Temperature-dependent structural evolution and electrochromic properties of peroxopolytungstic acid

A c c e p t e d M a n u s c r i p tThe intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics.In this study, we prepared two types of amorphous films via the sol-gel technique: one dense and one mesoporous in order to compare their response upon lithium intercalation and deintercalation.According to chronoamperometric measurements, Li + intercalates/de-intercalates faster in the mesoporous film (24s/6s) than in the dense film (48s/10s bronze.

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“…The reference was a bare silicon wafer. thus their electrochemical capacity is inferior than their amorphous counterparts [22,24].…”

Section: Raman and Ir Spectramentioning

confidence: 99%

“…Finally the films were calcined at a high temperature under air (heating ramp 1°C/min, natural cooling down in the furnace) to induce the formation of the oxide. The dense films were calcined at 300 o C for 1h to avoid crystallization [22]. The mesoporous films were calcined at 350 o C for 2h.…”

Section: Deposition Of Mesoporous and Dense Wo 3 Thin Filmsmentioning

confidence: 99%

Mesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior

Chatzikyriakou

Gilbert

Colson

et al. 2014

Electrochimica Acta

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“…01-084-0886. Tungstic acid is already known to have a good electrochromic behavior, which is dependent on both the hydration level and crystalline structure [97,98]. In this work, the terminal W=O and W-H 2 O bonds can increase the conduc- …”

Section: Liquid Packaging Cardboard (Lpc) Electrochromic Device Assesmentioning

confidence: 81%

Optoelectronics and Bio Devices on Paper Powered by Solar Cells

Vicente¹,

Araújo²,

Gaspar³

et al. 2017

Nanostructured Solar Cells

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The employment of printing techniques as cost-effective methods to fabricate low cost, flexible, disposable and sustainable solar cells is intimately dependent on the substrate properties and the adequate electronic devices to be powered by them. Among such devices, there is currently a growing interest in the development of user-oriented and multipurpose systems for intelligent packaging or on-site medical diagnostics, which would greatly benefit from printable solar cells as their energy source for autonomous operation.This chapter first describes and analyzes different types of cellulose-based substrates for flexible and cost effective optoelectronic and bio devices to be powered by printed solar cells. Cellulose is one of the most promising platforms for green recyclable electronics and it is fully compatible with large-scale printing techniques, although some critical requirements must be addressed. Paper substrates exist in many forms. From common office paper, to packaging cardboard used in the food industry, or nanoscale engineered cellulose (e.g. bacterial cellulose). However, it is the structure and content of paper that determines its end use. Secondly, proof-of-concept of optoelectronic and bio devices produced by inkjet printing are described and show the usefulness of solar cells as a power source or as a chemical reaction initiator for sensors.

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“…3b shows the crosslinked W-O-W networks and how the -OH, -OH 2 , and -O 2− link with tungsten in the corner-and edge-sharing array of WO 6 octahedra. 28 The structure of the hybrid film is such that it ensures an optimum electrochromic function. It is also obvious that grains devoid of plane facets in the film ͑region B͒ are amorphous, which complies with the XRD and SAED results.…”

Section: Resultsmentioning

confidence: 99%

Nanostructured Tungsten Oxide-Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) Hybrid Films: Synthesis, Electrochromic Response, and Durability Characteristics

Deepa

Srivastava

Sood

et al. 2008

J. Electrochem. Soc.

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Nanostructured hybrid thin films of the system tungsten oxide-poly͑3,4-ethylenedioxythiophene͒:poly͑styrenesulfonate͒ ͑WO 3 -PEDOT:PSS͒ were synthesized by first forming a tungsten-oxide layer by surfactant-assisted electrochemical method, followed by deposition of a PEDOT:PSS layer. The hybrid-film formation is primarily based on coulombic interactions between the surface hydroxyl groups of tungsten oxide and the positively charged centers on the polymer backbone; this has been confirmed by electron microscopy and X-ray diffraction. High-resolution transmission electron microscopy reveals that the tungsten-oxide host with a monoclinic unit cell resides along with the amorphous domains of PEDOT:PSS. The hybrid film, being a dual electrochrome, exhibits a much larger coloring efficiency ͑227 cm 2 C −1 at 600 nm͒, a higher redox activity ͑larger currents for ion ingress and egress are obtained within the same potential range͒, and, most importantly, a superior electrochemical cycling stability when compared to the neat polymer film. While the pristine polymer film lifts off irrevocably from the substrate upon 3000 cycles of coloring and bleaching, the hybrid film sustains about 5000 cycles, albeit with some changes in the nanoparticulate morphology, elemental composition, and development of some new artifacts on the film surface. The integration of organic and inorganic materials has aroused much interest in the scientific community for the use of hybrid organic-inorganic materials for catalysis, chiral synthesis, and enhancing electronic conductivity and electro-optical properties.1,2 To this end, this report describes a bilayer deposition of two different materials, an n-type semiconductor oxide, tungsten oxide ͑WO 3 ͒, and a p-type semiconductor, polymer ͑PEDOT:PSS͒, to yield a hybrid film and how its structure and composition influences the electrochemical and optical response and chemical stability of the film generated thereof. Since the discovery of electrochromism in WO 3 by Deb, 3 this oxide has been extensively investigated and has drawn considerable attention because of its application in electrochromic cells like smart windows, high-contrast displays, antiglare rearview mirrors, and so forth.4-6 PEDOT:PSS is one of the most widely studied electroactive polymers to date because of its excellent film forming ability, high conductivity, and high contrast ratio. [7][8][9] We found that the polymer forms a well-adherent uniform layer when deposited onto the WO 3 film, which indicates a strong affinity between the inorganic and organic species. The hybrid film offers the potential of realizing practical improvements of charge-transfer quanta through the bilayer/electrolyte interface and its reversibility as well. Furthermore, in the ever-growing field of solid-state electrochemical devices, the limited understanding of charge-transfer phenomena at the electrode-electrolyte interface is often a factor restricting operational lifetimes.In an approach to address these issues, in the past, PEDOT has been functio...

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Temperature-dependent structural evolution and electrochromic properties of peroxopolytungstic acid

Cited by 32 publications

References 27 publications

Mesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior

Mesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior

Optoelectronics and Bio Devices on Paper Powered by Solar Cells

Nanostructured Tungsten Oxide-Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) Hybrid Films: Synthesis, Electrochromic Response, and Durability Characteristics

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