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Dive into the research topics where Frédérique Donsanti is active.

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Featured researches published by Frédérique Donsanti.


Thin Solid Films | 2001

Atomic layer deposition of zinc oxide and indium sulfide layers for Cu(In,Ga)Se2 thin-film solar cells

El Bekkaye Yousfi; B. Weinberger; Frédérique Donsanti; Pierre Cowache; Daniel Lincot

Atomic layer deposition (ALD) of ZnO and indium sulfide layers has been investigated. In situ monitoring at the monolayer level has been made by using quartz crystal microgravimetry (QCM), with a special focus on extrinsic doping of ZnO with Al. Cu(In,Ga)Se2/In2S3 (ALE)/ZnO (ALE) cells present efficiencies up to 13.5%. Indium sulfide layers used in these cells are characterized by a high band-gap value (up to 3.3 eV). They possess an amorphous like structure and a composition close to In2S3 as determined by Rutherford Back Scattering measurements. Lowering of the band-gap and crystallization take place under annealing, indicating that the high band-gap value of ALE indium sulfide layer is most likely related to structural effects.


Nanotechnology | 2010

Electrodeposition of ZnO nanorod arrays on ZnO substrate with tunable orientation and optical properties

Z Jehl; Jean Rousset; Frédérique Donsanti; Gilles Renou; Negar Naghavi; Daniel Lincot

The electrodeposition of ZnO nanorods on ZnO:Al films with different orientations is reported. The influence of the total charge exchanged during electrodeposition on the nanorods geometry (length, diameter, aspect ratio and surface density) and the optical transmission properties of the nanorod arrays is studied on a [0001]-oriented ZnO:Al substrate. The nanorods are highly vertically oriented along the c axis, following the lattice matching with the substrate. The growth on a [1010] and [1120] ZnO:Al-oriented substrate with c axis parallel to the substrate leads to a systematic deviation angle of 55 degrees from the perpendicular direction. This finding has been explained by the occurrence of a minority orientation with the [1011] planes parallel to the surface, with a preferential growth on corresponding [0001] termination. Substrate crystalline orientation is thereby found to be a major parameter in finely tuning the orientation of the nanorod array. This new approach allows us to optimize the light scattering properties of the films.


Journal of Renewable and Sustainable Energy | 2013

Cu(In, Ga)Se2 microcells: High efficiency and low material consumption

Myriam Paire; Laurent Lombez; Frédérique Donsanti; Marie Jubault; Stéphane Collin; Jean-Luc Pelouard; Jean-François Guillemoles; Daniel Lincot

Using solar cells under concentrated illumination is known to improve the conversion efficiency while diminishing the active area and thus material consumption. Recent concentrator cell designs tend to go miniaturized devices, in the 0.5–1 mm range, enabling a better thermal evacuation due to higher surface to volume ratio. If the cell size is further reduced to the micrometric range, spreading resistance losses can be made vanishingly small. This is particularly interesting for the thin film technology which has been limited up to now to very low concentration systems, from ×1 to ×10, due to excessive resistive losses in the window layer and difficult thermal management of the cells, grown on glass substrates. A new solar cell architecture, based on polycrystalline Cu(In,Ga)Se2 (CIGS) absorber, is studied: microscale thin film solar cells. Due to the reduced lateral dimension of the microcells (5 to 500 μm in diameter), the resistive and thermal losses are drastically decreased, enabling the use of high ...


Journal of Vacuum Science and Technology | 2013

Atomic layer deposition of zinc indium sulfide films: Mechanistic studies and evidence of surface exchange reactions and diffusion processes

Pascal Genevée; Frédérique Donsanti; Nathanaelle Schneider; Daniel Lincot

The authors present the elaboration of zinc indium sulfide (ZnInxSy) thin films in the context of a cadmium-free buffer layer development for copper indium gallium diselenide photovoltaic solar cells. The films were deposited by atomic layer deposition (ALD) from ZnEt2 (DEZ), In(acac)3 (acac = acetylacetonate), and H2S at 200 °C. In situ growth kinetics studies were performed with the quartz crystal microbalance technique to determine the respective mass gain per cycle of ZnS and In2S3 layers, allowing determination of the atomic compositions of the ZnInxSy thin films to be expected if the deposition strictly follows the rule of mixtures. As the experimental atomic compositions of the ZnInxSy films differ significantly from this rule, a comprehensive study of the growth mechanism was performed to determine the nature of the side reactions. First, an exchange reaction between In2S3 and the Zn precursor was identified, though this process is not sufficient to account for the experimental data, and therefore...


