Photon Management in Two-Dimensional Disordered Media

TL;DR

This paper introduces a novel photon management strategy in thin films using two-dimensional disordered media, leveraging multiple scattering and interference to enhance light trapping for solar cells and LEDs.

Contribution

It combines coherent optical effects with broadband disorder to improve light absorption and emission, offering a new approach for thin-film optoelectronic devices.

Findings

Disordered photonic patterns can be tuned via structural correlations.

Spectral and angular responses are linked to in-plane light transport.

Numerical results show enhanced light trapping in disordered media.

Abstract

Elaborating reliable and versatile strategies for efficient light coupling between free space and thin films is of crucial importance for new technologies in energy efficiency. Nanostructured materials have opened unprecedented opportunities for light management, notably in thin-film solar cells. Efficient coherent light trapping has been accomplished through the careful design of plasmonic nanoparticles and gratings, resonant dielectric particles and photonic crystals. Alternative approaches have used randomly-textured surfaces as strong light diffusers to benefit from their broadband and wide-angle properties. Here, we propose a new strategy for photon management in thin films that combines both advantages of an efficient trapping due to coherent optical effects and broadband/wide-angle properties due to disorder. Our approach consists in the excitation of electromagnetic modes formed by multiple light scattering and wave interference in two-dimensional random media. We show, by numerical calculations, that the spectral and angular responses of thin films containing disordered photonic patterns are intimately related to the in-plane light transport process and can be tuned through structural correlations. Our findings, which are applicable to all waves, are particularly suited for improving the absorption efficiency of thin-film solar cells and can provide a novel approach for high-extraction efficiency light-emitting diodes.