Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Technology of Flexible Transparent Conductive Electrode for Flexible Electronic Devices

유연전자소자를 위한 차세대 유연 투명전극의 개발 동향

  • Kim, Joo-Hyun (Graduate School of Mechanics and Design, Kookmin University) ;
  • Chon, Min-Woo (Graduate School of Mechanics and Design, Kookmin University) ;
  • Choa, Sung-Hoon (Graduate School of NID Fusion Technology, Seoul National University of Science and Technology)
  • 김주현 (국민대학교 기계설계대학원) ;
  • 천민우 (국민대학교 기계설계대학원) ;
  • 좌성훈 (서울과학기술대학교 NID 융합기술대학원)
  • Received : 2014.05.30
  • Accepted : 2014.06.13
  • Published : 2014.06.30
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Abstract

Flexible transparent conductive electrodes (TCEs) have recently attracted a great deal of attention owing to rapid advances in flexible electronic devices, such as flexible displays, flexible photovoltanics, and e-papers. As the performance and reliability of flexible electronics are critically affected by the quality of TCE films, it is imperative to develop TCE films with low resistivity and high transparency as well as high flexibility. Indium tin oxide (ITO) has been the most dominant transparent conducting material due to its high optical transparency and electrical conductivity. However, ITO is susceptible to cracking and delamination when it is bent or deformed. Therefore, various types of flexible TCEs, such as carbon nanotube, conducting polymers, graphene, metal mesh, Ag nanowires (NWs), and metal mesh have been extensively investigated. Among several options to replace ITO film, Ag NWs and metal mesh have been suggested as the promising candidate for flexible TCEs. In this paper, we focused on Ag NWs and metal mesh, and summarized the current development status of Ag NWs and metal mesh. The several critical issues such as high contact resistance and haze are discussed, and newly developed technologies to resolve these issues are also presented. In particular, the flexibility and durability of Ag NWs and metal mesh was compared with ITO electrode.

