FDTD modeling of sputtered Mo–Al2O3 nanocomposites

Ceramic-metal nanocomposites (NCs) are the one of the most promising materials for selective solar absorbers (SSAs) in renewable energy applications. Design of efficient SSAs demands precise modeling of light propagation in NCs. We report on the synthesis, detailed characterization, and analytical and numerical modeling of Molybdenum (Mo)-alumina (Al2O3) NCs. In this study, Mo–Al2O3 NC films with thicknesses of 45 nm and 60 nm and nominal metal volume fraction (f) of 30%, 40%, and 60% were grown on polished glass substrates, using sequential DC and RF sputtering. TEM analysis of the samples with f = 40% showed that most 2 nm-diameter Mo particles are spherical and isolated. The reflectance (R) and transmittance (T) curves of the NC were measured in the spectral range of 300 nm and 1700 nm. The measured R and T characteristics were compared with the calculated FDTD simulations to analyze the prediction accuracy of the approach. •Precise modeling of light propagation in NCs through designing an efficient SSAs.•This work aims to study the optical properties of Mo–Al2O3 NCs by using the FDTD based approaches that consider the effects of sputtering on particle distribution and material characteristics and compare the results with the experimental ones to assess the accuracy of FDTD approaches.•It will help to understand the capabilities and limitations of FDTD to develop better approaches and ultimately design more efficient ceramic-metal nanocomposites for selective solar absorbers (SSAs).