Advertisement

Journal of Coatings Technology and Research

, Volume 14, Issue 5, pp 1029–1037 | Cite as

Slot die-coated blue SMOLED multilayers

  • Sebastian M. Raupp
  • Lisa Merklein
  • Sebastian Hietzschold
  • Martin Zürn
  • Philip Scharfer
  • Wilhelm Schabel
Article

Abstract

The key challenge in solution-processing efficient OLEDs is to realize the multilayer device architecture. We demonstrate that slot die coating is applicable to deposit small-molecule (SM) layers on top of each other without dissolving the underlying layer. A stack for a blue SMOLED is chosen comprising slot die-coated PEDOT:PSS, an SM emissive layer (EML) as well as an SM electron transport layer (ETL). The devices are fabricated in a sheet-to-sheet coating process with a slot die table coater under ambient conditions. While keeping the processing parameters constant for PEDOT:PSS and the EML, the composition of the ETL is varied. The choice of solvent for coating the ETL is crucial regarding wetting and dissolution of the underlying layer, solubility, surface roughness, and device efficiencies. Average roughness values down to 0.38 nm and peak to valley values around 10 nm were measured. Comparing device efficiencies of devices with and without ETL, an increase in efficiency with a factor up to 42 was achieved. In total, we show 135 blue SMOLEDs to demonstrate reproducibility.

Keywords

Slot die coating OLED SMOLED Multilayer Solution processed Organic electronics Drying Film morphology AFM 

Abbreviations

AA

Acetic acid

Al

Aluminum

CE

Current efficiency

EML

Emissive layer

ETL

Electron transport layer

EtOH

Ethanol

FA

Formic acid

FIrPic

Bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyr-idyl)iridium(III)

HBL

Hole blocking layer

HIL

Hole injection layer

HTL

Hole transport layer

ITO

Indium-tin-oxide

LiF

Lithiumfluoride

MeOH

Methanol

PE

Power efficiency

Prop

Propanol

SimCP2

Bis[3,5-di(9H-carbazol-9-yl)phenyl]diphenylsilane

Tol

Toluene

TPBi

2,2′,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)

Notes

Acknowledgments

The authors acknowledge financial support via the project Print OLED (Contract Number 13N10759) and POESIE (Contract Number 13N13692) of the Federal Ministry of Education and Research. We would like to thank all involved mechanics, assistants, and our students for contributing to this work as well as TSE Troller AG, Murgenthal, Switzerland, for technical support. The authors are also thankful for the support of the Light Technology Institute (LTI) of KIT as well as the Institute of Printing Science (IDD) of the Technical University of Darmstadt and InnovationLab GmbH, Heidelberg.

Supplementary material

11998_2017_9964_MOESM1_ESM.pdf (344 kb)
Supplementary material 1 (PDF 343 kb)

