9 results on '"Pierre‐Alexis Repecaud"'
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2. Correlated Metals Transparent Conductors with High UV to Visible Transparency on Amorphous Substrates
- Author
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Phu Tran Phong Le, Shu Ni, Pierre‐Alexis Repecaud, Emma van derMinne, Karin J. H. Van Den Nieuwenhuijzen, Minh Duc Nguyen, Johan E. ten Elshof, Monica Morales‐Masis, and Gertjan Koster
- Subjects
amorphous substrates ,correlated metals ,nanosheets ,perovskites ,transparent conducting oxides ,UV transparent conductors ,Physics ,QC1-999 ,Technology - Abstract
Abstract Correlated metals with high carrier density and strongly correlated electron effects provide an alternative route to achieve transparent conducting materials, different from the conventional degenerately doped wide‐bandgap transparent conducting oxides (TCO). The extremely low electrical resistivity and high optical transparency in the ultraviolet‐visible spectral range shown in 4d correlated metals present an advantage over conventional TCOs. However, most of the 4d correlated metals are grown epitaxially on single crystal substrates. Here, it has been shown that Ca2Nb3O10 nanosheets with different buffer layers promote the growth of high‐quality 4d2 SrMoO3 films on fused silica substrates, overcoming the use of expensive and size‐limited single‐crystal substrates. The room temperature electrical resistivity of SrMoO3 is as low as 61 µΩ cm, the lowest reported value on amorphous transparent substrates to date, without compromising its high optical transmittance. 4d1 correlated metal SrNbO3 on Ca2Nb3O10 nanosheets also exhibits similarly high optical transmittance but a higher room temperature resistivity of 174 µΩ cm. These findings facilitate the use of highly conducting and transparent 4d correlated metals not only as TCOs on technologically relevant substrates for the applications in the ultraviolet‐visible spectral range but also as electrodes for other oxide‐based thin film technologies.
- Published
- 2023
- Full Text
- View/download PDF
3. Correlated Metals Transparent Conductors with High UV to Visible Transparency on Amorphous Substrates
- Author
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Phu Tran Phong Le, Shu Ni, Pierre‐Alexis Repecaud, Emma van der Minne, Karin J. H. Van Den Nieuwenhuijzen, Minh Duc Nguyen, Johan E. ten Elshof, Monica Morales‐Masis, Gertjan Koster, Inorganic Materials Science, and MESA+ Institute
- Subjects
nanosheets ,correlated metals ,Mechanics of Materials ,Mechanical Engineering ,perovskites ,amorphous substrates ,transparent conducting oxides ,UV transparent conductors - Abstract
Correlated metals with high carrier density and strongly correlated electron effects provide an alternative route to achieve transparent conducting materials, different from the conventional degenerately doped wide-bandgap transparent conducting oxides (TCO). The extremely low electrical resistivity and high optical transparency in the ultraviolet-visible spectral range shown in 4d correlated metals present an advantage over conventional TCOs. However, most of the 4d correlated metals are grown epitaxially on single crystal substrates. Here, it has been shown that Ca2Nb3O10 nanosheets with different buffer layers promote the growth of high-quality 4d2 SrMoO3 films on fused silica substrates, overcoming the use of expensive and size-limited single-crystal substrates. The room temperature electrical resistivity of SrMoO3 is as low as 61 µΩ cm, the lowest reported value on amorphous transparent substrates to date, without compromising its high optical transmittance. 4d1 correlated metal SrNbO3 on Ca2Nb3O10 nanosheets also exhibits similarly high optical transmittance but a higher room temperature resistivity of 174 µΩ cm. These findings facilitate the use of highly conducting and transparent 4d correlated metals not only as TCOs on technologically relevant substrates for the applications in the ultraviolet-visible spectral range but also as electrodes for other oxide-based thin film technologies.
