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Moons, Ellen, professorORCID iD iconorcid.org/0000-0002-1609-8909
Biography [eng]

Since 2011 professor in Materials Physics at Karlstad University, Sweden. Previously employed as Research Scientist at Cambridge Display Technology in Cambridge,UK, and as Research Assistant at University of Cambridge. Post-doc research related to dye-sensitized solar cells at EPFL Lausanne and TU Delft. PhD. from the Weizmann Institute of Science in Rehovot, Israel.

Biography [swe]

Jag har studerat fysik vid Universiteit Gent i Belgien. Examensarbete inom fasta tillståndets fysik, halvledarfysik. Jag har också en gymnasielärarexamen i fysik. Jag disputerade 1995 vid Weizmann Institute of Science i Israel med avhandlingen: Linking the Interfacial Chemistry and Physics of CuInSe2- and CdTe-based Photovoltaic Cells and Diodes. Efter postdokvistelser i Delft, Lausanne och Cambridge samt forskning på företaget Cambridge Display Technology i Cambridge, UK, påbörjade jag min anställning på Karlstads universitet år 2000, först som forskarassistent, sedan som universitetslektor och sedan 2011 som professor. 

Publications (10 of 96) Show all publications
Züfle, S., Hansson, R., Katz, E. A. & Moons, E. (2019). Initial photo-degradation of PCDTBT:PC 70 BM solar cells studied under various illumination conditions: Role of the hole transport layer. Solar Energy, 183(1), 234-239
Open this publication in new window or tab >>Initial photo-degradation of PCDTBT:PC 70 BM solar cells studied under various illumination conditions: Role of the hole transport layer
2019 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 183, no 1, p. 234-239Article in journal (Refereed) Published
Abstract [en]

ncapsulated organic solar cells often show a burn-in behaviour under illumination. This burn-in manifests itself as a rapid performance loss followed by a much slower progression of the degradation. Here we investigate the burn-in for PCDTBT:PC 70 BM solar cells under a wide range of illumination intensities. We find that increasing the sunlight concentration from 1 Sun to up to 100 Suns does not change the degradation behaviour, i.e. the dependence of all principal photovoltaic parameters on the dose of solar exposure (in Sun hours). This suggests that the degradation mechanisms under solar concentration (≤100 Suns) are the same as those observed under 1 Sun. This result makes it possible to use concentrated sunlight for accelerated stability assessment of these devices. We also find that devices with PEDOT:PSS as hole transport material show a rapid drop in open-circuit voltage of around 100 mV during the first Sun hour of light exposure. By replacing PEDOT:PSS with MoO 3 this initial process can be prevented and only the much slower part of the photo-degradation takes place.

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-47260 (URN)10.1016/j.solener.2019.03.020 (DOI)
Funder
Swedish Energy Agency, 38327-1Swedish Research Council, 2015-03778Göran Gustafsson Foundation for Research in Natural Sciences and Medicine, MP1307,STSM-MP1307-090216-070777
Note

Publicerad i Hanssons doktorsavhandling Materials and Device Engineering for Efficient and Stable Polymer Solar Cells som manuskript med titeln: "The role of the hole transport layer in the initial photo-degradation of PCDTBTPC70BM solar cells"

Available from: 2016-11-23 Created: 2016-11-23 Last updated: 2019-04-05Bibliographically approved
Holmes, N. P., Marks, M., Cave, J. M., Feron, K., Barr, M. G., Fahy, A., . . . Dastoor, P. C. (2018). Engineering Two-Phase and Three-Phase Microstructures from Water-Based Dispersions of Nanoparticles for Eco-Friendly Polymer Solar Cell Applications. Chemistry of Materials, 30(18), 6521-6531
Open this publication in new window or tab >>Engineering Two-Phase and Three-Phase Microstructures from Water-Based Dispersions of Nanoparticles for Eco-Friendly Polymer Solar Cell Applications
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2018 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 30, no 18, p. 6521-6531Article in journal (Refereed) Published
Abstract [en]

