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BETA
Niklasson, G A, ProfessorORCID iD iconorcid.org/0000-0002-8279-5163
Alternative names
Publications (10 of 331) Show all publications
Arvizu, M. A., Qu, H.-Y., Niklasson, G. A. & Granqvist, C. G. (2018). Electrochemical pretreatment of electrochromic WO3 films gives greatly improved cycling durability. Thin Solid Films, 653, 1-3
Open this publication in new window or tab >>Electrochemical pretreatment of electrochromic WO3 films gives greatly improved cycling durability
2018 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 653, p. 1-3Article in journal (Refereed) Published
Abstract [en]

Electrochromic WO3 thin films have important applications in devices such as smart windows for energy-efficient buildings. Long-term electrochemical cycling durability of these films is essential and challenging. Here we investigate reactively sputter-deposited WO3 films, backed by indium-tin oxide layers and immersed in electrolytes of LiClO4 in propylene carbonate, and demonstrate unprecedented electrochemical cycling durability after straight-forward electrochemical pretreatments by the application of a voltage of 6 V vs. Li/Li+ for several hours.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2018
National Category
Materials Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-352465 (URN)10.1016/j.tsf.2018.02.032 (DOI)000429409800001 ()
Funder
Swedish Research Council, 821-2012-5144]EU, FP7, Seventh Framework Programme, 267234Swedish Foundation for Strategic Research , RIF14-0053
Available from: 2018-06-07 Created: 2018-06-07 Last updated: 2018-06-14Bibliographically approved
Granqvist, C. G., Arvizu, M. A., Bayrak Pehlivan, I., Qu, H.-Y., Wen, R.-T. & Niklasson, G. A. (2018). Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review. Electrochimica Acta, 259, 1170-1182
Open this publication in new window or tab >>Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review
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2018 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 259, p. 1170-1182Article, review/survey (Refereed) Published
Abstract [en]

Electrochromic (EC) materials can be integrated in thin-film devices and used for modulating optical transmittance. The technology has recently been implemented in large-area glazing (windows and glass facades) in order to create buildings which combine energy efficiency with good indoor comfort. This critical review describes the basics of EC technology, provides a case study related to EC foils for glass lamination, and discusses a number of future aspects. Ample literature references are given with the object of providing an easy entrance to the burgeoning research field of electrochromics.

National Category
Materials Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-350203 (URN)10.1016/j.electacta.2017.11.169 (DOI)000423968600129 ()
Available from: 2018-05-08 Created: 2018-05-08 Last updated: 2018-05-15Bibliographically approved
Granqvist, C. G., Bayrak Pehlivan, I. & Niklasson, G. A. (2018). Electrochromics on a roll: Web-coating and lamination for smart windows. Paper presented at 60th Annual Technical Conference of the Society-of-Vacuum-Coaters (SVC), APR 29-MAY 04, 2017, Providence, RI. Surface & Coatings Technology, 336, 133-138
Open this publication in new window or tab >>Electrochromics on a roll: Web-coating and lamination for smart windows
2018 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 336, p. 133-138Article in journal (Refereed) Published
Abstract [en]

Electrochromic devices can vary the throughput of solar energy and visible light in glazing for buildings, which are then able to combine improved energy efficiency with enhanced indoor comfort and convenience. The technology can be implemented in different ways; here the focus is on web-coated devices which can be delivered, on a roll or in the form of large sheets, as foil for glass lamination. The present paper introduces the technology, discusses web-coating versus in-line glass coating, mentions lamination, and touches on possibilities to combine electrochromism with other functionalities such as thermochromic control of solar energy transmittance. The purpose of the paper is to give a tutorial overview of a technology that is currently introduced in buildings.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2018
Keywords
Web-coated electrochromic device, Electrolyte functionalization, Infrared blocking, Thermochromism
National Category
Materials Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-348848 (URN)10.1016/j.surfcoat.2017.08.006 (DOI)000425478000021 ()
Conference
60th Annual Technical Conference of the Society-of-Vacuum-Coaters (SVC), APR 29-MAY 04, 2017, Providence, RI
Available from: 2018-04-20 Created: 2018-04-20 Last updated: 2018-05-02Bibliographically approved
Johnson, W. B., Worrell, W. L., Niklasson, G. A., Malmgren, S. & Strömme, M. (2018). Solid-State Devices: Impedance Response of Electrochromic Materials and Devices (3rded.). In: Evgenij Barsoukov and J. Ross Macdonald (Ed.), IMPEDANCE SPECTROSCOPY: Theory, Experiment, and Applications (pp. 247-291). Hoboken,: John Wiley & Sons
Open this publication in new window or tab >>Solid-State Devices: Impedance Response of Electrochromic Materials and Devices
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2018 (English)In: IMPEDANCE SPECTROSCOPY: Theory, Experiment, and Applications / [ed] Evgenij Barsoukov and J. Ross Macdonald, Hoboken,: John Wiley & Sons, 2018, 3rd, p. 247-291Chapter in book (Refereed)
Place, publisher, year, edition, pages
Hoboken,: John Wiley & Sons, 2018 Edition: 3rd
National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-340087 (URN)9781119333173 (ISBN)9781119074083 (ISBN)9781119333180 (ISBN)
Available from: 2018-01-26 Created: 2018-01-26 Last updated: 2018-02-27
Malmgren, S., Green, S. & Niklasson, G. A. (2017). Anomalous diffusion of ions in electrochromic tungsten oxide films. Electrochimica Acta, 247, 252-257
Open this publication in new window or tab >>Anomalous diffusion of ions in electrochromic tungsten oxide films
2017 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 247, p. 252-257Article in journal (Refereed) Published
Abstract [en]