Keywords

References

  1. J.-H. Ahn, H. Lee and S.-H. Choa, "Technology of flexible semiconductor/memory device", J. Microelectron. Packag. Soc., 20(2), 1 (2013).
  2. T. H. Lee, K. H Shin and Y. J. Kim, "Flexible and embedded packaging of thinned silicon chip", J. Microelectron. Packag. Soc., 11, 29 (2004).
  3. H. Hosono, "Recent progress in transparent oxide semiconductors: materials and device application", Thin Solid Films, 515(15), 6000 (2007). https://doi.org/10.1016/j.tsf.2006.12.125
  4. D. C. Paine, T. Whitson, D. Janiac, R. Beresford, C. O. Yang and B. Lewis, "A study of low temperature crystallization of amorphous thin film indium-tin-oxide", J. Appl. Phys., 85(12), 8445 (1999). https://doi.org/10.1063/1.370695
  5. D. R. Cairns, R. P. Witte II, D. K. Sparacin, S. M. Sachsman, D. C. Paine and G. P. Crawford, "Strain-dependent electrical resistance of tin-doped indium oxide on polymer substrates", Appl. Phys. Lett., 76(11), 1425 (2000). https://doi.org/10.1063/1.126052
  6. J. Lewis, "Material challenge for flexible organic devices", Mater. Today., 9(4), 38 (2006). https://doi.org/10.1016/S1369-7021(06)71446-8
  7. C. M. Trottier, P. Glatkowski, P. Wallis and J. Luo, "Properties and characterization of carbon-nanotube-based transparent conductive coating", J. Soc. Inf. Disp., 13(9), 759 (2005). https://doi.org/10.1889/1.2080514
  8. T. H. Seo, T. S. Oh, S. J. Chae, A. H. Park, K. J. Lee, Y. H. Lee and E. K. Suh, "Enhanced light output power of GaN light-emitting diodes with graphene film as a transparent conducting electrode", Jpn. J. Appl. Phys., 50(12), 125103 (2011). https://doi.org/10.7567/JJAP.50.125103
  9. S. I. Na, S. S. Kim, J. Jo and D. Y. Kim, "Efficient and flexible ITO-free organic solar cells using highly conductive polymer anodes", Adv. Mater., 20(21), 4061 (2008). https://doi.org/10.1002/adma.200800338
  10. J. Park, J. Lee and Y. Y. Noh, "Optical and thermal properties of large-area OLED lightings with metallic grids", Org. Electron., 13(1), 184 (2012). https://doi.org/10.1016/j.orgel.2011.10.024
  11. D.-S. Leem, A. Edwards, M. Faist, J Nelson, D. D. C. Bradley and J. C. Mello, "Efficient organic solar cells with solutionprocessed silver nanowire electrodes", Adv. Mater., 23(38), 4371 (2011). https://doi.org/10.1002/adma.201100871
  12. L. Hu, D. S. Hecht and G. Gruner, "Percolation in transparent and conducting carbon nanotube networks", Nano. Lett., 4(12), 2513 (2004). https://doi.org/10.1021/nl048435y
  13. M. W. Rowell and M. D. McGehee, "Transparent electrode requirements for thin film solar cell modules", Energy & Environ. Sci., 4(1), 131 (2010).
  14. D. S. Hecht, L. B. Hu and G. Irvin, "Emerging transparent electrodes based on thin films of carbon nanotubes, graphene, and metallic nanostructures", Adv. Mater., 23(13), 1482 (2011). https://doi.org/10.1002/adma.201003188
  15. Klaus Ellmer, "Past achievements and future challenges in the development of optically transparent electrodes", Nat. Photon., 6, 809 (2012). https://doi.org/10.1038/nphoton.2012.282
  16. S. Bae, H. Kim, Y. Lee, X. F. Xu, J. S. Park, Y. Zheng, J. Balakrishnan, T. Lei, H. R. Kim, Y. I. Song, Y. J. Kim, K. S. Kim, B. Ozyilmaz, J. H. Ahn, B. H. Hong and S. Iijima, "Roll-to-roll production of 30-inch graphene films for transparent electrodes", Nat. Nanotechnol., 5, 574 (2010). https://doi.org/10.1038/nnano.2010.132
  17. L. Hu, D. S. Hecht and G. Gruner, "Carbon nanotube thin films: fabrication, properties, and applications", Chem. Rev., 110(10), 5790 (2010). https://doi.org/10.1021/cr9002962
  18. J. K. Wassei and R. B. Kaner, "Graphene, a promising transparent conductor", Mater. Today., 13(3), 52 (2010).
  19. L. B. Hu, H. S. Kim, J. Y. Lee, P. Peumans and Y. Cui, "Scalable coating and properties of transparent, flexible, silver nanowire electrodes", ACS. Nano., 4, 2955 (2010). https://doi.org/10.1021/nn1005232
  20. C. H. Liu and X. Yu, "Silver nanowire-based transparent, flexible, and conductive thin film", Nanoscale Research Letters, 6, 75 (2011). https://doi.org/10.1186/1556-276X-6-75
  21. S. Sorel, P. E. Lyons, S. De, J. C. Dickerson and J. N. Coleman, "The dependence of the optoelectrical properties of silver nanowire networks on nanowire length and diameter", Nanotechnol., 23, 18 (2012).
  22. P.-C. Hsu, S. Wang, H. W, V. K. Narasimhan, D. Kong, H. R. Lee and Y. Cui, "Performance enhancement of metal nanowire transparent conducting electrodes by mesoscale metal wires", Nat. Commun., 4, 2522 (2013).
  23. P. Lee, J. Lee, H. Lee, J. Yeo, S. Hong, K. H. Nam, D. Lee, S. S. Lee and S. H. Ko, "Highly stretchable and highly conductive metal electrode by very long metal nanowire percolation network", Adv. Mater., 24, 3326 (2012). https://doi.org/10.1002/adma.201200359