Nanoparticle organic photovoltaics, a subfield of organic photovoltaics (OPV), has attracted increasing interest in recent years due to the eco-friendly fabrication of solar modules afforded by colloidal ink technology. Importantly, using this approach it is now possible to engineer the microstructure of the light absorbing/charge generating layer of organic photovoltaics; decoupling film morphology from film deposition. In this study, single-component nanoparticles of poly(3-hexylthiophene) (P3HT) and phenyl-C61 butyric acid methyl ester (PC61BM) were synthesized and used to generate a two-phase microstructure with control over domain size prior to film deposition. Scanning transmission X-ray microscopy (STXM) and electron microscopy were used to characterize the thin film morphology. Uniquely, the measured microstructure was a direct input for a nanoscopic kinetic Monte Carlo (KMC) model allowing us to assess exciton transport properties that are experimentally inaccessible in these single-component particles. Photoluminescence, UV-vis spectroscopy measurements, and KMC results of the nanoparticle thin films enabled the calculation of an experimental exciton dissociation efficiency (ηED) of 37% for the two-phase microstructure. The glass transition temperature (Tg) of the materials was characterized with dynamic mechanical thermal analysis (DMTA) and thermal annealing led to an increase in ηED to 64% due to an increase in donor-acceptor interfaces in the thin film from both sintering of neighboring opposite-type particles in addition to the generation of a third mixed phase from diffusion of PC61BM into amorphous P3HT domains. As such, this study demonstrates the higher level of control over donor-acceptor film morphology enabled by customizing nanoparticulate colloidal inks, where the optimal three-phase film morphology for an OPV photoactive layer can be designed and engineered.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
Amorphous films, Amorphous materials, Butyric acid, Cell engineering, Colloids, Deposition, Environmental protection, Excitons, Glass transition, Morphology, Nanoparticles, Polymer solar cells, Scanning electron microscopy, Sintering, Solar cells, Solar power generation, Synthesis (chemical), Thermoanalysis, Thin films, Ultraviolet visible spectroscopy, D. dynamic mechanical thermal analyses (DMTA), Donor-acceptor interfaces, Kinetic Monte Carlo modeling, Scanning transmission x ray microscopy, Solar-cell applications, Three phase microstructure, Two-phase microstructures, Water based dispersion, Microstructure
National Category
Physical Sciences Chemical Sciences
Research subject
Physics; Chemistry
Identifiers
urn:nbn:se:kau:diva-69365 (URN)10.1021/acs.chemmater.8b03222 (DOI)000445972100036 ()2-s2.0-85052858083 (Scopus ID)
Available from: 2018-09-21 Created: 2018-09-21 Last updated: 2018-10-24Bibliographically approved
Lindqvist, C., Moons, E. & van Stam, J. (2018). Fullerene aggregation in thin films of polymer blends for solar cell applications. Materials, 11(11), Article ID 2068.
Open this publication in new window or tab >>Fullerene aggregation in thin films of polymer blends for solar cell applications
2018 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 11, no 11, article id 2068Article in journal (Refereed) Published
Abstract [en]

We report on the effects of the film morphology on the fluorescence spectra for a thin film including a quinoxaline-based co-polymer (TQ1) and a fullerene derivative ([6,6]-phenyl-C71-butyric acid methyl ester-PC70BM). The ratio between the polymer and the fullerene derivative, as well as the processing solvent, were varied. Besides the main emission peak at 700 nm in the fluorescence spectra of thin films of this phase-separated blend, a broad emission band is observed with a maximum at 520-550 nm. The intensity of this emission band decreases with an increasing degree of mixing in the film and becomes most prominent in thicker films, films with high PC70BM content, and films that were spin-coated from solvents with lower PC70BM solubility. We assign this emission band to aggregated PC70BM.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
Fluorescence, Fullerene aggregation, Organic photovoltaics, Organic solar cells, Butyric acid, Fullerenes, Polymer blends, Polymer films, Solar cells, Solar power generation, Broad emission bands, Degree of mixing, Emission bands, Film morphology, Fluorescence spectra, Fullerene derivative, Solar-cell applications, Thin films
National Category
Chemical Sciences Physical Sciences
Research subject
Physics; Chemistry
Identifiers
urn:nbn:se:kau:diva-70341 (URN)10.3390/ma11112068 (DOI)000451755500003 ()2-s2.0-85055594581 (Scopus ID)
Available from: 2018-11-29 Created: 2018-11-29 Last updated: 2018-12-20Bibliographically approved
Wang, Y., Jafari, M. J., Wang, N., Qian, D., Zhang, F., Ederth, T., . . . Gao, F. (2018). Light-induced degradation of fullerenes in organic solar cells: a case study on TQ1:PC71BM. Journal of Materials Chemistry A, 6(25), 11884-11889
Open this publication in new window or tab >>Light-induced degradation of fullerenes in organic solar cells: a case study on TQ1:PC71BM
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2018 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 25, p. 11884-11889Article in journal (Refereed) Published
Abstract [en]

