Dissertations / Theses on the topic 'Electrochromic application'
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1
Ak, Metin. "Synthesis Of Polythiophene And Polypyrrole Derivatives And Their Application In Electrochromic Devices." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12608070/index.pdf.
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Different substituted thiophene and pyrrole monomers namely hexamethylene (bis-3-thiopheneacetamide) (HMTA), N-(4-(3-thienylmethylene)-oxycarbonylphenyl)maleimide (MBThi), 2,4,6-Tris-(4-pyrrol-1-yl-phenoxy)-[1,3,5]triazine (TriaPy), 2,4,6-Tris-(thiophen-3-ylmethoxy)-[1,3,5] triazine (TriaTh), and N-(2-(thiophen-3-yl)methylcarbonyloxyethyl) maleimide (NMT) were synthesized. The chemical structures of the monomers were characterized by Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) and Fourier Transform Infrared (FTIR) Spectroscopies. Electrochemical behavior of the monomers in the presence and absence of comonomers were studied by cyclic voltammetry. Subsequently, monomers were homopolymerized and copolymerized via electrochemical methods and the resultant polymers were characterized by FTIR, Scanning Electron Microscopy (SEM) and conductivity measurements.
Second part of the study was devoted to investigate one of most interesting property of conducting polymers, the ability to switch reversibly between the two states of different optical properties, &ldquoelectrochromism&rdquo
. In recent years there has been a growing interest in application of conducting polymers in electrochromic devices. Thus, electrochromic properties of the synthesized conducting polymers were investigated by several methods like spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemistry experiments were performed in order to investigate key properties of conjugated polymers such as band gap, maximum absorption wavelength, the intergap states that appear upon doping and evolution of polaron and bipolaron bands. Switching time and optical contrast of the homopolymers and copolymers were evaluated via kinetic studies. Results implied the possible use of these materials in electrochromic devices due to their good electrochromic properties.
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Dillingham, J. L. "Investigation of bipyridilium and Prussian blue systems for their potential application in electrochromic devices." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/7181.
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Tarkuc, Simge. "Synthesis And Characterization Of A New Soluble Polythiophene Derivative And Its Electrochromic Application." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607993/index.pdf.
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The Knorr-Paal reaction of 1,4-di(2-thienyl)-1,4-butanedione with aniline to yield 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole (PTP) was performed in the presence of catalytical amounts of p-toluenesulfonic acid (PTSA). Chemical polymerization of the monomer yielded a soluble polymer. Structures of both the monomer and the polymer were investigated by Nuclear Magnetic Resonance (1H and 13C NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the chemically synthesized polymer was determined by Gel Permeation Chromatography (GPC) as
Mn = 7.2 x 103 g/mol. The electrochemical oxidative polymerization of PTP was carried out via potentiodynamic electrolysis in the presence of LiClO4, NaClO4 (1:1) being the supporting electrolyte in acetonitrile. Electrochemical copolymerization of PTP with 3,4-ethylenedioxythiophene (EDOT) was carried out in acetonitrile (ACN)/ NaClO4/LiClO4 (0.1M) solvent-electrolyte couple system via potentiodynamic electrolysis. Cyclic voltammetry was used to investigate electrochemical behavior of the monomer and redox reactions of conducting polymers. Conductivities of films of the polymers were measured by four-probe technique. Surface morphologies of the films were investigated by Scanning Electron Microscope (SEM). Electrochromic properties of the conducting polymers were investigated via spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemical analysis of P(PTP) revealed electronic transitions at 413, 600 and 900 nm corresponding to π
-&
#960
* transition, polaron, and bipolaron band formations, respectively. The spectroelectrochemical behavior of the P(PTP-co-EDOT) in comparison to those of the respective homopolymers revealed solid evidence of copolymerization based upon the differences in the spectral signatures. Switching time of the polymers was evaluated by kinetic studies upon measuring the percent transmittance (%T) at the maximum contrast point. As an application, absorption/transmission type electrochromic devices with ITO/homopolymer(copolymer)/gel electrolyte/PEDOT/ITO configuration was constructed, where homopolymer (copolymer) and PEDOT functioned as the anodically and the cathodically coloring layers, respectively. Spectroelectrochemistry, switching ability and open circuit memory of the devices were investigated. The results revealed that these devices have good switching times, reasonable contrasts and optical memories.
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Spence, Graham Harvey. "New polymer and gel electrolytes for potential application in smart windows." Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/614.
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Murray, Keith Russell. "Electrochromic materials their contribution to sustainability in the built environment /." Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=26226.
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Schwendeman, Irina. "Optical and transport properties of conjugated polymers and their application to electrochromic devices." [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000606.
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Kenny, Leo Thomas. "Preparation and characterization of lithium cobalt oxide by chemical vapor deposition for application in thin film battery and electrochromic devices /." Thesis, Connect to Dissertations & Theses @ Tufts University, 1996.
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Thesis (Ph.D.)--Tufts University, 1996.Adviser: Terry E. Haas. Submitted to the Dept. of Chemistry. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Apaydin, Dogukan Hazar. "Electrochromic And Photovoltaic Applications Of Conjugated Polymers." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614481/index.pdf.
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Three new azobenzene containing conjugated monomers were designed and synthesized. Resulting monomers were characterized by means of 1H NMR and 13C NMR techniques. Monomers (E)-1,2-bis(4-(thiophen-2-yl)phenyl)diazene (M1), (E)-1,2-bis(4-(4-hexylthiophen-2-yl) phenyl) diazene (M2) and (E)-1,2-bis(2-fluoro-4-(4-hexylthiophen-2-yl)phenyl) diazene (M3) were electrochemically polymerized using cyclic voltammetry to give polymers P1, P2 and P3. The polymers were subjected to spectroelectrochemical and kinetic studies in order to obtain information about their elecrochromic characteristics. P1 and P2 were pale-yellow in their neutral states and blue in oxidized states while P3 showed multichromic property due to having polaron bands in visible region of the spectrum. Addition of fluorine atoms to the backbone of P3, lowered the LUMO level of P3 thus gained the polymer n-doping property.
In the second part of this thesis poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(thien-2-yl) 2-dodecyl-benzo[1,2,3]triazole)) (PFTBT) polymer was mixed with common electron acceptor Phenyl-C61-butyric acid methyl ester (PCBM) and used in organic solar cell applications. Active layers containing PFTBT and PCBM were spin casted on ITO coated substrates at varying rotational speeds to obtain active layer thicknesses having different values. Thickness of the active layer was optimized so was the efficiency of organic solar cells. As a result of this optimization study, efficiency of PFTBT containing organic solar cells were increased to 1.06% which is a higher value than previosly reported literature results.
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Cruz, Ana Sofia Rações da. "Dual-phase inkjet printed electrochromic layers based on PTA and WOX/TiO2 nanoparticles for electrochromic applications." Master's thesis, Faculdade de Ciências e Tecnologia, 2010. http://hdl.handle.net/10362/5093.
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Thesis submitted in Faculdade de Ciências e
Tecnologia da Universidade Nova de Lisboa for
the degree of Master in Materials EngineeringThe aim of the work was to develop flexible electrochromic windows via Inkjet Printing Technique based on amorphous Peroxotungstic Acid (PTA) and metal oxide nanocrystals. A unique selection of materials allows for a solution processed deposition of low temperature electrochromic layer which is compatible with flexible substrates such as PET, PEN and paper. The use of Inkjet Printing Technique was motivated by the fact that it is a cost efficient method (mass production) which has a reduced consumption of materials and energy. It is also a non-contact, digital, no mask and no vacuum patterning method which greatly simplifies the technological process. Developed devices were tested using optical, electrochemical, and structural characterization techniques, in order to find the optimum electrochromic layer composition which would guarantee desirable electrochromic behavior of the material. Laboratory studies were supported by statistical techniques such as Design of Experiment (DOE) and Multiple Regression which leads to a fitting of mathematical model of the optical and electrical responses. The dual-phase electrochromic layer consists in the combination of both amorphous and nanocrystalline phases significantly improve the electrochromic performance of the devices. The developed method of electrochromic windows manufacturing meets all the objectives at the beginning of the study.
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Sibuyi, Praise. "Nano-rods WO3-δ for electrochromic smart windows applications." Thesis, University of the Western Cape, 2006. http://hdl.handle.net/11394/2367.
