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Granqvist, Claes Göran
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Publications (10 of 519) Show all publications
Granqvist, C. G., Arvizu, M. A., Qu, H.-Y., Wen, R.-T. & Niklasson, G. (2019). Advances in electrochromic device technology: Multiple roads towards superior durability. Surface & Coatings Technology, 357, 619-625
Open this publication in new window or tab >>Advances in electrochromic device technology: Multiple roads towards superior durability
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2019 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 357, p. 619-625Article in journal (Refereed) Published
Abstract [en]

Most electrochromic (EC) devices must have a service lifetime of many years, and this is particularly so for“smart windows” in buildings with good energy efficiency and indoor comfort. The central part of oxide-based EC devices contains thin films based on W oxide and Ni oxide together with an interposed electrolyte. Depending on operating conditions, these films may show degradation at a slower or faster pace, and means to prevent or reverse this phenomenon, or as a minimum allow reliable lifetime prediction, have been sought ever since the beginnings of EC technology. Here we survey recent endeavors related to EC films of W oxide and Ni oxide and show that (i) electrochemical pretreatment of films in a liquid electrolyte can significantly improve durability, (ii)electrochemical posttreatment in a liquid electrolyte can rejuvenate degraded films, (iii) mixed oxides can have better durability and optical performance than corresponding pure oxides, and (iv) lifetime prediction is possible.

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Materials Chemistry
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-369882 (URN)10.1016/j.surfcoat.2018.10.048 (DOI)
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2019-01-16Bibliographically approved
Granqvist, C. G., Arvizu, M. A., Qu, H.-Y., Wen, R.-T. & Niklasson, G. (2018). Advances in electrochromic device technology: Multiple roads towards superior durability. In: Proceedings SVC: . Paper presented at Society of Vacuum Coaters 61st Annual Technical Conference, Orlando, FL. , Article ID 9 pages.
Open this publication in new window or tab >>Advances in electrochromic device technology: Multiple roads towards superior durability
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2018 (English)In: Proceedings SVC, 2018, article id 9 pagesConference paper, Published paper (Refereed)
Abstract [en]

Most electrochromic (EC) devices must have a service lifetime of many years, and this is particularly so for “smart windows” in buildings with good energy efficiency and indoor comfort. The central part of oxide-based EC devices contains thin films based on W oxide and Ni oxide together with an interposed electrolyte. Depending on operating conditions, these films may show degradation at a slower or faster pace, and means to prevent or reverse this phenomenon, or as a minimum allow reliable lifetime prediction, have been sought ever since the beginnings of EC technology. Here we survey recent endeavors related to EC films of W oxide and Ni oxide and show that (i) electrochemical pretreatment of films in a liquid electrolyte can significantly improve durability, (ii) electrochemical posttreatment in a liquid electrolyte can rejuvenate degraded films, (iii) mixed oxides can have better durability and optical performance than corresponding pure oxides, and (iv) lifetime prediction is possible.

National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-368957 (URN)
Conference
Society of Vacuum Coaters 61st Annual Technical Conference, Orlando, FL
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-17
Garrett, M. J. & Granqvist, C. G. (2018). Basic Sciences and Development: Rethinking Donor Policy (reissueded.). Abingdon, UK & New York, USA: Routledge Revivals
Open this publication in new window or tab >>Basic Sciences and Development: Rethinking Donor Policy
2018 (English)Book (Refereed)
Place, publisher, year, edition, pages
Abingdon, UK & New York, USA: Routledge Revivals, 2018. p. 180 Edition: reissued
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-368944 (URN)978-1-138-61099-6 (ISBN)
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10
Qu, H.-Y., Primetzhofer, D., Qiu, Z., Österlund, L., Granqvist, C. G. & Niklasson, G. (2018). Cation/Anion-based electrochemical degradation and rejuvenation of electrochromic nickel oxide films. ChemElectroChem, 5(22), 3548-3556
Open this publication in new window or tab >>Cation/Anion-based electrochemical degradation and rejuvenation of electrochromic nickel oxide films
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2018 (English)In: ChemElectroChem, ISSN 2196-0216, Vol. 5, no 22, p. 3548-3556Article in journal (Refereed) Published
Abstract [en]

