scholarly journals Electrochromic Devices Based on Porous Tungsten Oxide Thin Films

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Y. Djaoued ◽  
S. Balaji ◽  
R. Brüning
Keyword(s):  
Thin Films ◽  
Transition Metal Oxides ◽  
Structural Phase ◽  
Phase Changes ◽  
Optical Modulation ◽  
Electrochromic Devices ◽  
Smart Windows ◽  
Porous Thin Films ◽  
Recent Developments ◽  
Ion Intercalation

Recent developments in the synthesis of transition metal oxides in the form of porous thin films have opened up opportunities in the construction of electrochromic devices with enhanced properties. In this paper, synthesis, characterization and electrochromic applications of porous WO3thin films with different nanocrystalline phases, such as hexagonal, monoclinic, and orthorhombic, are presented. Asymmetric electrochromic devices have been constructed based on these porous WO3thin films. XRD measurements of the intercalation/deintercalation of Li+into/from the WO3layer of the device as a function of applied coloration/bleaching voltages show systematic changes in the lattice parameters associated with structural phase transitions in LixWO3. Micro-Raman studies show systematic crystalline phase changes in the spectra of WO3layers during Li+ion intercalation and deintercalation, which agree with the XRD data. These devices exhibit interesting optical modulation (up to ~70%) due to intercalation/deintercalation of Li ions into/from the WO3layer of the devices as a function of applied coloration/bleaching voltages. The obtained optical modulation of the electrochromic devices indicates that, they are suitable for applications in electrochromic smart windows.

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 Enhanced Electrochromic Properties by Improvement of Crystallinity for Sputtered WO3 Film

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 577
Author(s):  
Zhu-jie Xia ◽  
Hong-li Wang ◽  
Yi-fan Su ◽  
Peng Tang ◽  
Ming-jiang Dai ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Amorphous State ◽  
Xrd Analysis ◽  
Optical Modulation ◽  
Modulation Amplitude ◽  
Cyclic Stability ◽  
Smart Windows ◽  
Electrochromic Properties ◽  
Wo3 Thin Films

Tungsten oxide (WO3) is widely used as a functional material for “smart windows” due to its excellent electrochromic properties, however it is difficult to overcome the conflict between its optical modulation and cyclic stability. In this work, WO3 thin films with different crystal structures were prepared by DC reactive magnetron sputtering method. The effects of substrate temperature on the structure, composition, and electrochromic properties of WO3 films were investigated. The results show that the crystallinity of the WO3 film increases with increasing deposition temperature, indicating that temperature plays an important role in controlling the structure of the WO3 film. For WO3 thin films formed at a substrate temperature of 573 K, the film is in an amorphous state to a crystalline transition state. From X-ray diffraction (XRD) analysis, the thin film showed a weak WO3 crystallization peak, which was in the composite structure of amorphous and nanocrystalline. Which has the best electrochromic properties, with modulation amplitude of 73.1% and bleached state with a coloration efficiency of 42.9 cm2/C at a wavelength of 550 nm. Even after 1500 cycles, the optical modulation still contains 65.4%, delivering the best cyclic stability.

Thickness and ion irradiation induced structural phase changes in the thin films of titanium dioxide

2021 ◽  
pp. 138917
Author(s):  
P. Devaraj ◽  
R. Meena ◽  
P. Sivakumar ◽  
P. Peranantham ◽  
V.V. Siva Kumar ◽  
...  
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Ion Irradiation ◽  
Structural Phase ◽  
Phase Changes

Electrochromic Properties of Nano-Columnar Nickel Oxide

2010 ◽  
Vol 654-656 ◽  
pp. 1904-1907 ◽  
Author(s):  
Chih Ming Wang ◽  
Kuo Sheng Kao ◽  
Da Long Cheng ◽  
Chien Chuan Cheng ◽  
Po Tsung Hsieh ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Transition Metal Oxides ◽  
Electrochromic Devices ◽  
Smart Windows ◽  
Electrochromic Properties ◽  
Electrode Cell ◽  
Electrochemical Analyzer ◽  
Surface Microstructures ◽  
Nio Films

Electrochromic properties of transition metal oxides had much attention in recent years. The electrochromic thin films can be assembly as electrochromic devices (ECDs) and then used for applications in devices such as mirrors, panels and smart windows. A kind of complementary ECD is popular in resent years. Therefore, a specific investigation on nickel oxide (NiO) electrochromic properties is completed in this study. The crystalline structure of the NiO films was analyzed using XRD (PANalytical X’Pert PRO) with Cu-Kα radiation. The atmosphere of oxygen concentration increasing has changed the NiO films crystalline from (200) to (111). The thicknesses and surface microstructures of the NiO films were investigated using a scanning electron microscope (SEM, Philips/FEI XL40 FEG). It is observed that films are relatively smooth deposited without oxygen. The characterization of the electrochromic properties was carried out in a two-electrode cell with an electrochemical analyzer (CHI 611B). The NiOx changes the transmittance of NiO films in the wavelength range of 300-1500 nm and the color of the film changes from transparent to brown. The nano-crack exhibits in the NiO film did enhance the electrochromic properties.