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>Magister Scientiae - MScTungsten oxide is a good electrochromic material which has been used in the construction of smart windows through visible modulation. These smart materials can reversibly change their optical properties with the application of an external voltage. Their ability to lighten and darken on command is ideally suited for energy-efficiency windows. The process itself or the overall reaction should respond in seconds and as quick as possible. The goal of this project was to prepare epitaxial well defined tungsten oxide nanorods by the thermal evaporation technique.
South Africa
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Bartlett, I. D. "Characterisation and optimisation of carbazole modified polysiloxanes for electrochromic applications." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636047.
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Novel molecular materials have been the focus of a dynamic international research effort in recent years, due to their many possible applications. One such application is electrochromic devices. This thesis is concerned with the electrochromic properties of Carbazole Modified Polysiloxanes (CMPs). Electrical cross-linking forms thin films of electrochromic material adherent to either Gold of Indium Tin Oxide (ITO) substrates. Film preparation conditions are studied using analysis techniques, with constant current deposition at 50μAcm-2 found optimal. Thin films of CMP are found to be transparent in the reduced state, and deep green in the oxidised state, similar to the colour change of cross-linked polyvinyl carbazole. However the increased flexibility of the polysiloxane backbone leads to increased cross-linking efficiencies and therefore higher densities of dicarbazolyl moieties (colouration centres). Studies reveal the density in CMP films to be ≃ 1019-20cm-3. Cyclic voltammetry and potential-step chronoamperometry are used to study the dynamics of charge transfer in CMP films. The data suggests that the colouration step is rate limited by charge transfer across the electrolyte-film interface, while the bleaching step is controlled by a double charge extraction mechanism dependent on colour-ion mobility. Film lifetime, defined as the number of redox cycles a film may undergo whilst maintaining acceptable colour contrast, is measured under a wide range of conditions. Deposition conditions and switching potential are found to have a strong influence, whilst counter-ion choice (C1O4', PF6 or BF4) has only a weak influence. Film lifetimes of ≃ 3 x 103 are observed with contrast ratios of ≃ 9.
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Golden, Stephen John. "Behaviour of thin film oxide based electrodes in electrochromic applications." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47080.
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Ma, Yun. "Photofunctional molecular materials for chemical sensing, bioimaging and electrochromic applications." HKBU Institutional Repository, 2015. https://repository.hkbu.edu.hk/etd_oa/206.
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This thesis is dedicated to developing novel photofunctional molecular materials for the applications in chemical sensing, bioimaging and electrochromic. To begin with, a brief introduction of photofunctional molecular materials and an overview of their applications in chemical sensing, bioimaging and electrochromic were presented in Chapter 1. In chapter 2, we have synthesized a series of water-soluble phosphorescent cationic iridium(III) solvato complexes (1-7) as multicolor cellular probes for imaging in living cells. All of these complexes can be dissolved in PBS. The emission of complexes can be tuned from green to red by changing the chemical structure of cyclomedtalating ligands. All complexes exhibit low cytotoxicity to living cells and exhibit cell membrane permeability and specific staining of cytoplasm. They enter the cells by the mechanism of energy-independent passive diffusion mechanisms. More importantly, complex 7 can act as a two-photon phosphorescent cellular probe, and fluorescence lifetime imaging microscopy is successfully applied for bioimaging in the presence of short-lived background fluorescence. We developed two excellent optical probes for CO2 detection in Chapter 3. The first one for the CO2 detection is a phosphorescent probe based on an iridium(III) complex with 2-phenylimidazo-[4,5-f][1,10]phenanthroline. After bubbling CO2 into the detection solution, the quenched phosphorescence by the addition of CH3COO can be recovered. Photobleaching experiment demonstrates that this phosphorescent CO2 probe shows higher photostability than some of the reported organic probes. More importantly, the time-resolved PL experiment demonstrates that this probe can be used to detect CO2 in the presence of strong background fluorescence, which improves the sensitivity and signal-to-noise ratio of the sensor in complicated media. The second one is a water-soluble fluorescent probe based on tetraphenylethene derivative. After bubbling CO2 into the detection solution, remarkable color change and fluorescence enhancement could be observed. The response of this probe to CO2 in aqueous solution is fast and the detection limit is about 2.4 × 106 M. To emphasize the practical application of this probe, a porous film was successfully fabricated by mixing the dye with sodium carboxymethyl cellulose in water, which can serve as an efficient CO2 gas sensor. More importantly, this probe exhibits low cytotoxicity towards live cells and has the ability to monitor the external CO2 concentration changes of living cells. Chapter 4 focused on the development of novel soft salt based phosphorescent probe. This type of probe consists of two oppositely charged ionic complexes with two distinguishable emission colors, which makes it a perfect candidate as a ratiometric probe. The emission color of 10 changes from blue to red with increasing pH value. 10 is cell-permeable and exhibits low cytotoxicity, and it has been successfully applied for ratiometric pH imaging with the use of confocal microscopy, demonstrating its great potential for intracellular environment monitoring. Furthermore, phosphorescence lifetime imaging experiments can detect intracellular pH variations by photoluminescence lifetime measurements, which allowed for eliminating background fluorescence and selecting long-lived phosphorescence images. Quantitative measurement of intracellular pH fluctuations caused by oxidative stress has been successfully carried out for 10 based on the pH-dependent calibration curve. A series of cationic Zn(II) complexes has been designed and synthesized in chapter 5. The photophysical properties of these Zn(II) complexes are affected by the counterions. By altering the counterions, the emission peak can be changed from 549 nm to 622 nm. Interestingly, the CIE coordinate and the emission colors can be simply tuned by adjusting the concentration of 11d in the polyether. Under an electric field of about 15 V applied onto the electrodes, the emission color of the solution of 11b-11d near the cathode changed its original emission color to sky blue. Based on this interesting electrochromic fluorescence of 11d, a quasi-solid information recording device has been successfully designed. Furthermore, data encryption has been realized by combining 1d with BODIPY, and information decoding processed has been accomplished, for the first time, by employing TPA excitation techniques, in which the large TPA cross section of 11d is differentiated from small TPA cross section of common organic dyes. Finally, Chapters 6 and 7 present the concluding remarksand the experimental details of the work described in Chapters 25
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McMeeking, Graham Donald. "Deposition and characterisation of nickel oxide based coatings for advanced glazing applications." Thesis, Oxford Brookes University, 1997. http://radar.brookes.ac.uk/radar/items/dbc17ff5-9a46-895e-1cf3-925fd43fa47b/1.
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This thesis is a comparative study of nickel oxide based thin films for use as a counter electrode in a variable transmittance electrochromic device. Coatings have been prepared using anodic electrodeposition, colloidal precipitation and radio frequency (r.f.) sputtering. Systematic studies of the effect of deposition process parameters on optical and electrochromic properties of such films have been undertaken. Optimum conditions for the deposition of coatings deposited by colloidal and anodic deposition have been determined. A novel process for the colloidal deposition of electrochromic a-Ni(OH)2 coatings using a simple one dip process is reported. Also the electrochromic properties of coatings anodically deposited from aqueous solutions containing NiS04 and NH40H were improved by the addition of the non-ionic surfactant polyoxyethylene sorbitan monolaurate. Spectroscopic and electrochemical analytical techniques were used to identify the chemical composition of the coloured and bleached states. It was found using Fourier transform infra-red spectrophotometry (FTIR) that coatings deposited by anodic and colloidal deposition contained f3-Ni(OH)2 and a-Ni(OH)2 respectively in the as-deposited and transparent states. For coatings deposited by both techniques 13 or y-NiOOH was detected in the coloured state using FTIR. Using Raman spectroscopy, y-NiOOH was detected in the coloured state for coatings deposited by anodic deposition from solutions containing the additive polyoxyethylene sorbitan monolaurate. I3-Ni(OH)2 was also detected in the transparent state of r.f. sputtered coatings that were electrochemically cycled in 1M KOH(aq). Using cyclic voltammetry the oxidation of nickel hydroxide to the oxyhydroxide was detected during colouration for coatings produced using anodic electrodeposition, colloidal precipitation and r.f. sputtering (after cycling sputtered films for 1 hour in 1M KOH(aq)). This information has been compared for films prepared using the different deposition techniques to enable the respective colouration mechanisms to be elucidated. Prototype electrochromic devices have been constructed and their performances assessed. It can be concluded that nickel oxide based coatings can be used as suitable counter electrodes for hydrated electrochromic devices.
