| 1. |
- Edoff, Marika, 1965-, et al.
(författare)
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Ultrathin CIGS Solar Cells with Passivated and Highly Reflective Back Contacts – : Results from the ARCIGS-M Consortium
- 2019
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Ingår i: Proceedings of 36th European Photovoltaic Solar Energy Conference and Exhibition. ; , s. 597-600
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, we report results from the EU-funded project ARCIGS-M. The project started in 2016 and aims to reduce the use of indium and gallium by enabling the use of very thin Cu(In,Ga)Se2 (CIGS) layers while retaining high efficiency and developing innovative low-cost steel substrates as alternatives to glass. In the project, reflective layers containing TCO´s and silver have successfully been used to enhance the reflective properties of the rear contact. In addition, passivation layers based on alumina (Al2O3) deposited by atomic layer deposition (ALD) have been found to yield good passivation of the rear contact. Since the alumina layers are dielectric, perforation of these layers is necessary to provide adequate contacting. The design of the perforation patterns has been investigated by a combination of modeling and experimental verification by electron beam lithography. In parallel a nano-imprint lithography (NIL) process is further developed for scale-up and application in prototype modules. Advanced optoelectrical characterization supported by modeling is used to fill in the missing gaps in optical and electrical properties, regarding CIGS, interfaces and back contact materials.
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| 2. |
- Gaget, Elie, et al.
(författare)
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Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming
- 2021
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Ingår i: Conservation Biology. - : Wiley. - 0888-8892 .- 1523-1739. ; 35:3, s. 834-845
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.
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| 3. |
- Kovacic, Milan, et al.
(författare)
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Light Management in Ultra-Thin Cu(In, Ga)Se2 Photovoltaic Devices
- 2019
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Ingår i: Proceedings of 36th European Photovoltaic Solar Energy Conference and Exhibition. - 3936338604 ; , s. 654-660
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Cu(In, Ga)Se2 (CIGS) solar cells exhibit high conversion efficiencies, with a recent record of 23.35 % on the cell level. However, an absorber thickness >1.8 m is required for efficient absorption of long-wavelength light. In order to minimize the material consumption (In, Ga and other elements) and to accelerate the fabrication process, further thinning down of CIGS absorber layer is important. One of the main challenges of ultra-thin absorber devices is to increase light absorption and consequently the photocurrent. We employ advanced optical simulations of ultra-thin (500 nm) CIGS devices in a PV module configuration, thus solar cell structure including encapsulation and front glass. Using simulations, we design and investigate different solutions for increased short circuit current, in particular (i) highly reflective back reflectors (BR), (ii) internal nano-textures and (iii) external textures by applying a light management foil. We show that any single solution (i, ii, iii) is not enough to compensate for the lower photocurrent, when thinning down (1800 nm -> 500 nm) the absorber layer. A combination of properly optimized internal or external textures and highly reflective back reflector is needed to reach, or even exceed (by ~3-5 %), the short circuit current of a standard thick (1800 nm) CIGS module structure.
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