This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
The current standard material used for transparent electrodes in displays, touch screens and solar cells is indium tin oxide (ITO) which has low sheet resistance (10 Ω/□), high optical transmission in the visible wavelength (85%) and does not suffer of optical haze. However, ITO is mechanically rigid and incompatible with future demands for flexible applications. Graphene materials share many of the properties desirable for flexible transparent conductors, including high optical transparency, high mechanical flexibility and strength. Whilst pristine graphene is not a good transparent conductor, functionalised graphene is at least 1000 times a better conductor than its pristine counterpart and it outperforms ITO. Here the authors review recent work on a novel graphene-based conductor with sheet resistance as low as 8.8 Ω/□ and 84% optical transmission. This material is obtained by ferric chloride (FeCl3) intercalation into few-layer-graphene (FLG), giving rise to a new system which is the best known flexible and transparent electricity conductor. FeCl3-FLG shows no significant changes in the electrical and structural properties for a long exposure to air, to high levels of humidity and at temperatures of up to 150°C in atmosphere. These properties position FeCl3-FLG as a viable and attractive replacement to ITO.
References
-
-
1)
-
16. Lin, J., Peng, Z., Liu, Y., et al: ‘Laser-induced porous graphene films from commercial polymers’, Nat. Commun., 2014, 5, p. 5714 (doi: 10.1038/ncomms6714).
-
2)
-
12. Wassei, J.K., Cha, K.C., Tung, V.C., et al: ‘The effects of thionyl chloride on the properties of graphene and graphene–carbon nanotube composites’, J. Mater. Chem., 2011, 21, p. 3391 (doi: 10.1039/c0jm02910f).
-
3)
-
51. Shioya, H., Craciun, M.F., Russo, S., et al: ‘Straining graphene using thin film shrinkage methods’, Nano Lett., 2014, 14, pp. 1158–1163 (doi: 10.1021/nl403679f).
-
4)
-
15. Park, H., Howden, R.M., Barr, M.C., et al: ‘Organic solar cells with graphene electrodes and vapor printed poly(3,4-ethylenedioxythiophene) as the hole transporting layers’, ACS Nano, 2012, 6, (7), pp. 6370–6377 (doi: 10.1021/nn301901v).
-
5)
-
19. Kim, N., Kim, K.S., Jung, N., et al: ‘Synthesis and electrical characterization of magnetic bilayer graphene intercalate’, Nano Lett., 2011, 11, pp. 860–865 (doi: 10.1021/nl104228f).
-
6)
-
25. Hwang, J., Carbotte, J.P., Tongay, S., et al: ‘Ultrapure multilayer graphene in bromine-intercalated graphite’, Phys. Rev. B, 2011, 84, p. 041410 (doi: 10.1103/PhysRevB.84.041410).
-
7)
-
31. Wehenkel, D.J., Bointon, T.H., Booth, T., et al: ‘Unforeseen high temperature and humidity stability of FeCl3 intercalated few layer graphene’, Sci. Rep., 2015, 5, p. 7609 (doi: 10.1038/srep07609).
-
8)
-
18. Wu, Y., Ye, P.D., Capano, M.A., et al: ‘Top-gated graphene field-effect-transistors formed by decomposition of SiC’, Appl. Phys. Lett., 2008, 92, p. 092102 (doi: 10.1063/1.2889959).
-
9)
-
23. Howard, C.A., Dean, M.P.M., Withers, F.: ‘Phonons in potassium-doped graphene: the effects of electron-phonon interactions, dimensionality, and adatom ordering’, Phys. Rev. B, 2011, 84, p. 241404 (doi: 10.1103/PhysRevB.84.241404).
-
10)
-
2. Lee, C., Wei, X., Kysar, J.W., et al: ‘Measurement of the elastic properties and intrinsic strength of monolayer graphene’, Science, 2008, 321, pp. 385–388 (doi: 10.1126/science.1157996).
-
11)
-
17. Lee, D.S., Riedl, C., Krauss, B., et al: ‘Raman spectra of epitaxial graphene on SiC and of epitaxial graphene transferred to SiO2’, Nano Lett., 2008, 8, p. 4320 (doi: 10.1021/nl802156w).
