A new standard method to calculate electrochromic switching time

Hassab, Sofiane; Shen, D. Eric; Österholm, Anna M.; Rocha, Mathias Da; Song, Giljoo; Alesanco, Yolanda; Viñuales, Ana; Rougier, Aline; Reynolds, John R.; Padilla, Javier

doi:10.1016/j.solmat.2018.04.031

Cited by 72 publications

(61 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This switching time, labeled t 2.3 , can be calculated for both the coloration and bleaching for each subsection of the lateral ECD. As expected, the switching times for the first 1 mm subsection are the fastest (8 s for bleaching and 5 s for coloring) and as the subsection grows in size, the switching time is increased to 12 s coloration and 13 s bleaching for the entire pixel . For both the paper and ITO ECDs, there is a slight difference between the bleaching and coloring of the pixel indicated by differing slopes in the t 2.3 as a function of time data.…”

Section: Resultssupporting

confidence: 68%

Paper‐Based Electrochromic Devices Enabled by Nanocellulose‐Coated Substrates

Lang

Österholm

Reynolds

2019

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

As environmental considerations for both the processing and disposal of electronic devices become increasingly important, the ability to replace plastic and glass substrates with bioderived and biodegradable materials remains a major technological goal. Here, the use of cellulose nanofiber-coated paper is explored as an environmentally benign substrate for preparing low-resistance (460 Ω sq −1 ), colorless (a* = −2.3, b* = −2.7) printed poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) electrodes. The PEDOT:PSS/paper electrodes support the reversible oxidation of three electrochromic polymers (ECPs) (cyan, magenta, and yellow), affording the possibility for fully printed, color displays on paper. Lateral electrochromic devices (ECDs) incorporating an ion gel electrolyte are demonstrated where a magenta-to-colorless device achieves a color contrast (ΔE*) of 56 owing to a highly color-neutral bleached state of the ECP (a* = −0.5, b* = 2.9). Black-tocolorless devices achieve ΔE* = 29 and are able to retain 86% of their color contrast after 9000 switches. The switching times of these lateral devices are quantified through colorimetric image analysis which shows comparable performance for devices constructed on paper as devices using ITO/glass electrodes (10 Ω sq −1 ). The paper ECDs are then combusted in air leaving 3% of the initial mass at 600 °C, highlighting this approach as a promising route toward disposable displays. Figure 2. Optimization of printed electrodes showing a) reflectance as a function of sheet resistance for printed electrodes on glass, CNF coated paper, and office paper. Photographs of PEDOT:PSS electrodes on CNF coated paper with sheet resistances of b) 5000 Ω sq −1 , c) 460 Ω sq −1 , d) 160 Ω sq −1 , and e) 109 Ω sq −1 . CIELAB color coordinates are labeled below each image. www.afm-journal.de www.advancedsciencenews.com 1903487 (4 of 11)

show abstract

Section: Resultssupporting

confidence: 68%

Paper‐Based Electrochromic Devices Enabled by Nanocellulose‐Coated Substrates

Lang

Österholm

Reynolds

2019

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…[12][13][14][15][16][17] Furthermore, ECPs feature a wide range of vivid colors, response times in the range of seconds, and light transmittance change over 60%. [3,6,7,[27][28][29][30][31][32][33][34] Other materials, such as multichromophoric polymers, can actually offer suitable bleached and colored states, but require elaborate synthesis routes and have an electrochemical operating window, which poses serious stability problems. The bandgap between the highest occupied π-electron band and the lowest unoccupied band determines the EC properties like color and color change.…”

mentioning

confidence: 99%

New Roll‐to‐Roll Processable PEDOT‐Based Polymer with Colorless Bleached State for Flexible Electrochromic Devices

Macher

Schott

Sassi

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Conjugated electrochromic (EC) polymers for flexible EC devices (ECDs) generally lack a fully colorless bleached state. A strategy to overcome this drawback is the implementation of a new sidechain-modified poly(3,4-ethylene dioxythiophene) derivative that can be deposited in thin-film form in a customized high-throughput and large-area roll-to-roll polymerization process. The sidechain modification provides enhanced EC properties interms of visible light transmittance change, Δτ v = 59% (ΔL* = 54.1), contrast ratio (CR = 15.8), coloration efficiency (η = 530 cm² C −1 ), and color neutrality (L* = 83.8, a* = −4.3, b* = −4.1) in the bleached state. The intense bluecolored polymer thin films exhibit high cycle stability (10 000 cycles) and fast response times. The design, synthesis, and polymerization of the modified 3,4-ethylene dioxythiophene derivative are discussed along with a detailed optical, electrochemical, and spectroelectrochemical characterization of the resulting EC thin films. Finally, a flexible see-through ECD with a visible light transmittance change of Δτ v = 47% (ΔL* = 51.9) and a neutral-colored bleached state is developed.

show abstract

“…To allow a comparison of our switching time with those of the different ECDs in the literature, we followed the method of Hassab et al 33 by using the equationThe time constant can be calculated from the switching times to an arbitrary fraction of by usingFor our ECD was measured at 90% of ( = 0.9) and results in = 0.24 s. We have also evaluated for competing ECDs from the literature and collected these data in Table 1. It shows that our time constant is lower, and we received concurrently the largest reported OD.…”

Section: Discussionmentioning

confidence: 99%

Complementary hybrid electrodes for high contrast electrochromic devices with fast response

et al. 2019

View full text Add to dashboard Cite

Fast switching ‘transparent-to-black’ electrochromic devices are currently under investigation as potential candidates in modern applications like e-papers or with additional functionality as ultracompact iris or switchable neutral filter in camera systems. However, recent electrochromic devices show either a lack of contrast or slow response times. To overcome these deficiencies we focus on a careful material composition of the colouring hybrid electrodes in our device. We have established a nanoporous Sb-doped SnO electrode as supporting electrode for chemisorbed electrochromic tetraphenylbenzidine molecules due to its good conductivity in the redox potential range of the molecule. This hybrid electrode was combined with a modified nanoporous TiO / viologen electrode to realize a high performance, complementary electrochromic device. Fast switching time constants of 0.5 s and concurrently high change in optical density OD = 2.04 at 605 nm confirm our successful concept. The achieved colouration efficiency of 440 cm C exceeds every high contrast device presented so far.

show abstract

A new standard method to calculate electrochromic switching time

Cited by 72 publications

References 12 publications

Paper‐Based Electrochromic Devices Enabled by Nanocellulose‐Coated Substrates

Paper‐Based Electrochromic Devices Enabled by Nanocellulose‐Coated Substrates

New Roll‐to‐Roll Processable PEDOT‐Based Polymer with Colorless Bleached State for Flexible Electrochromic Devices

Complementary hybrid electrodes for high contrast electrochromic devices with fast response

Contact Info

Product

Resources

About