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Wei, Guang. "Lithium cobalt oxide thin films : preparation and characterization for electrochromic applications /." Thesis, Connect to Dissertations & Theses @ Tufts University, 1991.
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Thesis (Ph.D.)--Tufts University, 1991.Submitted to the Dept. of Electrical Engineering (Electro-Optics Option). Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Baran, Derya. "Electrochromic And Photovoltaic Applications Of Benzotriazole Bearing Donor Acceptor Type Conjugated Polymers." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611593/index.pdf.
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Organic semi-conductors are of great interest since these compounds can be utilized as active layers in many device applications such as ECDs, LEDs and solar cells. Incorporating the benzotriazole units into the polymer backbone enhances the optical properties of donor units. Hexyl thiophene and pyrrole are commonly used as electron donor materials. Benzotriazole can be coupled to hexyl thiophene or pyrrole to yield materials which can be polymerized to give donor acceptor type polymers. These materials are promising components in fast switching polymeric electrochromic devices and highly efficient photovoltaic devices. During thesis studies,poly(2-dodecyl-4,7-bis(4-hexylthiophen-2-yl)-2H-benzo[d][1,2,3]triazole) (PHTBT) and poly(2-dodecyl-4,7-di(1H-pyrrol-2-yl)- 2H- benzo [d] [1,2,3] triazole) (PPyBT) will be synthesized via N-alkylation, bromination, stannylation and Stille coupling reactions. Electrochromic and photovoltaic properties of the polymers will be investigated in detail.
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Deininger, James J. "Synthesis of pi conjugated polymers for use in photovoltaic and electrochromic applications." Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53873.
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Conjugated polymers are currently being used for a wide range of electronic applications. In this thesis, we studied two different synthetic approaches that lead to novel monomers and polymers that can be potentially used in electrochromic, or photovoltaic devices. The first approach described in this thesis is the utilization of olefin cross metathesis to create a family of dithienogermole (DTG) monomer derivatives in which synthetic control of the solubilizing side chains is achieved through an alkenyl building block. This alkenyl intermediate allows one to functionalize the DTG moiety though olefin cross metathesis to obtain a wide range of alkyl chain lengths and pendant functionalities on the polymer backbone. This work lead to the first example in the literature in which the synthesis of DTG moieties was not limited by the chain length of the solubilizing alkyl units. It provides a route that avoids the use of distillation for the purification the DTG monomer, allowing for the synthesis of a wide range of DTG derivatives that were previously unobtainable though the conventional synthetic methods. Finally, in this thesis we also describe the work of the use of direct (hetero)arylation polymerizations (DHAP) as a means of obtaining 3,4-propylenedioxythiophene-based conjugated polymers for use in electrochromic applications. This synthetic method offers a rapid route to achieving polymers in high yields with simplified purification procedures and low residual metal content, as determined by inductive coupled plasma-mass spectrometry (ICP-MS). The studied polymers possess comparable electrochromic properties to those previously reported by the Reynolds group, implying that their switching ability from a colored to a transmissive state is independent of the residual metallic impurities.
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Jain, Vaibhav. "Applications of Layer-by-Layer Films in Electrochromic Devices and Bending Actuators." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/28907.
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This thesis presents work done to improve the switching speed and contrast performance of electrochromic devices. Layer-by-Layer (LbL) assembly was used to deposit thin electrochromic films of materials ranging from organic, inorganic, conducting polymers, etc. The focus was on developing new materials with high contrast and long lifecycles. A detailed switching-speed study of solid-state EC devices of already-developed (PEDOT (Poly(3,4-ethylenedioxythiophene)), polyviologen, inorganic) materials and some new materials (Prodot-Sultone) was performed. Work was done to achieve the optimum thickness and number of bilayers in LbL films resulting in high-contrast and fast switching. Device sizes were varied for comparison of the performance of the lab-made prototype device with the commercially available â small pixelâ size displays. Symmetrical EC devices were fabricated and tested whenever conducting polymers are used as an EC material. This symmetrical configuration utilizes conducting polymers as an electroactive layer on each of two ITO-coated substrates; potential is applied to the two layers of similar conducting polymers and the device changes color from one redox state to another. This method, along with LbL film assembly, are the main factors in the improvement of switching speed results over already-published work in the literature. PEDOT results show that EC devices fabricated by LbL assembly with a switching speed of less than 30 ms make EC flat-panel displays possible by adjusting film thickness, device size, and type of material. The high contrast value (84%) for RuP suggests that its LbL films can be used for low-power consumption displays where contrast, not fastest switching, is the prime importance.
In addition to the electrochromic work, this thesis also includes a section on the application of LbL assembly in fabricating electromechanical bending actuators. For bending actuators based on ionic polymer metal composites (IPMCs), a new class of conductive composite network (CNC) electrode was investigated, based on LbL self-assembled multilayers of conductive gold (Au) nanoparticles. The CNC of an electromechanical actuator fabricated with 100 bilayers of polyallylamine hydrochloride (PAH)/Au NPs exhibits high strain value of 6.8% with an actuation speed of 0.18 seconds for a 26 µm thick IPMC with 0.4 µm thick LbL CNCs under 4 volts.Ph. D.
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BLANC, BRUDE CHRISTOPHE. "Etude d'une pile metal/gel/halogene application a l'affichage electrochrome." Paris 6, 1997. http://www.theses.fr/1997PA066027.
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Une pile metal/gel/halogene est utilisee pour realiser des afficheurs electrochromes. L'application d'une difference de potentiel entre l'electrode transparente et conductrice de dioxyde d'etain et la contre-electrode de carbone micro-cristallin entraine la reduction de cations bi#i#i#i en bi a la premiere, et l'oxydation d'anions br#- en br#3#- a la seconde. L'electrolyte supporte par une matrice cellulosique, contient les cations bi#i#i#i et cu#i#i dont nous avons determine l'etat fortement complexe par br#-. Le cation cu#i est stable dans ce milieu. Le domaine de stabilite de l'electrode de dioxyde d'etain en polarisation cathodique est limite a -0,7 v/ecs, potentiel auquel sn#i#v est reduit en sn. Le domaine de polarisation anodique ne conduit pas a la corrosion de l'electrode. Un electrolyte contenant comme seul sel metallique bicl#3 permet un depot de bi amorphe dont on montre que la reoxydation n'est pas totale. La presence du couple cu#i#i/cu#i permet la reoxydation complete. En effet au potentiel ou cu#i est oxyde en cu#i#i, ce dernier oxyde spontanement tous les cristallites residuels de bi en bi#i#i#i. Il est en outre montre que la partie gelifiee de l'electrolyte n'altere pas les reactions electrochimiques precedentes. De plus l'abaissement de la teneur en eau de l'electrolyte de 70% a 30% en poids rend le systeme cu#i#i/cu#i rapide, avec un effet benefique sur l'oxydation complete de bi. L'oxydation des ions bromure en br a l'electrode de carbone est rapide et ne limite pas les echanges a l'electrode de sno#2#-#x, f#x, lorsque celles-ci sont assemblees pour constituer l'afficheur. L'etude en cellule electrochimique avec electrode de reference a permis de determiner precisement les differences de potentiel de commande de l'afficheur. Il est ainsi possible d'ajuster la composition de l'electrolyte en cellule electrochimique classique en prevoyant les caracteristiques d'ecran qui en decoulent, ainsi que les differences de potentiel de commande qui lui sont le mieux adaptees. On montre qu'il est possible de suivre le procede de fabrication d'un afficheur par voltammetrie. Cette methode permet d'identifier certains dysfonctionnements de l'afficheur des leur apparition, ainsi que de comparer plusieurs afficheurs entre eux ou le comportement d'un meme afficheur au cours d'un test de duree de vie.
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Shahi, Sandeep Kaur. "The synthesis and testing of fast switching, novel conjugated polymers for electrochromic applications." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28503.