Amorphous tungsten oxide thinfilms were deposited by sputtering at different O2/Ar ratios onto conducting substrates. Ion intercalation and diffusion in thefilms was studied by electrochemical impedance spectroscopy measurements in the frequency range 10 mHz–100 kHz and for potentials between 1.0 and 3.2 V vs. Li/Li+, using the film as working electrode in a Li+ containing electrolyte. The impedance data were in very good agreement with anomalous diffusion models. Different models were found to be applicable at potentials >1.8 V and <1.8 V. At high potentials ion intercalation was found to be reversible and an anomalous diffusion model describing ion hopping was favored. At low potentials ion intercalation was found to be irreversible and ion trapping takes place. In this latter range an anomalous diffusion model for the case of non-conserved number of charge carriers gave the best fit to experimentaldata. We obtained potential dependent diffusion coefficients in the range from 109 to 1011cm2/s, and anomalous diffusion exponents in the range 0.1 to 0.4, with the films deposited at lower O2/Ar ratios exhibiting the higher values.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Electrochromism impedance spectroscopy anomalous diffusion tungsten oxide
National Category
Materials Engineering
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-332918 (URN)10.1016/j.electacta.2017.06.079 (DOI)000408582300027 ()
Funder
Swedish Research Council, 2016-03713
Available from: 2017-11-02 Created: 2017-11-02 Last updated: 2017-11-29Bibliographically approved
Montero, J., Guillén, C., Granqvist, C. G., Herrero, J. & Niklasson, G. A. (2017). Beyond transparency and low resistivity in Antimony-doped tin oxide thin films. In: Abstracts: . Paper presented at Norwegian Solar Cell Conference (NSCC) 2017, Son, Norge, 5-10 maj..
Open this publication in new window or tab >>Beyond transparency and low resistivity in Antimony-doped tin oxide thin films
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2017 (English)In: Abstracts, 2017Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-336927 (URN)
Conference
Norwegian Solar Cell Conference (NSCC) 2017, Son, Norge, 5-10 maj.
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2017-12-19
Montero, J. A., Guillén, C., Granqvist, C. G., Herrero, J. & Niklasson, G. A. (2017). Beyond transparency and low resistivity in Antimony-doped tin oxide thin films. In: : . Paper presented at Norwegian Solar Cell Conference 2017, Son, Norway, May 9-10, 2017.
Open this publication in new window or tab >>Beyond transparency and low resistivity in Antimony-doped tin oxide thin films
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2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Materials Engineering
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-332973 (URN)
Conference
Norwegian Solar Cell Conference 2017, Son, Norway, May 9-10, 2017
Available from: 2017-11-03 Created: 2017-11-03 Last updated: 2017-12-29Bibliographically approved
Qiu, Z., Ma, Y., Edström, K., Niklasson, G. A. & Edvinsson, T. (2017). Controlled crystal growth orientation and surface charge effects in self-assembled nickel oxide nanoflakes and their activity for the oxygen evolution reaction. International journal of hydrogen energy, 42(47), 28397-28407
Open this publication in new window or tab >>Controlled crystal growth orientation and surface charge effects in self-assembled nickel oxide nanoflakes and their activity for the oxygen evolution reaction
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2017 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 47, p. 28397-28407Article in journal (Refereed) Published
Abstract [en]

