Broadband Anti-Reflective Coating Based on Plasmonic Nanocomposite

Hedayati, Mehdi Keshavarz; Abdelaziz, Moheb; Etrich, Christoph; Homaeigohar, Shahin; Rockstuhl, Carsten; Elbahri, Mady

Abstract

We report on the fabrication, the characterization, and the optical simulation of a gold–silica nanocomposite and present its integration into a broadband anti-reflective coating (ARC) for a silicon substrate. The two-layer ARC consists of a nanocomposite (randomly distributed gold cluster in a silica matrix) and a pure silica film. We capitalize on the large refractive index of the composite to impose an abrupt phase change at the interface of the coating to diminish the light reflection from the substrate through the ultrathin nanocoating. The average reflectivity of the silicon can be reduced by such a coating to less than 0.1% in the entire visible spectrum. We experimentally and numerically prove that percolated nanocomposites with an overall thickness of 20 nm can provide anti-reflectivity up to near infrared (NIR). The ARC bandwidth can be shifted more than 500 nm and broadened to cover even the NIR wavelength by changing the volume filling fraction of the gold clusters. The angular sensitivity of thin ultrathin antireflective coating is negligible up to 60°. The present ARC could find applications in thermo-photovoltaics and bolometers.

Citation

Hedayati, M. K., Abdelaziz, M., Etrich, C., Homaeigohar, S., Rockstuhl, C., & Elbahri, M. (2016). Broadband Anti-Reflective Coating Based on Plasmonic Nanocomposite. Materials, 9(8), Article 636. https://doi.org/10.3390/ma9080636

• Journal Article Type: Article
• Acceptance Date: Jul 25, 2016
• Online Publication Date: Jul 28, 2016
• Publication Date: 2016-08
• Deposit Date: Oct 1, 2018
• Journal: Materials
• Print ISSN: 1996-1944
• Electronic ISSN: 1996-1944
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 8
• Article Number: 636
• DOI: https://doi.org/10.3390/ma9080636
• Public URL: https://durham-repository.worktribe.com/output/1318035