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Modern technology is an essential aspect of our everyday lifestyle being vitally important to lighting, mobile phones, laptops, toys etc. The majority of these gadgets concentrate on visual electronic displays as a key selling feature. Hence, industry is in constant competition to excel while delivering new consumer demands of higher colouration efficiency, faster response times, inexpensive yet robust hardware, flexible displays and with the possibility of incorporating electronics into textiles. Traditionally, inorganic small molecules were extensively used for optical displays devices such as cathode ray tubes, liquid crystal displays, light emitting diiodes [sic] and plasma screens. However, in the past decade, significant progress in polymer electrochromism has shown many organic electroactive polymers to have the potential to satisfy the above consumer demands. Electrochromic materials (EC) have the ability to undergo a reversible colour transformation switch upon electrochemical doping, such as colour bleaching transformations. Herein, this thesis discusses how organic chemistry facilitates the advantage of structurally modifying monomeric heterocyclics to fine tune materials with interesting optical and physical properties. The polymeric form of an teraryl monomer containing a 1,4-dithiin-furan illustrated superior switching performances and electrochromic properties when compared to its parent poly 3,4-ethylene dioxythiophene (PEDOT). Poly(dithienylfuran) films displayed fast switching and reversible colour transformation at high colour contrast (CE = 212 cm2 C-1 cf. 183 cm2 C_1 for PEDOT at 95% optical switch). Formerly overlooked furan materials in organic electronics was revisted here, in which a polyfuran substituted at the 2,3-positions with an S-alkylated dithiin unit, was studied. The employment of the dithiin moiety provides intrinsic additional electroactivity, as well as a functional handle for substitution with alkyl groups, enhancing the processability of the polymer. The new polymer is compared with the closely related and well-established literature compounds PEDOT and PEDTT as well-studied, highly chalcogenated polythiophenes. The electrochromism phenomenon is not only of importance for visual optical displays but also has the potential for extended application in telecommunications with electromagnetic responses into the near infra-red (NIR) region. Herein, describe a series of symmetric and asymmetric chalcogenated azomethine monomers, robustly exherting electrochemical activity within the NIR.
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Thompson, Barry C. "Variable band gap poly(3,4-alkylenedioxythiophene)-based polymers for photovoltaic and electrochromic applications." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009960.
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Costa, Cláudia Brito da. "Printed electronics for ubiquitous computing applications." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/9317.
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Dissertação para obtenção do Grau de Doutor em
QuímicaThis Ph.D. project is focused on the synthesis of functional inorganic materials, their formulation into inks and their deposition using inkjet printing on non-conventional substrates, such as paper, with the ultimate goal of advancing the state-of-the-art in the area of printed electrochromic displays. Other materials, inks,techniques and substrates were also explored. The first step in building a printed electrochromic display is to synthesize the functional materials necessary for the different layers of the device; this part of the work focused on inorganic electrochromic materials (tungsten oxide and vanadium oxide) and on transparent conductive oxides (TCO). ATO(antimony tin oxide) was synthesized using the Pechini method and the results obtained were promising. Tungsten oxide and vanadium oxide nanoparticles were also synthesized via a sol-gel route. FTIR,Raman and X-ray diffraction spectroscopic measurements showed that tungsten oxide nanoparticles synthesized via sol-gel are mainly in an amorphous state, with hexagonal crystalline domains, and allowed the analysis of the hydration extent of those nanoparticles. Vanadium oxide gel synthesized in this work is similar to those previously described in the literature, consisting of V2O5.6H2O, with microstructures similar to orthorhombic V2O5, while Raman spectroscopy also showed the presence of amorphous domains. The nanoparticle sizes were measured combining Dynamic Light Scattering, sedimentation and microscopic techniques (AFM and TEM). Tungsten oxide particles presented an average nanoparticle size between 160 and 200 nm, and vanadium oxide of 60 nm. The nanoparticles were used to produce ink formulations for application in inkjet printing. In addition to tungsten oxide and vanadium oxide, other electrochromic materials were printed. This part of the work examined the possibility of inkjet printing several organic (poly(thiophene)s) and inorganic electrochromic materials (metal oxides and metal hexacyanometallates) and also evaluated the performance of the resulting electrochromic devices. Poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate), poly(3-hexylthiophene), tungsten oxide, vanadium oxide and Prussian blue were inkjet printed on flexible substrates, such as plastic and paper. Solid-state electrochromic devices were assembled at room temperature on plastic and on paper substrates, without sintering the printed films, showing, in some cases, excellent contrast between the on and off state. The tungsten oxide and vanadium oxide devices were then tested through spectroelectrochemistry by Visible/NIR absorption spectroscopy. Tungsten oxide showed a dual spectroscopic response depending on the applied voltage and vanadium oxide presented several redox steps, which give rise to a variety of color transitions, also as a function of the applied voltage. Color space analysis was used to characterize the electrochromic transitions; monitorization of the color contrast and cycling tests, as well as techniques such as cyclic voltammetry, were also used to characterize device performance.
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Shen, Jue. "Interactive RFID for Industrial and Healthcare Applications." Doctoral thesis, KTH, Industriell och Medicinsk Elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174380.
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This thesis introduces the circuit and system design of interactive Radio-Frequency Identification (RFID) for Internet of Things (IoT) applications. IoT has the vision of connectivity for anything, at anytime and anywhere. One of the most important characteristics of IoT is the automatic and massive interaction of real physical world (things and human) with the virtual Internet world.RFID tags integrated with sensors have been considered as one suitable technology for realizing the interaction. However, while it is important to have RFID tags with sensors as the input interaction, it is also important to have RFID tags with displays as the output interaction.Display interfaces vary based on the information and application scenarios. On one side, remote and centralized display interface is more suitable for scenarios such as monitoring and localization. On the other side, tag level display interface is more suitable for scenarios such as object identification and online to offline propagation. For tag level display, though a substantial number of researches have focused on introducing sensing functionalities to low power Ultra-High Frequency (UHF) RFID tags, few works address UHF RFID tags with display interfaces. Power consumption and integration with display of rigid substrate are two main challenges.With the recent emerging of Electronic Paper Display (EPD) technologies, it becomes possible to overcome the two challenges. EPD resembles ordinary ink on paper by characteristics of substrate flexibility, pattern printability and material bi-stability. Average power consumption of display is significantly reduced due to bi-stability, the ability to hold color for certain periods without power supplies. Among different EPD types, Electrochromic (EC) display shows advantage of low driving voltage compatible to chip supply voltage.Therefore this thesis designs a low power UHF RFID tag integrated in 180 nm CMOS process with inkjet-printed EC polyimide display. For applications where refresh rate is ultra-low (such as electronic label in retailing and warehouse), the wireless display tag is passive and supplied by the energy harvested from UHF RF wave. For applications where refresh rate is not ultra-low (such as object identification label in mass customized manufacturing), the wireless display tag is semi-passive and supplied by soft battery. It works at low average power consumption and with out-of-battery alert. For remote and centralized display, the limitations of uplink (from tags to reader) capacity and massive-tag information feedback in IoT scenarios is the main challenge. Compared to conventional UHF RFID backscattering whose data rate is limited within hundreds of kb/s, Ultra-wideband (UWB) transmission have been verified with the performance of Mb/s data rate with several tens of pJ/pulse energy consumption.Therefore, a circuit prototype of UHF/UWB RFID tag replacing UHF backscattering with UWB transmitter is implemented. It also consists of Analog-to-Digital Converter (ADC) and Electrocardiogram (ECG) electrodes for healthcare applications of real-time remote monitoring of multiple patients ECG signals. The ECG electrodes are fabricated on paper substrate by inkjet printing to improve patient comfort. Key contribution of the thesis includes: 1) the power management scheme and circuit design of passive UHF/UWB RFID display tag. The tag sensitivity (the input RF power) is -10.5 dBm for EC display driving, comparable to the performance of conventional passive UHF RFID tags without display functions, and -18.5 dBm for UWB transmission, comparable to the state-of-the-art performance of passive UHF RFID tag. 2) communication flow and circuit design of UHF/UWB RFID tag with ECG sensing. The optimum system throughout is 400 tags/second with 1.5 KHz ECG sampling rate and 10 Mb/s UWB pulse rate.QC 20151012
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Nemani, Srinivasa Kartik. "Developing Engineered Thin Films for Applications in Organic Electronic and Photonic Devices." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo154470406813256.
