A1 Journal article (refereed)
Modeling optical constants from the absorption of organic thin films using a modified Lorentz oscillator model (2022)

Dutta, A., Tiainen, V., Qureshi, H. A., Duarte, L., & Toppari, J. J. (2022). Modeling optical constants from the absorption of organic thin films using a modified Lorentz oscillator model. Optical Materials Express, 12(7), 2855-2869. https://doi.org/10.1364/OME.459938

JYU authors or editors

Dutta, Arpan
Tiainen, Ville
Ferreira de Deus da Rocha Duarte, Luis
Toppari, Jussi

Publication details

All authors or editors: Dutta, Arpan; Tiainen, Ville; Qureshi, Hassan Ali; Duarte, Luís; Toppari, J. Jussi

Journal or series: Optical Materials Express

eISSN: 2159-3930

Publication year: 2022

Publication date: 29/06/2022

Volume: 12

Issue number: 7

Pages range: 2855-2869

Publisher: Optica Publishing Group

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1364/OME.459938

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/82711

Abstract

Optical constants of organic thin films can be evaluated using the Lorentz oscillator model (LOM) which fails to fit inhomogeneously broadened absorption of highly concentrated molecular films. In modified LOM (MLOM), the inhomogeneous broadening is implemented through a frequency-dependent adjustable broadening function. In this work, we evaluate the optical constants of rhodamine 6G doped poly-vinyl alcohol thin films with varying doping concentration (including also extensively high concentrations) using MLOM, which outperforms LOM by showing a better agreement with the experimental results. Our proposed method provides a way to accurately determine optical constants of isotropic organic thin films only from their absorption spectra without spectroscopic ellipsometry.

Keywords: thin films; polymers; colouring agents; doping (semiconductor technology); optical properties; modelling (representation)