Features of photothermal transformation in porous silicon based multilayered structures

TL;DR

This study investigates photothermal effects in porous silicon multilayer structures by combining theoretical modeling of optical and thermal properties with experimental photoacoustic measurements, enabling accurate thermal conductivity evaluation.

Contribution

It introduces a comprehensive approach integrating electromagnetic, thermal modeling, and photoacoustic experiments to analyze photothermal transformations in porous silicon multilayers.

Findings

Theoretical models accurately predict temperature profiles within the structure.

Photoacoustic signals match simulations, validating the thermal analysis method.

Thermal conductivity can be reliably determined from photoacoustic data.

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.