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Valyukh, Iryna. "Optical Characterization and Optimization of Display Components Some Applications to Liquid-Crystal-Based and Electrochromics-Based Devices /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-107429.
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GIRON, JEAN-CHRISTOPHE. "Couches minces d'hydroxyde de nickel et d'oxydes mixtes nickel/lithium et nickel/sodium. Application aux systemes electrochromes." Paris 6, 1994. http://www.theses.fr/1994PA066373.
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La premiere partie de ce memoire est consacree a l'etude, par effet mirage, des flux ioniques mis en jeu lors de l'oxydo-reduction, dans une solution alcaline, d'un film d'hydroxyde de nickel electrodepose. La seconde partie concerne la croissance par ablation laser et par pulverisation magnetron de films d'oxydes mixtes nickel/lithium et nickel/sodium. Leur structure, leurs proprietes electrochimiques et leurs caracteristiques electrochromes ont ete etudiees par diverses techniques (diffraction x, microscopie electronique en transmission, spectroscopie infrarouge a transformee de fourier, xps, voltammetrie cyclique,). Finalement, un dispositif electrochrome incorporant un film d'oxyde de tungstene et un film d'oxyde mixte nickel/lithium a ete realise et ses performances ont ete caracterisees
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Gunbas, Gorkem E. "Novel Donor-acceptor Type Polymers Towards Excellent Neutral State Green Polymeric Materials For Realization Of Rgb Based Electrochromic Device Applications." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12609002/index.pdf.
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Polymers having one of the three complementary colors (red, green, and blue) in the reduced state and high transmissivity in the oxidized state are key materials towards use in electrochromic devices and displays. Although many neutral state red and blue polymers were reported up to date, neutral state green polymeric materials appear to be limited. For potential application of electrochromic materials in display technologies, one should have to create the entire color spectrum and this can be only achieved by having materials with additive or subtractive primary colors in their neutral states. To obtain a green color there should be at least two simultaneous absorption bands. Although the neutral state color is of great importance, the transmittance in the oxidized state is crucial too. The materials having one of the three primary colors should also possess highly transmissive oxidized states in order to be used in commercial electrochromic device applications. Donor-acceptor molecules lead to lower band gap due to resonances that enable a stronger double bond character between the donor and acceptor units. The materials with low band-gaps produce cathodically coloring polymers due to the lower energy transition in the doped state. Moreover, donor-acceptor type materials commonly show two absorption maxima. Since donor-acceptor approach seems to be the key to the complex nature of producing these materials, novel donor-acceptor type polymers were synthesized, and electrochromic properties were investigated in detail.Additionally a solution-processable donor-acceptor type polymer was realized using method of introducing alkyl side chains in the polymer structures.
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Marque, Pascal. "Proprietes spectroelectrochimiques des couches minces de polythiophenes : application electrochromique." Paris 6, 1988. http://www.theses.fr/1988PA066396.
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Preparation par polymerisation electrolytique de couches minces de polythiophene; les conditions de reaction determinent les proprietes optiques et electrochimiques par action sur notamment la longueur moyenne de conjugaison. Etude du mecanisme d'insertion ionique accompagnant l'oxydoreduction et de la thermodynamique de la reaction, permettant d'etablir les compromis structuraux et fonctionnels pour l'optimisation des performances
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Chen, Shih-ming, and 陳仕銘. "Application of conducting polymers and nanocomposites in electrochromic devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/23470287237697942051.
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碩士國立高雄大學
化學工程及材料工程學系碩士班
102
Nitrogen-doped graphene (NDG)/titanium dioxide (TiO2) nanoparticles were coated on indium tin oxide (ITO) glass substrates to fabricate NDG-TiO2 nanocomposite electrodes. 3-methylthiophene (3MT) was electrochemically deposited on the NDG-TiO2 films to form poly(3-methylthiophene) (P3MT/NDG/TiO2) composite electrochromic electrodes. The introduction of NDG and TiO2 mesoporous films significantly increased the initial maximum optical contrast (ΔT%) to 70 % as compared 41 % of pure ITO electrodes， whereas the P3MT/NDG/TiO2 composite electrodes enhanced the adhesion of P3MT polymers to the NDG/TiO2/ITO substrate， thereby increasing the long-term stability of the corresponding electrochromic devices. After the stability test of 100 cycles, experimental results reveal that P3MT/NDG/TiO2 composite electrodes retained up to 90 % of ΔT%， relative to 70 % remaining ΔT% of pure ITO electrodes. This illustrates the enhanced long-term stability achieved through the introduction of a NDG-TiO2 nanocomposite films in electrochromic devices， and shown that conductive polymer/NDG/TiO2 composite electrodes are well suited to electrochromic devices for the promotion of performance and stability. In comparision to previous part， TiO2 nanoparticle was combined with 2,5-dimethoxyaniline (DMA) and 3-trimethoxysilanyl-propyl-N- aniline (TMSPA) in 1 M HCl aqueous solution for different feed ratios of TMSPA， then deposited P(TMSPA-co-DMA)-TiO2 film on ITO glass using cyclic voltammetry and used as an electrode in an electrochromic. The optical contrast (∆T%) and long-term stability of the device were determined by in-situ UV-visible spectrochronoamperometric studies. Experimental results reveal the introduction of TiO2 nanoparticle enhanced the adhesion of P(TMSPA-co-DMA) copolymer as compared a bare ITO substrate also we found that this system can inhibit the association/condensation effect of TMSPA network on ITO substrate during electrochemical copolymerization. This system speeds up the deposition rate of P(TMSPA-co-DMA) copolymer on the ITO substrate and enhanced long-term stability of P(TMSPA-co-DMA) electrochromic device.
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Hu, Ding Yih, and 胡定毅. "Synthesis and Application Studies on Electrochromic Dye-Lutetium Diphthalocyanine." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/39073415344509000474.
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Chia-Ching, Liao, and 廖家慶. "The Study of Molybdenum Oxide Nanowires Growth and Application on Electrochromic Device." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/97225386278136472630.
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Chen, Yu-Lin, and 陳玉麟. "Application of novel materials for Dye-Sensitized Solar Cells and Electrochromic Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/90949340786241304525.
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碩士國立東華大學
光電工程學系
104
Dye-sensitized solar cell (DSSC) is a low-cost thin-film solar cell. Because it can be fabricated using inexpensive materials, does not need to make with a fine instrument, and can generate electricity under a weak light source, many research teams have involved in the dye-sensitized solar cell research. Electrochromic phenomenon means that under the effect of electric field or electric current, the optical properties of materials such as transmittance, reflectance, and absorption may present a stable and reversible change in the visible wavelength range. The advantage of an electrochromic device is its changable and reversible color and transparency. Electrochromic devices can be used as passive display elements (also commonly known as electrochromic display elements). In recent years, many research teams put their efforts into the research of electrochromic smart windows. There are three parts in this study. First, gel-based electrolytes were produced by mixing PMMA with a liquid-based electrolyte to reduce electrolyte evaporation and leakage, thus extending the life of DSSC devices. By adding lithium bis(trifluoromethanesulphonyl)imide and camphorsulfonic acid into gel-based electrolytes, this study successfully enhanced the conductivity of gel-based electrolytes, further increasing the power conversion efficiency of gel-based DSSCs. The properties of the DSSCs were analyzed by J–V, IPCE, electrochemical impedance, and stability measurements. Second, this study investigated the fabrication technologies and the material properties of the solid-state electrochromic devices. WO3 thin films, NiO thin films, and gel-state electrolyte were prepared and used to fabricate solid-state electrochromic devices. The opticl properties of the electrochromic devices were analyzed. Fhird, novel organic dyes were investigated for DSSC. The J-V curves, IPCE curves, and the EIS of device performance parameters of DSSCs based on these novel organic dyes were analyzed.
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Wu, Jung-Tsu, and 吳榮祖. "Synthesis and Application in Electrochromic DevicesDerived from Novel Multi-Arylamine Based Materials." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/vtgzpp.
