scholarly journals Applications of Electrochromic Copolymers Based on Tris(4-carbazoyl-9-ylphenyl)amine and Bithiophene Derivatives in Electrochromic Devices

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1895 ◽  
Author(s):  
Chung-Wen Kuo ◽  
Jui-Cheng Chang ◽  
Po-Ying Lee ◽  
Tzi-Yi Wu ◽  
Yu-Chang Huang
Keyword(s):  
Indium Tin Oxide ◽  
Switching Time ◽  
Electrochemical Polymerization ◽  
Green Light ◽  
Open Circuit ◽  
Electrochromic Devices ◽  
Light Yellow ◽  
Redox Stability ◽  
Transmittance Change ◽  
Dark Blue

Four copolymers (P(tCz (tris(4-carbazoyl-9-ylphenyl)amine)-co-bTP (2,2'-bithiophene)), P(tCz-co-CPDT (4H-cyclopenta[2,1-b:3,4-b’]dithiophene)), P(tCz-co-DTC (3,6-di(2-thienyl)carbazole)), and P(tCz-co-CPDTK (cyclopentadithiophene ketone))) are deposited on indium tin oxide (ITO) surfaces using electrochemical polymerization. Spectroelectrochemical properties of copolymer electrodes reveal that the colors of P(tCz-co-bTP) film are pinkish-orange, light olive green, light grayish blue, and dark blue at 0.0, 0.8, 1.2, and 1.6 V, respectively, whereas the color variations of P(tCz-co-CPDTK) film are light yellow, yellow, and blue at 0.0 V, 0.8 V, and 1.5 V, respectively. The ΔT of P(tCz-co-bTP), P(tCz-co-CPDT), P(tCz-co-DTC), and P(tCz-co-CPDTK) films are estimated to be 43.0% at 967 nm, 28.7% at 864 nm, 43.6% at 870 nm, and 24.5% at 984 nm, respectively. Five electrochromic devices (ECDs) are assembled using the tCz-based homopolymer and copolymers as coloring electrodes, and poly(2,2-dimethyl-3,4-propylenedioxythiophene) (PProDOT-Me2) as the complementary electrode. P(tCz-co-DTC)/PProDOT-Me2 ECD reveals high transmittance change (45.9% at 624 nm), P(tCz-co-CPDTK)/PProDOT-Me2 ECD shows high η (513.0 cm2 C−1 at 582 nm), and P(tCz-co-bTP)/PProDOT-Me2 ECD presents short switching time (less than 0.4 s) at 628 nm. Moreover, these ECDs show satisfactory redox stability and open circuit stability.

scholarly journals Applications of Copolymers Consisting of 2,6-di(9H-carbazol-9-yl)pyridine and 3,6-di(2-thienyl)carbazole Units as Electrodes in Electrochromic Devices

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1251 ◽  
Author(s):  
Chung-Wen Kuo ◽  
Jui-Cheng Chang ◽  
Yu-Ting Huang ◽  
Jeng-Kuei Chang ◽  
Li-Ting Lee ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Switching Time ◽  
Electrochemical Polymerization ◽  
Redox Cycling ◽  
Electrochromic Devices ◽  
Optical Contrast ◽  
Cathodic Material ◽  
Redox States ◽  
Coloration Efficiency

A series of carbazole-based polymers (PdCz, P(dCz2-co-dTC1), P(dCz2-co-dTC2), P(dCz1-co-dTC2), and PdTC) were deposited on indium tin oxide (ITO) conductive electrodes using electrochemical polymerization. The as-prepared P(dCz2-co-dTC2) displayed a high ΔT (57.0%) and multichromic behaviors ranging from yellowish green, greenish gray, gray to purplish gray in different redox states. Five organic electrochromic devices (ECDs) were built using dCz- and dTC-containing homopolymers and copolymers as anodic materials, and poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProdot-Me2) as the cathodic material. The P(dCz2-co-dTC2)/PProdot-Me2 ECD presented remarkable electrochromic behaviors from the bleached to colored states. Moreover, P(dCz2-co-dTC2)/PProdot-Me2 ECD displayed a high optical contrast (ΔT, 45.8%), short switching time (ca. 0.3 s), high coloration efficiency (528.8 cm2 C−1) at 580 nm, and high redox cycling stability.

