MgF2 antireflective coatings by sol–gel processing: film preparation and thermal densification

Noack, Joachim; Scheurell, Kerstin; Kemnitz, Erhard; Garcia-Juan, Plácido; Rau, H. L.; Lacroix, Marc; Eicher, Johannes; Lintner, Birgit; Sontheimer, Thomas; Hofmann, Thomas; Hegmann, Joachim; Jahn, Rainer; Löbmann, Peer

doi:10.1039/c2jm33324d

Cited by 63 publications

(59 citation statements)

References 17 publications

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“…This minor difference should not be over interpreted, though. Still both films investigated in this study are significantly less porous than those previously reported [13] (34 %, Fig. 1b).…”

Section: Resultscontrasting

confidence: 47%

“…This reaction already has been observed with the MgCl 2 -based system [13]. From the industrial viewpoint, glass substrates should not be annealed above their transition temperature for a prolonged time; therefore, this transformation will not hinder the commercialization of the coating process.…”

Section: Resultsmentioning

confidence: 81%

“…For other sol-gel systems, abrupt transformations from the amorphous to the crystalline state leading to material disintegration have been reported [23]. The presence of preformed MgF 2 seeds of nanoscopic regularity that do not show up in regular XRD measurements below 300°C can account for this behavior [13,21]. The structural differences between the film systems originate from the size and packing density of these subunits into ''secondary clusters.…”

Section: Resultsmentioning

confidence: 94%

“…1b). These materials therefore provide abrasion resistance against steel wool in crockmeter testing [13]. The synthesis of these precursor solutions, however, is based on MgCl 2 resulting in the formation of HCl and thus corrosion during practical application will be an issue.…”

Section: Resultsmentioning

confidence: 99%

“…We recently reported the preparation of MgF 2 antireflective coatings [13] that showed a remarkable abrasion even against steel wool. These films could be combined with TiO 2 films, and the resulting multilayer assemblies were thoroughly characterized [14,15].…”

Section: Introductionmentioning

confidence: 99%

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Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

Scheurell

Kemnitz

Garcia-Juan

et al. 2015

J Sol-Gel Sci Technol

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Porous MgF 2 is a highly promising film material for the preparation of durable antireflective coatings. Synthesis routes based on Mg(OMe) 2 and Mg(OAc) 2 precursors are described, and the resulting sol-gel films and their thermal consolidation are compared using thermal analysis (TGA/DTA), scanning electron microscopy, ellipsometric porosimetry and X-ray diffraction. Due to their constant viscosity, Mg(OAc) 2 -based coating solutions are superior from the practical point of view. The porous films are stable against degradation under the steady-state temperature humidity life test (85/85), and they can successfully be integrated into TiO 2 -MgF 2 -TiO 2 interference filters. Graphical Abstract Porous MgF 2 antireflective k/4 coatings were prepared by sol-gel processing. Synthesis routes based on Mg(OMe) 2 and Mg(OAc) 2 precursors are established, and the properties of the resulting film materials are compared, respectively.

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Section: Resultscontrasting

confidence: 47%

Section: Resultsmentioning

confidence: 81%

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

Scheurell

Kemnitz

Garcia-Juan

et al. 2015

J Sol-Gel Sci Technol

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On the Properties of Nanoporous SiO₂ Films for Single Layer Antireflection Coating

et al. 2019

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Single layer antireflection coatings (SLAR) consisting of nanoporous silica (NP SiO 2 ) films are developed by selective chemical etching of atomic layer deposited (ALD) Al 2 O 3 :SiO 2 composite films. The reflective index of the final NP SiO 2 film is finely adjusted from 1.132 to 1.400 at 600 nm wavelength by applying an appropriate ratio in the composite. To meet the requirements of the SLAR coatings from the deep UV (DUV) to the near IR (NIR) spectral range, the film thickness is controlled with nanometer precision by the ALD process. The SLAR are simultaneously applied on both sides of flat or highly curved substrates. Transmittance values above 99.4% are achieved even at a wavelength of 193 nm on fused silica substrates. Various characterization methods demonstrate the advantages of these SLAR with regard to impurities, optical losses, laser induced damage threshold (LIDT) properties, and surface super-hydrophilicity. The absorption losses at 193 nm wavelength as determined by laser induced deflection measurements amount to approximately 200 ppm, and to approximately 2 ppm at a wavelength of 1064 nm, while the scattering losses are around 30 ppm at 532 nm wavelength for quarter-wave layers. The LIDT values at 1064 nm are in the range of 93 J cm À2 being close to the values measured on the uncoated substrate.

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Passive Photovoltaic Cooling: Advances Toward Low‐Temperature Operation

Liu,

Zhou,

Zhou

et al. 2023

Advanced Energy Materials

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With the great increase in installation, photovoltaics will develop as the main power supply source for the world shortly. However, the actual power generation and lifetime of photovoltaics are greatly compromised by the high working temperature under outdoor operation. In this review, the recent advances of four promising passive photovoltaic cooling methods are summarized with the aim to uncover their working principles, cooling performance, and application potential in photovoltaic devices. For radiative cooling, light management strategies with ultraviolet‐photon downshift and sub‐bandgap reflection are discussed in detail to reveal their great potential in reducing photovoltaic working temperature and enhancing power generation. Subsequently, the great cooling benefits of passive evaporative cooling are underlined in terms of its superior cooling power and temperature drop of photovoltaic devices. Moreover, the promising integrated cooling strategy is further highlighted due to its great potential in enhancing electricity production and fresh water supply. Most crucially, the remaining challenges and the authors'r insights are presented to advance the commercial applications of passive cooling methods in photovoltaics.

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MgF2 antireflective coatings by sol–gel processing: film preparation and thermal densification

Cited by 63 publications

References 17 publications

Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

On the Properties of Nanoporous SiO₂ Films for Single Layer Antireflection Coating

Passive Photovoltaic Cooling: Advances Toward Low‐Temperature Operation

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MgF2 antireflective coatings by sol–gel processing: film preparation and thermal densification

Cited by 63 publications

References 17 publications

Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches

On the Properties of Nanoporous SiO2 Films for Single Layer Antireflection Coating

Passive Photovoltaic Cooling: Advances Toward Low‐Temperature Operation

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Product

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On the Properties of Nanoporous SiO₂ Films for Single Layer Antireflection Coating