| 1. |
- Allsopp, Benjamin, et al.
(författare)
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Towards improved cover glasses for photovoltaic devices
- 2020
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Ingår i: Progress in Photovoltaics. - : John Wiley and Sons Ltd. - 1062-7995 .- 1099-159X. ; 28, s. 1187-1206
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Tidskriftsartikel (refereegranskat)abstract
- For the solar energy industry to increase its competitiveness, there is a global drive to lower the cost of solar-generated electricity. Photovoltaic (PV) module assembly is material-demanding, and the cover glass constitutes a significant proportion of the cost. Currently, 3-mm-thick glass is the predominant cover material for PV modules, accounting for 10%–25% of the total cost. Here, we review the state-of-the-art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re-emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies and (iii) successful laboratory-scale demonstration of proof of concept, with increases of 1%–6% in Isc and 1%–8% in Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints. © 2020 The Authors.
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| 2. |
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| 3. |
- Grund Bäck, Lina, et al.
(författare)
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Improved mechanical properties and chemical durability by modifying the float glass composition and thermo-chemical strengthening for photovoltaic cover glass
- 2017
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Konferensbidrag (refereegranskat)abstract
- Solar energy is promising renewable energy where glass is an important material and have a significant impact on the efficiency of the photovoltaic (PV) module. The cover glass of PV-modules constitutes a large part of the total weight of the unit. In a recent Solar-ERA.NET project, LIMES (www.limes.nu), have we been aiming towards developing 1 mm thin glass for PV modules by improving the indentation mechanical properties and by investigating a novel thermo-chemical strengthening method.Starting from traditional soda-lime-silicate float composition different components was studied in a DoE fashion. The mechanical properties were studied using nano- and microindentation, the chemical durability by P98 analysis and weathering experiments. The findings resulted in a suggested composition for improving the properties of float glass by adding small amounts of zinc and titanium oxide as well as increasing the amount of aluminum and magnesium oxide. The components found to improve the chemical resistance were alumina, zirconia, zinc, lanthanum and titanium oxide. The surface hardness, crack- and scratch resistance were improved when magnesia was replaced with zinc oxide. When magnesia was replaced with titania, the hardness was increased.Some results from the thermo-chemical strengthening experiments will be presented. Heating and quenching in a reactive gas atmosphere using aluminum precursors have resulted in chemically modified surface in addition to the thermal strengthening.
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| 4. |
- Sundberg, Peter, et al.
(författare)
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Novel thermo-chemical strengthening of glass for solar energy applications and its impact on the physical properties
- 2017
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Konferensbidrag (refereegranskat)abstract
- The LIMES project (Light Innovative Materials for Enhanced Solar Efficiency), a Solar-ERA.NET project, have been a fruitful collaboration project to optimize many different properties in state-of-the-art solar glasses for photovoltaic (PV) modules. Here, we present results related to the effectiveness of reactive gas strengthening and its improvement of the physical properties of thin glasses. Novel thermo-chemical strengthening has been created using reactive chemicals that react with the glass surface during the thermal strengthening process. The glass surface gets a markedly increase of Al2O3, which in previous studies has been shown to have a beneficial effect on the mechanical properties. Successful thermo-chemical strengthening of 4 and 2 mm glasses to a similar strengthening level have repeatedly been performed, polariscope images in Figure 1. The strengthening level has been quantified using SCALP (Scattered Light Polariscope) and were found to be in the range of 85-110 MPa of compressive stresses in the surface which are comparable to values for conventional thermally strengthened glass.The strength of the glasses was quantified using the ring-on-ring method and the surface mechanical properties were evaluated by means of nano/microindentation. UV-Vis spectroscopy measurements have also been performed.Results for the ring-on-ring tests show that the 2 mm thin glass were positively affected by the while 4 mm did not show any significant change as compared to thermally strengthened. The thermo-chemically strengthened glasses have a significantly higher crack resistance than both the reference float glass and the traditionally thermally strengthened glass. The hardness results show that for low loads, ≥1 mN, the hardness follow the order thermo-chemically strengthened glass > thermally strengthened glass > annealed float glass. The scratch resistance for thermo-chemically strengthened glass is increased as compared to ordinary float glass. In addition, the transmission is not markedly reduced.
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| 5. |
- Sundberg, Peter, et al.
(författare)
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Simultaneous chemical vapor deposition and thermal strengthening of glass
- 2018
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Ingår i: 12th International Conference on Coatings on Glass and Plastics (ICCG 12).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The LIMES project (Light Innovative Materials for Enhanced Solar Efficiency), a Solar-ERA.NET project, was a fruitful collaboration to optimize many different properties in state-of-the-art solar glasses for photovoltaic (PV) modules. Here, we present results related to the effectiveness of combining chemical vapor deposition and thermal strengthening of glass in a simultaneous process. The treated glass surfaces gets a markedly increase of Al2O3, which in previous studies has been shown to have a beneficial effect on the mechanical properties. Successful thermal strengthening and in-situ Chemical Vapor Deposition (CVD) have repeatedly been performed on 4 and 2 mm flat glasses. The strengthening level has been quantified using SCALP (Scattered Light Polariscope). The samples were found to have a surface compressive stress in the range of 85-110 MPa which is comparable to the level of conventional thermally strengthened safety glass. The surface mechanical properties of the samples have been investigated by means of nano/microindentation and the strength of glasses has been quantified by ring-on-ring method. The transparency of the samples after washing was characterized by UV-Vis spectroscopy.The in-situ CVD thermally strengthened glasses gets an Al2O3 coated surface which exhibits increased crack resistance and increased scratch resistance as compared to traditionally thermally strengthened glass. The nanohardness for low loads, ≤ 1 mN, follow the order thermo-chemically strengthened glass > thermally strengthened glass > annealed float glass. The results of the strength tests show that the 2 mm thin glass were positively affected by the Al2O3 coating while the 4 mm did not show any significant change. The light transmittance of the treated glasses was not markedly reduced. In summary, this novel process show possibilities to increase specific properties, in this case surface mechanical properties, by simultaneous CVD and thermal strengthening.
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| 6. |
- Sundberg, Peter, et al.
(författare)
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Simultaneous chemical vapor deposition and thermal strengthening of glass
- 2019
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 669:1, s. 487-493
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Tidskriftsartikel (refereegranskat)abstract
- In the current paper we present a concept combining metal organic chemical vapor deposition with thermal strengthening process of flat glass. As the flat glass is heated to be thermally strengthened, which takes up to 20 minutes, there is an opportunity for performing a surface modification. We describe the application of transparent and amorphous Al2O3 thin films during the thermal strengthening process. Al2O3 was chosen due to the following desirable properties: increased surface mechanical properties and increased chemical durability, the latter has not been investigated in the current paper. The residual surface compressive stresses after performed strengthening of the coated glasses were quantified to be in the range of 80–110 MPa. The Al2O3 content in the surface was measured using the Surface Ablation Cell employed with Inductively Coupled Plasma Atomic Emission Spectroscopy and found to be at least doubled at the surface and having an increased Al2O3 content at least 0.5 μm underneath the glass surface. During the surface reaction, sodium is migrating to the surface giving a hazy salt layer on the glass which can easily be washed off with water. The applied coatings are transparent and provide increased surface hardness and crack resistance at low indentation loads. At higher indentation loads the interaction volume is larger and displays the same effect on the surface mechanical properties as for thermally strengthened glass. The contact angle with water compared to annealed float glass is significantly increased from 5° to 45° due to the different surface chemistry and surface topography.
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