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Gasiorowski J, Hingerl K, Menon R, Plach T, Neugebauer H, Wiesauer K, Yumusak C, Sariciftci NS. Dielectric Function of Undoped and Doped Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene-vinylene] by Ellipsometry in a Wide Spectral Range. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2013; 117:22010-22016. [PMID: 24175008 PMCID: PMC3809355 DOI: 10.1021/jp4061957] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/03/2013] [Indexed: 06/01/2023]
Abstract
Ellipsometric measurements in a wide spectral range (from 0.05 to 6.5 eV) have been carried out on the organic semiconducting polymer, poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene-vinylene] (MDMO-PPV), in both undoped and doped states. The real and imaginary parts of the dielectric function and the refractive index are determined accurately, provided that the layer thickness is measured independently. After doping, the optical properties show the presence of new peaks, which could be well-resolved by spectroscopic ellipsometry. Also for the doped material, the complex refractive index, with respect to the dielectric function, has been determined. The broadening of the optical transitions is due to the delocalization of polarons at higher doping level. The detailed information about the dielectric function as well as refractive index function obtained by spectroscopic ellipsometry allows not only qualitative but also quantitative description of the optical properties of the undoped/doped polymer. For the direct characterization of the optical properties of MDMO-PPV, ellipsometry turns out to be advantageous compared to conventional reflection and transmission measurements.
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Affiliation(s)
- Jacek Gasiorowski
- Linz Institute for Organic Solar
Cells (LIOS), Physical Chemistry, and Center for Surface
and Nanoanalytics, Johannes Kepler University
of Linz, Altenberger
Strasse 69, 4040 Linz, Austria
| | - Kurt Hingerl
- Linz Institute for Organic Solar
Cells (LIOS), Physical Chemistry, and Center for Surface
and Nanoanalytics, Johannes Kepler University
of Linz, Altenberger
Strasse 69, 4040 Linz, Austria
| | - Reghu Menon
- Department
of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Thomas Plach
- Linz Institute for Organic Solar
Cells (LIOS), Physical Chemistry, and Center for Surface
and Nanoanalytics, Johannes Kepler University
of Linz, Altenberger
Strasse 69, 4040 Linz, Austria
| | - Helmut Neugebauer
- Linz Institute for Organic Solar
Cells (LIOS), Physical Chemistry, and Center for Surface
and Nanoanalytics, Johannes Kepler University
of Linz, Altenberger
Strasse 69, 4040 Linz, Austria
| | - Karin Wiesauer
- RECENDT
Research Center for Non-destructive Testing GmbH, Altenberger Strasse 69, 4040 Linz, Austria
| | - Cigdem Yumusak
- Department
of Physics, Faculty of Arts and Sciences, Yildiz Technical University, Davutpasa
Campus, Esenler, 34210 Istanbul, Turkey
| | - Niyazi S. Sariciftci
- Linz Institute for Organic Solar
Cells (LIOS), Physical Chemistry, and Center for Surface
and Nanoanalytics, Johannes Kepler University
of Linz, Altenberger
Strasse 69, 4040 Linz, Austria
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Gasiorowski J, Mardare AI, Sariciftci NS, Hassel AW. Electrochemical characterization of sub-micro-gram amounts of organic semiconductors using scanning droplet cell microscopy. J Electroanal Chem (Lausanne) 2013; 691:77-82. [PMID: 24926226 PMCID: PMC4047611 DOI: 10.1016/j.jelechem.2012.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 11/05/2012] [Accepted: 11/07/2012] [Indexed: 11/26/2022]
Abstract
Scanning droplet cell microscopy (SDCM) uses a very small electrolyte droplet at the tip of a capillary which comes in contact with the working electrode. This method is particularly interesting for studies on organic semiconductors since it provides localized electrochemical investigations with high reproducibility. One clear advantage of applying SDCM is represented by the very small amounts of material necessary (less than 1 mg). Organic materials can be investigated quickly and inexpensively in electrochemical studies with a high throughput. In the present study, thin layers of poly(3-hexylthiophene) (P3HT), which is one of the most often used material for organic solar cells, were deposited on ITO/glass as working electrodes in SDCM studies. The redox reactions in 0.1 M tetra(n-butyl)ammonium hexafluorophosphate (TBAPF6) dissolved in propylene carbonate were studied by cyclic voltammetry and by electrochemical impedance spectroscopy. Two reversible, distinct oxidation steps of the P3HT were detected and their kinetics were studied in detail. The doping of P3HT increased due to the electrochemical oxidation and had resulted in a decrease of the film resistance by a few orders of magnitude. Due to localization on the sample various parameter combinations can be studied quantitatively and reproducibly.
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Affiliation(s)
- Jacek Gasiorowski
- Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz, Austria
| | - Andrei I. Mardare
- Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Linz, Austria
| | - Niyazi S. Sariciftci
- Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz, Austria
| | - Achim Walter Hassel
- Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Linz, Austria
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Meana-Esteban B, Balan A, Baran D, Neugebauer H, Toppare L, Sariciftci NS. In Situ Spectroelectrochemical Study of Positively and Negatively Charged States in a Donor/Acceptor EDOT/Benzotriazole-Based Polymer. MACROMOL CHEM PHYS 2011. [DOI: 10.1002/macp.201100322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lukoyanova O, Lepeltier M, Laferrière M, Perepichka DF. Donor–Acceptor Intermediates and Low-Bandgap Polymers by Electropolymerization of Thienoazaborines. Macromolecules 2011. [DOI: 10.1021/ma200503f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Olena Lukoyanova
- Department of Chemistry, McGill University, Montreal, Quebec, H3A 2K6
| | - Marc Lepeltier
- Department of Chemistry, McGill University, Montreal, Quebec, H3A 2K6
| | - Marie Laferrière
- Department of Chemistry, McGill University, Montreal, Quebec, H3A 2K6
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Baran D, Balan A, Esteban BM, Neugebauer H, Sariciftci NS, Toppare L. Spectroelectrochemical and Photovoltaic Characterization of a Solution-Processable n-and-p Type Dopable Pyrrole-Bearing Conjugated Polymer. MACROMOL CHEM PHYS 2010. [DOI: 10.1002/macp.201000371] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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