The stability of organic solar cells (OSCs) is critical for practical applications of this emerging technology. Unfortunately, in spite of intensive investigations, the degradation mechanisms in OSCs have not been clearly understood yet. In this report, we employ a range of spectroscopic and transport measurements, coupled with drift-diffusion modelling, to investigate the light-induced degradation mechanisms of fullerene-based OSCs. We find that trap states formed in the fullerene phase under illumination play a critical role in the degradation of the open-circuit voltage (V-OC) in OSCs. Our results indicate that the degradation is intrinsic to the fullerenes in OSCs and that alternative acceptor materials are desired for the development of stable OSCs.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2018
Keywords
highly efficient, oxygen, films, interlayer, photodegradation
National Category
Other Physics Topics
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-68925 (URN)10.1039/c8ta03112f (DOI)000436516700031 ()
Available from: 2018-08-29 Created: 2018-08-29 Last updated: 2018-08-29
Blazinic, V., Ericsson, L., Muntean, S. A. & Moons, E. (2018). Photo-degradation in air of spin-coated PC60BM and PC70BM films. Synthetic metals, 241, 26-30
Open this publication in new window or tab >>Photo-degradation in air of spin-coated PC60BM and PC70BM films
2018 (English)In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 241, p. 26-30Article in journal (Refereed) Published
Abstract [en]

The fullerene derivatives PC60BM and PC70BM are widely used as electron accepting components in the active layer of polymer solar cells. Here we compare their photochemical stability by exposing thin films of PC60BM and PC70BM to simulated sunlight in ambient air for up to 47 h, and study changes in their UV–vis and FT-IR spectra. We quantify the photo-degradation by tracking the development of oxidation products in the transmission FT-IR spectra. Results indicate that PC60BM photodegrades faster than PC70BM. The rate of photo-oxidation of the thin films is dependent on the rate of oxygen diffusion in to the film and on the photo-oxidation rate of a single molecule. Both factors are dependent on the nature of the fullerene cage. The faster photo-oxidation of PC60BM than of PC70BM is in agreement with its slightly lower density and its higher reactivity. The use of PC70BM in solar cells is advantageous not only because of its absorption spectrum, but also because of its higher stability.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Fullerene derivatives, Photo-oxidation, UV-vis spectroscopy, IR spectroscopy
National Category
Condensed Matter Physics
Research subject
Materials Science
Identifiers
urn:nbn:se:kau:diva-66953 (URN)10.1016/j.synthmet.2018.03.021 (DOI)
Available from: 2018-04-09 Created: 2018-04-09 Last updated: 2018-04-09Bibliographically approved
Ciammaruchi, L., Hansson, R., Moons, E. & Galagan, Y. (2018). Stability of organic solar cells with PCDTBT donor polymer: An interlaboratory study. Journal of Materials Research, 33(13), 1909-1924
Open this publication in new window or tab >>Stability of organic solar cells with PCDTBT donor polymer: An interlaboratory study
2018 (English)In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 33, no 13, p. 1909-1924Article in journal (Refereed) Published
Abstract [en]

This work is part of the interlaboratory collaboration to study the stability of organic solar cells containing PCDTBT polymer as a donor material. The varieties of the OPV devices with different device architectures, electrode materials, encapsulation, and device dimensions were prepared by seven research laboratories. Sets of identical devices were aged according to four different protocols: shelf lifetime, laboratory weathering under simulated illumination at ambient temperature, laboratory weathering under simulated illumination, and elevated temperature (65 degrees C) and daylight outdoor weathering under sunlight. The results generated in this study allow us to outline several general conclusions related to PCDTBT-based bulk heterojunction (BHJ) solar cells. The results herein reported can be considered as practical guidance for the realization of stabilization approaches in BHJ solar cells containing PCDTBT.