References

  1. 1.
    You, J, Tseng, S, Meng, H, Yen, F, Lin, I, Horng, S, “All-Solution-Processed Blue Small Molecular Organic Light-Emitting Diodes with Multilayer Device Structure.” Organ. Electron., 10 (8) 1610–1614 (2009)CrossRefGoogle Scholar
  2. 2.
    Xue, S, Qiu, X, Yao, L, Wang, L, Yao, M, Gu, C, Wang, Y, Xie, Z, Wu, H, “Fully Solution-Processed and Multilayer Blue Organic Light-Emitting Diodes Based on Efficient Small Molecule Emissive Layer and Intergrated Interlayer Optimization.” Organ. Electron., 27 35–40 (2015)CrossRefGoogle Scholar
  3. 3.
    Henwood, AF, Bansal, AK, Cordes, DB, Slawin, AMZ, Samuel, IDW, Zysman-Colman, E, “Solubilised Bright Blue-Emitting Iridium Complexes for Solution Processed OLEDs.” J. Mater. Chem. C Mater. Opt. Electron. Devices, 4 (17) 3726–3737 (2016)CrossRefGoogle Scholar
  4. 4.
    Duan, L, Hou, L, Lee, T, Qiao, J, Zhang, D, Dong, G, Wang, L, Qiu, Y, “Solution Processable Small Molecules for Organic Light-Emitting Diodes.” J. Mater. Chem., 20 (31) 6392 (2010)CrossRefGoogle Scholar
  5. 5.
    Choi, K, Lee, J, Park, J, Seo, Y, “Multilayer Slot-Die Coating of Large-Area Organic Light-Emitting Diodes.” Organic Electronics, 26 66–74 (2015)CrossRefGoogle Scholar
  6. 6.
    Choi, K, Lee, J, Shin, D, Park, J, “Investigation on Slot-Die Coating of Hybrid Material Structure for OLED Lightings.” J. Phys. Chem. Solids, 95 119–128 (2016)CrossRefGoogle Scholar
  7. 7.
    Carvalho, MS, Kheshgi, HS, “Low-Flow Limit in Slot Coating: Theory and Experiments.” AIChE J., 46 (10) 1907–1917 (2000)CrossRefGoogle Scholar
  8. 8.
    Kistler, SF, Schweizer, PM (eds.), Liquid Film Coating. Springer, Netherlands, Dordrecht (1997)Google Scholar
  9. 9.
    Han, GH, Lee, SH, Ahn, W, Nam, J, Jung, HW, “Effect of Shim Configuration on Flow Dynamics and Operability Windows in Stripe Slot Coating Process.” J. Coat. Technol. Res., 11 (1) 19–29 (2014)CrossRefGoogle Scholar
  10. 10.
    Schmitt, M, Scharfer, P, Schabel, W, “Slot Die Coating of Lithium-Ion Battery Electrodes. Investigations on Edge Effect Issues for Stripe and Pattern Coatings.” J. Coat. Technol. Res., 11 (1) 57–63 (2014)CrossRefGoogle Scholar
  11. 11.
    Schmitt, M, Diehm, R, Scharfer, P, Schabel, W, “An Experimental and Analytical Study on Intermittent Slot Die Coating of Viscoelastic Battery Slurries.” J. Coat. Technol. Res., 12 (5) 927–938 (2015)CrossRefGoogle Scholar
  12. 12.
    Kang, H, Park, J, Shin, K, “Statistical Analysis for the Manufacturing of Multi-Strip Patterns by Roll-to-Roll Single Slot-Die Systems.” Robot. Comput. Integr. Manuf., 30 (4) 363–368 (2014)CrossRefGoogle Scholar
  13. 13.
    Lin, C, Wang, B, Lo, S, Wong, DS, Liu, T, Tiu, C, “Operating Windows of Stripe Coating.” Asia Pac. J. Chem. Eng., 9 (1) 134–145 (2014)CrossRefGoogle Scholar
  14. 14.
    Wen, S, Liu, T, “Extrusion Die Design for Multiple Stripes.” Polym. Eng. Sci., 9 (35) 759–767 (1995)CrossRefGoogle Scholar
  15. 15.
    Larsen-Olsen, TT, Andreasen, B, Andersen, TR, Böttiger, AP, Bundgaard, E, Norrman, K, Andreasen, JW, Jørgensen, M, Krebs, FC, “Simultaneous Multilayer Formation of the Polymer Solar Cell Stack Using Roll-to-Roll Double Slot-Die Coating from Water.” Sol. Energy Mater. Sol. Cells, 97 22–27 (2012)CrossRefGoogle Scholar
  16. 16.
    Horiuchi, R, Suszynski, WJ, Carvalho, MS, “Simultaneous Multilayer Coating of Water-Based and Alcohol-Based Solutions.” J. Coat. Technol. Res., 12 (5) 819–826 (2015)CrossRefGoogle Scholar
  17. 17.