Journal of Renewable and Sustainable Energy | 2014

Ga gradients in Cu(In,Ga)Se2: Formation, characterization, and consequences

Torben Klinkert; Marie Jubault; Frédérique Donsanti; D. Lincot; Jean-François Guillemoles

We report on the influence of the substrate temperature during the 2nd and 3rd stage of the Cu(In,Ga)Se2 3-stage co-evaporation process on the in-depth Ga and In concentrations and correlate these with the solar cell parameters and external quantum efficiency of soda-lime glass/Mo/CIGS/CdS/i-ZnO/ZnO:Al devices. An increased homogenization of the [Ga]/[III] fraction ([III] refers to the total concentration of the group 3 elements Ga and In) with temperature is found. In the investigated temperature range, the highest efficiency was measured for the lowest temperature and the steepest Ga-profile. The tendency of the short-circuit current density matches well with the notch-deepness. Surprisingly, the open-circuit voltage decreases for higher substrate temperatures, even though the Ga-concentration in the space-charge region increases. We propose back-grading variations and reduced back-interface recombination to explain this observation. For the highest of the tested temperatures of 540 °C, a homogenization...


Nanotechnology | 2015

Deposition of ultra thin CuInS2 absorber layers by ALD for thin film solar cells at low temperature (down to 150 ?C)

Nathanaelle Schneider; Muriel Bouttemy; Pascal Genevée; Daniel Lincot; Frédérique Donsanti

Two new processes for the atomic layer deposition of copper indium sulfide (CuInS₂) based on the use of two different sets of precursors are reported. Metal chloride precursors (CuCl, InCl₃) in combination with H2S imply relatively high deposition temperature (Tdep = 380 °C), and due to exchange reactions, CuInS₂ stoechiometry was only achieved by depositing In₂S3 layers on a CuxS film. However, the use of acac- metal precursors (Cu(acac)₂, In(acac)₃) allows the direct deposition of CuInS₂ at temperature as low as 150 °C, involving in situ copper-reduction, exchange reaction and diffusion processes. The morphology, crystallographic structure, chemical composition and optical band gap of thin films were investigated using scanning electronic microscope, x-ray diffraction under grazing incidence conditions, x-ray fluorescence, energy dispersive spectrometry, secondary ion mass spectrometry, x-ray photoelectron spectroscopy and UV-vis spectroscopy. Films were implemented as ultra-thin absorbers in a typical CIS-solar cell architecture and allowed conversion efficiencies up to 2.8%.


Beilstein Journal of Nanotechnology | 2013

Synthesis of indium oxi-sulfide films by atomic layer deposition: The essential role of plasma enhancement.

Cathy Bugot; Nathanaelle Schneider; Daniel Lincot; Frédérique Donsanti

Summary This paper describes the atomic layer deposition of In2(S,O)3 films by using In(acac)3 (acac = acetylacetonate), H2S and either H2O or O2 plasma as oxygen sources. First, the growth of pure In2S3 films was studied in order to better understand the influence of the oxygen pulses. X-Ray diffraction measurements, optical analysis and energy dispersive X-ray spectroscopy were performed to characterize the samples. When H2O was used as the oxygen source, the films have structural and optical properties, and the atomic composition of pure In2S3. No pure In2O3 films could be grown by using H2O or O2 plasma. However, In2(S,O)3 films could be successfully grown by using O2 plasma as oxygen source at a deposition temperature of T = 160 °C, because of an exchange reaction between S and O atoms. By adjusting the number of In2O3 growth cycles in relation to the number of In2S3 growth cycles, the optical band gap of the resulting thin films could be tuned.