Place, publisher, year, edition, pages
New York: Cambridge University Press, 2018
Keywords
energetic material, nanoscale, organic
National Category
Physical Sciences Materials Chemistry
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-68746 (URN)10.1557/jmr.2018.163 (DOI)000438739300009 ()
Available from: 2018-08-16 Created: 2018-08-16 Last updated: 2018-10-18Bibliographically approved
Talyzin, A. V., Mercier, G., Klechikov, A., Hedenstrom, M., Johnels, D., Wei, D., . . . Moons, E. (2017). Brodie vs Hummers graphite oxides for preparation of multi-layered materials. Carbon, 115, 430-440
Open this publication in new window or tab >>Brodie vs Hummers graphite oxides for preparation of multi-layered materials
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2017 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 115, p. 430-440Article in journal (Refereed) Published
Abstract [en]

Graphite oxides synthesized by one and two step Brodie oxidation (BGO) and Hummers (HGO) methods were analyzed by a variety of characterization methods in order to evaluate the reasons behind the difference in their properties. It is found that the Brodie method results in a higher relative amount of hydroxyl groups and a more homogeneous overall distribution of functional groups over the planar surface of the graphene oxide flakes. The higher number of carbonyl and carboxyl groups in HGO, detected by several methods, including XPS, NMR and FTIR, unavoidably results in defects of the graphene "skeleton", holes and overall disruption of the carbon-carbon bond network, stronger deviation from planar flake shape and poor ordering of the graphene oxide layers. It is also suggested that functional groups in HGO are less homogeneously distributed over the flake surface, forming some nanometer-sized graphene areas. The presence of differently oxidized areas on the GO surface results in inhomogeneous solvation and hydration of HGO and effects of inter- and intra-stratification. The proposed interpretation of the data explains the higher mechanical strength of multi-layered BGO membranes/papers, which are also less affected by humidity changes, thus providing an example of a membrane property superior to that of HGO. (C) 2016 Published by Elsevier Ltd.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Graphite oxides, Brodie oxidation (BGO), Hummers oxidation (HGO)
National Category
Materials Engineering Physical Sciences
Identifiers
urn:nbn:se:kau:diva-65297 (URN)10.1016/j.carbon.2016.12.097 (DOI)000395601300045 ()
Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2018-06-25Bibliographically approved
Hansson, R., Ericsson, L., Holmes, N. P., Blazinic, V., Dastoor, P. & Moons, E. (2017). Opportunities and challenges in probing local composition of organic material blends for photovoltaics. Journal of Materials Research, 32(10), 1982-1992
Open this publication in new window or tab >>Opportunities and challenges in probing local composition of organic material blends for photovoltaics
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2017 (English)In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 32, no 10, p. 1982-1992Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Materials Research Society, 2017
National Category
Physical Sciences
Identifiers
urn:nbn:se:kau:diva-47259 (URN)10.1557/jmr.2017.7 (DOI)000402284600014 ()
Funder
Swedish Energy Agency, 38327-1Swedish Research Council, 2015-03778Göran Gustafsson Foundation for Research in Natural Sciences and Medicine
Available from: 2016-11-23 Created: 2016-11-23 Last updated: 2018-01-05Bibliographically approved
Lestelius, M., Nyflött, Å., Moons, E., Järnström, L., Carlsson, G., Bonnerup, C. & Govindarajan, V. (2017). Oxygen permeabilityand economic-environmental impact studies of some polyvinyl alcohol dispersionbarrier coatings for packaging applications. In: : . Paper presented at PTS Coating Symposium, September 5-6, Munich, Germany.
Open this publication in new window or tab >>Oxygen permeabilityand economic-environmental impact studies of some polyvinyl alcohol dispersionbarrier coatings for packaging applications
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2017 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