-
12)
-
36. Hecht, D.S., Heintz, A.M., Lee, R., et al: ‘High conductivity transparent carbon nanotube films deposited from superacid’, Nanotechnology, 2011, 22, p. 075201 (doi: 10.1088/0957-4484/22/7/075201).
-
13)
-
28. Bader, S.D.: ‘Thin film magnetism’, Proc. IEEE, 1990, 78, pp. 909–922 (doi: 10.1109/5.56907).
-
14)
-
21. Zhan, D., Sun, L., Ni, Z.H., et al: ‘FeCl3-based few-layer graphene intercalation compounds: single linear dispersion electronic band structure and strong charge transfer doping’, Adv. Func. Mater., 2010, 20, p. 3504 (doi: 10.1002/adfm.201000641).
-
15)
-
27. Dresselhaus, M.S., Dresselhaus, G.: ‘Intercalation compounds of graphite’, Adv. Phys., 1981, 30, pp. 139–326 (doi: 10.1080/00018738100101367).
-
16)
-
44. Caldwell, J.D., Anderson, T.J., Culbertson, J.C., et al: ‘Technique for the dry transfer of epitaxial graphene onto arbitrary aubstrates’, ACS Nano, 2010, 4, (2), pp. 1108–1114 (doi: 10.1021/nn901585p).
-
17)
-
11. Bointon, T.H., Khrapach, I., Yakimova, R., et al: ‘Approaching magnetic ordering in graphene materials by FeCl3 intercalation’, Nano Lett., 2014, 14, (4), pp. 1751–1755 (doi: 10.1021/nl4040779).
-
18)
-
33. Russo, S., Craciun, M.F., Bointon, T.H.: ‘Doped graphene’. .
-
19)
-
6. Kim, K.K., Reina, A., Shi, Y., et al: ‘Enhancing the conductivity of transparent graphene films via doping’, Nanotechnology, 2010, 21, (28), pp. 285205–285211 (doi: 10.1088/0957-4484/21/28/285205).
-
20)
-
47. Jung, W., Kim, D., Lee, M., et al: ‘Ultraconformal contact transfer of monolayer graphene on metal to various substrates’, Adv. Mater., 2014, 26, pp. 6394–6400 (doi: 10.1002/adma.201400773).
-
21)
-
38. Park, J., Ahn, Y.H., Ruiz-Vargas, C.: ‘Imaging of photocurrent generation and collection in single layer graphene’, Nano Lett., 2009, 9, pp. 1742–1746 (doi: 10.1021/nl8029493).
-
22)
-
50. Craciun, M.F., Russo, S., Yamamoto, M., et al: ‘Trilayer graphene is a semimetal with a gate-tunable band overlap’, Nat. Nanotechnol., 2009, 4, pp. 383–388 (doi: 10.1038/nnano.2009.89).
-
23)
-
58. Withers, F., Russo, S., Dubois, M., et al: ‘Tuning the electronic transport properties of graphene through functionalisation with fluorine’, Nanoscale Res. Lett., 2011, 6, p. 526 (doi: 10.1186/1556-276X-6-526).
-
24)
-
24. Jung, N., Kim, B., Crowther, A.C., et al: ‘optical reflectivity and Raman scattering in few-layer-thick graphene highly doped by K and Rb’, ACS Nano, 2011, 5, p. 5708 (doi: 10.1021/nn201368g).
-
25)
-
39. Xia, F., Mueller, T., Lin, Y., et al: ‘Ultrafast graphene photodetector’, Nat. Nanotechnol., 2009, 4, pp. 839–843 (doi: 10.1038/nnano.2009.292).
-
26)
-
40. Mueller, T., Xia, F., Avouris, P.: ‘Graphene photodetectors for high-speed optical communications’, Nat. Photonics, 2010, 4, pp. 297–301 (doi: 10.1038/nphoton.2010.40).
-
27)
-
28)
-
3. Nair, R.R., Blake, P., Grigorenko, A.N., et al: ‘Fine structure constant defines visual transparency of graphene’, Science, 2008, 320, (5881), p. 1308 (doi: 10.1126/science.1156965).
-
29)
-
15. Weller, T.E., Euerby, M., Saxena, S., et al: ‘Superconductivity in the intercalated graphite compounds C6Yb and C6Ca’, Nat. Phys., 2005, 1, (1), pp. 39–41 (doi: 10.1038/nphys0010).
