Enhancement of plasmonic transmittance of porous gold thin films via gold/metal oxide bi-layers for solar energy-saving applications
| Autor: | M.F. Al-Kuhaili |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment business.industry Band gap Infrared 020209 energy Oxide 02 engineering and technology Dielectric 021001 nanoscience & nanotechnology law.invention chemistry.chemical_compound Anti-reflective coating chemistry law 0202 electrical engineering electronic engineering information engineering Transmittance Optoelectronics General Materials Science Thin film 0210 nano-technology business Plasmon |
| Zdroj: | Solar Energy. 181:456-463 |
| ISSN: | 0038-092X |
| DOI: | 10.1016/j.solener.2019.02.025 |
| Popis: | Thin films of noble metals, such as gold, have high visible transparency and infrared reflectance. The former is due to the presence of surface plasmons, and the latter is due to the large density of free electrons. Gold thin films have a transmittance peak at 520 nm, which is closely matched to the maximum emission of solar radiation. These properties have been utilized in several applications, including energy-saving transparent heat mirrors that consist of a bi-layer of a thin gold film over-coated with a dielectric layer. These coatings transmit light and reflect heat. For such an application, the transmittance of the thin gold film needs to be enhanced; this is achieved by the dielectric layer that functions as an antireflective coating. In this work, the dielectrics were metal oxides that are transparent in the visible range. The selection criteria based on the band gap, and refractive index were first imposed to identify potential metal oxides. This resulted in the choice of ten metal oxides (CeO2, HfO2, MoO3, Nb2O5, NiO, SnO2, Ta2O5, TiO2, WO3, and ZrO2). The bi-layer performance was then optimized theoretically. The gold-metal oxide layers were subsequently fabricated, and their optical spectra were measured over the ultraviolet–visible-near infrared ranges. The performance of the heat mirrors was assessed in terms of their visible and solar transmittance and reflectance. A figure of merit was defined to evaluate the suitability of the oxides. The optical properties suggest that tungsten oxide (WO3) is the best oxide; however, hafnium oxide (HfO2) has the best performance for solar energy applications. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect