Aerosol-based deposition of broadband antireflective silica coating with closed mesoporous structure

Durability of Antireflective Sio2 Coatings with Closed Pore Structure

“…The niche of desert climates could be especially interesting considering the challenge of utilizing the abundance of solar irradiance due to soiling and irreversible sand erosion as the dominant degrading process [32,102]. Furthermore, primarily due to a better positioned transmittance peak than AR Etch , and better durability than AR Roll , and secondly due to the broadband antireflective behavior and closed porous surface (both originating from the hexagonal structure) [27], AR Aero would be superior for applications in photovoltaics [11]. Now, as shown in our previous publication [27], increased T SW gives a leveraged increase in thermal energy yield for a solar collector field due to the constant working temperature.…”

“…By careful control of the synthesis parameters and post-processing steps in a climate chamber and calcination oven, a coating with ordered hexagonal pores, a smooth closed surface and an optimum thickness of 105 nm was achieved. A more in depth description of the synthesis is given in a previous paper [27]. The aerosol deposited hexagonal AR coating, herein denoted as "AR Aero ", was benchmarked against two commercial coatings deposited on the same kind of substrate.…”

“…1a-c. The surface of the AR Aero coating is smooth and has closed pores, revealing nothing of the underlying ordered hexagonal pore structure (see details in previous publication [27]). In contrast, AR Etch exhibits open pores of 10-20 nm in diameter on an otherwise smooth surface, while the pore structure of AR Roll is very open, randomly oriented, and larger, with pores up to 50 nm, which are still small enough to avoid scattering >300 nm.…”

“…By applying single layer sol-gel deposited silica AR coatings the transmittance of the glass is typically increased by 4-6% depending on the wavelength interval investigated [20][21][22][23][24][25][26][27], giving up to 8% higher yield from the solar energy system [28][29][30][31]. Consequently, efficient AR coatings are almost universally applied on solar glass, and the research focus has therefore shifted more towards durability and soiling mitigation [32].…”

“…In a previous paper we have presented a sol-gel based, superhydrophilic AR coating with hexagonally ordered closed pores [27]. The AR thin film was applied using an aerosol-based deposition technique called nFOG™ [70], combining easy upscaling [71] with pros related to simplicity similar to spray coating [72].…”