New electrochromic memory display

Schoot, C. J.; Ponjeé, J. J.; Dam, Herman T. van; Doorn, R. A. van; Bolwijn, Piet

doi:10.1063/1.1654808

Cited by 226 publications

(97 citation statements)

References 3 publications

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“…Different electrochromic materials are used as the active material, which could be in the form of metal oxide like tungsten oxide [7] or a cationic molecule. [8][9][10] One particularly intriguing class of materials in this context is bipyridinium species, which are formed upon N,N-diquaternization of 4,4'-bipyridine, also known as viologens. An example of such a violgen molecule is shown in scheme-1.…”

Section: Introductionmentioning

confidence: 99%

Interfacial redox centers as origin of color switching in organic electrochromic device

et al. 2017

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Fabrication and operation of simple solid state electrochromic devices using ethyl viologen diperchlorate in a polymer matrix is presented here. In-situ Raman and transmission/absorption studies have been done to establish the origin of bias induced color change, between a transparent and navy blue color, in the electrochromic device. The origin of bias induced color change has been attributed to the bias induced redox switching between its viologen dication and free redicle forms. Fundamental reason behind colour changes of viologen molecule has been established. In-situ UV-Vis spectra reveals that the navy blue color of the device under biased condition is not due to increase in the transparency corresponding to blue wavelength but due to suppression of the transparency corresponding to the complementary colors. Absorption modulation has been reported from the device with good ON/OFF contrast of the device.

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Section: Introductionmentioning

confidence: 99%

Interfacial redox centers as origin of color switching in organic electrochromic device

et al. 2017

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“…Os viológenos [72][73][74] são compostos orgânicos de uma família de haletos de bases quaternárias específicas derivadas do 4,4'-dipiridinium (C 5 H 4 N) 2 com a fórmula geral (V 2+ , 2X -). Estes compostos incolores podem ser reduzidos no cátodo para formar o radical V + , o qual apresenta uma forte coloração azul:…”

Section: Materiais Eletrocrômicos Catódicosunclassified

Uma visão das tendências e perspectivas em eletrocromismo: a busca de novos materiais e desenhos mais simples

Oliveira¹,

Torresi²,

Torresi³

2000

Quím. Nova

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are presented in this review paper. A deep literature revision about the subject dealing with materials and device configurations developed in the last years, is presented. Great efforts of the scientific community have been done in this field. On the other hand, new electrochomic devices based on reversible deposition of metals are specially emphasized here. These devices present many advantages such as simple operation and construction and they have also shown high cycling rates. These factors make them suitable for application in display industry. In this way, many concepts used in the developement of electrodeposition baths are very useful for the improvement of these new devices; specially, all knowledge about the use of additives for modifying films microstructure and morfology.Keywords: electrochromism; cromogenic materials; reversible electrodeposition devices. REVISÃO INTRODUÇÃO Considerações GeraisO interesse por pesquisas relacionadas ao aproveitamento da energia solar tem se intensificado nos últimos anos. Hoje é notório o desenvolvimento de tecnologias para a utilização desta energia, assim como a maximização da eficiência em seus processos de aproveitamento. Há também a possibilidade de, utilizando esta energia, aliviar os impactos ambientais como o aquecimento global através do efeito estufa e o aumento da incidência de radiação ultravioleta (U.V.) através dos buracos na camada de ozônio. No entanto, esta renovada preocupação se deve também, ao grande interesse por outros mercados especializados tais como o automobilístico, aeroespacial, militar, de diversão, entre outros, os quais parecem muito promissores a curto prazo, podendo haver grande movimentação financeira.Uma ampla classe de materiais opticamente ativos vem despertando enorme interesse, especialmente aqueles com absorção, transmissão ou reflexão controláveis, devido às suas potenciais aplicações. Estes materiais são chamados materiais cromógenos e são conhecidos pela sua capacidade de mudar suas propriedades ópticas, em resposta a uma mudança nas condições do meio 1 . O eletrocromismo, efeito cromógeno, é uma propriedade característica que alguns materiais ou sistemas apresentam de mudar de cor (absorção e/ou reflexão espectral) reversivelmente, em resposta a um potencial externo aplicado.Recentemente, têm-se desenvolvido dispositivos eletrocrô-micos bastante promissores baseados na deposição -dissolução reversível de metais. Estes dispositivos também chamados de janelas e visores inteligentes contém o material eletrocrômico no eletrólito e um filme fino de metal é formado sobre um substrato transparente por passagem de corrente elétrica.O interesse por dispositivos eletrocrômicos reside no fato de apresentarem um grande número de vantagens bastante específicas tais como: alto contraste óptico com contínua variação de transmitância e independência em relação ao ângulo de visão, memória óptica, estabilidade aos raios ultra -violeta, além de ampla operação nas mais variadas faixas de temperatura. Estas características favoráveis podem, fi...