Purposes of employing barrier coatings in packaging, and in particular food packaging, can be to increase the shelf life, preserve colour, odour, and taste, and to protect from a harmful environment in general. Barrier coatings can thus help to reduce food waste along the value chain until end use. Including both materials choice for packaging and the possible fates of the used package, even further steps to provide greater knowledge for decisions on choices of packaging solutions. To that end, we have conducted several experimental and transport modeling studies on oxygen barrier coatings performance. The coating system of choice    has been dispersion coatings of poly vinyl alcohol (PVOH), with additions of kaolin. Physical and chemical features of the coatings were characterized to obtain information on polymer crystallinity, free volume and filler orientation as these characteristics are influential to the oxygen mass transport performance. In turn, the oxygen mass transport was also measured, both in steady state and dynamically. In so doing, we obtained information    useful for developing a general model to describe the oxygen permeability taking into account the physical and chemical features, described above, of the coating layer. Attempts on describing the interdependence and impact, for instance between crystalline and amorphous polymer regions and moisture, was added to the model. The model showed agreement to experimental data for PVOH-kaolin coating in this particular case. However, the basic permeability model has been applied to  many different polymers.

To further explore the potential of these types of coating, which are technically possible to    produce in paperboard production, an economic-environmental impact comparison to other existing material solutions was made. Four barrier material alternatives – starch, polyethylene, ethyl vinyl alcohol (chosen as an alternative for PVOH, where data was difficult to obtain) and kaolin, and latex and kaolin, were analyzed with respect to cost and global warming potential. Weighting and comparing cost to environmental aspect, weighting    factors based on interviews with experts in the packaging value chain, starch emerges as the most sustainable alternative. However, previous coating and mass transport studies also shows how these renewable materials require some further technical development to be competitive.

The mass transport model can serve as a tool for customizing barrier coatings and to predict the barrier performance, as permeability is obtained and thus shelf-life estimation is    possible. The overall concept, the combination of assessment of structural performance and the environmental studies, can be employed to find sustainable food packaging solutions.

National Category
Paper, Pulp and Fiber Technology
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-63024 (URN)
Conference
PTS Coating Symposium, September 5-6, Munich, Germany
Projects
VIPP
Funder
Knowledge FoundationStora Enso
Available from: 2017-09-11 Created: 2017-09-11 Last updated: 2018-06-25Bibliographically approved
Emanuelsson, C., Zhang, H., Moons, E. & Johansson, L. (2017). Scanning tunneling microscopy study of thin PTCDI films on Ag/Si(111)-root 3 x root 3. Journal of Chemical Physics, 146(11), Article ID 114702.
Open this publication in new window or tab >>Scanning tunneling microscopy study of thin PTCDI films on Ag/Si(111)-root 3 x root 3
2017 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 146, no 11, article id 114702Article in journal (Refereed) Published
Abstract [en]

3,4,9,10-perylene tetracarboxylic diimide molecules were evaporated onto a Ag/Si(111)-root 3 x root 3 surface and studied by scanning tunneling microscopy/spectroscopy and low energy electron diffraction (LEED). The growth mode was characterized as layer-by-layer growth with a single molecular unit cell in a short range order. The growth of the first two monolayers involves a molecule/substrate superstructure and a molecule/molecule superstructure. At higher coverages, the molecules in each layer were found to align so that unit cells are on top of each other. The experimentally obtained LEED pattern is described as a combination of patterns from the molecular unit cell and the molecule/substrate superstructure. The electronic structure was found to be strongly dependent on the film thickness for the first few layers: Several extra states are found at low coverages compared to higher coverages resulting in a very small pseudo gap of 0.9 eV for the first layer, which widens up to 4.0 eV for thicker films.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2017
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-65295 (URN)10.1063/1.4978470 (DOI)000397313600027 ()28330354 (PubMedID)
Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2018-11-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1609-8909

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