Organic conducting polymers derived from substituted thiophenes as electrochromic material
About: This article is published in Journal of Electroanalytical Chemistry.The article was published on 1983-06-24. It has received 290 citations till now. The article focuses on the topics: Electrochromism & Conductive polymer.
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1,521 citations
TL;DR: In this article, the authors present an overview of the recent trends in gap engineering in field-effect transistors, light-emitting diodes, electrochromic devices and solar cells.
Abstract: For almost two decades, the search of an intrinsically-conductive organic metal has represented the major driving force for research on control of the band gap of extended π-conjugated systems. However, the emergence of the application of π-conjugated oligomers and polymers in field-effect transistors, light-emitting diodes, electrochromic devices and solar cells has introduced major changes in the chemistry of gap engineering. Besides controlled band gap, active materials for electronic and photonic applications must present appropriate absorption and/or emission properties, highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO) energy levels and charge-transport properties. The aim of this short review is to present an overview of the recent trends in this area in order to identify possible directions for future research.
648 citations
TL;DR: Revetement en couche mince d'electrodes en platine, par oxydation galvanostatique d'aniline a 0,1m Acm −2 en solutions 2M d'acide chlorhydrique contenant 1M aniline
625 citations
TL;DR: Solid-state polymer light-emitting electrochemical cells have been fabricated using thin films of blends of poly(1,4-phenylenevinylene) and poly(ethylene oxide) complexed with lithium trifluoromethanesulfonate, with an internal built-in potential close to the band gap of the redox-active conjugated polymer.
Abstract: Solid-state polymer light-emitting electrochemical cells have been fabricated using thin films of blends of poly(1,4-phenylenevinylene) and poly(ethylene oxide) complexed with lithium trifluoromethanesulfonate. The cells contain three layers: the polymer film (as the emissive layer) and indium-tin oxide and aluminum films as the two contact electrodes. When externally biased, the conjugated polymers are p-doped and n-doped on opposite sides of the polymer layer, and a light-emitting p-n junction is formed in between. The admixed polymer electrolyte provides the counterions and the ionic conductivity necessary for doping. The p-n junction is dynamic and reversible, with an internal built-in potential close to the band gap of the redox-active conjugated polymer (2.4 eV for PPV). Green light emitted from the p-n junction was observed with a turn-on voltage of about 2.4 V. The devices reached 8 cd/m(2) at 3 V and 100 cd/m(2) at 4 V, with an external quantum efficiency of 0.3-0.4% photons/electron. The response speed of these cells was around 1 s, depending on the diffusion of ions. Once the light-emitting junction had been formed, the subsequent operation had fast response (microsecond scale or faster) and was no longer diffusion-controlled.
587 citations
TL;DR: In this article, the most important examples from the major classes of organic electrochromic materials, namely the 1,1′-disubstituted-4,4′-bipyridilium salts (the ''viologens'), conducting polymers, metallopolymers and metallophthalocyanines are reviewed.
482 citations
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TL;DR: In this paper, the electrochemical properties of thin films of metal phthalocyanines on conducting substrates are investigated and a film electrode model is proposed based on an irreversible charge transfer step.
127 citations
TL;DR: In this article, it was shown that the positive ion remains fully ionized even in the presence of high densities of injected electrons in amorphous WO3 films and in tungsten bronzes.
Abstract: X‐ray photoelectron spectra of colored WO3 films, thermodynamic analysis of galvanic behavior of the tungstic oxide cathode, plus other new lines of evidence, clearly establish the previously uncertain mechanism of the electro‐optic effect in amorphous WO3, viz., a simultaneous injection of electrons and positive ions into a film via an electrochemical process, with the consequent development of a low‐x tungsten bronze. The positive ion, in both the films and in tungsten bronzes, remains fully ionized even in the presence of high densities of injected electrons.
114 citations
TL;DR: In this article, the electrochromic behavior of symmetric and asymmetric cells has been studied by potentiostatic and galvanostatic measurements for both asymmetric and symmetric cells, and the kinetics of coloration and bleaching are ascribed to barrier-limited and space charge-limited current flow, respectively.
Abstract: The electrochromic behavior of has been studied by potentiostatic and galvanostatic measurements for both symmetric and asymmetric cells. The kinetics of coloration and bleaching are ascribed to barrier‐limited and space charge‐limited current flow, respectively, similar to the case of . Galvanostatic measurements indicate linearity of optical density with injected charge at low injection levels. At high injection levels a nonlinear response is observed which is attributed to the approach of a phase boundary with increasing in . A general comparison of and in indicates greater stability for open‐circuit memory of the cells. Response times for various symmetric cells are tabulated.
106 citations