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“…

bon source and carbonization was performed at 900 C for 7 h [3,4]. The mesoporous carbon was then recovered by etching the silica in HF acid.

Characterization: Powder XRD analysis was performed using a Philips 1830 powder diffractometer with Cu K radiation (40 kV, 40 mA).

…”

mentioning

confidence: 99%

Switchable Electrochromic Images Based on a Combined Top–Down Bottom–Up Approach

Möller

Asaftei

Corr³

et al. 2004

Advanced Materials

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bon source and carbonization was performed at 900 C for 7 h [3,4]. The mesoporous carbon was then recovered by etching the silica in HF acid.Characterization: Powder XRD analysis was performed using a Philips 1830 powder diffractometer with Cu K radiation (40 kV, 40 mA). Nitrogen sorption isotherms and textural properties of the materials were determined at ±196 C using nitrogen in a conventional volumetric technique by a Coulter SA3100 sorptometer. Before analysis the samples were oven dried at 150 C and evacuated for 12 h at 200 C under vacuum. The surface area was calculated using the BET method based on adsorption data in the partial pressure (P/P 0 ) range 0.05 to 0.2 and total pore volume was determined from the amount of the nitrogen adsorbed at P/P 0 » 0.99. Scanning electron microscopy (SEM) images were recorded using a JEOL JSM-820 scanning electron microscope. Samples were mounted using a conductive carbon double-sided sticky tape. A thin (ca. 10 nm) coating of gold sputter was deposited onto the samples to reduce the effects of charging. Transmission electron microscopy (TEM) images were recorded on a JEOL 2000-FX electron microscope operating at 200 kV. Samples for analysis were prepared by spreading them on a holey carbon film supported on a grid. Elemental analysis (of the nitrogen-doped carbons) was carried out using a CHNS analyzer (Fishons EA 1108). X-ray photoelectron spectroscopy (XPS) was performed using a Kratos AXIS ULTRA spectrometer with a mono-chromated Al Ka X-ray source (1486.6 eV) operated at 10 mA emission current and 15 kV anode potential. The analysis chamber pressure was better than 10 ±9 torr. FAT (fixed analyser transmission) mode was used, with pass energies of 160 eV (or 80 eV) for survey scans and 40 eV for high resolution scans. A magnetic immersion lens system allowed the area of analysis to be defined by apertures, a slot' aperture of 300 lm 700 lm for wide/survey scans and a 110 lm aperture for high resolution scans. The take off angle for the photoelectron analyzer was 90 and the acceptance angle was 30 (in magnetic lens modes). Data analysis was carried out using CASAXPS software with Kratos sensitivity factors to determine atomic % values from the peak areas. Charge correction was applied to the data at the processing stage. The recent development in mobile electronic equipment has boosted the demand for low-cost flat-panel displays. Today, 90 % of the market is dominated by liquid-crystal displays (LCD), but new technologies such as organic light-emitting diode (OLED) and microencapsulated electrophoretic (MEP) displays have emerged recently.[1] Active or passive matrix addressable displays attract most commercial interest. However, for certain applications, other parameters, such as cost, power consumption, or high contrast are prevailing criteria, and switchable pictograms or icons are sufficient. The phenomenon of electrochromism is well known and involves electrically controlled light absorption in thin layers. [2,3] Alphanumeric electrochromic displays (ECDs) w...

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New electrochromic memory display

Abstract: The principle of a new electrochromic display based on an oxidation-reduction reaction of an organic compound of the viologen family is described. The result is a display having a built-in memory, high contrast, a low switching voltage, and a low mean power consumption.

Cited by 226 publications

References 3 publications

Interfacial redox centers as origin of color switching in organic electrochromic device

Interfacial redox centers as origin of color switching in organic electrochromic device

Uma visão das tendências e perspectivas em eletrocromismo: a busca de novos materiais e desenhos mais simples

Switchable Electrochromic Images Based on a Combined Top–Down Bottom–Up Approach

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