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 Dual-Cation Electrolytes Crosslinked with MXene for High-Performance Electrochromic Devices

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 874
Author(s):  
Soyoung Bae ◽  
Youngno Kim ◽  
Jeong Min Kim ◽  
Jung Hyun Kim
Keyword(s):  
Ionic Conductivity ◽  
Response Time ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Fast Response ◽  
High Ionic Conductivity ◽  
Electrochromic Device ◽  
Fast Response Time ◽  
Coloration Efficiency ◽  
Conduction Pathway

MXene, a 2D material, is used as a filler to manufacture polymer electrolytes with high ionic conductivity because of its unique sheet shape, large specific surface area and high aspect ratio. Because MXene has numerous -OH groups on its surface, it can cause dehydration and condensation reactions with poly(4-styrenesulfonic acid) (PSSA) and consequently create pathways for the conduction of cations. The movement of Grotthuss-type hydrogen ions along the cation-conduction pathway is promoted and a high ionic conductivity can be obtained. In addition, when electrolytes composed of a conventional acid or metal salt alone is applied to an electrochromic device (ECD), it does not bring out fast response time, high coloration efficiency and transmittance contrast simultaneously. Therefore, dual-cation electrolytes are designed for high-performance ECDs. Bis(trifluoromethylsulfonyl)amine lithium salt (LiTFSI) was used as a source of lithium ions and PSSA crosslinked with MXene was used as a source of protons. Dual-Cation electrolytes crosslinked with MXene was applied to an indium tin oxide-free, all-solution-processable ECD. The effect of applying the electrolyte to the device was verified in terms of response time, coloration efficiency and transmittance contrast. The ECD with a size of 5 × 5 cm2 showed a high transmittance contrast of 66.7%, fast response time (8 s/15 s) and high coloration efficiency of 340.6 cm2/C.

High performance electrochromic devices based on a polyindole derivative, poly(1H-benzo[g]indole)

2015 ◽  
Vol 3 (43) ◽  
pp. 11318-11325 ◽  
Author(s):  
Guangming Nie ◽  
Ling Wang ◽  
Changlong Liu
Keyword(s):  
Response Time ◽  
High Performance ◽  
Optical Memory ◽  
Fast Response ◽  
Electrochromic Devices ◽  
Optical Contrast ◽  
Fast Response Time ◽  
Coloration Efficiency ◽  
Long Term Stability

An ECD based on electrochromic poly(1H-benzo[g]indole) was fabricated. The color of this ECD can switch between green and navy blue with good optical contrast, high coloration efficiency, fast response time, better optical memory and long-term stability.

scholarly journals Flexible and High-Performance Electrochromic Devices Enabled by Self-Assembled 2D TiO2/MXene Heterostructures

2020 ◽  
Author(s):  
Ran Li ◽  
Xiaoyuan Ma ◽  
Jianmin Li ◽  
Jun Cao ◽  
Hongze Gao ◽  
...  
Keyword(s):  
Transition Metal Oxides ◽  
High Performance ◽  
Transparent Electrode ◽  
Fast Response ◽  
Electrochromic Devices ◽  
Large Area ◽  
Smart Windows ◽  
Coloration Efficiency ◽  
Flexible Devices ◽  
Self Assembled

Abstract Transition metal oxides (TMO) are promising electrochromic (EC) materials for applications such as smart windows and displays, yet challenge still exists to achieve good flexibility, high coloration efficiency and fast response simultaneously. MXenes (e.g. Ti3C2Tx) and their derived TMOs (e.g. 2D TiO2) are good candidates for high-performance and flexible EC devices because of their 2D nature and the possibility of assembling them into loosely networked structures. Here we demonstrate flexible, fast, and high-coloration-efficiency EC devices based on self-assembled 2D TiO2/Ti3C2Tx heterostructures, with the Ti3C2Tx layer as the transparent electrode, and the 2D TiO2 layer as the EC layer. Benefiting from the well-balanced porosity and connectivity of these assembled nanometer-thick heterostructures, they present fast and efficient ion and electron transport, as well as superior mechanical and electrochemical stability. We further demonstrate large-area flexible devices which could potentially be integrated onto curved and flexible surfaces for future ubiquitous electronics.

scholarly journals Complementary hybrid electrodes for high contrast electrochromic devices with fast response

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Carsten Kortz ◽  
Alexander Hein ◽  
Marius Ciobanu ◽  
Lorenz Walder ◽  
Egbert Oesterschulze
Keyword(s):  
High Performance ◽  
Response Times ◽  
Fast Response ◽  
Electrochromic Device ◽  
Potential Range ◽  
High Contrast ◽  
Electrochromic Devices ◽  
Fast Switching ◽  
Camera Systems ◽  
Supporting Electrode