scholarly journals Electrochromic Properties of Lithium-Doped Tungsten Oxide Prepared by Electron Beam Evaporation

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 191 ◽  
Author(s):  
Jui-Yang Chang ◽  
Ying-Chung Chen ◽  
Chih-Ming Wang ◽  
Wen-Nan Wang ◽  
Chih-Yu Wen ◽  
...  
Keyword(s):  
Electron Beam ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Cathode Materials ◽  
Room Temperature ◽  
Electron Beam Evaporation ◽  
Electrochromic Devices ◽  
Electrochromic Properties ◽  
Coloration Efficiency ◽  
Transmittance Change

In this study, xLi2O-(1−x)WO3 powders were mixed with WO3 and Li2O and pressed into target pellets to fabricate electrochromic films on indium tin oxide (ITO) glasses prepared by electron beam evaporation under the parameters of room temperature, and thicknesses of about 530 nm. It was expected that the amount of charge stored in the electrochromic devices (ECDs) could be enhanced by using the doping method in the cathode materials. The experimental results show that as the composition of Li0.18W0.82O2.6 powder was formed, the optimal characteristics of ECD can be obtained. In which, as a voltage of 3.5 V was applied on ECD, a transmittance change (ΔT%) of 53.1%, an optical density (ΔOD) of 0.502, an intercalation charge (Q) of 12.9 mC/cm2 and a coloration efficiency (η) of 41.6 cm2/C at a wavelength of 550 nm can be achieved. These results demonstrate that Li2O doping in WO3 films could effectively improve the coloration and electrochromic properties of ECD devices.

scholarly journals Electrodeposited Copolymers Based on 9,9′-(5-Bromo-1,3-Phenylene)Biscarbazole and Dithiophene Derivatives for High-Performance Electrochromic Devices

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1136
Author(s):  
Chung-Wen Kuo ◽  
Jui-Cheng Chang ◽  
Jeng-Kuei Chang ◽  
Sheng-Wei Huang ◽  
Pei-Ying Lee ◽  
...  
Keyword(s):  
High Performance ◽  
Electrochemical Polymerization ◽  
Fast Response ◽  
Electrochromic Device ◽  
Benzene Derivative ◽  
Electrochromic Devices ◽  
Coloration Efficiency ◽  
Optical Circuit ◽  
Transmittance Change ◽  
Grey Iron

A 1,3-bis(carbazol-9-yl)benzene derivative (BPBC) was synthesized and its related homopolymer (PBPBC) and copolymers (P(BPBC-co-BT), P(BPBC-co-CDT), and P(BPBC-co-CDTK)) were prepared using electrochemical polymerization. Investigations of polymeric spectra showed that PBPBC film was grey, iron-grey, yellowish-grey, and greyish-green from the neutral to the oxidized state. P(BPBC-co-BT), P(BPBC-co-CDT), and P(BPBC-co-CDTK) films showed multicolor transitions from the reduced to the oxidized state. The transmittance change (DT) of PBPBC, P(BPBC-co-BT), P(BPBC-co-CDT), and P(BPBC-co-CDTK) films were 29.6% at 1040 nm, 44.4% at 1030 nm, 22.3% at 1050 nm, and 41.4% at 1070 nm. The coloration efficiency (η) of PBPBC and P(BPBC-co-CDTK) films were evaluated to be 140.3 cm2 C−1 at 1040 nm and 283.7 cm2 C−1 at 1070 nm, respectively. A P(BPBC-co-BT)/PEDOT electrochromic device (ECD) showed a large DT (36.2% at 625 nm) and a fast response time (less than 0.5 s), whereas a P(BPBC-co-CDTK)/PEDOT ECD revealed a large η (534.4 cm2 C–1 at 610 nm) and sufficient optical circuit memory.

