Reversible Zn2+ Insertion in Tungsten Ion-Activated Titanium Dioxide Nanocrystals for Electrochromic Windows

AbstractZinc-anode-based electrochromic devices (ZECDs) are emerging as the next-generation energy-efficient transparent electronics. We report anatase W-doped TiO2 nanocrystals (NCs) as a Zn2+ active electrochromic material. It demonstrates that the W doping in TiO2 highly reduces the Zn2+ intercalation energy, thus triggering the electrochromism. The prototype ZECDs based on W-doped TiO2 NCs deliver a high optical modulation (66% at 550 nm), fast spectral response times (9/2.7 s at 550 nm for coloration/bleaching), and good electrochemical stability (8.2% optical modulation loss after 1000 cycles).

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Chromogenics for Sustainable Energy: Some Advances in Thermochromics and Electrochromics

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.75.55 ◽

2010 ◽

Vol 75 ◽

pp. 55-64 ◽

Cited By ~ 3

Author(s):

Claes Goran Granqvist ◽

Sara V. Green ◽

Shu Yi Li ◽

N.R. Mlyuka ◽

Gunnar A. Niklasson ◽

...

Keyword(s):

Energy Efficient ◽

Recent Progress ◽

Large Temperature ◽

Electrochromic Devices ◽

Temperature Dependent ◽

Roll Coating ◽

Coloration Efficiency ◽

Roll To Roll ◽

External Stimuli ◽

Initial Results

Chromogenic materials are able to change their optical properties in response to external stimuli such as temperature (in thermochromic materials) and electrical charge insertion (in electrochromic materials). Below we review some recent advances for these types of materials. Specifically we first discuss the limitations of thermochromic VO2 films for energy efficient fenestration and show from calculations that nanocomposites containing VO2 can have superior properties and display high luminous transmittance and large temperature-dependent solar transmittance modulation. Even better results may be found for nanoparticles of VO2:Mg. In the second part of the paper we survey some recent progress for electrochromic devices and show that W oxide films have increased coloration efficiency when some Ni oxide is added. We also present initial results for flexible electrochromic foils produced by roll-to-roll coating and continuous lamination.

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Synthesis of high-performance electrochromic material for facile fabrication of truly black electrochromic devices

Electrochimica Acta ◽

10.1016/j.electacta.2020.137474 ◽

2021 ◽

Vol 367 ◽

pp. 137474

Author(s):

Fang-Wei Li ◽

Tzu-Chieh Yen ◽

Guey-Sheng Liou

Keyword(s):

High Performance ◽

Electrochromic Devices ◽

Electrochromic Material ◽

Facile Fabrication

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Luminescent Electrochromic Devices for Smart Windows of Energy-Efficient Buildings

Energies ◽

10.3390/en11123513 ◽

2018 ◽

Vol 11 (12) ◽

pp. 3513 ◽

Cited By ~ 6

Author(s):

Mariana Fernandes ◽

Vânia Freitas ◽

Sónia Pereira ◽

Rita Leones ◽

Maria Silva ◽

...

Keyword(s):

Energy Efficient ◽

Near Infrared ◽

Sol Gel ◽

Average Molecular Weight ◽

The Novel ◽

Electrochromic Devices ◽

Lithium Triflate ◽

Smart Windows ◽

Energy Efficient Buildings ◽

Nir Emission

To address the challenges of the next generation of smart windows for energy-efficient buildings, new electrochromic devices (ECDs) are introduced. These include indium molybdenum oxide (IMO), a conducting oxide transparent in the near-infrared (NIR) region, and a NIR-emitting electrolyte. The novel electrolytes are based on a sol-gel-derived di-urethane cross-linked siloxane-based host structure, including short chains of poly (ε-caprolactone) (PCL(530) (where 530 represents the average molecular weight in g mol−1). This hybrid framework was doped with a combination of either, lithium triflate (LiTrif) and erbium triflate (ErTrif3), or LiTrif and bisaquatris (thenoyltrifluoroacetonate) erbium (III) ([Er(tta)3(H2O)2]). The ECD@LiTrif-[Er(tta)3(H2O)2] device presents a typical Er3+ NIR emission around 1550 nm. The figures of merit of these devices are high cycling stability, good reversibility, and unusually high coloration efficiency (CE = ΔOD/ΔQ, where Q is the inserted/de-inserted charge density). CE values of −8824/+6569 cm2 C−1 and −8243/+5200 cm2 C−1 were achieved at 555 nm on the 400th cycle, for ECD@LiTrif-ErTrif3 and ECD@LiTrif-[Er(tta)3(H2O)2], respectively.

