Experimental and Theoretical Investigation of Photosensitive ITO/PEDOT:PSS/MEH-PPV/Al Detector

Abstract

One of widely investigated materials for photodiode, light-emitting device, and solar cell applications is a soluble conjugated polymer poly(2-methoxy-5- (2,9-ethyl-hexyloxy)-1,4-phenylene vinylene) or MEH-PPV. In this paper we present experimental results on MEH-PPV polymer and ITO/PEDOT:PSS/MEH-PPV/Al photodetector, where ITO and PEDOT:PSS stand for indium tin oxide and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), respectively. Thin polymer films were fabricated by spin-coating technique. The characterization of the material and devices are done in air at room temperature. The experimental results include optical absorption of MEH-PPV and determination of the optical absorption coefficient, photocurrent dependence on optical power, light wavelength, bias voltage, and polymer thin film thickness. Theoretical modeling is based on drift-diffusion and continuity equations for hole polarons, as well as assumption that the charge carrier recombination process is bimolecular. The bimolecular recombination mechanism implies that the photocurrent depends on the square root of the optical power, which is confirmed with our experimental results.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    M. G. Harrison, and J. Gruner, “Analysis of the photocurrent spectra of MEH-PPV polymer photodiodes”, Physical Review B, v.55, n.12, pp.7831–7849,1997.

    CAS  Article  Google Scholar 

  2. 2.

    B. A. Gregg, and M. C Hanna, “Comparing organic to inorganic photovoltaic cells: Theory, experiment, and simulation”, Journal of Applied Physics, vol. 93, no.6, pp. 3605–3614,2003.

    CAS  Article  Google Scholar 

  3. 3.

    M. S Lee, H. S Kang, H. S Kang, J Joo, A. J Epstein, and J. Y Lee, “Flexible all-polymer field effect transistors with optical transparency using electrically conducting polymers”, Thin Solid Films, vol.477, no.1–2, pp. 169–173, 2005.

    CAS  Article  Google Scholar 

  4. 4.

    J. J. M. Halls and R. H. Friend, The photovoltaic effect in a PPV/perylene heterojunction, Synthetic Metals, vol.85, no.1–3, pp.1307–1308, 1996.

    Google Scholar 

  5. 5.

    E. Moons, “Conjugated polymer blends: linking film morphology to performance of light emitting diodes and photodiodes”, Journal of Physics: Condensed Matte, vo.14, pp. 12235–12260, 2002.

    CAS  Google Scholar 

  6. 6.

    A. J. Lewis, A. Ruseckas, O. P. M. Gaudin, G. R. Webster, P. L Burn, I. D. W. Samuel, “Singlet exciton diffusion in MEH:PPV films studied by exciton-exciton annihilation,” Organic Electronics, vol.7, pp.452–456, 2006.

    CAS  Article  Google Scholar 

  7. 7.

    J. Petrović, P. Matavulj, D. Qi, D. K. Chambers, and S. Šelmić, “A Model for the Current-Voltage Characteristics of ITO/PEDOT:PSS/MEHPPV/AL Photodetectors,” IEEE Photonics Technology Letters, vol.20, no.5, pp.348–350, March 2008.

    Article  Google Scholar 

  8. 8.

    B. Kraabel, V. I. Klimov, R. Kohlman, S. Xu, H-L. Wang, D. W. McBranch, “Unified picture of the photoexcitations in phenylene-based conjugated polymers: Universal spectral and dynamical features in subpicosecond transient absorption,” Phys. Rev. B, vol. 61, pp. 8501–8515, 2000.

    CAS  Article  Google Scholar 

  9. 9.

    V. I. Arkhipov, H. Bassler, M. Deussen, E. O. Gobel, “Field-induced exciton breaking in conjugated polymers,” Phys. Rev. B, vol. 52, pp. 4932–4940, 1995.

    CAS  Article  Google Scholar 

  10. 10.

    H. B. DeVore, “Spectral Distribution of photoconductivity,” Physica Review, vol. 102, no. 1, pp. 86–91, April 1956.

    CAS  Article  Google Scholar 

Download references

Acknowledgments

This material is based upon work in part supported by the Louisiana Experimental Program to Stimulate Competitive Research (EPSCoR), funded by the National Science Foundation and the Board of regents Support Fund contract No. NSF(2008)-PFUND-111, and the Serbian Ministry of Science and Technological Development, contract No. 16001A.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Leon R. Pinto.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Pinto, L.R., Petrovic, J., Matavulj, P. et al. Experimental and Theoretical Investigation of Photosensitive ITO/PEDOT:PSS/MEH-PPV/Al Detector. MRS Online Proceedings Library 1190, 1101 (2009). https://doi.org/10.1557/PROC-1190-NN11-01

Download citation