Mode Splitting for Efficient Plasmoinc Thin-film Solar Cell

TL;DR

This paper introduces a plasmonic structure with metal strips and thin-film silicon that significantly enhances solar energy absorption through mode coupling and symmetry-breaking, achieving nearly 90% efficiency improvement.

Contribution

It presents a novel plasmonic design utilizing mode coupling and symmetry-breaking to boost thin-film silicon solar cell efficiency.

Findings

Absorption enhancement demonstrated via numerical simulations.

Symmetry-breaking excites dark modes for further absorption increase.

Quantum efficiency improved by nearly 90% compared to bare silicon cells.

Abstract

We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the localized plasmonic mode in Ag strip pair and the excited waveguide mode in silicon slab. Then we explore the method of symmetry-breaking to excite the dark modes that can further enhance the absorption ability. We compare our structure with bare thin-film Si solar cell, and results show that the integrated quantum efficiency is improved by nearly 90% in such thin geometry. It is a promising way for the solar cell.