Journal of Materials Science

, Volume 54, Issue 19, pp 12688–12697 | Cite as

Enhanced electroluminescent performance by doping organic conjugated ionic compound into graphene oxide hole-injecting layer

  • Pan Liu
  • Junna Liu
  • Bingbing Zhang
  • Wansheng Zong
  • Shengang Xu
  • Yingliang LiuEmail author
  • Shaokui CaoEmail author
Electronic materials


Organic conjugated ionic compound 10,10′-dimethyl-9,9′-biacridinum bis(monomethyl terephthalate) (MMT) is doped into graphene oxide (GO) hole-injecting layer to enhance the electroluminescent performance of organic light-emitting diodes (OLEDs). The composite films are characterized in detail by FTIR, SEM, XPS, and UPS. The XPS result indicates the evident ππ stacking interaction between the conjugated structures of GO and MMT. The UPS result shows the decrease in ionization potential of GO due to MMT-doping. As a result, at the optimal doping ratio of 4 wt%, the maximum luminous efficiency of OLEDs is increased to 15.46 cd/A, which is 3.4 times as 4.55 cd/A of the control device. Besides, the luminance is also enhanced to 19950 cd/m2, while the turn-on voltage is decreased to 2.5 V. Doping organic conjugated ionic compound into the GO hole-injecting layer is a facile and efficient approach to improve the electroluminescent performance of OLEDs.



We gratefully acknowledge the financial support from the National Natural Science Foundation of China (NSFC; Grant Nos. U1304212, 21274133, 20774088 and 21374106) and the Development Foundation for Distinguished Junior Researchers at Zhengzhou University (Grant No. 1421320043).

Supplementary material

10853_2019_3820_MOESM1_ESM.docx (20 kb)
Supplementary material 1 (DOCX 20 kb)