Abstract Fast switching ‘transparent-to-black’ electrochromic devices are currently under investigation as potential candidates in modern applications like e-papers or with additional functionality as ultracompact iris or switchable neutral filter in camera systems. However, recent electrochromic devices show either a lack of contrast or slow response times. To overcome these deficiencies we focus on a careful material composition of the colouring hybrid electrodes in our device. We have established a nanoporous Sb-doped SnO$${}_{2}$$ 2 electrode as supporting electrode for chemisorbed electrochromic tetraphenylbenzidine molecules due to its good conductivity in the redox potential range of the molecule. This hybrid electrode was combined with a modified nanoporous TiO$${}_{2}$$ 2 / viologen electrode to realize a high performance, complementary electrochromic device. Fast switching time constants of 0.5 s and concurrently high change in optical density $$\Delta$$ Δ OD = 2.04 at 605 nm confirm our successful concept. The achieved colouration efficiency of 440 cm$${}^{2}$$ 2 C$${}^{-1}$$ − 1 exceeds every high contrast device presented so far.

scholarly journals Flexible and high-performance electrochromic devices enabled by self-assembled 2D TiO2/MXene heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ran Li ◽  
Xiaoyuan Ma ◽  
Jianmin Li ◽  
Jun Cao ◽  
Hongze Gao ◽  
...  
Keyword(s):  
Transition Metal Oxides ◽  
High Performance ◽  
Transparent Electrode ◽  
Fast Response ◽  
Electrochromic Devices ◽  
Large Area ◽  
Smart Windows ◽  
Coloration Efficiency ◽  
Flexible Devices ◽  
Self Assembled

AbstractTransition metal oxides (TMOs) are promising electrochromic (EC) materials for applications such as smart windows and displays, yet the challenge still exists to achieve good flexibility, high coloration efficiency and fast response simultaneously. MXenes (e.g. Ti3C2Tx) and their derived TMOs (e.g. 2D TiO2) are good candidates for high-performance and flexible EC devices because of their 2D nature and the possibility of assembling them into loosely networked structures. Here we demonstrate flexible, fast, and high-coloration-efficiency EC devices based on self-assembled 2D TiO2/Ti3C2Tx heterostructures, with the Ti3C2Tx layer as the transparent electrode, and the 2D TiO2 layer as the EC layer. Benefiting from the well-balanced porosity and connectivity of these assembled nanometer-thick heterostructures, they present fast and efficient ion and electron transport, as well as superior mechanical and electrochemical stability. We further demonstrate large-area flexible devices which could potentially be integrated onto curved and flexible surfaces for future ubiquitous electronics.

scholarly journals Electrosynthesis of Electrochromic Polymer Membranes Based on 3,6-Di(2-thienyl)carbazole and Thiophene Derivatives

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Chung-Wen Kuo ◽  
Jui-Cheng Chang ◽  
Jeng-Kuei Chang ◽  
Sheng-Wei Huang ◽  
Pei-Ying Lee ◽  
...  
Keyword(s):  
Optical Memory ◽  
Polymeric Membranes ◽  
Electrochromic Device ◽  
Electrochromic Devices ◽  
Colored State ◽  
Thiophene Derivatives ◽  
Transmittance Change ◽  
Rapid Switching ◽  
Electrochromic Polymer ◽  
Transparent Conductive Electrodes

Five carbazole-containing polymeric membranes (PDTC, P(DTC-co-BTP), P(DTC-co-BTP2), P(DTC-co-TF), and P(DTC-co-TF2)) were electrodeposited on transparent conductive electrodes. P(DTC-co-BTP2) shows a high ΔT (68.4%) at 855 nm. The multichromic properties of P(DTC-co-TF2) membrane range between dark yellow, yellowish-green, gunmetal gray, and dark gray in various reduced and oxidized states. Polymer-based organic electrochromic devices are assembled using 2,2′-bithiophene- and 2-(2-thienyl)furan-based copolymers as anodic membranes, and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as the cathodic membrane. P(DTC-co-TF)/PEDOT-PSS electrochromic device (ECD) displays a high transmittance change (ΔT%) (43.4%) at 627 nm as well as a rapid switching time (less than 0.6 s) from a colored to a bleached state. Moreover, P(DTC-co-TF2)/PEDOT-PSS ECD shows satisfactory optical memory (the transmittance change is less than 2.9% in the colored state) and high coloration efficiency (512.6 cm2 C−1) at 627 nm.

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.

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