-
30)
-
43. Ferrari, A.C., Meyer, J.C., Scardaci, V., et al: ‘Raman spectrum of graphene and graphene layers’, Phys. Rev. Lett., 2006, 97, pp. 187401–187404 (doi: 10.1103/PhysRevLett.97.187401).
-
31)
-
62. Withers, F., Bointon, T.H., Craciun, M.F., et al: ‘Detector’. .
-
32)
-
26. Kanetani, K., Sugawara, K., Sato, T., et al: ‘Ca intercalated bilayer graphene as a thinnest limit of superconducting C6Ca’, PNAS, 2012, 109, pp. 19610–19613 (doi: 10.1073/pnas.1208889109).
-
33)
-
16. Eriksson, J., Pearce, R., Iakimov, T., et al: ‘the influence of substrate morphology on thickness uniformity and unintentional doping of epitaxial graphene on SiC’, Appl. Phys. Lett., 2012, 100, p. 241607 (doi: 10.1063/1.4729556).
-
34)
-
46. Fechine, G.J.M., Martin-Fernandez, I., Yiapanis, G., et al: ‘Direct dry transfer of chemical vapor deposition graphene to polymeric substrates’, Carbon, 2015, 83, pp. 224–231 (doi: 10.1016/j.carbon.2014.11.038).
-
35)
-
1. Kumar, A., Zhou, C.: ‘The race to replace tin-doped indium oxide: which material will win?’, ACS Nano, 2010, 4, (1), pp. 11–14 (doi: 10.1021/nn901903b).
-
36)
-
21. Han, T.H., Youngbin, L., Choi, M., et al: ‘Extremely efficient flexible organic light-emitting diodes with modified graphene anode’, Nat. Photon., 2012, 6, pp. 105–110 (doi: 10.1038/nphoton.2011.318).
-
37)
-
53. Shioya, H., Yamamoto, M., Russo, S., et al: ‘Gate tunable non-linear currents in bilayer graphene diodes’, Appl. Phys. Lett., 2012, 100, pp. 033113–033117 (doi: 10.1063/1.3676441).
-
38)
-
57. Withers, F., Bointon, T.H., Dubois, M., et al: ‘Nanopatterning of fluorinated graphene by electron beam irradiation’, Nano Lett., 2011, 11, pp. 3912–3916 (doi: 10.1021/nl2020697).
-
39)
-
2. Hecht, D.S., Hu, L., Irvin, G.: ‘Emerging transparent electrodes based on thin films of carbon nanotubes, graphene, and metallic nanostructures’, Adv. Mater., 2011, 23, (13), pp. 1482–1513 (doi: 10.1002/adma.201003188).
-
40)
-
20. Zhao, W.P., Tan, H., Liu, J., et al: ‘Intercalation of few-layer graphite flakes with FeCl3: Raman determination of Fermi level, layer by layer decoupling, and stability’, J. Am. Chem. Soc., 2011, 133, p. 5941 (doi: 10.1021/ja110939a).
-
41)
-
41. Nazin, G., Zhang, Y., Zhang, L., et al: ‘Visualization of charge transport through Landau levels in graphene’, Nat. Phys., 2010, 6, pp. 870–874 (doi: 10.1038/nphys1745).
-
42)
-
37. Surajit, G., Biddut, K.S., Anindarupa, C., et al: ‘Position dependent photodetector from large area reduced graphene oxide thin films’, Appl. Phys. Lett., 2010, 96, p. 163109 (doi: 10.1063/1.3415499).
-
43)
-
35. Uesugi, E., Goto, H., Eguchi, R., et al: ‘Electric double-layer capacitance between an ionic liquid and few layer graphene’, Sci. Rep., 2013, 3, p. 1595 (doi: 10.1038/srep01595).
-
44)
-
48. Craciun, M.F., Russo, S., Yamamoto, M., et al: ‘Tuneable electronic properties in graphene’, Nano Today, 2011, 6, pp. 42–60 (doi: 10.1016/j.nantod.2010.12.001).
-
45)
-
10. Khrapach, I., Withers, F., Bointon, T.H., et al: ‘Novel highly conductive and transparent graphene-based conductors’, Adv. Mater., 2012, 24, pp. 2844–2849 (doi: 10.1002/adma.201200489).