Ni oxide thin films are widely used in electrochromic (EC) devices with variable throughput of visible light and solarenergy. However, the mechanisms underlying the optical modulation – and its degradation under extended operationand subsequent rejuvenation – are poorly understood especially for Li+-conducting electrolytes. Here, we report a comprehensive study of the EC properties of sputter-deposited Ni oxide films immersed in an electrolyte of LiClO4 in propylene carbonate. Cyclic voltammetry and optical transmittance measurements were used to document degradation and subsequent potentiostatic rejuvenation. X-ray diffraction did not show evidence for accompanying changes in crystallinity, whereas vibrational spectroscopy indicated that degraded films had carbonaceous surface layers. Time-of-flight elastic recoil detection analysis demonstrated that both Li+ and Cl-based ions participate in the electrochromism and its degradation and rejuvenation. A major result was that degradation is associated with a reduced difference in the concentrations of Li+ and Cl based ions in the nickel oxide during extended electrochemical cycling, and rejuvenation of degraded films is achieved by removal of Li+ ions and accumulation of Cl-based anions to regain their initial concentration difference. Our work provides new insights into the use of ion-exchange-based devices incorporating nickel oxide.

Keywords
electrochromism, degradation, nickel oxide film, rejuvenation, ToF-ERDA
National Category
Engineering and Technology Physical Chemistry Condensed Matter Physics
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-368950 (URN)10.1002/celc.201800791 (DOI)000450042200027 ()
Funder
Swedish Research Council, 821-2012-5144Swedish Research Council, VR-2016-03713Swedish Foundation for Strategic Research , SSF-RIF14-0053
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2019-01-07Bibliographically approved
Rojas González, E. A., Qu, H.-Y., Granqvist, C. G. & Niklasson, G. (2018). Electrochemical impedance spectroscopy analysis of Indium-Tin oxide films at high applied potentials. In: IS-TCMs: 7^th International Symposium on Transparent Conductive Materials and 4^th E-MRS & MRS-J Bilateral Symposium on Advanced Oxides and Wide Bandgap Semiconductors, Chania Crete Grekland. Paper presented at 7^th International Symposium on Transparent Conductive Materials and 4^th E-MRS & MRS-J Bilateral Symposium on Advanced Oxides and Wide Bandgap Semiconductors, Chania Crete Greece, Oct 14-19, 2018 (pp. 223). , Article ID PS1-33.
Open this publication in new window or tab >>Electrochemical impedance spectroscopy analysis of Indium-Tin oxide films at high applied potentials
2018 (English)In: IS-TCMs: 7^th International Symposium on Transparent Conductive Materials and 4^th E-MRS & MRS-J Bilateral Symposium on Advanced Oxides and Wide Bandgap Semiconductors, Chania Crete Grekland, 2018, p. 223-, article id PS1-33Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Indium-tin oxide (ITO) coated substrates are readily used as transparent conductors in energy-related applications like photovoltaics and smart window technology. Recently, it has been reported that electrochemical treatments at high applied voltages can enhance the durability of electrochromic (EC) films [1], and in addition rejuvenate already degraded films [2]. However, the EC electrode consists of an EC film on a transparent conductor, usually ITO, and changes in the ITO film may affect the durability and rejuvenation properties of the system. In a Li+-containing electrolyte, the safe potential range of ITO is 2-4 V vs. Li/Li+. At low potentials below 2 V vs. Li/Li+ Li compounds will form and result in a color change of ITO [3]. However, the behavior of ITO in Li+-containing electrolyte at high potentials up to 6 V vs. Li/Li+ is to our knowledge virtually unknown.   

In this work, ITO coated glass substrates with nominal sheet resistance of 60 Ω/sq, and 15 Ω/sq, having thicknesses of 50 nm, and 150 nm, respectively were used as working electrodes (WE) in a three-electrode electrochemical cell. Lithium foils were used both as counter and reference electrodes in an electrolyte consisting of 1 M LiClO4 dissolved in propylene carbonate.

