In previous works, an efficient light trapping performed by arrays of metal nanoantennas whose building block was a slightly tapered (trapezoidal) substantially thick nanostrip was revealed. This light trapping implied a broad spectrum of solar light concentrated in a subwavelength depth of the semiconductor substrate. This is a very advantageous feature allowing our structure to enhance thin-film solar cells. However, the physics of the broadband resonant absorption in the substrate was not investigated. In the present paper, we show that our arrays support so-called leaky domino-modes, responsible for such the light trapping. These modes are multipole oscillations of the array of substantially thick nanostrips. In this work we have thoroughly studied these leaky modes relating them to resonances of high-order multipole moments and to broadband light-trapping effect.
|Number of pages||13|
|Journal||PHOTONICS AND NANOSTRUCTURES: FUNDAMENTALS AND APPLICATIONS|
|Publication status||Published - 1 Jul 2016|
|MoE publication type||A1 Journal article-refereed|
- Leaky modes
- Light-trapping structures
- Multipole resonances