General Method for Determining Light Scattering and Absorption of Nanoparticle Composites

• Published in: Advanced Optical Materials 2019-02, Vol.7 (4), p.n/a
• Main Authors: Wang, Junxin, Xu, Changgang, Nilsson, Annica M., Fernandes, Daniel L. A., Strömberg, Mattias, Wang, Jianfang, Niklasson, Gunnar A.
• Format: Article
• Language: English
• Subjects: absorption coefficient; Absorptivity; angle‐resolved scattering; Backscattering; Composite materials; Dependence; Engineering Science with specialization in Solid State Physics; Ferromagnetism; Gold; Iron oxides; Light scattering; Materials science; Metamaterials; Meteorological satellites; nanoparticle composites; Nanoparticles; Optics; Parameters; Photovoltaic cells; Polymer matrix composites; Radiative transfer; Reflectance; scattering coefficient; Shielding; Solar cells; Teknisk fysik med inriktning mot fasta tillståndets fysik; Titanium dioxide; Transmittance
• ISSN: 2195-1071; 2162-7568; 2195-1071
• DOI: 10.1002/adom.201801315

Scattering and absorption from nanoparticles are of major importance in optical research as well as in a range of applications. The Kubelka–Munk two‐flux radiative transfer model gives a simple description of light scattering in nanoparticle composite materials, but inversion of experimental transmittance and reflectance data to obtain backscattering and absorption coefficients remains challenging. Here, a general method for evaluating these parameters from transmittance and reflectance spectra, combined with spectral angle resolved light scattering measurements is developed. The angular dependence is approximated by an extension of the empirical Reynolds–McCormick phase function, which is fitted to the experimental angle resolved light scattering data. This approach is verified by measurements on three typical nanoparticle/polymer composites containing plasmonic Au, ferromagnetic Fe3O4, and dielectric TiO2 particles. An approximation to the angular scattering pattern is further demonstrated, which can be applied to obtain the optical parameters using only reflectance and transmittance data, in cases where angle‐resolved measurements are not available. These results can be extended to a wide range of isotropic, anisotropic, and multiple scattering systems, and will be highly useful in the fields of light scattering coatings/metamaterials, UV‐shielding films, displays, absorption/scattering layers in solar cells and biological scatterers. A general approach for determining light‐scattering and absorption parameters from angular and spectral resolved measurements is presented. Scattering and absorption coefficients are obtained using a radiative transfer model applied to synthesized Au, Fe3O4, and TiO2 nanosphere composites. This work can be extended to a wide range of isotropic, anisotropic, and multiple scattering systems.