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碩士國立臺灣大學
高分子科學與工程學研究所
105
This study has been separated into five chapters. Chapter 1 is the general introduction. Chapter 2 includes the synthesis of electrochromic materials (ECMs) and fabrication of high contrast electrochromic devices (ECDs). Chapter 3 includes five novel polyethers and their basic electrochromic properties. Chapter 4 includes two novel materials derived from the materials in chapter 2, TPPA and TPB and their basic electrochromic materials. The fabrication, basic characterization, electrochromic properties of a novel ECD was investigated and improved. The ECD combined three different kinds of ECMs, TPPA, TPB and HV. By introducing HV as an efficient charge trapping layer, the working voltage could be greatly reduced and the performance of overall system was also enhanced. The ECD without electrolyte exhibits ultra-high contrast from bleached state with transmittance in visible region up to 76% to colored state with transmittance only 1% both in visible region. High ΔL* (86) and ΔT (75% at visible light region) could be achieved by the colorless ECD. Thus, it could be claimed to be a truly “transparent-to-black” ECD, implying high potential of application as shutter for transparent displays and energy saving devices. In the next part, all the polyether films cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited similar oxidation potential and the film also exhibited multi-color at different oxidation state and good reversibility. In the last part, two novel materials exhibited a lower working potential for the first and second oxidation states while the absorption area in the visible light region is broader the origin materials which may lead to better materials for the full absorption electrochromic device.
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I-FanWang and 王逸帆. "Preparation of Titania Nanotube Arrays by Anodization and their Application in Electrochromic Device." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/59133864127170762994.
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Hsiao, Chun-Lung, and 蕭俊龍. "Tungsten Oxide Films Prepared by Radio-Frequency Magnetron Sputtering for Flexible Electrochromic Application." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/n2h342.
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碩士國立虎尾科技大學
光電與材料科技研究所
96
In this study, the tungsten oxide films were deposited on PET/ITO（polyethylene terephthalate / indium tin oxide ; 30Ω/sq.）substrate by RF magnetron sputtering. The electrochromic properties of WO3 thin films were analyzed in a three-electrode cell with a mixture of 1 M LiClO4 and propylene carbonate solution as an electrolyte. The results indicated that the WO3 crystal structure was amorphous at the oxygen flow rate from 5~10 sccm. The optimum condition for electrochromic occurs at the oxygen flow rate of 7sccm. The transmittance difference at 550 nm wavelength (ΔT550 nm) was 64.1% between colored and bleached states, and takes about 51 seconds. The coloration efficiency of the film is 17.65 cm2/C. The reproducibility and the transmission of colored and bleached state were not affected after 300 cycles. Using the AC impedance spectroscopy determined the resistivity variation of WO3 films as a function of frequency from 100 kHz to 1 Hz. The resistivity variation relates with the Li+ ion and electron transport characters at the TCE/WO3 interface. The surface roughness of WO3 films was observed by AFM and concluded a strong effect on the electrochromic properties.
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Santos, Lídia Sofia Leitão. "Engineering of metal oxide nanoparticles for application in electrochemical devices." Doctoral thesis, 2015. http://hdl.handle.net/10362/15429.
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The growing demand for materials and devices with new functionalities led to the increased inter-est in the field of nanomaterials and nanotechnologies. Nanoparticles, not only present a reduced size as well as high reactivity, which allows the development of electronic and electrochemical devices with exclusive properties, when compared with thin films.
This dissertation aims to explore the development of several nanostructured metal oxides by sol-vothermal synthesis and its application in different electrochemical devices. Within this broad theme, this study has a specific number of objectives: a) research of the influence of the synthesis parameters to the structure and morphology of the nanoparticles; b) improvement of the perfor-mance of the electrochromic devices with the application of the nanoparticles as electrode; c) application of the nanoparticles as probes to sensing devices; and d) production of solution-pro-cessed transistors with a nanostructured metal oxide semiconductor.
Regarding the results, several conclusions can be exposed. Solvothermal synthesis shows to be a very versatile method to control the growth and morphology of the nanoparticles.
The electrochromic device performance is influenced by the different structures and morphologies of WO3 nanoparticles, mainly due to the surface area and conductivity of the materials. The dep-osition of the electrochromic layer by inkjet printing allows the patterning of the electrodes without wasting material and without any additional steps.
Nanostructured WO3 probes were produced by electrodeposition and drop casting and applied as pH sensor and biosensor, respectively. The good performance and sensitivity of the devices is explained by the high number of electrochemical reactions occurring at the surface of the na-noparticles.
GIZO nanoparticles were deposited by spin coating and used in electrolyte-gated transistors, which promotes a good interface between the semiconductor and the dielectric. The produced transistors work at low potential and with improved ON-OFF current ratio, up to 6 orders of mag-nitude.
To summarize, the low temperatures used in the production of the devices are compatible with flexible substrates and additionally, the low cost of the techniques involved can be adapted for disposable devices.Fundação para a Ciência e Tecnologia(FCT) - (SFRH/BD/73810/2010)
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Li, Wen-Bin, and 李文斌. "Study of poly(methyl methacrylate)-based polymer electrolyte and its application to electrochromic device." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/56145877850971667740.
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碩士國立高雄應用科技大學
化學工程與材料工程系博碩士班
101
Blended polymer electrolytes with poly(methyl methacrylate) (PMMA) are prepared with various propylene carbonate (PC) plasticizer concentrations and lithium perchlorate (LiClO4) ratio by the solution-casting technique. Fourier transform infrared studies show the evidence of the complexation between PMMA, LiClO4, and PC. The composite polymer electrolytes show good thermal property, which are confirmed by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). LiClO4 is added to the PMMA–PC blend polymer electrolytes as Li-salt to enhance the conductivity, and the highest conductivity obtained is 5×10−4 S/cm at 30 ℃. Electrochromic device is reported by using polyaniline (PANI) doped with poly(styrene sulfonic acid) (PSS) as coloring electrodes and poly(ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as complementary electrodes, and PMMA-based electrolyte as gel electrolyte. Characterizations of the PANI-PSS are performed using Fourier tramsform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XRD), cyclic voltammetric(CV), and UV–vis spectroscopy(UV-vis). The maximim color change of electrochromic device is 41% from pale yellow(−0.5 V) to dark blue (+2.5 V). The improvement of optical properties, such as coloration efficiency and stability on the basis of electrochromic device (PANI doped with PSS and PEDOT-PSS).
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Wu, Cheng Hung, and 吳政鴻. "WO3-Nb2O5 Composite Films Application On Fabrication Of High Contrast Reflection-Type Electrochromic Device." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/58072182846945353270.
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碩士國立聯合大學
光電工程學系碩士班
103
Electrochromism is the phenomenon displayed by some materials of reversibly changing color while a burst of charge is applied. Various types of materials and structures can be used to construct electrochromic devices, depending on the specific applications. The electro-chromatic devices are promising in the application of electronic paper display because they can be operated on low voltage either in the transmission or reflection mode. However, low contrast ratio of the electrochromic display, short life time, poor environmental stability and immature device fabrication process are key drawbacks of the electrochromic devices application; therefore, we attempt to treat the problems mentioned above to improve the performance of electrochromic devices. In this study, the each film of electrochromic device was deposited by fast-alternative bipolar-pulsed magnetron sputtering system. The colored films of WO3-Nb2O5 composite films are deposited by different sputtering powers of the Niobium target and the stationary sputtering powers of the Tungsten. These films mentioned above were measured by visible near-infrared spectrometry and ellipseometer. Moreover, the change of the molecular bond at reversibility and duration was examined by the Raman spectroscopy. The results showed the most obvious changes in the optical constant and the extinction coefficient of the composite WO3-Nb2O5 film was observed while the power of 250 watts at Tungsten and the power of 350 watts at Niobium target. Finally, we use the known refractive index and absorption coefficient of layers of electrochromic device and the concept of the optical multilayer film to design electrochromic reflective device which can be achieved nearly zero reflectance of electrochromic device in colored state. The difference of average reflectance reached 34% in bleached/ colored state to raise contrast ration of reflective display to 25.
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Tseng, Chen-Ya, and 曾晨雅. "On the Electro-Optical Properties of PDMICA Thin Film and Its Application to Electrochromic Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/99455076794488032149.
