Transmissive to black electrochromic aramids with high near-infrared and multicolor electrochromism based on electroactive tetraphenylbenzidine units

Yen, Hung‐Ju; Lin, Kuan‐Yu; Liou, Guey‐Sheng

doi:10.1039/c1jm10210a

Cited by 71 publications

(40 citation statements)

References 55 publications

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“…To the best of our knowledge, the optical contrast based on the L * , a * , b * colorimetric index is superior to the values of previously reported black electrochromic materials. [26][27][28][29][30] EXPERIMENTAL METHODS Cobalt(II) acetate (Co(OAC)2) and sodium hydroxide (NaOH) were purchased from Wako Chemicals. 4′,4′′′′-(1,4-phenylene)bis(2,2′:6′,2′′-terpyridine) (ligand, 97%) and potassium chloride (KCl) were purchased from Aldrich.…”

Section: Introductionmentioning

confidence: 99%

Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications

Hsu

Zhang²,

Sato³

et al. 2015

ACS Appl. Mater. Interfaces

100

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Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation.

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Section: Introductionmentioning

confidence: 99%

Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications

Hsu

Zhang²,

Sato³

et al. 2015

ACS Appl. Mater. Interfaces

100

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“…[6][7][8] Electrochromic materials (ECMs) have advantages of high contrast of transmittance, low driving voltage and bistable characteristics, indicating their great market opportunity in green energy applications and the display industry. However, ECMs with high contrast (ΔL*) in the CIE L*a*b* coordinates have not been easily obtained in the past decade, [9][10][11][12][13] and the adjective 'black-to-transmissive' was first termed by Reynolds and co-workers in 2008. 12 They developed readily oxidized conjugated polymers with extensive absorption bandwidths extending over the entire visible spectrum that could be totally bleached in their oxidized states.…”

Section: Introductionmentioning

confidence: 99%

Highly transparent to truly black electrochromic devices based on an ambipolar system of polyamides and viologen

et al. 2017

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A novel electrochromic device (ECD) based on an electroactive ambipolar system was constructed and designed through an absorption-complementary approach. The system consisted of electroactive polyamides (PAs) with N,N,N′,N′-tetraphenyl-pphenylenediamine (TPPA) and tetraphenylbenzidine (TPB) units in the backbone and heptyl viologen (HV) in the supporting electrolyte. Each of the electrochromic materials (ECMs), including TPPA-PA, TPB-PA and HV, provided one of the three primary colors that merged into a black color. Because of the suitable counter electrode materials used in this study, the overall operating voltage was effectively reduced; thus, the electrochemical stability and lifetime of the ECD were greatly enhanced. Furthermore, the whole system was completely transparent in its neutral or bleaching state, and the transmittance was reduced to only 6% in the colored state in both the visible and near-infrared (NIR) regions. The ECD demonstrated a high L* change (ΔL*) of 81 and a significant transmittance change (ΔT) of 60% in the visible region. Thus, through the excellent combination of the electrochromic and ambipolar characteristics of the system, a genuine 'highly transparent to truly black' ECD was successfully fabricated, implying the great potential of this device as a shutter in transparent displays and related devices.

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“…Because the realization of a multicolor switch is preferred in the majority of their applications in displays, [4][5][6][7][8][9][10] various electrochromic materials including polymers, 11,12 small organic molecules 13,14 and metal-organic complexes, 15 and technologies aimed at multicolor switches have been intensively explored. Transition metals based on metal-organic complex multicolor electrochromic materials exhibit attractive properties, such as high stability and chemiluminescence.…”

Section: Introductionmentioning

confidence: 99%

A single-molecule multicolor electrochromic device generated through medium engineering

et al. 2015

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Multicolor organic electrochromic materials are important for the generation of full-color devices. However, achieving multiple colors using a single-molecule material has proved challenging. In this study, a multicolor electrochromic prototype device is generated by integrating medium engineering/in situ 'electro base'/laminated electrode technologies with the simple flying fish-shaped methyl ketone TM1. This multicolor electrochromic (green, blue and magenta) device is durable and has a high coloration efficiency (350 cm 2 C 21 ), a fast switching time (50 ms) and superior reversibility. This study is a successful attempt to integrate solvatochromism and basochromism in an electronic display. This integration not only introduces a new avenue for color tuning, in addition to the structural design of the colorant, but will also inspire further developments in the tuning of many other properties by this medium engineering approach, such as conductance and the redox property, and thereby accelerate versatile applications in data recording, ultrathin flexible displays, and optical communication and sensing. Keywords: electrochromic materials; laminated electrodes; microenvironment; multicolor devices; solvatochromic materials INTRODUCTION Owing to the increasing demand for low-power, ultrathin, flexible electronic displays, organic electrochromic materials 1-3 have become a research focus because of their distinct merits: low weight, high contrast, wide viewing angle, flexibility and the potential for low power consumption. Because the realization of a multicolor switch is preferred in the majority of their applications in displays, 4-10 various electrochromic materials including polymers, 11,12 small organic molecules 13,14 and metal-organic complexes, 15 and technologies aimed at multicolor switches have been intensively explored. Transition metals based on metal-organic complex multicolor electrochromic materials exhibit attractive properties, such as high stability and chemiluminescence. 16 However, the expense and scarcity of the precious metals, such as ruthenium, 15,16 osmium 17 and iridium, 18 limit their practical applications. Polymeric multicolor electrochromic materials with different electrochromic activation units [19][20][21] possess the advantages of easy processing, diverse resources and facile color tunability. However, some intrinsic problems, such as the lack of colorless states, poor transparency, poor color purity and complicated synthesis procedures, hinder their applications. Compared with electrochromic polymers, small organic color switches possess the advantages of low cost, good color purity, distinct transition from colorless to colored states and fine tunability of their photoelectronic properties via easy structure modifications. The lack of multicolor abilities is their intrinsic

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Transmissive to black electrochromic aramids with high near-infrared and multicolor electrochromism based on electroactive tetraphenylbenzidine units

Cited by 71 publications

References 55 publications

Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications

Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications

Highly transparent to truly black electrochromic devices based on an ambipolar system of polyamides and viologen

A single-molecule multicolor electrochromic device generated through medium engineering

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