Advertisement

Influence of Deposition Rate on Morphology and Optical Properties of Alq3, Used as Emitter in OLEDs

  • Vivek Kumar Shukla
  • Vibha Tripathi
  • Debjit Datta
  • Satyendra Kumar
Part of the Environmental Science and Engineering book series (ESE)

Abstract

Film deposition rates during vacuum evaporation influences the nucleation and growth of thin films affecting the film microstructure and hence the physical and device properties. The microstructure and surface morphologies of thin films affect the device behavior of OLEDs, particularly when films are very thin. We are reporting a systematic study on the role of film deposition rate in determining the microstructure of small molecular organic thin films. The study would be important for the throughput, performance and stability of OLED based displays and white lights. In this work, we deposited a large number of organic thin films of popular small molecular material Alq3 (Tris (8-hydroxyquinoline) aluminium) at a wide deposition range from ~ 1 to 100 A0/s. The influence of deposition rates on the surface roughness and optical constants of Alq3 films has been studied using atomic force microscopy (AFM), photoluminescence (PL), spectroscopic ellipsometry (SE) and Time Correlated Single Photon Counting (TCSPC) measurements. We find a correlation between deposition rates, film densities and surface roughness.

Keywords

Tris-(8-hydroxyquinoline) metal complex; Alq3; N N’–diphenyl-NN’-bis(3-methylphenyl)-1 1’–biphenyl-4 4’-diamine (TPD); Spectroscopic Ellipsometry (SE); Time Correlated Single Photon Counting (TCSPC) 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgments

Financial and technical support from Samtel Group of Industries and IIT Kanpur is gratefully acknowledged. Authors also thank Dr. Dinesh Deva for AFM and Professor Asima Pradhan (IIT Kanpur) for photoluminescence measurements.

References

  1. 1.
    C. W. Tang and S.A. VanSlyke, Appl. Phys. Lett. 51 (1987) 913.CrossRefGoogle Scholar
  2. 2.
    L.F.Cheng, L.S.Liao, W.Y.Lai, X.H.Sun, N.B.Wong, C.S.Lee, S.T.Lee, Chem. Phys. Lett. 319 (2000) 418.Google Scholar
  3. 3.
    L.F. Cheng et al., Chemical Physics Letters 319(2000)418422.CrossRefGoogle Scholar
  4. 4.
    Kuo-ChunTang, Pei-Wen Cheng, Volume Chein, Cheu Pyeng Cheng, Po-Yuan Cheng, I-Chia Chen, J. Chin. Chem. Soc. No. 4B, 47(2000) 875.Google Scholar
  5. 5.
    Richard Priestley, Igor Sokolik, Ardie D. Walser, Ching W. Tang, Roger Dorsinville Synthetic Metals. 84 (1997) 915CrossRefGoogle Scholar
  6. 6.
    Satyendra Kumar, Vivek Kumar Shukla, Ashutosh Tripathi, Thin Solid Films 477 (2005) 240CrossRefGoogle Scholar
  7. 7.
    A.B. Djurisic, C.Y. Kwong, W.L. Guo, T.W. Lau, E.H. Li, H.S. Kwok, L.S.M. Lam and W.K. Chan, Thin Solid Films 416 (2002) 233.CrossRefGoogle Scholar
  8. 8.
    H. Aziz, Z.D. Popovic, S. Xie, A.M. Hor, N.X. Hu, C.P. Tripp, G. Xu, Appl. Phys. Lett. 72 (1998) 756.CrossRefGoogle Scholar
  9. 9.
    V.K. Shukla, S. Kumar, Synthetic Metals 160 (2010) 450454.Google Scholar
  10. 10.
    H. Mu et al., Solid-State Electronics 48 (2004) 2085–2088.CrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Vivek Kumar Shukla
    • 1
  • Vibha Tripathi
    • 2
  • Debjit Datta
    • 2
  • Satyendra Kumar
    • 2
  1. 1.Department of Applied Physics, School of Applied SciencesGautam Buddha UniversityGreater NoidaIndia
  2. 2.Indian Institute of Technology KanpurKanpurIndia

Personalised recommendations