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碩士國立臺灣大學
化學工程學研究所
100
In this research, the main objective is to analyze the electrochemical properties of a novel conducting polymer, poly(5,6-dimethoxyindole-2-carboxylic acid) (PDMICA), and its electrochromic device assembled with poly(3,4-ethylenedioxythiophene) (PEDOT). In the first part (Chapter 4), the transport phenomena of anions, cations, and water molecules through the film of PDMICA was studied in the electrolytes of LiTFSI, LiNO3, LiI, and NaNO3, by means of electrochemical quartz crystal microbalance (EQCM), intending to throw more light on its electrochromic behavior. Cations do not affect the ion transport, but anions play an important role during the reduction and oxidation of the film. The molar fluxes of anions and water molecules in the film of PDMICA were estimated for LiTFSI and LiNO3. Besides, the number of accompanying water molecules with TFSI- and NO3-, during the redox switching of PDMICA in LiTFSI and LiNO3 were calculated to be 14.7 and 3.4 per TFSI- and NO3-, respectively. In the second part (Chapter 4 and Chapter 5), PDMICA is prepared by electro-polymerization and investigated using in situ spectro-electrochemical analyses, including cyclic voltammertry (CV) and UV-visible (UV-vis) spectroscopy. A significant change from transparent (-0.5 V vs. Ag/AgCl) to green (0.5 V vs. Ag/AgCl) and a reversible electrochromic behavior of PDMICA film are observed when the film is performed in an aqueous solution consisting of 0.1 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1.0 mM hydrochloric acid (HCl). The maximum transmittance change (∆T) and the coloration efficiency (η) of PDMICA film are 15% and 73 cm2/C, respectively, at 520 nm. The PDMICA thin film and a thin film of PEDOT are chosen as an anode and a cathode, respectively, in a complementary manner to form a film-type electrochromic device (ECD). A remarkable absorbance attenuation of this ECD is observed in the visible region. The maximum ∆T of the ECD gives a value of 39% (@583 nm) when the applied potential for the device is switched between -0.5 and 1.0 V (PDMICA vs. PEDOT); the η of this ECD is estimated to be 372 cm2/C at 583 nm.
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HUANG, SHENG-WEI, and 黃聖瑋. "Electrosynthesis of copolymers from carbazole derivatives and dithiophene derivatives and their application in electrochromic devices." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/ggmbse.
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碩士國立高雄科技大學
化學工程與材料工程系
107
Homopolymer (poly(3,6-di(2-thienyl)carbazole)) (P(DTC)) and copolymers (P(DTC-co-BTP), P(DTC-co-BTP2), P(DTC-co-TF), and P(DTC-co-TF2)) were synthesized electrochemically. P(DTC-co-TF) film displayed light yellow at 0.0 V, yellow at 0.4 V, grey-yellow at 0.8 V, and dark grey at 1.2 V in 0.2 M LiClO4/ACN solution. The anodic copolymer P(DTC-co-TF) with DTC/TF = 1/1 feed molar ratio showed high optical contrast (ΔT%) and coloring efficiency (η), measured as 67.3% and 161.6 cm2 C−1 at 870 nm, respectively. Electrochromic devices (ECDs) were constructed using P(DTC), P(DTC-co-BTP), P(DTC-co-BTP2), P(DTC-co-TF), or P(DTC-co-TF2) films as anodic layer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) as cathodic layer, and hybrid polymer electrolytes as gel electrolytes. The spectroelectrochemical properties of five devices were performed using cyclic voltammetry (CV) and UV–Vis spectroscopy. P(DTC-co-TF)/PEDOT-PSS ECD showed yellow at -0.5 V, grey-yellow at 0.0 V, dark purple at 0.8 V, and blue at 2.0 V. Moreover, P(DTC-co-TF)/PEDOT-PSS ECD presented high ΔT (43.4%) and high coloration efficiency (496.0 cm2 C−1) at 627 nm. Five ECDs had satisfactory optical memory and redox stability. One homopolymer (poly(9,9’-(5-bromo-1,3-phenylene)bis(9H-carbazole))) (P(BPC)) and three copolymers P(BPC-co-BTP), P(BPC-co-CPDT), and P(BPC-co-CPDTK) were electrochemical polymerized on ITO electrode. Electrochemical and electrochromic properties of P(BPC), P(BPC-co-BTP), P(BPC-co-CPDT), and P(BPC-co-CPDTK) films were characterized using cyclic voltammetry (CV) and in situ UV-Vis spectroscopy. Spectroelectrochemical properties of polymer films revealed that P(BPC-co-BTP) film is yellow in the reduced state, green in the intermediate state, and blue in highly oxidized state. P(BPC-co-BTP) anodic copolymer showed high optical contrast (ΔT%), and it was measured as 44.5% at 1030 nm. ECDs were fabricated using P(BPC), P(BPC-co-BTP), P(BPC-co-CPDT), and P(BPC-co-CPDTK) as anodic polymer layers, and poly(3,4-ethylenedioxythiophene) (PEDOT) as complementary electrodes, and hybrid polymer electrolytes as gel electrolytes. P(BPC-co-BTP)/PEDOT ECD showed light yellow at 0.0 V, yellowish blue at 0.8 V, and blue at 1.8 V. P(BPC-co-BTP)/PEDOT ECD showed high ∆T (36.2%) at 625 nm, and high coloration efficiency (418.3 cm2 C−1) at 625 nm. Moreover, four ECDs had satisfactory optical memory and redox stability.
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Wei-TingWu and 吳偉庭. "Synthesis of tungsten oxide and its application to electrochromic devices and nonvolatile resistance random access memories." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04331482264745497744.
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Su, Yuan-tsen, and 蘇元岑. "Synthesis of triphenylamine-styrene-based dyes and its application in sensitized solar cells and electrochromic devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/43377652422616115364.
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碩士國立高雄大學
化學工程及材料工程學系碩士班
102
Linking organic dye small molecules are synthesized by linking triphenylamine with styrene structure. Four different methods were employed to synthesize：the Vilsmeier-Haack reaction to link one and two aldehyde groups respectively, the Mizoroki-Heck reaction to link 4-bromobenzaldehyde regarding as a bridge, and the nucleophilic addition and dehydration between the aldehyde groups on TSC1, TSC2, and the methylene of rhodanine-3-acetic acid or 2-isocyanoacetic acid individually by using the Knoevenagel condensation reaction. The above two dyes(STPACA and STPAR) are anchored on the surface of titanium dioxide nanoparticles via the carboxylic acid of dyes by using the self-assembly method. An integration of dye-sensitized solar cells and electrochromic devices was fabricated and subjected to measure the performance of these integrated devices.
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Wu, You-rong, and 吳囿蓉. "Investigation of Nickel Oxide Films Prepared by Magnetron Sputtering for the Application of Solid State Electrochromic Devices." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64418617397625014861.
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碩士國立成功大學
材料科學及工程學系碩博士班
95
Electrochromic materials are being studied for applications involving solar radiation modulation. Thin-film nonstoichiometric nickel oxide (NiOX) is an intercalation electrode with unique electrochemical and optical properties which can be successfully used for improved electrochromic windows. However, the intercalation process of lithium and the application of all solid state devices are not yet fully understood. In this paper, nonstoichiometric nickel oxide thin films were deposited by D.C. magnetron reactive sputtering in various O2 atmospheres (the flow rate range is 3~50sccm). The electrochromic properties of NiOX thin films were brought out using a three-electrode cell system with a 0.1M solution of lithium perchlorate in propylene carbonate. The optical properties, composition and microstructure of NiOX thin films with various O2 flow rate were be determined by UV-visible spectrometer, XPS, X-ray diffraction, and SEM. As the result, all of the films deposited under various O2 flow rate were nonstoichiometric nickel oxide and with Ni+2 and Ni+3. Due to the number of interstitial oxygen atom and Ni3+ increased, the films transmittance decreased with increasing O2 flow rate. The microstructure of the films deposited at 5~50sccm O2 flow rate had NiO (111) preferred orientation which was the most suitable direction for electrochromic properties. They can be found the surface morphology showed the presence of tetrahedral islands structure. At the double intercalation process between lithium ion and electron, the NiOX thin film exited an optimum value of O2 flow rate. When the O2 flow rate was 5sccm the NiOX thin film had a largest transmittance change about 38.8%, and the transmittance of bleach state and color state was 72.5% and 33.7%. The NiOX thin film which had the best electrochromic properties was used as a counter electrochromic layer on the solid electrochromic device with electrochromic layer WO3-y and electrolyte Ta2O5. Then the solid electrochromic device was also studied about its electrochromic properties. As the result, the transmittance change of the device reached 52% when the applied voltage were -4V and 2.2V, and the device had a wider adsorption wavelength range than single layer half device of NiO or WO3. The only fly in the ointment was the poor electric insulation of Ta2O5 thin film resulted in reducing the device memory effect. Therefore, the device memory effect will need to improve further.
