Plasmonic Light Trapping in an Ultrathin Photovoltaic Layer with Film-Coupled Metamaterial Structures

TL;DR

This study demonstrates that film-coupled metamaterial structures can significantly enhance light absorption in ultrathin GaAs solar cells, leading to threefold increases in current density and potential for more efficient, cost-effective solar energy devices.

Contribution

The paper introduces a novel film-coupled metamaterial design that improves light trapping and charge collection in ultrathin photovoltaic layers, advancing solar cell technology.

Findings

Absorption in active layer increased significantly.

Short-circuit current density tripled.

Structure enables effective light trapping and charge collection.

Abstract

A film-coupled metamaterial structure is numerically investigated for enhancing the light absorption in an ultrathin photovoltaic layer of crystalline gallium arsenide (GaAs). The top subwavelength concave grating and the bottom metallic film could not only effectively trap light with the help of wave interference and magnetic resonance effects excited above the bandgap, but also practically serve as electrical contacts for photon-generated charge collection. The energy absorbed by the active layer is greatly enhanced in the film-coupled metamaterial structure, resulting in significant enhancement on the short-circuit current density by three times over a free-standing GaAs layer at the same thickness. The results would facilitate the development of next-generation ultrathin solar cells with lower cost and higher efficiency.