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Flämmich M, Danz N, Michaelis D, Bräuer A, Gather MC, Kremer JHWM, Meerholz K. Dispersion-model-free determination of optical constants: application to materials for organic thin film devices. APPLIED OPTICS 2009; 48:1507-1513. [PMID: 19277083 DOI: 10.1364/ao.48.001507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We describe a method to determine the refractive index and extinction coefficient of thin film materials without prior knowledge of the film thickness and without the assumption of a dispersion model. A straightforward back calculation to the optical parameters can be performed starting from simple measurements of reflection and transmission spectra of a 100-250 nm thick supported film. The exact film thickness is found simultaneously by fulfilling the intrinsic demand of continuity of the refractive index as a function of wavelength. If both the layer and the substrate are homogeneous and isotropic media with plane and parallel interfaces, effects like surface roughness, scattering, or thickness inhomogeneities can be neglected. Then, the accuracy of the measurement is approximately 10(-2) and 10(-3) for the refractive index and the extinction coefficient, respectively. The error of the thin film thickness determination is well below 1 nm. Thus this technique is well suited to determine the input parameters for optical simulations of organic thin film devices, such as organic light-emitting diodes (OLEDs) or organic photovoltaic (OPV) cells. We apply the method to the electroluminescent polymer poly(2,5-dioctyl-p-phenylene vinylene) (PDO-PPV) and show its applicability by comparing the measured and calculated reflection and transmission spectra of OLED stacks with up to five layers.
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Affiliation(s)
- Michael Flämmich
- Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Strasse 7, 07745 Jena, Germany
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Kutavichus VP, Filippov VV, Huzouski VH. Determination of optical parameters and thickness of weakly absorbing thin films from reflectance and transmittance spectra. APPLIED OPTICS 2006; 45:4547-53. [PMID: 16799663 DOI: 10.1364/ao.45.004547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A method for determining the optical constants and the thickness of weakly absorbing thin films on substrates is proposed. In this method only the reflectance and transmittance spectra obtained at a single arbitrary angle of incidence are used, provided that the former reveals several interference extrema. The calculation procedure is based on relatively simple relations suitable for the programmed realization and does not call for the prescription of the initial values of the parameters to be determined. The method proposed is fairly accurate and allows one to uniquely solve the inverse problem of spectrophotometry. The optical constants and the thickness of an As(x)Se(y) film formed on a glass substrate have been determined by the proposed method in the visible region of the spectrum.
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Affiliation(s)
- Vitaly P Kutavichus
- B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Belarus.
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Sakakibara Y, Bera RN, Mizutani T, Ishida K, Tokumoto M, Tani T. Photoluminescence Properties of Magnesium, Chloroaluminum, Bromoaluminum, and Metal-Free Phthalocyanine Solid Films. J Phys Chem B 2001. [DOI: 10.1021/jp002943o] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Youichi Sakakibara
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
| | - Raghu N. Bera
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
| | - Toshiyuki Mizutani
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
| | - Kohtaro Ishida
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
| | - Madoka Tokumoto
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
| | - Toshiro Tani
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, and Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei, Tokyo 184-8588, Japan
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