  24. X. Ho, J. N. Tey, W. Liu, C. K. Cheng and J. Wei, "Biaxially stretchable silver nanowire transparent conductors", J. Appl. Phys., 113(4), 044311 (2013). https://doi.org/10.1063/1.4789795
  25. D. H. Lee, H. G. Lee, Y. M. Ahn, Y. J. Jeong, D. Y. Lee and Y. U. Lee, "Highly stable and flexible silver nanowire-grapheme hybrid transparent on ducting electrodes for emerging optoelectronic devices", Nanoscale, 5, 7750 (2013). https://doi.org/10.1039/c3nr02320f
  26. Y. Chang, M. L. Lye and H. C. Zeng, "Large-scale synthesis of high-quality ultralong copper nanowires", Langmuir, 21, 3746 (2005). https://doi.org/10.1021/la050220w
  27. A. R. Rathmell, S. M. Bergin, Y. L. Hua, Z. Y. Li and B. J. Wiley, "The growth mechanism of copper nanowires and their properties in flexible, transparent conducting films", Adv. Mater., 22, 3558 (2010). https://doi.org/10.1002/adma.201000775
  28. T. G. Kim, A. Canlier, G. H. Kim, J. H. Choi, M. K. Park and S. M. Han, "Electrostatic spray deposition of highly transparent silver nanowire electrode on flexible substrate", ACS Appl. Mater. Interfaces, 5(3), 788 (2013). https://doi.org/10.1021/am3023543
  29. E. C. Garnett, W. Cai, J. J. Cha, F. Mahmood, S. T. Connor, M. G. Christoforo, Y. Cui, M. D. McGehee and M. L. Brongersma, "Self-limited plasmonic welding of silver nanowire junctions", Nat. Mater., 11, 241 (2012). https://doi.org/10.1038/nmat3238
  30. J. W. Lim, D. Y. Cho, K. T. Eun, S. H. Choa, S. I. Na, J. H. Kim and H. K. Kim, "Mechanical integrity of flexible Ag nanowire network electrodes coated on colorless PI substrates for flexible organic solar cells", Sol. Energy. Mater. Sol. Cells., 105, 69 (2012). https://doi.org/10.1016/j.solmat.2012.05.036
  31. D. Y. Choi, H. W. Kang, H. J. Sung and S. S. Kim, "Annealing- free, flexible silver nanowire-polymer composite electrodes via a continuous two-step spray-coating method", Nanoscale, 5(3), 977 (2013). https://doi.org/10.1039/c2nr32221h
  32. H. H. Khaligh and I. A. Goldthorpe, "Failure of silver nanowire transparent electrodes under current flow", Nanoscale, 8, 235 (2013).
  33. M. G Kang, M. S. Kim, J. Kim and L. J. Guo, "Organic solar cells using nanoimprinted transparent metal electrodes", Adv. Mater., 20(23), 4408 (2008). https://doi.org/10.1002/adma.200800750
  34. K. Tvingstedt and O. Inganas, "Electrode grid for ITO-free organic photovoltaic devices", Adv. Mater., 19(19), 2893 (2007). https://doi.org/10.1002/adma.200602561
  35. Y. Galagan, J. M. Rubingh, R. Andriessen, C. Fan, P. M. Blom, S. Veenstra and J. Kroon, "ITO-free flexible organic solar cells with printed current collecting grids", Sol. Energy. Mater. Sol. Cells., 95(5), 1339 (2011). https://doi.org/10.1016/j.solmat.2010.08.011
  36. J.-S. Yu, G. H. Jung, J. Jo, J. S. Kim, J. W. Kim, S.-W. Kwak, J.-L. Lee, I. Kim and D. Kim, "Transparent conductive film with printable embedded patterns for organic solar cells", Sol. Energy. Mater. Sol. Cells., 109, 142 (2013). https://doi.org/10.1016/j.solmat.2012.10.013
  37. Y. Jang, J. Kim and D. Byun, "Invisible metal-grid transparent electrode prepared by electrohydrodynamic(EHD) jet printing", Appl. Phys. Lett., 46(15), 155103 (2013).
  38. S. Hong, J. Yeo, G. Kim, H. Lee, J. Kwon, H. Lee, P. Lee and S. H. Ko, "Nonvacuum, maskless fabrication of a flexible metal grid transparent conductor by low-temperature selective laser sintering of nanoparticle ink", ACS. Nano., 7(6), 5024 (2013). https://doi.org/10.1021/nn400432z
  39. Y. Jin, D. Deng and F. Xiao, "Site-selective fabrication of patterned transparent copper mesh on flexible substrates at mild temperature for green, low cost electronics", Electronic Components and Technology Conference, 1315 (2013).
  40. M.-G. Kang, H. J. Park, S. H. Ahn and L. J. Guo, "Transparent Cu nanowire mesh electrode on flexible substrates fabricated by transfer printing and its application in organic solar cells", Sol. Energy. Mater. Sol. Cells., 94(6), 1179 (2010). https://doi.org/10.1016/j.solmat.2010.02.039
  41. J.-A. Jeong, H.-K. Kim and J. Kim, "Invisible Ag grid embedded with ITO nanoparticle layer as a transparent hybrid electrode", Sol. Energy. Mater. Sol. Cells., 125, 113 (2014). https://doi.org/10.1016/j.solmat.2014.03.003
  42. Y. H. Kahng, M.-K. Kim, J.-H. Lee, Y. J. Kim, N. Kim, D.- W. Park and K. Lee, "Highly conductive flexible transparent electrodes fabricated by combining graphene films and inkjetprinted silver grids", Sol. Energy. Mater. Sol. Cells., 124, 86 (2014). https://doi.org/10.1016/j.solmat.2014.01.040
  43. Y. Xiang, T. Li, Z. Suo and J. J. Vlassak, "High ductility of a metal film adherent on a polymer substrate", Appl. Phys. Lett., 87, 161910 (2005). https://doi.org/10.1063/1.2108110

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