  1. 1.
    Walzer K, Maennig B, Pfeiffer M, Leo K (2007) Highly efficient organic devices based on electrically doped transport layers. Chem Rev 107(4):1233–1271Google Scholar
  2. 2.
    Liam SCP, MacLeod BA, Ginger DS (2008) The changing face of PEDOT:PSS films: substrate, bias, and processing effects on vertical charge transport. J Phys Chem C 112(21):7922–7927Google Scholar
  3. 3.
    Hau SK, Yip HL, Zou JY, Jen AK (2009) Indium tin oxide-free semi-transparent inverted polymer solar cells using conducting polymer as both bottom and top electrodes. Org Electron 10(7):1401–1407Google Scholar
  4. 4.
    Wong KW, Yip HL, Luo Y, Wong KY, Lau KM, Chow HF, Gao ZQ, Yeung WL, Chang CC (2002) Blocking reactions between indium–tin oxide and poly (3,4-ethylene dioxythiophene):poly(styrene sulphonate) with a self-assembly monolayer. Appl Phys Lett 80(15):2788–2790Google Scholar
  5. 5.
    Kion N, Morton VM, Suren VG, Frederik CK (2010) Degradation patterns in water and oxygen of an inverted polymer solar cell. J Am Chem Soc 47(132):16883–16892Google Scholar
  6. 6.
    Li SS, Tu KH, Lin CC, Chen CW, Manish C (2010) Solution-processable graphene oxide as an efficient hole transport layer in polymer solar cell. ACS Nano 4(6):3169–3174Google Scholar
  7. 7.
    Lee BR, Kim J, Kang D, Lee DW, Ko SJ, Lee HJ, Lee CL, Kim JY, Shin HC, Song MH (2012) Highly efficient polymer light-emitting diodes using graphene oxide as a hole transport layer. ACS Nano 6(4):2984–2991Google Scholar
  8. 8.
    Scholes GD, Rumbles G (2006) Excitons in nanoscale systems. Nat Mater 9(5):683–696Google Scholar
  9. 9.
    Liu CC, Xu JK, Lu BY, Yue RR, Kong FF (2012) Simultaneous increases in electrical conductivity and Seebeck coefficient of PEDOT:PSS films by adding ionic liquids into a polymer solution. J Electron Mater 41(4):639–645Google Scholar
  10. 10.
    Lee SK, Lee KK (2010) Conductivity enhancement of PEDOT:PSS films with ionic liquids as dopants. Adv Mater Res 93–94:501–504Google Scholar
  11. 11.
    Döbbelin M, Marcilla R, Salsamendi M, Pozo-Gonzalo C, Carrasco PM, Pomposo JA, Mecerreyes D (2007) Influnce of ionic liquids on the electrical conductivity and morphology of PEDOT:PSS films. Chem Mater 19(9):2147–2149Google Scholar
  12. 12.
    Chantal B, Ludovic M, Ahmed MA, Lawrence AH (2012) Highly conductive poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) films using 1-ethyl-3-methylimidazolium tetracyanoborate ionic liquid. Adv Funct Mater 22:2723–2727Google Scholar
  13. 13.
    Liu YL, Zhao Y, Xu SG, Cao SK (2015) Enhanced electroluminescent efficiency with ionic liquid doped into PEDOT:PSS hole-injecting layer. Polymer 77:42–47Google Scholar
  14. 14.
    Li CT, Lee CP, Fan MS, Chen PY, Vittal R, Ho KC (2014) Ionic liquid-doped poly(3,4-ethylenedioxy thiophene) counter electrodes for dye-sensitized solar cells: cationic and anionic effects on the photovoltaic performance. Nano Energy 9:1–14Google Scholar
  15. 15.
    Balandin AA, Ghosh S, Bao W, Calizo A, Teweldebrhan D, Miao F, Lau CN (2008) Superior thermal conductivity of single-layer graphene. Nano Lett 8(3):902–907Google Scholar
  16. 16.
    Lee C, Wei X, Kysar JW, Honen J (2008) Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321(5887):385–388Google Scholar
  17. 17.
    Cheng TC, Ku TA, Huang KY, Chou AS, Chang PH, Chao C, Yue CF, Liu CW, Wang PH, Wong KT, Wu CI (2018) Surface modification of graphene using HBC-6ImBr in solution-processed OLEDs. J Appl Phys 123(2):024303(1–7)Google Scholar
  18. 18.
    Kim DH, Kim TW (2018) Highly-efficient organic light-emitting devices based on poly(N, N′-bis-4-butylphenyl-N, N′-bisphenyl) benzidine: octadecylamine-graphene quantum dots. Org Electron 57:305–310Google Scholar
  19. 19.
    Jesuraj PJ, Parameshwari R, Kanthasamy K, Koch J, Pfnür H, Jeganathan K (2017) Hole injection enhancement in organic light emitting devices using plasma treated graphene oxide. Appl Surf Sci 397:144–151Google Scholar
  20. 20.
    Dou L, Cui F, Yu Y, Khanarian G, Eaton SW, Yang Q, Resasco J, Schildknecht C, Schierle-Arndt K, Yang P (2016) Solution-processed copper/reduced-graphene-oxide core/shell nanowire transparent conductors. ACS Nano 10:2600–2606Google Scholar
  21. 21.
    Varghese SS, Lonkar S, Singh KK, Swaminathan S, Abdala A (2016) Recent advances in graphene based gas sensors. Sens Actuators B Chem 218:160–183Google Scholar
  22. 22.
    Kim Y, Lee EY, Lee HH, Seo TS (2017) Characteristics of reduced graphene oxide quantum dots for a flexible memory thin film transistor. ACS Appl Mater Interfaces 9:16375–16380Google Scholar
  23. 23.
    Hou ZQ, Wang ZY, Yang LX (2017) Nitrogen-doped reduced graphene oxide intertwined with V2O3 nanoflakes as self-supported electrodes for flexible all-solid-state supercapacitors. RSC Adv 7:25732–25739Google Scholar
  24. 24.
    Rafique S, Abdullah SM, Shahid MM, Ansari MO, Sulaiman K (2017) Significantly improved photovoltaic performance in polymer bulk heterojunction solar cells with graphene oxide/PEDOT:PSS double decked hole transport layer. Sci Rep 7:39555Google Scholar
  25. 25.
    Hafsi B, Boubaker A, Guerin D, Lenfant S, Kalboussi A, Lmimouni K (2017) N-type polymeric organic flash memory device: effect of reduced graphene oxide floating gate. Org Electron 45:81–88Google Scholar
  26. 26.
    Gao Y, Yip HL, Chen KS, O’Malley KM, Acton O, Sun Y, Ting G, Chen H, Jen AKY (2011) Surface doping of conjugated polymers by graphene oxide and its application for organic electronic device. Adv Mater 23:1903–1908Google Scholar
  27. 27.
    Fernández-Merino MJ, Guardia L, Paredes JI, Villar-Rodil S, Solís-Fernández P, Martínez-Alonso A, Tascón JMD (2010) Vitamin C is an ideal substitute for hydrazine in the reduction of graphene oxide suspensions. J Phys Chem C 114:6426–6432Google Scholar
  28. 28.
    Ruben R, Juan IP, Silvia VR, Amelia MA, Juan MDT (2013) Towards full repair of defects in reduced graphene oxide films by two-step graphitization. Nano Res 6:216–233Google Scholar
  29. 29.
    Stankovich S, Dikin DA, Piner RD, Kohlhaas KA, Kleinhammes A, Jia Y, Wu Y, Nguyen ST, Ruoff RS (2007) Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon 45:1558–1565Google Scholar
  30. 30.
    Liu Z, Botana J, Hermann A, Valdez S, Zurek E, Yan DD, Lin HQ, Miao MS (2018) Reactivity of He with ionic compounds under high pressure. Nat Commun 9:951Google Scholar
  31. 31.
    Xu Z, Chen LM, Chen MH (2009) Energy level alignment of poly(3-hexylthiophene): [6,6]-phenyl C61 butyric acid methyl ester bulk heterojunction. Appl Phys Lett 95:013301Google Scholar
  32. 32.
    Rebeca M, David M, Gustaf W, Sergio B, Maria MRY, Franco C (2010) Light-emitting electrochemical cells using polymeric ionic liquid_polyfluorene blends as luminescent material. Appl Phys Lett 96:043308Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.School of Materials Science and EngineeringZhengzhou UniversityZhengzhouPeople’s Republic of China
  2. 2.Henan Key Laboratory of Advanced Nylon Materials and ApplicationZhengzhou UniversityZhengzhouPeople’s Republic of China

Personalised recommendations