07- Porous polymer films with tailored light scattering properties

In the "PROPOLIS" project, we aim at developing porous polymer films with tailorable light scattering properties. The porous network is inspired by the scales of brilliant white beetles and is fabricated using a highly scalable foaming process with supercritical CO2. Structural disorder is tuned by controlling the pores nucleation and growth, resulting in adjustable diameter distributions (from micrometer to nanometer scale), density and distribution of the pores within the films.

Understanding the relationship between the optical properties of the developed films (light scattering and transport mean free path, scattering anisotropy, relative fraction of forward/backscattered etc.) and the porous network morphology is a pivotal aspect of our project. This is achieved by combining spectroscopic measurements and dedicated numerical methods either based on ray-tracing (Monte Carlo) simulations as well as on the T-matrix method to account for coherent multiple scattering effects.

The developed porous polymer layers offer a cost-effective and flexible solution for different energy-related applications. This is demonstrated by optimizing the light scattering properties of such films in order to improve the light conversion efficiency of quantum dots-based light emitting diodes, the cooling power of passive radiative cooling systems and light harvesting in thin film solar cells.