-
46)
-
13. Bae, S., Hyeongkeun, K., Youngbin, L., et al: ‘Roll-to-roll production of 30-inch graphene films for transparent electrodes’, Nat. Nanotechnol, 2010, 5, pp. 574–578 (doi: 10.1038/nnano.2010.132).
-
47)
-
45. Lock, E.H., Baraket, M., Laskoski, M., et al: ‘High-quality uniform dry transfer of graphene to polymers’, Nano Lett., 2012, 12, pp. 102–107 (doi: 10.1021/nl203058s).
-
48)
-
30. Pan, Z.H., Camacho, J., Upton, M.H., et al: ‘Electronic structure of superconducting KC8 and nonsuperconducting LiC6 graphite intercalation compounds: evidence for a graphene-sheet-driven superconducting state’, Phys. Rev. Lett., 2011, 106, p. 187002 (doi: 10.1103/PhysRevLett.106.187002).
-
49)
-
42. Withers, F., Bointon, T.H., Craciun, M.F., et al: ‘All-graphene photodetectors’, ACS Nano, 2013, 7, (6), pp. 5052–5057 (doi: 10.1021/nn4005704).
-
50)
-
52. Khodkov, T., Withers, F., Hudson, D.C., et al: ‘Electrical transport in suspended and double gated trilayer graphene’, Appl. Phys. Lett., 2012, 100, pp. 013114–013117 (doi: 10.1063/1.3675337).
-
51)
-
61. Russo, S., Craciun, M.F.: ‘Graphene-based material’. .
-
52)
-
59. ‘GraphExeter-University of Exeter’.
-
53)
-
22. Boa, W., Wan, J., Han, X., et al: ‘Approaching the limits of transparency and conductivity in graphitic materials through lithium intercalation’, Nat. Commun., 2014, 5, p. 4224.
-
54)
-
60. Russo, S., Craciun, M.F.: ‘Graphene-based material’. .
-
55)
-
13. Tongay, S., Berke, K., Lemaitre, M., et al: ‘Stable hole doping of graphene for low electrical resistance and high optical transparency’, Nanotechnology, 2011, 22, p. 425701 (doi: 10.1088/0957-4484/22/42/425701).
-
56)
-
49. Jhang, S.H., Craciun, M.F., Schmidmeier, S., et al: ‘Stacking-order dependent transport properties of trilayer graphene’, Phys. Rev. B, Rapid Commun., 2011, 84, pp. 161408–161412 (doi: 10.1103/PhysRevB.84.161408).
-
57)
-
55. Craciun, M.F., Khrapach, I., Barnes, M.D., et al: ‘Properties and applications of chemically functionalized graphene’, J. Phys. Condens. Matter, 2013, 25, p. 423201 (doi: 10.1088/0953-8984/25/42/423201).
-
58)
-
7. De, S., Coleman, J.N.: ‘Are there fundamental limitations on the sheet resistance and transmittance of thin graphene films?’, ACS Nano, 2010, 4, (5), pp. 2713–2720 (doi: 10.1021/nn100343f).
-
59)
-
14. Hsu, C.L., Lin, C.T., Huang, J.H., et al: ‘Layer-by-layer graphene/TCNQ stacked films as conducting anodes for organic solar cells’, ACS Nano, 2012, 6, (6), pp. 5031–5039 (doi: 10.1021/nn301721q).
-
60)
-
54. Neves, A.I.S., Bointon, T.H., Melo, L.V., et al: ‘Transparent conductive graphene textile fibers’, Sci. Rep., 2015, 5, p. 9866 (doi: 10.1038/srep09866).
-
61)
-
9. Song, Y., Fang, W., Hsu, A.L., et al: ‘Iron (III) chloride doping of CVD graphene’, Nanotechnology, 2014, 25, p. 395701 (doi: 10.1088/0957-4484/25/39/395701).
-
62)
-
56. Martins, S.E., Withers, F., Dubois, M., et al: ‘Tuning the transport gap of functionalized graphene via electron beam irradiation’, New J. Phys., 2013, 15, p. 033024 (doi: 10.1088/1367-2630/15/3/033024).
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