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- 2022
4. Wafer-Scale Pulsed Laser Deposition of ITO for Silicon Heterojunction Solar Cells: Reduced Damage vs Interfacial Resistance
- Author
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Yury Smirnov, Pierre-Alexis Repecaud, Leonard Tutsch, Ileana Florea, Pere Roca i Cabarrocas, Martin Bivour, and Monica Morales-Masis
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- 2022
5. Three-Dimensional In-Situ Imaging of Single-Grain Growth in Polycrystalline Films
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Dmitry Dzhigaev, Pierre-Alexis Repecaud, Yury Smirnov, Lucas Marçal, Giovanni Fevola, Dina Sheyfer, Quentin Jeangros, Wonsuk Cha, Ross Harder, Anders Mikkelsen, Jesper Wallentin, Monica Morales-Masis, and Michael Stuckelberger
- Abstract
Strain and interactions at grain boundaries during solid-phase crystallization are known to play a significant role in the functional properties of polycrystalline materials. However, elucidating three-dimensional nanoscale grain morphology, kinetics, and strain under realistic conditions is challenging. Here, we image a single-grain growth during the amorphous-to-polycrystalline transition in technologically relevant transparent conductive oxide (TCO) film of In2O3:Zr with in-situ Bragg coherent X-ray diffraction imaging and transmission electron microscopy. We find that the Johnson-Mehl-Avrami-Kolmogorov theory, which describes the average kinetics of polycrystalline films growth, can be applied to the single grains as well. The quantitative analysis stems directly from imaging results. We elucidate the interface-controlled nature of the single-grain growth in thin films and reveal the surface strains which may be a driving force for anisotropic crystallization rates. Our results bring in-situ imaging with coherent X-rays towards understanding and controlling the crystallization processes of TCOs and other polycrystalline materials at the nanoscale.
- Published
- 2022
6. Wafer-scale pulsed laser deposition of ITO for solar cells: reduced damage vs. interfacial resistance
- Author
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Yury Smirnov, Pierre-Alexis Repecaud, Leonard Tutsch, Ileana Florea, Kassio P.S. Zanoni, Abhyuday Paliwal, Henk J. Bolink, Pere Roca i Cabarrocas, Martin Bivour, Monica Morales-Masis, Publica, MESA+ Institute, and Inorganic Materials Science
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integumentary system ,Chemistry (miscellaneous) ,General Materials Science ,digestive system ,Materials ,Cèl·lules fotoelèctriques - Abstract
Transparent conducting oxides (TCOs) used in solar cells must be optimized to achieve minimum parasitic absorption losses while providing sufficient lateral conductivity. Low contact resistance with the adjacent device layers and low damage to the substrate during deposition of the TCO are also important requirements to ensure high solar cell efficiencies. Pulsed laser deposition (PLD) has been proposed as an alternative low-damage TCO deposition technique on top of sensitive layers and interfaces in organic and perovskite solar cells but is yet to be studied for the more mature silicon technology. Focusing on the PLD deposition pressure as the key parameter to reduce damage, we developed tin-doped indium oxide (ITO) with a sheet resistance of 60 ω □-1 at different pressures and implemented it in silicon heterojunction (SHJ) solar cells. Buffer-free semi-transparent perovskite cells with the same PLD ITO electrodes were also fabricated for comparison. While in the perovskite cells increased ITO deposition pressure leads to an improved open circuit voltage and fill factor indicative of damage reduction, SHJ cells with PLD ITO at all conditions maintained a high passivation quality, but increased pressures lead to high series resistance. Transmission electron microscopy and time-of-flight secondary ion mass spectrometry confirmed the formation of a parasitic SiOx at the ITO/a-Si:H interface of the SHJ cell causing a transport barrier. The optimized ITO films with the highest carrier density were able to obtain >21% SHJ efficiency with 75 nm-thick PLD ITO. Moreover, reducing the ITO thickness to ∼45 nm and using TiOx for optical compensation enables fabrication of SHJ devices with reduced indium consumption and efficiencies of >22%. This journal is
- Published
- 2022
7. ITO top-electrodes via industrial-scale PLD for efficient buffer-layer-free semitransparent perovskite solar cells
- Author
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Kassio P. S. Zanoni, Abhyuday Paliwal, M Angeles Hernández‐Fenollosa, Pierre‐Alexis Repecaud, Monica Morales‐Masis, Henk J. Bolink, Inorganic Materials Science, and MESA+ Institute
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Mechanics of Materials ,optoelectronic devices ,General Materials Science ,perovskite solar cells ,pulsed laser deposition ,Materials ,indium tin oxide ,Industrial and Manufacturing Engineering ,Cèl·lules fotoelèctriques - Abstract
The deposition of transparent conductive oxides (TCO) usually employs harsh conditions that are frequently harmful to soft/organic underlayers. Herein, successful use of an industrial pulsed laser deposition (PLD) tool to directly deposit indium tin oxide (ITO) films on semitransparent vacuum-deposited perovskite solar cells without damage to the device stack is demonstrated. The morphological, electronic, and optical properties of the PLD deposited ITO films are optimized. A direct relation between the PLD chamber pressure and the solar cell performance is obtained. The semitransparent perovskite solar cells prepared exclusively by vacuum-assisted techniques had fill factors of 78% and exceeded 18% in power conversion efficiencies. This demonstrates that the direct deposition of TCO-based top electrodes without protective buffer layers is possible and leads to efficient devices.