    Ji, HS, Ahn, W, Kwon, I, Nam, J, Jung, HW, “Operability Coating Window of Dual-Layer Slot Coating Process Using Viscocapillary Model.” Chem. Eng. Sci., 143 122–129 (2015)CrossRefGoogle Scholar
  18. 18.
    Schmitt, M, Raupp, S, Wagner, D, Scharfer, P, Schabel, W, “Analytical Determination of Process Windows for Bilayer Slot Die Coating.” J. Coat. Technol. Res., 12 (5) 877–887 (2015)CrossRefGoogle Scholar
  19. 19.
    Schmitt, M, Baunach, M, Wengeler, L, Peters, K, Junges, P, Scharfer, P, Schabel, W, “Slot-Die Processing of Lithium-Ion Battery Electrodes—Coating Window Characterization.” Chem. Eng. Process. Process Intensif., 68 32–37 (2013)CrossRefGoogle Scholar
  20. 20.
    Yang, CK, Wong, DSH, Liu, TJ, “The Effects of Polymer Additives on the Operating Windows of Slot Coating.” Polym. Eng. Sci., 44 (10) 1970–1976 (2004)CrossRefGoogle Scholar
  21. 21.
    Ding, X, Liu, J, Harris, TA, “A Review of the Operating Limits in Slot Die Coating Processes.” AIChE J., 62 (7) 2508–2524 (2016)CrossRefGoogle Scholar
  22. 22.
    Romero, OJ, Carvalho, MS, “Response of Slot Coating Flows to Periodic Disturbances.” Chem. Eng. Sci., 63 (8) 2161–2173 (2008)CrossRefGoogle Scholar
  23. 23.
    Carlé, JE, Andersen, TR, Helgesen, M, Bundgaard, E, Jørgensen, M, Krebs, FC, “A Laboratory Scale Approach to Polymer Solar Cells Using One Coating/Printing Machine, Flexible Substrates, No ITO, No Vacuum and No Spincoating.” Sol. Energy Mater. Sol. Cells, 108 126–128 (2013)CrossRefGoogle Scholar
  24. 24.
    Dam, HF, Krebs, FC, “Simple Roll Coater with Variable Coating and Temperature Control for Printed Polymer Solar Cells.” Sol. Energy Mater. Sol. Cells, 97 191–196 (2012)CrossRefGoogle Scholar
  25. 25.
    Hösel, M, Søndergaard, RR, Jørgensen, M, Krebs, FC, “Fast Inline Roll-to-Roll Printing for Indium-Tin-Oxide-Free Polymer Solar Cells Using Automatic Registration.” Energy Technol., 1 (1) 102–107 (2013)CrossRefGoogle Scholar
  26. 26.
    Krebs, FC, “Fabrication and Processing of Polymer Solar Cells. A Review of Printing and Coating Techniques.” Sol. Energy Mater. Sol. Cells, 93 (4) 394–412 (2009)CrossRefGoogle Scholar
  27. 27.
    Roth, B, dos Reis Benatto, GA, Corazza, M, Søndergaard, RR, Gevorgyan, SA, Jørgensen, M, Krebs, FC “The Critical Choice of PEDOT:PSS Additives for Long Term Stability of Roll-to-Roll Processed OPVs.” Adv. Energy Mater., 5 (9) 1401912 (2015)CrossRefGoogle Scholar
  28. 28.
    Liu, F, Ferdous, S, Schaible, E, Hexemer, A, Church, M, Ding, X, Wang, C, Russell, TP, “Fast Printing and In Situ Morphology Observation of Organic Photovoltaics Using Slot-Die Coating.” Adv. Mater. (Deerfield Beach, Fla.), 27 (5) 886–891 (2015)CrossRefGoogle Scholar
  29. 29.
    Pröller, S, Liu, F, Zhu, C, Wang, C, Russell, TP, Hexemer, A, Müller-Buschbaum, P, Herzig, EM, “Following the Morphology Formation In Situ in Printed Active Layers for Organic Solar Cells.” Adv. Energy Mater., 6 (1) 1501580 (2016)CrossRefGoogle Scholar
  30. 30.
    Wengeler, L, Peters, K, Schmitt, M, Wenz, T, Scharfer, P, Schabel, W, “Fluid-dynamic properties and wetting behavior of coating inks for roll-to-roll production of polymer-based solar cells.” J. Coat Technol. Res., 11 (1) 65–73 (2014)CrossRefGoogle Scholar
  31. 31.
    Chang, J, Chi, C, Zhang, J, Wu, J, “Controlled Growth of Large-Area High-Performance Small-Molecule Organic Single-Crystalline Transistors by Slot-Die Coating Using a Mixed Solvent System.” Adv. Mater., 25 (44) 6442–6447 (2013)CrossRefGoogle Scholar
