Effect of Self-Assembled Monolayers on the Performance of Organic Photovoltaic Cells

DOI: 10.4236/jsemat.2011.12007   PDF   HTML     3,946 Downloads   8,947 Views   Citations


The improvement of the performance of organic photovoltaic cells (OPVCs) and the photogeneration process in these devices may occur via multiple mechanisms depending on their structure and/or architecture. For this purpose we investigate how self-assembled monolayers of thiol molecules (C12H25SH and 3T(CH2)6SH) and benzoic acid molecules (ABA and NBA) affect the efficiency and the photogeneration of free carriers in a sexithiophene based photovoltaic cells. Firstly, we provide the results of absorption spectra for samples with SAM of thiol that show there effect on orientation of 6T molecules on these structures and the organization degree of the thiol molecules on ITO substrate. Afterward, we describe from current vs. applied voltage after illumination, the enhancement of the performance of these cells. In the second, we study the effect of SAM of benzoic acids molecules on the photovoltaic behavior. A theoretical model is used for quantitative description of the open circuit voltage as a function of carrier’s generation rates at the electrodes. The results of I-V characterization under illumination show that open circuit voltage as well as short circuit current is dramatically affected by the dipolar layer. The orientation and the magnitude of dipole moment of benzoic acid molecules are the crucial factors that affect the organic photovoltaic parameters.

Share and Cite:

H. Bedis, "Effect of Self-Assembled Monolayers on the Performance of Organic Photovoltaic Cells," Journal of Surface Engineered Materials and Advanced Technology, Vol. 1 No. 2, 2011, pp. 42-50. doi: 10.4236/jsemat.2011.12007.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] G. Yu and A. J. Heeger, “Polymer Photovoltaic Cells: Enhanced Efficiencies via a Network of Internal Donor-Acceptor Heterojunctions,” Science, Vol. 270, No. 5243, 1995, pp. 1789-1791. doi:10.1126/science.270.5243.1789
[2] P. Peumans and S. R. Forrest, “Very-High-Efficiency Double-Hetero-Structure Copper Pthalocyanine/C60 Photovoltaic Cells,” Applied Physics Letters, Vol. 79, No. 1, 2001, pp.126-128. doi:10.1063/1.1384001
[3] G. Li and Y. Yang, “High Efficiency Solution Processable Polymer Photovoltaic Cells by Self-Organization of Polymer Blends,” Nature Materials, Vol. 4, No. 11, 2005, pp. 864-868. doi:10.1038/nmat1500
[4] C. L. Braun, “Electric Field Assisted Dissociation of Charge Transfer States as a Mechanism of Photocarrier Production,” Journal of Chemical Physics, Vol. 80, No. 9, 1984, pp. 4157-4161. doi:10.1063/1.447243
[5] F. Kouki and H. Bouchriha, “Photogeneration Process in Pristine Sexithiophene Based Photovoltaic Cells,” Organic Electronics, Vol. 11, No. 8, 2010, pp.1439-1444. doi:10.1016/j.orgel.2010.06.005
[6] S. F. Alvaradoand and D. D. C. Bradley, “Direct Determination of the Exciton Binding Energy of Conjugated Polymers Using a Scanning Tunneling Microscope,” Physical Review Letters, Vol. 81, 1998, pp. 1082-1085. doi:10.1103/PhysRevLett.81.1082
[7] X. Crispin, “Interface Dipole at Organic/Metal Interfaces and Organic Solar Cells,” Solar Energy Mater and Solar Cell, Vol. 83, No. 2-3, 2004, pp. 147-168. doi:10.1016/j.solmat.2004.02.022
[8] D.H. Kim and S. Young Oh, “Effects of ITO Surface Modification Using Self-Assembly Molecules on the Characteristics of OLEDs,” Ultramicroscopy, Vol. 108, No. 10, 2008, pp. 1233-1236. doi:10.1016/j.ultramic.2008.04.026
[9] H. Sirringhaus and R. Friend, “Integrated Optoelectronic Devices Based on Conjugated Polymers,” Science, Vol. 280, No. 5370, 1998, pp.1741-1744. doi:10.1126/science.280.5370.1741
[10] S. Goncalves-Conto and L. Zuppiroli, “Interface Morphology in Organic Light-Emitting Diodes,” Advanced Materials, Vol. 11, No. 2, 1999, pp.112-115. doi:10.1002/(SICI)1521-4095(199902)11:2<112::AID-ADMA112>3.0.CO;2-Z
[11] H. Bedis Ouerghemmi and F. Kouki, “Self-Assembled Monolayer Effect on the Characteristics of Organic Diodes,” Synthetic Metals, Vol. 159, No. 7-8, 2009, pp. 551-555. doi:10.1016/j.synthmet.2008.11.031
[12] G. G. Malliaras and J. C. Scott, “Photovoltaic Measurement of The Built-in Potential in Organic Light Emitting Diodes and Photodiodes,” Journal of Applied Physics, Vol. 84, No. 3, 1998, pp. 1583-1587. doi:10.1063/1.368227
[13] S. G. Ray and H. Waldeck, “Organization-Induced Charge Redistribution in Self-Assembled Organic Monolayers on Gold,” Journal of Physical Chemistry B, Vol. 109, No. 29, July 2005, pp. 14064-14073. doi:10.1021/jp050398r
[14] H. B?ssler and G. Vaubel, “Exciton-Induced Photocurrents in Molecular Crystals,” Discussions of the Faraday Society, Vol. 51, 1971, pp. 48-53. doi: 10.1039/DF9715100048
[15] L. Zuppiroli1 and M. Gr?tzel, “Self-assembled Monolayers as Interfaces for Organic Opto-Electronic Devices,” European Physical Journal B, Vol. 11, No. 3, 1999, pp. 505-512. doi:10.1007/s100510050962
[16] F. Kouki and F. Garnier, “Experimental Determination of Excitonic Levels in Alpha-Oligothiophenes,” Journal of Chemical Physics, Vol. 113, No. 1, 2000, pp. 385-391. doi:10.1063/1.481804
[17] J. Tauc and A. Vancu, “Optical Properties and Electronic Structure of Amorphous Germanium,” Physica Status Solidi, Vol.15, No. 2, 1966, pp. 627-637. doi:10.1002/pssb.19660150224
[18] N. Camaioni and Giovanna Barbarella, “Branched Thio-Phene-Based Oligomers as Electron Acceptors for Organic Photovoltaics,” Journal of Materials Chemistry, Vol. 15, No. 22, 2005, pp. 2220-2225. doi:10.1039/B503062E
[19] H. Hoppe and N. Serdar Sariciftci, “Polymer Solar Cells,” Advances in Polymer Science, Vol. 214, 2007, pp.1-86. doi: 10.1007/12_2007_121
[20] J. W. King and S. P. Molnar, “Molecular Structural Index Control in Property-Directed Clustering and Correlation,” International Journal of Quantum Chemistry, Vol. 80, No. 6, 2000, pp. 1164-1171. doi:10.1002/1097-461X(2000)80:6<1164::AID-QUA3>3.0.CO;2-C
[21] I. H. Campbell and D. L. Smith, “Electrical Impedance Measurements of Polymer Light Emitting Diodes”, Applied Physics Letters, Vol. 66, No. 22, 1995, p. 3030. doi:10.1063/1.114267
[22] P. S. Davids and D. L. Smith, “Nondegenerate Continuum Model for Polymer Light-Emitting Diodes,” Journal of Applied Physics, Vol. 78, No. 6, 1995, pp. 4244-4252. doi:10.1063/1.359886
[23] A. J. Cambell and D. G. Lidzey, “Space-Charge Limited Conduction with Traps in Poly (Phenylene Vinylene) Light Emitting Diodes,” Journal of Applied Physics, Vol. 82, No. 12, 1997, pp. 6326-6342. doi:10.1063/1.366523
[24] M. Carrara and L. Zuppiroli, “Carboxylic Acid Anchoring Groups for the Construction of Self-Assembled Monolayers on Organic Device Electrodes,” Synthetic Metals, Vol. 121, 2001, pp. 1633-1634. doi:10.1016/S0379-6779(00)00728-1
[25] H. Bedis, F. Kouki and H. Bouchriha, “Effect of Self Assembled Monolayers on Carrier Photogeneration in Organic Photovoltaic Cells,” International conference ELECMOL’08 Grenoble-HMMNT-Minatec, 2008.

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.