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 Simulation of the temperature profile of BaCaZrTiO3 thin films during laser annealing

2020 ◽  
Vol 233 ◽  
pp. 05008
Author(s):  
Tiago Rebelo ◽  
João Alves ◽  
Bernardo Almeida
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Room Temperature ◽  
Laser Annealing ◽  
Laser Intensity ◽  
Structural Phase ◽  
Phase Changes ◽  
Heat Diffusion ◽  
Maximum Temperature ◽  
Heat Diffusion Equation

The laser annealing of a Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) thin film on a metglas substrate was simulated in order to understand how the annealing parameters (energy and fluence of the laser, pulse duration, etc) influence the optimization of the crystallinity of the film. Using a 1D heat diffusion equation combined with a finite difference method, the variation of the temperature with the depth relative to the film’s surface and on annealing time was studied. The laser intensity, BCZT’s reflectivity and the temperature dependence of the ther¬mal conductivity and specific heat of the BCZT were considered. No structural phase changes were detected in both the BCZT and the metglas for the values of laser fluence studied, but for 80 mJ/cm2 the maximum temperature approached near the BCZT’s melting temperature. It was observed that since the film’s ther¬mal conductivity decreases with increasing fluence, lower fluences allow for a better distribution of the laser’s energy throughout the crystal lattice, increasing the crystallinity. It was further observed that between consecutive pulses the film’s temperature stabilizes at room temperature.

Improvement on optical modulation and stability of the NiO based electrochromic devices by nanocrystalline modified nanocomb hybrid structure

RSC Advances ◽  
2015 ◽  
Vol 5 (123) ◽  
pp. 101487-101493 ◽  
Author(s):  
Xin Zhang ◽  
Yongzhe Zhang ◽  
Bowen Zhao ◽  
Shujuan Lu ◽  
Hao Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Ion Exchange ◽  
Hybrid Structure ◽  
Optical Modulation ◽  
Electrochromic Devices ◽  
Nickel Oxides ◽  
Anodic Layer

Among the explored materials for electrochromic devices (ECDs), nickel oxides thin films have been widely applied as an optical anodic layer due to its ability to adjust the optical properties by ion exchange.

scholarly journals Probing the role of thermal vibrational disorder in the SPT of VO$$_2$$ by Raman spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aminat Oyiza Suleiman ◽  
Sabeur Mansouri ◽  
Nicolas Émond ◽  
Boris Le Drogoff ◽  
Théophile Bégin ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transitions ◽  
Transition Metal Oxides ◽  
Critical Role ◽  
Structural Phase ◽  
Electrical Measurements ◽  
Concurrent Study ◽  
The Mean ◽  
Microstructural Effect

AbstractPhase competition in transition metal oxides has attracted remarkable interest for fundamental aspects and technological applications. Here, we report a concurrent study of the phase transitions in undoped and Cr-doped VO$$_2$$ 2 thin films. The structural, morphological and electrical properties of our films are examined and the microstructural effect on the metal–insulator transition (MIT) are highlighted. We further present a distinctive approach for analyzing the Raman data of undoped and Cr-doped VO$$_2$$ 2 thin films as a function of temperature, which are quantitatively correlated to the electrical measurements of VO$$_2$$ 2 films to give an insight into the coupling between the structural phase transition (SPT) and the MIT. These data are also combined with reported EXAFS measurements and a connection between the Raman intensities and the mean Debye–Waller factors $$\sigma ^2$$ σ 2 is established. We found that the temperature dependence of the $$\sigma _{R}^{2}(V-V)$$ σ R 2 ( V - V ) as calculated from the Raman intensity retraces the temperature profile of the $$\sigma _{EXAFS}^{2}(V-V)$$ σ EXAFS 2 ( V - V ) as obtained from the EXAFS data analysis. Our findings provide an evidence on the critical role of the thermal vibrational disorder in the VO$$_2$$ 2 phase transitions. Our study demonstrates that correlating Raman data with EXAFS analysis, the lattice and electronic structural dynamics can be probed.

scholarly journals An approach to emerging optical and optoelectronic applications based on NiO micro- and nanostructures

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
María Taeño ◽  
David Maestre ◽  
Ana Cremades
Keyword(s):  
Gas Sensors ◽  
High Frequency ◽  
Future Research ◽  
Electrochromic Devices ◽  
Fuel Cell Electrodes ◽  
Magnetic Devices ◽  
Optical Microresonators ◽  
Optical Limiters ◽  
Recent Developments ◽  
Potential Applicability

Abstract Nickel oxide (NiO) is one of the very few p-type semiconducting oxides, the study of which is gaining increasing attention in recent years due to its potential applicability in many emerging fields of technological research. Actually, a growing number of scientific works focus on NiO-based electrochromic devices, high-frequency spintronics, fuel cell electrodes, supercapacitors, photocatalyst, chemical/gas sensors, or magnetic devices, among others. However, less has been done so far in the development of NiO-based optical devices, a field in which this versatile transition metal oxide still lags in performance despite its potential applicability. This review could contribute with novelty and new forefront insights on NiO micro and nanostructures with promising applicability in optical and optoelectronic devices. As some examples, NiO lighting devices, optical microresonators, waveguides, optical limiters, and neuromorphic applications are reviewed and analyzed in this work. These emerging functionalities, together with some other recent developments based on NiO micro and nanostructures, can open a new field of research based on this p-type material which still remains scarcely explored from an optical perspective, and would pave the way to future research and scientific advances.

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