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.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
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.
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.
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.
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.
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.
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.
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.
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.
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.
H. B. DeVore, “Spectral Distribution of photoconductivity,” Physica Review, vol. 102, no. 1, pp. 86–91, April 1956.
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.
About this article
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