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Electrochromic Devices Based on Porous Tungsten Oxide Thin Films

Journal of Nanomaterials ◽

10.1155/2012/674168 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 34

Author(s):

Y. Djaoued ◽

S. Balaji ◽

R. Brüning

Keyword(s):

Thin Films ◽

Transition Metal Oxides ◽

Structural Phase ◽

Phase Changes ◽

Optical Modulation ◽

Electrochromic Devices ◽

Smart Windows ◽

Porous Thin Films ◽

Recent Developments ◽

Ion Intercalation

Recent developments in the synthesis of transition metal oxides in the form of porous thin films have opened up opportunities in the construction of electrochromic devices with enhanced properties. In this paper, synthesis, characterization and electrochromic applications of porous WO3thin films with different nanocrystalline phases, such as hexagonal, monoclinic, and orthorhombic, are presented. Asymmetric electrochromic devices have been constructed based on these porous WO3thin films. XRD measurements of the intercalation/deintercalation of Li+into/from the WO3layer of the device as a function of applied coloration/bleaching voltages show systematic changes in the lattice parameters associated with structural phase transitions in LixWO3. Micro-Raman studies show systematic crystalline phase changes in the spectra of WO3layers during Li+ion intercalation and deintercalation, which agree with the XRD data. These devices exhibit interesting optical modulation (up to ~70%) due to intercalation/deintercalation of Li ions into/from the WO3layer of the devices as a function of applied coloration/bleaching voltages. The obtained optical modulation of the electrochromic devices indicates that, they are suitable for applications in electrochromic smart windows.

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A new electrochromic material from an indole derivative and its application in high-quality electrochromic devices

Electrochemistry Communications ◽

10.1016/j.elecom.2009.11.013 ◽

2010 ◽

Vol 12 (1) ◽

pp. 160-163 ◽

Cited By ~ 69

Author(s):

Guangming Nie ◽

Liangjie Zhou ◽

Qingfu Guo ◽

Shusheng Zhang

Keyword(s):

Indole Derivative ◽

Electrochromic Devices ◽

High Quality ◽

Electrochromic Material

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Solid hybrid polyelectrolyte with high performance in electrochromic devices: Electrochemical stability and optical study

Solar Energy Materials and Solar Cells ◽

10.1016/j.solmat.2007.06.011 ◽

2007 ◽

Vol 91 (19) ◽

pp. 1825-1830 ◽

Cited By ~ 8

Author(s):

Flavio L. Souza ◽

Michel A. Aegerter ◽

Edson R. Leite

Keyword(s):

High Performance ◽

Electrochemical Stability ◽

Optical Study ◽

Electrochromic Devices

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An All-Solid-State Electrochromic Device Based on WO3–Nb2O5 Composite Films Prepared by Fast-Alternating Bipolar-Pulsed Reactive Magnetron Sputtering

Coatings ◽

10.3390/coatings9010009 ◽

2018 ◽

Vol 9 (1) ◽

pp. 9 ◽

Cited By ~ 5

Author(s):

Chien-Jen Tang ◽

Ju-Liang He ◽

Cheng-Chung Jaing ◽

Chen-Jui Liang ◽

Ching-Hung Chou ◽

...

Keyword(s):

Solid State ◽

Magnetron Sputtering ◽

Response Times ◽

Composite Films ◽

Optical Modulation ◽

Electrochromic Device ◽

Coloration Efficiency ◽

Sputtering Power ◽

Bleaching Response ◽

Negative Effect

In this study, WO3–Nb2O5 electrochromic films and an ITO/WO3–Nb2O5/Nb2O5/NiVOx/ITO all-solid-state electrochromic device were deposited using fast-alternating bipolar-pulsed magnetron sputtering using tungsten and niobium targets. The influence of different sputtering powers from the niobium target on the refractive index, extinction coefficient, optical modulation, coloration efficiency, reversibility, and durability of the WO3–Nb2O5 films is discussed. The aim of this work is to find the suitable Nb proportion to increase durability and less negative effect in the electrochromic performance of Nb2O5-doped WO3 films. The lifetime of the WO3–Nb2O5 films is 4 times longer than pure WO3 films when the sputtering power of the Nb target is higher than 250 W. The results show that WO3–Nb2O5 composite films used for an all-solid-state electrochromic device can sustain over 3 × 104 repeated coloring and bleaching cycles while the transmission modulations can be kept above 20%. The coloring and bleaching response times are 7.0 and 0.7 s, respectively.

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Electrochromic Properties of Sputtered Iridium Oxide Thin Films with Various Film Thicknesses

Journal of Materials Science Research ◽

10.5539/jmsr.v6n1p44 ◽

2016 ◽

Vol 6 (1) ◽

pp. 44 ◽

Cited By ~ 6

Author(s):

Yoshio Abe ◽

Satoshi Ito ◽

Kyung Ho Kim ◽

Midori Kawamura ◽

Takayuki Kiba

Keyword(s):

Thin Films ◽

Film Thickness ◽

Color Change ◽

Response Times ◽

Response Speed ◽

Iridium Oxide ◽

Oxide Thin Films ◽

Electrochromic Material ◽

Transmittance Change ◽

Almost All

Iridium oxide is an anodic electrochromic material, which takes on a blue-black color through electrochemical oxidation and turns to transparent via reduction. Hydrated amorphous Ir oxide thin films with various thicknesses from 20 to 400 nm were prepared by reactive sputtering in a H2O atmosphere, and their transmittance spectra in both the bleached and colored states as well as their response times were examined in this study. The bleached and colored transmittances decreased with increasing film thickness according to Lambert’s law, and the absorption coefficients in the bleached and colored states were estimated to be 3.2 ´ 103 and 1.1 ´ 105 cm-1, respectively, at a wavelength of 600 nm. The results point to almost all the Ir atoms being electrochemically active and contributing to the color change. A maximum transmittance change of 81% was obtained for the 400 nm-thick film. Further, there was a trade-off between the response speed and the transmittance change. The response speed slowed down with increasing the film thickness, while the coloring and bleaching response time for the thick films was several tens of seconds.

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