A potentiostatic pretreatment at 6 V vs Li/Li+ during 24 h was applied on the WE. The current during the pretreatment showed an initial rapid decrease followed by a plateau, after which it decreased ~2 orders of magnitude. The width of the plateau for the 15 Ω/sq film was ~3 times longer than for the 60  Ω/sq film, which correlates to their thickness ratio. Cyclic voltammetry between 3.5 V and 6 V vs. Li/Li+ showed a significant current response only for potentials above 5 V for an as-deposited sample, and very little activity for a pretreated WE. The latter result indicates that the film had been stabilized by the pre-treatment.

Electrochemical impedance spectroscopy (EIS) spectra were measured at pseudo equilibrium potentials from 3.5 V vs. Li/Li+, and up to 6 V vs. Li/Li+. The spectra were modeled and fitted in terms of equivalent circuits. The spectra for potentials below 5 V were dominated by a blocking electrode response, whereas for higher voltages a low-frequency response was identified as being due to an electrochemical reaction which becomes more intense as the potential is increased. In addition the high frequency series resistance, mainly due to the ITO, is increased at high voltages and after pretreatment. Supplementary investigations by Scanning electron microscopy and X-ray photoelectron spectroscopy gave evidence for a smaller film thickness and a significantly decreased In content in films exposed to treatments at high potentials.

A better understanding of the effects of high applied potentials on transparent conductors like ITO will help to unravel mechanisms of durability enhancement and rejuvenation, and may provide guidelines for designing new procedures to enhance the durability of EC systems for energy-efficient smart windows.

 

1. M.A. Arvizu, H.-Y Qu, G.A. Niklasson and C.G. Granqvist, Thin Solid Films 653 (2018) 1-3.

2. R.-T. Wen, G.A. Niklasson and C.G. Granqvist, Nature Materials, 14 (2015) 996-1001.

3. P.M.M.C. Bressers and E.A. Meulenkamp, J. Electrochem. Soc. 145 (1998) 2225-2230.

National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-369143 (URN)
Conference
7^th International Symposium on Transparent Conductive Materials and 4^th E-MRS & MRS-J Bilateral Symposium on Advanced Oxides and Wide Bandgap Semiconductors, Chania Crete Greece, Oct 14-19, 2018
Available from: 2018-12-11 Created: 2018-12-11 Last updated: 2018-12-17
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
Research subject
Engineering Science with specialization in Solid State Physics
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: 2018-12-17
Niklasson, G., Abatte, L., Rojas González, E. A., Arvizu, M. A., Qu, H.-Y. & Granqvist, C. G. (2018). Electrochemical rejuvenation of Tungsten oxide electrochromic thin films: Evidence from impedance spectroscopy. In: 13th International Meeting on Electrochromism, IME-13: Book of Abstracts. Paper presented at 13th International Meeting on Electrochromism, Chiba University, Chiba, Japan, Aug 27-31, 2018 (pp. 11). , Article ID IN-3.
Open this publication in new window or tab >>Electrochemical rejuvenation of Tungsten oxide electrochromic thin films: Evidence from impedance spectroscopy
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2018 (English)In: 13th International Meeting on Electrochromism, IME-13: Book of Abstracts, 2018, p. 11-, article id IN-3Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

A major challenge for energy-efficient smart window technology is to ensure the durability of electrochromic (EC) devices capable of render a service life significantly higher than 20 years. The development of more durable EC materials would also make it possible to increase the transmittance contrast between bleached and colored states without the risk of limiting service life. Recently, it has been shown that degraded EC coatings can be restored to their initial state by electrochemical rejuvenation treatments.1,2 In addition, it was found that tungsten oxide EC films could gain vastly improved durability after extended electrochemical treatments at high applied potentials.3 In this paper we present an attempt to unravel the complex mechanisms behind high potential rejuvenation and durability-enhancing treatments. We study EC amorphous tungsten oxide, which is the most commonly used EC oxide. It is used in most commercial device designs, often in combination with a nickel oxide-based complementary EC layer.

Amorphous tungsten oxide thin films were deposited by sputtering onto conducting indium-tin oxide (ITO) coated glass substrates. Ion intercalation and diffusion in the films were studied by electrochemical impedance spectroscopy measurements in the frequency range 10 mHz-10 kHz and for potentials between 2.0 and 3.3 V vs. Li/Li+, using the film as working electrode in a Li+ containing electrolyte. Measurements were carried out for as-deposited EC tungsten oxide films, degraded and rejuvenated films as well as durability-enhanced WOx films. The impedance data were in good agreement with a Randles-type equivalent circuit containing an anomalous diffusion element.4 In this study we focus on changes at the electrolyte/EC film and EC film/ITO interfaces during degradation and after different electrochemical treatments.