- Published
- 2022
8. Scalable Pulsed Laser Deposition of Transparent Rear Electrode for Perovskite Solar Cells
- Author
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Monica Morales-Masis, Erkan Aydin, Mehrdad Najafi, Mirjam Theelen, Yury Smirnov, Laura Schmengler, Dong Zhang, Pierre Alexis Repecaud, Stefaan De Wolf, Riemer Kuik, Sjoerd Veenstra, MESA+ Institute, and Inorganic Materials Science
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Materials science ,business.industry ,UT-Hybrid-D ,02 engineering and technology ,Sputter deposition ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,perovskite solar cells ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Pulsed laser deposition ,Amorphous solid ,Mechanics of Materials ,Sputtering ,Electrode ,Optoelectronics ,Deposition (phase transition) ,General Materials Science ,0210 nano-technology ,business ,transparent conducting oxides ,pulsed laser deposition ,Sheet resistance ,Perovskite (structure) - Abstract
Sputtered transparent conducting oxides (TCOs) are widely accepted transparent electrodes for several types of high-efficiency solar cells. However, the different sputtering yield of atoms makes stoichiometric transfer of target material challenging for multi-compounds. Additionally, the high kinetic energies of the arriving species may damage sensitive functional layers beneath. Conversely, pulsed laser deposition (PLD) is operated at higher deposition pressures promoting thermalization of particles. This leads to stoichiometric transfer and additionally reduces the kinetic energy of ablated species. Despite these advantages, PLD is rarely used within the photovoltaic community due to concerns about low deposition rates and the scalability of the technique. In this study, wafer-scale (4-inch) PLD of high-mobility Zr-doped In2O3 (IZrO) TCO for solar cells is demonstrated. IZrO films are grown at room temperature with deposition rate on par with RF-sputtering (>4 nm min−1). As-deposited IZrO films are mostly amorphous and exhibit excellent optoelectronic properties after solid phase crystallization at
- Published
- 2021
9. Brownmillerites CaFeO2.5 and SrFeO2.5 as Catalyst Support for CO Oxidation
- Author
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Pierre-Alexis Répécaud, Monica Ceretti, Mimoun Aouine, Céline Delwaulle, Emmanuel Nonnet, Werner Paulus, and Helena Kaper
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oxygen mobility ,CO oxidation ,support interaction ,phase stability ,heterogeneous catalysis ,Organic chemistry ,QD241-441 - Abstract
The support material can play an important role in oxidation catalysis, notably for CO oxidation. Here, we study two materials of the Brownmillerite family, CaFeO2.5 and SrFeO2.5, as one example of a stoichiometric phase (CaFeO2.5, CFO) and one existing in different modifications (SrFeO2.75, SrFeO2.875 and SrFeO3, SFO). The two materials are synthesized using two synthesis methods, one bottom-up approach via a complexation route and one top-down method (electric arc fusion), allowing to study the impact of the specific surface area on the oxygen mobility and catalytic performance. CO oxidation on 18O-exchanged materials shows that oxygen from SFO participates in the reaction as soon as the reaction starts, while for CFO, this onset takes place 185 °C after reaction onset. This indicates that the structure of the support material has an impact on the catalytic performance. We report here on significant differences in the catalytic activity linked to long-term stability of CFO and SFO, which is an important parameter not only for possible applications, but equally to better understand the mechanism of the catalytic activity itself.
- Published
- 2021
- Full Text
- View/download PDF
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