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Ching-LinWu and 吳京霖. "Synthesis of Electrochromic Tungsten Oxide Nanostructured Films by Sol-gel Method and its Application to Thermal Shielding." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/35288905008657137909.
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博士國立成功大學
材料科學及工程學系
102
Electrochromic device have the ability to change the transmittance to block the solar radiation by controlling the applied voltage and have the application for energy-saving windows. State-of-the art, the challenges of the device are nanostructured electrodes and large-scale fabricating. In this research, porous tungsten oxide is synthesized by the surfactant-assisted sol-gel method. Porous structure, crystallinity, and composition can be modified by the concentration of surfactant, annealing temperature, and curing condition. The effects of different morphology and structure are studied by chronoampermetry and cyclic voltammetry. Transmittance modulation and coloration efficiencies are 67.6 % and ~60 cm2C-1. It needs less than 10 s to switch from colored state to beach state. All solid electrochromic devices are fabricated by all-solution method. Thermal shielding ability is measured by UV-Vis-IR spectroscopy and illuminating meter. Visible light transmittances and solar heat transmittances are 55.2/35.9 % and 38.2/20.1 % in colored/bleach state respectively. The transmitted illumination can be modulated from 36 % to 16 %. The transmittance in visible light region is higher than 50 % and the ability of blocking infrared is enough to use as energy-saving smart window.
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Guo, Yeping [Verfasser]. "Nanocrystalline sol gel Nb2O5 coatings : preparation, characterisation and application to photovoltaic cell, lithium battery and electrochromic device / von Yeping Guo." 2007. http://d-nb.info/983137501/34.
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Lu, Hsing-Yi, and 呂幸宜. "Electrochemical Synthesis and Electrochromic Application of Polymers from Triphenylamine or Bis(triphenylamine) Derivatives with Triphenylamine or N-Phenylcarbazole End-Cappers." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/cpys2f.
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碩士國立臺北科技大學
化學工程研究所
105
Four electropolymerizable monomers, namely 4,4’-bis(4-diphenylamino- benzamido)-4’’-methoxytriphenylamine [MeOTPA-(TPA)2], 4,4’-bis[4-(carbazol-9- yl)benzamido)-4’’-methoxytriphenylamine [MeOTPA-(NPC)2], bis{N-[4-(4- diphenylaminobenzamido)phenyl]-N’-(4-methoxyphenyl)}-1,4-phenylenediamine [(MeO)2TPPA-(TPA)2] and bis{N-[4-(4-carbazol-9-ylbenzamido)phenyl]-N’-(4- methoxyphenyl)}-1,4-phenylenediamine [(MeO)2TPPA-(NPC)2], were synthesized and characterized by FTIR and 1H NMR spectroscopy, mass spectrometry, elemental analysis, and cyclic voltammetry. The electrochemical polymerization reactions of these MeOTPA-cored and (MeO)2TPPA-cored monomers over indium tin oxide (ITO) electrode allow the generation of electroactiive polymeric films. The electro-generated polymer films exhibited reversible redox processes and multi-colored electrochromic behaviors upon electro-oxidation. The electrochromic films possess high coloration efficiency and good cycling stability. Single-layer electrochromic devices using the electrodeposited polymer films as active layers were fabricated and tested as preliminary investigation for their electrochromic applications.
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HUANG, MING-WEI, and 黃明維. "Synthesis of Copolymers Based on 4,4′-Bis(N-carbazolyl)-1,1′-Biphenyl and Indole-6-Carboxylic Acid for Application of Electrochromic Device." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/46g48n.
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碩士國立高雄應用科技大學
化學工程與材料工程系博碩士班
104
Two homopolymers (poly(4,4′-bis(N-carbazolyl)-1,1′-biphenyl) (PCBP) and poly(indole-6-carboxylic acid) (PI6CA)) and three copolymers (P(CBP1-co-I6CA1), P(CBP1-co-I6CA2), and P(CBP1-co-I6CA4)) with various CBP/I6CA feed molar ratios are electrochemical polymerized on ITO electrode. The P(CBP1-co-I6CA2) can change between yellow in the reduced state and greyish black in the oxidized state. The optical contrast (Tmax, 32.2 %) of P(CBP1-co-I6CA2) film at 767 nm is higher than that of PI6CA at 724 nm (19.3 %). Five dual-type electrochromic devices (ECDs) are fabricated using the CBP- and I6CA-based polymers as coloring layers, and poly(3,4-(2,2-diethylpropylenedioxy)thiophene) (P(ProDOT-Et2)) as the complementary layer with hybrid polymer electrolytes as gel electrolytes. The ECD fabricated using anodic copolymer P(CBP1-co-I6CA2) with a CBP/I6CA feed molar ratio of 1/2 has the highest optical contrast (41.0%) and coloration efficiency (249.27 cm2 C-1) at 587 nm. In addition, this ECD has satisfactory optical memory effect and long-term cycling stability.
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Tsao, Wei-Lun, and 曹瑋倫. "Utilizing Suzuki Coupling Reaction in the Synthesis of Triphenylamine-Based Conjugated Microporous Polymers, Their Electrochemical Properties and Application in Electrochromic Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/45z7ar.
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碩士國立臺灣大學
化學研究所
105
In my study, we use Suzuki coupling reaction to forming a series of triphenylamine-based monomers that have sulfonate segment in the side chain. Due to the sulfonate segment inside, we can add surfactant in solution to let molecules become nanomicelles. The other is triphenylamine group can be polymerized by electropolymerization and so we use this method to obtain conducting microporous polymer films with nano-sized. Because the films have electrochromic properties, we use it to black electrochromic device, which is rarely reported so far.
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Wu, Yurun, and 吳侑潤. "Study Of Dye Sensitized Solar Cell And Electrochromic Deviced Application Of TiO2 Doped ZnO Films By Atmospheric Pressure Plasma Jet Deposition System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/13023515024031069663.
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碩士義守大學
材料科學與工程學系
100
The purpose of this work is to use a self-developed low temperature atmospheric pressure (AP) plasma system with quartz glass- and metal- plasma electrodes to deposit titanium dioxide (TiO2) doped with zinc oxide (ZnO) film on indium doped tin oxide (ITO) conductive glass as dye-sensitized solar cell of the photo-anodes. N719 dyes as well as the iodine ions electrolyte were served as the dye-sensitized solar cell (DSSC) components, and the DSSC devices were analyzed by I-V meters to determine the photovoltaic conversion efficiency. Simultaneously, the films electrochromic properties were studied by the cyclic voltammetry. In the deposition process, it was revealed that the variations of air-compressor pressures and plasma wattages would result in the effective reduction in the films thickness and morphologies. In the deposition of TiO2 doped with ZnO films processes, it was found the film thicknesses increased and porosities decreased as the zinc oxide doping increased. However, the un-doped TiO2 films revealed porous morphologies, and resulted in more dyes absorption and higher photovoltaic conversion efficiency. Under the plasma wattage of 286W with the deposition times of 3 min and 5.5 min, the photovoltaic conversion efficiencies could reach to 2.711% and 4.455%, respectively. The best photovoltaic conversion efficiency could reach to 6.44% by using FTO substrate to replace ITO substrate under the same optimized process parameters. The electrochromic experimental results indicated that the TiO2 films possessed reasonable colouring and bleaching characteristics for the precursor flow rate of 75sccm, the plasma wattage of 154W and the deposition time of 30sec, with argon and oxygen flow rates of 7slm and 200sccm, respectively.
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Sibuyi, Praise. "Nano-rods woâ- δ for electrochromic smart windows applications." Thesis, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1153_1194339960.
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Tungsten oxide is a good electrochromic material which has been used in the construction of smart windows through visible modulation. These smart materials can reversibly change their optical properties with the application of an external voltage. Their ability to lighten and darken on command is ideally suited for energy-efficiency windows. The process itself or the overall reaction should respond in seconds and as quick as possible. The goal of this project was to prepare epitaxial well defined tungsten oxide nanorods by the thermal evaporation technique.