The most notable changes were associated with the high frequency and charge transfer resistances. The high frequency resistance increased significantly during degradation as well as extended rejuvenation treatments; a similar effect was observed in durability-enhanced WOx films. This might indicate compositional or chemical changes in the ITO backing or at the film/ITO interface. The charge transfer resistance associated with the electrolyte/film interface also increased after treatments, but in addition exhibited a strong potential dependence. The appearance of a second high-frequency process after rejuvenation is considered to be more interesting. Possible explanations include an additional adsorption step preceding ion intercalation into the EC film, or alternatively the appearance of a solid-electrolyte interphase layer of the type commonly observed in Li-ion batteries.

Ion diffusion coefficients were not significantly different for rejuvenated EC films as compared to the as-deposited ones. On the other hand degraded films exhibited a completely different impedance response, which could be interpreted as being due to parasitic chemical reactions in the system.

An increased understanding of ageing and rejuvenation processes will facilitate the search for more durable EC materials and preliminary results suggest that interfacial characteristics may influence durability. Eventually, improved EC coatings will be important for large-scale practical application of electrochromic materials, for example in smart windows.

 

 

References

[1]     R.-T. Wen, C.G. Granqvist, G.A. Niklasson, Nature Mater., 14, 996 (2015).

[2]     H.-Y. Qu, D. Primetzhofer, M.A. Arvizu, Z. Qiu, U. Cindemir, C.G. Granqvist, G.A. Niklasson, ACS Appl. Mater. Interf., 9, 42420 (2017).

[3]     M.A. Arvizu, H.-Y. Qu, G.A. Niklasson, C.G. Granqvist, Thin Solid Films, 653, 1 (2018).

[4]     S. Malmgren, S.V. Green, G.A. Niklasson, Electrochim. Acta, 247, 252 (2017).

 

National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-368961 (URN)
Conference
13th International Meeting on Electrochromism, Chiba University, Chiba, Japan, Aug 27-31, 2018
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-17
Granqvist, C. G. (2018). Electrochromic glazing for energy efficient buildings. In: F Pacheco-Torgal, MV Diamanti, A Nazari, CG Granqvist, A Pruna, S Amirkhanian (Ed.), Nanotechnology in Eco-Efficient Construction: (pp. 467-501). Cambridge, UK: Woodhead Publishing Limited
Open this publication in new window or tab >>Electrochromic glazing for energy efficient buildings
2018 (English)In: Nanotechnology in Eco-Efficient Construction / [ed] F Pacheco-Torgal, MV Diamanti, A Nazari, CG Granqvist, A Pruna, S Amirkhanian, Cambridge, UK: Woodhead Publishing Limited, 2018, p. 467-501Chapter in book (Refereed)
Place, publisher, year, edition, pages
Cambridge, UK: Woodhead Publishing Limited, 2018
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-368948 (URN)978-0-08-102641-0 (ISBN)
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10
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
Research subject
Engineering Science with specialization in Solid State Physics
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: 2018-12-17
Granqvist, C. G. (2018). Electrochromic oxide-based materials and devices for glazing in energy efficient buildings. In: D Levy, E Castellón (Ed.), Transparent Conductive Materials: Materials, Synthesis, Characterization, Applications (pp. 265-300). Weinheim, Tyskland: Wiley-VCH Verlagsgesellschaft
Open this publication in new window or tab >>Electrochromic oxide-based materials and devices for glazing in energy efficient buildings
2018 (English)In: Transparent Conductive Materials: Materials, Synthesis, Characterization, Applications / [ed] D Levy, E Castellón, Weinheim, Tyskland: Wiley-VCH Verlagsgesellschaft, 2018, p. 265-300Chapter in book (Refereed)
Place, publisher, year, edition, pages
Weinheim, Tyskland: Wiley-VCH Verlagsgesellschaft, 2018
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-368946 (URN)
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10
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