Features of photothermal transformation in porous silicon based multilayered structures

Abstract

This paper is devoted to the study of photothermal transformations in multilayered structures. As a modelled sample, porous silicon with a periodic distribution of the porosity was chosen. The spatial distribution of the optical properties inside the structure was evaluated under Brugmann approximation. The heat sources arising as a result of electromagnetic radiation absorption in the structure were estimated by solving Maxwell equations. This allowed us to calculate temperature profiles inside photo-excited sample. For experimental measurements, photoacoustic set-up with a gas-microphone transduction system was chosen to investigate thermal properties of the structure. The results of the photoacoustic response simulation based on the gas-piston model demonstrated an excellent agreement with experiments. This allows a reliable evaluation of the thermal conductivity by fitting the experimental amplitude-frequency photoacoustic signal with the simulated one.