scholarly journals Textile Based Electrochromic Cells Prepared with PEDOT: PSS and Gelled Electrolyte

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5691
Author(s):  
Carsten Graßmann ◽  
Maureen Mann ◽  
Lieva Van Langenhove ◽  
Anne Schwarz-Pfeiffer
Keyword(s):  
Titanium Dioxide ◽  
Switching Time ◽  
Low Voltage ◽  
Spray Coating ◽  
Charge Carriers ◽  
Electrochromic Devices ◽  
Host Matrix ◽  
Ion Storage ◽  
Dark Blue ◽  
Reduced State

Electrochromic devices can act as passive displays. They change their color when a low voltage is applied. Flexible and bendable hybrid textile-film electrochromic devices with poly-3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS) were prepared on polyethylene polyethylene terephthalate (PEPES) membranes using a spray coating technique. The electrolyte consisted of a gelatin glycerol mixture as host matrix and calcium chloride. Titanium dioxide was used as an ion storage layer and a carbon containing dispersion was used for the counter electrode on a polyester rip-stop fabric. The sheet resistance of PEDOT:PSS on PEPES was 500 Ohm/sq. A 5 × 5 electrochromic matrix with individually addressable pixels was successfully designed and assembled. The switching time of the pixels was 2 s at a voltage of 2.0 V directly after assembling. The use of titanium dioxide as ion storage also increased the contrast of the dark-blue reduced electrochromic layer. Coloration was not self-sustaining. The PEDOT:PSS layer needed a constant low voltage of at least 0.5 V to sustain in the dark-blue reduced state. The switching time increased with time. After 12 months the switching time was ~4 s at a voltage of 2.8 V. The addition of glycerol into the electrolyte extended the lifetime of a non-encapsulated textile electrochromic cell, because moisture is retained in the electrolyte. Charge carriers can be transported into and out of the electrochromic layer.

scholarly journals Construction of Interface Dipoles by Surface Doping and Their Role in the Open Circuit Voltage in Polymer Solar Cells

2020 ◽  
Vol 02 (02) ◽  
pp. 071-077
Author(s):  
Shiyu Li ◽  
Xinbo Wen ◽  
Jiadong Zhou ◽  
Nan Zheng ◽  
Linlin Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Indium Tin Oxide ◽  
Open Circuit Voltage ◽  
Electrochemical Polymerization ◽  
Polymer Solar Cells ◽  
Open Circuit ◽  
Interface Dipole ◽  
Surface Doping ◽  
Surface Work ◽  
Bilayered Structure

A kind of dipolar interface is realized by surface doping of poly-(3,4-ethylenedioxythiophene) (PEDOT) with tetrafluoro-tetracyano-quinodimethane (F4TCNQ). PEDOT is in situ synthesized by electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) on an indium tin oxide (ITO) electrode, and then F4TCNQ is spin-coated atop the PEDOT layer. Because the LUMO of F4TCNQ is lower than the HOMO of PEDOT, the spontaneous electron transfer from PEDOT to F4TCNQ results in a bilayered structure of PEDOT cations and F4TCNQ anions. Thus, a permanent interfacial dipole is formed in the surface-doping system. The surface doping not only enhances the conductivity of PEDOT, but also increases the surface work function of the electrode. The dipolar film is applied as the anode interface in polymer solar cells (PSCs), and the results show that such an interface dipole plays a very important role in the open circuit voltage (V oc) of the PSCs.

scholarly journals 4-(Trifluoromethoxy)phenyl-Containing Polymers as Promising Anodic Materials for Electrochromic Devices