Although sustainable hydrogen production from solar energy is a promising route for the future, the cost of the necessary photovoltaic and photoelectrochemical devices as well as a lack of detailed understanding and control of catalyst interfaces in nanomaterials with high catalytic activity are the largest impediments to commercial implementation. Here, we report how a higher catalytic efficiency can be achieved by utilizing an earth-abundant Nickel oxide (NiO) catalyst via an improved control of the crystalline growth orientation and self-assembly. The relationship between the surface charge and the morphology of the nano-catalysts is investigated using a hydrothermal method where the pH is utilized to control both the crystal growth direction and crystallization of Ni(OH)2 and eventually in NiO, where the self-assembly properties of nanoflakes (NFs) into hierarchical flower-like nickel oxide NFs depend on balancing of forces during synthesis. The surface charge ofthe NiO at different pH values was measured with electrophoretic dynamic light scattering (EDLS) and is known to be closely related to that of Ni(OH)2 and is here utilized to control the relative change in the surface charge in the precursor solution. By preparing NiO NFs under variation of the pH conditions of the precursor Ni(OH)2 system, the surface energies of exposed lattice planes of the growing nanostructures can be altered and an enhanced crystal growth orientation in a different direction can be controlled. Specifically, the [111] and [220] growth orientation in cubic NiO can be favored or suppressed with respect to the [200] direction. Benefiting from the large surface area provided by the mesoporous NiO NFs, the catalyst electrode exhibits high activity toward the oxygen evolution reactions in alkaline electrolyte. The NiO nanostructure synthesized at pH 10 displays oxygen evolution reaction (OER) overpotential of 0.29 V and 0.35 V versus the reversible hydrogen electrode (RHE) at 1 mA cm2 and 10 mA cm2 current density, respectively. This is compared to commercial NiO with more than 0.15 V additional overpotential and the same or lower overpotential compared to RuO2 and IrO2 at alkaline conditions. The results show that the OER catalytic activity can be drastically increased by a detailed control of the crystal growth orientation and the self-assembly behavior where the active surface charge around the point of zero charge during synthesis of the metal hydroxides/oxides is introduced as an important design principle for producing efficient electrocatalysts.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Nickel oxide Electrocatalyst, Crystalline growth directio, n Oxygen evolution reaction, Surface charge
National Category
Nano Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-334825 (URN)10.1016/j.ijhydene.2017.09.117 (DOI)000416495200025 ()
Funder
Swedish Energy AgencySwedish Research Council
Available from: 2017-11-28 Created: 2017-11-28 Last updated: 2018-03-19Bibliographically approved
Qu, H.-Y., Arvizu, M., Granqvist, C. G. & Niklasson, G. A. (2017). Degradation and rejuvenation in electrochromic nickel oxide films. In: Abstracts: . Paper presented at Hybrid & Organic Photovoltaics (HOPV 17), Lausanne, Schweiz, 21-24 maj.
Open this publication in new window or tab >>Degradation and rejuvenation in electrochromic nickel oxide films
2017 (English)In: Abstracts, 2017Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-336932 (URN)
Conference
Hybrid & Organic Photovoltaics (HOPV 17), Lausanne, Schweiz, 21-24 maj
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2017-12-19
Wen, R.-T., Malmgren, S., Granqvist, C. G. & Niklasson, G. A. (2017). Degradation Dynamics for Electrochromic WO3 Films under Extended Charge Insertion and Extraction: Unveiling Physicochemical Mechanisms. ACS Applied Materials and Interfaces, 9(14), 12872-12877
Open this publication in new window or tab >>Degradation Dynamics for Electrochromic WO3 Films under Extended Charge Insertion and Extraction: Unveiling Physicochemical Mechanisms
2017 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 14, p. 12872-12877Article in journal (Refereed) Published
Abstract [en]

Degradation of electrochromic thin films under extended charge insertion and extraction is a technically important phenomenon for which no in-depth understanding is currently on hand. Here, we report on an explorative study of sputter-deposited WO3 films in a Li-ion-conducting electrolyte by use of cyclic voltammetry, in situ optical transmittance, and impedance spectroscopy. A cycling-dependent decrease of the charge capacity could be accurately modeled by a power-law function, and impedance spectroscopy gave evidence for anomalous diffusion as well as a higher charge transfer resistance during deintercalation than during intercalation. Thus, a consistent conceptual picture emerged for the degradation dynamics; it includes the growth of an interfacial barrier layer and also embraces anomalous diffusion coupled with dispersive power-law chemical kinetics.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
Keywords
WO3, thin films, electrochromism, detrapping physicochemical mechanisms
National Category
Materials Engineering Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-322183 (URN)10.1021/acsami.7b01324 (DOI)000399354100082 ()28328195 (PubMedID)
Funder
EU, FP7, Seventh Framework Programme, 267234Swedish Research Council
Available from: 2017-05-17 Created: 2017-05-17 Last updated: 2017-11-02
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8279-5163

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