    CAS  Article  Google Scholar 

  24. 24

    de Oteyza, D. G. et al. Direct imaging of covalent bond structure in single-molecule chemical reactions. Science 340, 1434–1437 (2013).

    CAS  Article  Google Scholar 

  25. 25

    Kroemer, H. Heterostructure bipolar transistors and integrated circuits. Proc. IEEE 70, 13–25 (1982).

    Article  Google Scholar 

  26. 26

    Yang, L., Park, C.-H., Son, Y.-W., Cohen, M. L. & Louie, S. G. Quasiparticle energies and band gaps in graphene nanoribbons. Phys. Rev. Lett. 99, 6–9 (2007).

    Google Scholar 

  27. 27

    Ugeda, M. M. et al. Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor. Nature Mater. 13, 1091–1095 (2014).

    CAS  Article  Google Scholar 

  28. 28

    Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009).

    Article  Google Scholar 

  29. 29

    Troullier, N. & Martins, J. L. Efficient pseudopotentials for plane-wave calculations. Phys. Rev. B 43, 1993–2006 (1991).

    CAS  Article  Google Scholar 

Download references


This research was supported by the Office of Naval Research BRC Program (spectroscopic imaging), by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award no. DE-SC0010409 (design, synthesis, and characterization of molecular precursors) and Nanomachine Program award no. DE-AC02-05CH11231 (surface reaction characterization and band structure calculations), by DARPA, the US Army Research Laboratory and the US Army Research Office under contract/grant no. W911NF-15-1-0237 (tip-based manipulation), and by the National Science Foundation (NSF) under grant no. DMR-1508412 (development of theory formalism and STM analyses). Computational resources were provided by the DOE at Lawrence Berkeley National Laboratory's NERSC facility and by the NSF through XSEDE resources at NICS. Y.S. and J.R.C. acknowledge support from the US DOE under contract no. DOE/DE-FG02-06ER46286 (AFM simulation) and the Welch Foundation under grant F-1837 (image analysis). A.A.O. acknowledges support from the Swiss National Science Foundation (SNSF) Postdoctoral Research Fellowship under grant no. P2ELP2-151852.

Author information




T.M., R.R.C., R.A.D. and F.R.F. designed, synthesized and characterized the molecular precursors. G.D.N., H.T., A.A.O., D.J.R., G.F.R., F.L. and A.S.A. performed STM and nc-AFM measurements. G.D.N., H.T., A.A.O. and D.J.R. performed data analysis. M.W. and S.G.L. performed DFT calculations and interpretation of STM data. Y.S. and J.R.C. performed theoretical simulation for BRSTM imaging. M.F.C. supervised the experimental scanned probe measurements and helped to interpret the results. All authors contributed to the scientific discussion and helped in writing the manuscript.

Corresponding authors

Correspondence to Steven G. Louie or Felix R. Fischer or Michael F. Crommie.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1157 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Nguyen, G., Tsai, H., Omrani, A. et al. Atomically precise graphene nanoribbon heterojunctions from a single molecular precursor. Nature Nanotech 12, 1077–1082 (2017).

Download citation


Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research