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1251
Author(s):  
Wen-Hsin Wang ◽  
Jui-Cheng Chang ◽  
Pei-Ying Lee ◽  
Yuan-Chung Lin ◽  
Tzi-Yi Wu
Keyword(s):  
Energy Levels ◽  
Open Circuit ◽  
Side Chain ◽  
Electrochromic Devices ◽  
Electrochromic Polymers ◽  
High Efficient ◽  
Homo And Lumo ◽  
Electrochemical Redox ◽  
Transmittance Change ◽  
Homo And Lumo Energy

Three 4-(trifluoromethoxy)phenyl-based polydithienylpyrroles (PTTPP, P(TTPP-co-DTC), and P(TTPP-co-DTP)) were synthesized electrochemically and their electrochromic behaviors were characterized. The introduction of electron withdrawing trifluoromethoxy unit in the side chain of polydithienylpyrroles (PSNS) decreases the HOMO and LUMO energy levels of PSNS. PTTPP film displays three various colors (grayish-yellow at 0 V, grayish-blue at 1.0 V, and bluish-violet at 1.4 V) from reduced to oxidized states. The optical contrast of PTTPP, P(TTPP-co-DTC), and P(TTPP-co-DTP) electrodes are 24.5% at 1050 nm, 49.0% at 916 nm, and 53.8% at 1302 nm, respectively. The highest η of the PTTPP electrode is 379.64 cm2 C−1 at 1050 nm. Three ECDs based on PTTPP, P(TTPP-co-DTC), or P(TTPP-co-DTP) as anodic film and PProDOT-Et2 as cathodic film were fabricated. PTTPP/PProDOT-Et2 ECD showed high transmittance change (35.7% at 588 nm) and high η (890.96 cm2·C−1 at 588 nm). P(TTPP-co-DTC)/PProDOT-Et2 and P(TTPP-co-DTP)/PProDOT-Et2 ECDs showed high transmittance change, rapid response time, adequate open circuit memory, and good electrochemical redox stability. Based on these findings, this work provides novel insights for appropriate design of high transmittance change and high efficient multi-colored electrochromic polymers.

scholarly journals Electrodeposited Gold Nanostructures for the Enhancement of Electrochromic Properties of PANI–PEDOT Film Deposited on Transparent Electrode

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2778 ◽  
Author(s):  
Anton Popov ◽  
Benediktas Brasiunas ◽  
Anzelika Damaskaite ◽  
Ieva Plikusiene ◽  
Arunas Ramanavicius ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Switching Time ◽  
Transparent Electrode ◽  
Glass Electrode ◽  
Gold Nanostructures ◽  
Oxide Glass ◽  
Electrochromic Devices ◽  
Electrochromic Properties ◽  
Constant Potential ◽  
Indium Tin Oxide Glass

Conjugated polymers (CPs) are attractive materials for use in different areas; nevertheless, the enhancement of electrochromic stability and switching time is still necessary to expand the commercialization of electrochromic devices. To our best knowledge, this is the first study demonstrating the employment of electrodeposited gold nanostructures (AuNS) for the enhancement of CPs’ electrochromic properties when a transparent electrode is used as a substrate. Polyaniline–poly(3,4-ethylenedioxythiophene) (PANI-PEDOT) films were electrodeposited on a transparent indium tin oxide glass electrode, which was pre-modified by two different methods. AuNS were electrodeposited at −0.2 V constant potential for 60 s using both the 1st method (synthesis solution consisted of 3 mM HAuCl4 and 0.1 M H2SO4) and 2nd method (15 mM HAuCl4 and 1 M KNO3) resulting in an improvement of optical contrast by 3% and 22%, respectively. Additionally, when using the 1st method, the coloration efficiency was improved by 50% while the switching time was reduced by 17%. Furthermore, in both cases, the employment of AuNS resulted in an enhancement of the electrochromic stability of the CPs layer. A further selection of AuNS pre-modification conditions with the aim to control their morphology and size can be a possible stepping stone for the further improvement of CPs electrochromic properties.