Journal of Renewable and Sustainable Energy | 2015

Atomic layer deposition of ZnInxSy buffer layers for Cu(In,Ga)Se2 solar cells

P. Genevée; A. Darga; C. Longeaud; D. Lincot; Frédérique Donsanti

We report in this paper the use of ZnInxSy films deposited by atomic layer deposition as cadmium free buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells. Buffer layers with different In/(In + Zn) ratios over the whole composition range were prepared on glass substrate and characterized optically by transmission and reflection measurement and electrically by steady state photoconductivity and modulated photocurrent. CIGS solar cells were prepared with the different buffer layers and characterized. A compromise between the properties of In2S3 and ZnS was found for intermediate compositions as aimed for this study. Best efficiencies were obtained for intermediate composition (In/(In + Zn) close to 28 at. %) which also allows a higher open circuit voltage. Solar cell simulations allowed to point out the major role played by interface defect states in these devices.


photovoltaic specialists conference | 2015

Temperature effect during atomic layer deposition of zinc oxysulfide -Zn(O,S) buffer layers on Cu(In,Ga)(S,Se)2 synthesized by co-evaporation and electro-deposition techniques

Cathy Bugot; C. Broussillou; A. Sorba; L. Parissi; Nathanaelle Schneider; Daniel Lincot; Frédérique Donsanti

In this study, we investigate the performances of Cu(In,Ga)(S,Se)2/Zn(O,S) devices varying both the absorber and the deposition temperature of the atomic layer deposited Zn(O,S) buffer layer. For both types of devices, two ranges of Zn(O,S) deposition temperatures were found to improve significantly the opto-electronic parameters, due to either specific Zn(O,S) properties or interdiffusion mechanisms. With this approach, we demonstrated the existence of two distinct favorable band alignments at the CIGS/Zn(O,S) junction. This study also demonstrates the benefits of using Atomic layer Deposition to accurately control the Zn(O,S) properties and therefore avoid device annealing and i-ZnO replacement by (Zn,Mg)O window layer.


Spie Newsroom | 2013

Thin-film microcells: a new generation of photovoltaic devices

Myriam Paire; Laurent Lombez; Frédérique Donsanti; Marie Jubault; Daniel Lincot; Jean-François Guillemoles; Stéphane Collin; Jean-Luc Pelouard

One way to increase the efficiency of a solar cell is to increase the power density of the light incident upon it. Indeed, if light is concentrated on a solar cell (e.g., via a lens), its voltage, and thus its efficiency, increases logarithmically. There are, however, limits to this efficiency increase; for example, the temperature of a device under intense light can become high enough to decrease the efficiency and eventually destroy it. Additionally, the output power for large current densities is limited by series resistance. Detrimental effects such as these are manageable on commercial concentrator cells based on high-quality crystalline materials, but it has not been possible to use high light concentrations of >50 suns (where one sun is 1kW/m2/ efficiently on thin-film solar cells. Indeed, most such cells are grown on glass substrates, which are poor thermal conductors, while thin-film semiconductive layers—especially the top, window, layers—are not sufficiently conductive for high-current-density operation. Overcoming these limitations is a particularly attractive prospect because thin-film solar cells can be rapidly deposited on large areas, through the self-assembly of microstructures, at a cost lower than for the current concentrator cells (which are based on epitaxial growth of single crystals). However, thin film solar cells such as copper indium gallium diselenide (Cu(In,Ga)Se2), cadmium telluride (CdTe), and gallium arsenide (GaAs) are based on elements that are not abundant on earth (rare earths). Due to their scarcity, a reduction in the required quantity of these materials could lead to cheaper cells. We have designed a new solar cell architecture that fulfills both the requirements. Figure 1. In this schematic of a photovoltaic device, light passing through a microlens array is concentrated and focused onto miniaturized solar cells.

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Daniel Lincot

École Normale Supérieure

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Jean-François Guillemoles

Centre national de la recherche scientifique

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Arnaud Etcheberry

Centre national de la recherche scientifique

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Laurent Lombez

Centre national de la recherche scientifique

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Muriel Bouttemy

Centre national de la recherche scientifique

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Jean-Luc Pelouard

Centre national de la recherche scientifique

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N. Naghavi

Centre national de la recherche scientifique

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