  32. 32.
    Chang, J, Lin, Z, Li, J, Lim, SL, Wang, F, Li, G, Zhang, J, Wu, J, “Enhanced Polymer Thin Film Transistor Performance by Carefully Controlling the Solution Self-Assembly and Film Alignment with Slot Die Coating.” Adv. Electron. Mater., 1 (7) 1500036 (2015)CrossRefGoogle Scholar
  33. 33.
    Sandström, A, Dam, HF, Krebs, FC, Edman, L, “Ambient Fabrication of Flexible and Large-Area Organic Light-Emitting Devices Using Slot-Die Coating.” Nat. Comms., 3 1002 (2012)CrossRefGoogle Scholar
  34. 34.
    Park, B, Kwon, OE, Yun, SH, Jeon, HG, Huh, YH, “Organic Semiconducting Layers Fabricated by Self-Metered Slot-Die Coating for Solution-Processable Organic Light-Emitting Devices.” J. Mater. Chem. C, 2 (40) 8614–8621 (2014)CrossRefGoogle Scholar
  35. 35.
    Raupp, SM, Merklein, L, Pathak, M, Scharfer, P, Schabel, W, “An Experimental Study on the Reproducibility of Different Multilayer OLED Materials Processed by Slot Die Coating.” Chem. Eng. Sci., 160 113–120 (2017)CrossRefGoogle Scholar
  36. 36.
    Raupp, SM, Daume, D, Tekoglu, S, Merklein, L, Lemmer, U, Hernandez-Sosa, G, Sauer, HM, Dörsam, E, Scharfer, P, Schabel, W, “Slot Die Coated and Flexo Printed Highly Efficient SMOLEDs.” Adv. Mater. Technol., 2 (2) 1600230 (2017)CrossRefGoogle Scholar
  37. 37.
    Meerholz, K, “Device Physics: Enlightening Solutions.” Nature, 437 (7057) 327–328 (2005)CrossRefGoogle Scholar
  38. 38.
    Chang, Y, Chiu, Y, Chang, H, Wang, Y, Shih, Y, Wu, C, Liu, Y, Lin, Y, Meng, H, Chi, Y, Huang, H, Tseng, M, Lin, H, Zan, H, Horng, S, Juang, J, “Interface and Thickness Tuning for Blade Coated Small-Molecule Organic Light-Emitting Diodes with High Power Efficiency.” J. Appl. Phys., 114 (12) 123101 (2013)CrossRefGoogle Scholar
  39. 39.
    Chang, H, Lee, Y, Tseng, M, Jang, M, Yeh, H, Luo, F, Meng, H, Chen, C, Chi, Y, Qiu, Y, Duan, L, Lin, H, Horng, S, Zan, H, “General Application of Blade Coating to Small-Molecule Hosts for Organic Light-Emitting Diode.” Synth. Met., 196 99–109 (2014)CrossRefGoogle Scholar
  40. 40.
    Liu, S, Yuan, C, Yeh, S, Wu, M, Chen, C, Lee, C, “Efficiency Enhancement of Solution-Processed Single-Layer Blue-Phosphorescence Organic Light-Emitting Devices Having Co-host Materials of Polymer (PVK) and Small-Molecule (SimCP2).” J. Soc. Inf. Display, 19 (4) 346 (2011)CrossRefGoogle Scholar
  41. 41.
    Knauer, KA, Najafabadi, E, Haske, W, Kippelen, B, “Inverted Top-Emitting Blue Electrophosphorescent Organic Light-Emitting Diodes with High Current Efficacy.” Appl. Phys. Lett., 101 (10) 103304 (2012)CrossRefGoogle Scholar
  42. 42.
    Bhansali, US, Polikarpov, E, Swensen, JS, Chen, W, Jia, H, Gaspar, DJ, Gnade, BE, Padmaperuma, AB, Omary, MA, “High-Efficiency Turquoise-Blue Electrophosphorescence from a Pt(II)-Pyridyltriazolate Complex in a Phosphine Oxide Host.” Appl. Phys. Lett., 95 (23) 233304 (2009)CrossRefGoogle Scholar

Copyright information

© American Coatings Association 2017

Authors and Affiliations

  • Sebastian M. Raupp
    • 1
    • 2
  • Lisa Merklein
    • 1
    • 2
  • Sebastian Hietzschold
    • 2
    • 3
  • Martin Zürn
    • 1
    • 2
  • Philip Scharfer
    • 1
    • 2
  • Wilhelm Schabel
    • 1
  1. 1.Institute of Thermal Process Engineering, Thin Film TechnologyKarlsruhe Institute of TechnologyKarlsruheGermany
  2. 2.InnovationLab (iL)HeidelbergGermany
  3. 3.Institute for High-Frequency TechnologyTU BraunschweigBrunswickGermany

Personalised recommendations