Electrochromic Properties of the Multicolored Polyaniline Nanofilms

2012 ◽  
Vol 465 ◽  
pp. 91-94
Author(s):  
Ying Bai ◽  
Xin Li ◽  
Jian Xin Du
Keyword(s):  
Electrochemical Polymerization ◽  
Color Variation ◽  
Polymerization Time ◽  
Optical Contrast ◽  
Sem Images ◽  
Light Yellow ◽  
Full Color ◽  
Color System ◽  
Polymerization Method ◽  
Dark Blue

In this paper, electrochemical polymerization method was used to prepare electrochromic PANI films with different thicknesses via changing the polymerization time. It is found that the obtained PANI films are uniform and have good adherence with the ITO bases. Scanning electron microscope (SEM) images further show that the obtained films exhibited the tremella like lamellar structures with the diameter of each leaf about 100nm and the thickness of about 20nm at polymerization time of 8min. Optical electronic tests indicated that the films showed a gradient color variation from pale yellow, light yellow to green, blue-green, blue and dark blue among -0.2V and 1.0V. Furthermore, the color saturation increased and the hues became more abundant as polymerization time extended. The optical contrast ratios (ΔT) firstly increased to the maximum of 35% and then decreased, while the response time became longer. The results illustrate that the different shades of color are probably obtained through electrochemical polymerization method, which is important for the preparation of RGB full color system.

scholarly journals Color Tuning by Oxide Addition in PEDOT:PSS-Based Electrochromic Devices

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 179 ◽  
Author(s):  
Delphin Levasseur ◽  
Issam Mjejri ◽  
Thomas Rolland ◽  
Aline Rougier
Keyword(s):  
Thin Films ◽  
Iron Oxide ◽  
Conducting Polymers ◽  
Applied Voltage ◽  
Oxide Content ◽  
Electrochromic Devices ◽  
Careful Evaluation ◽  
Pedot Film ◽  
Oxide Addition ◽  
Dark Blue

Poly(3,4-ethylenedi-oxythiophene) (PEDOT) derivatives conducting polymers are known for their great electrochromic (EC) properties offering a reversible blue switch under an applied voltage. Characterizations of symmetrical EC devices, built on combinations of PEDOT thin films, deposited with a bar coater from commercial inks, and separated by a lithium-based ionic membrane, show highest performance for 800 nm thickness. Tuning of the color is further achieved by mixing the PEDOT film with oxides. Taking, in particular, the example of optically inactive iron oxide Fe2O3, a dark blue to reddish switch, of which intensity depends on the oxide content, is reported. Careful evaluation of the chromaticity parameters L*, a*, and b*, with oxidizing/reducing potentials, evidences a possible monitoring of the bluish tint.

Thin mesoporous polyaniline films manifesting a water-promoted photovoltaic effect

2013 ◽  
Vol 67 (8) ◽  
Author(s):  
Natalia Gospodinova ◽  
Elena Tomšík ◽  
Julia Romanova
Keyword(s):  
Indium Tin Oxide ◽  
Theoretical Calculations ◽  
Photovoltaic Effect ◽  
Water Environment ◽  
Solvent Polarity ◽  
Open Circuit ◽  
Interpenetrating Network ◽  
Hydrated Ions ◽  
Polyaniline Films ◽  
Oxide Anode

AbstractPhotovoltaic cells composed of thin mesoporous polyaniline films sandwiched between an indium-tin oxide anode and aluminium cathode have been fabricated. The cells show an increase in the photo-generated open-circuit voltage (V oc) from 0.2 V to 0.6 V and stable-in-time V oc generation following the addition of water containing highly hydrated ions, e.g. tap water.We explain the waterpromoted photo-voltaic effect by the polarity of the water environment. Theoretical calculations show that increasing the solvent polarity increases the energy of the electronic transition related to the measured V oc. The stable-in-time V oc generation could be explained by the increase in the lifetime of the excitons as well as by their more efficient dissociation in the interpenetrating network of polyaniline and water. The penetration of water into the mesoporous polyaniline films is promoted by the presence of highly hydrated ions.

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