Organic/inorganic electrochromic nanocomposites with various interfacial interactions: A review

Research Impact on Emerging Quantum Materials for Electrochromic Applications

“…As a major result, Cai et al reported the hierarchical structure Ti-doped WO 3 films prepared using the hydrothermal method (see Figure 3a). [19] The effect of Ti doping into WO 3 caused the formation of a star-like surface structure and a reduction of the WO 3 crystallization, which have an important effect on obtaining the outstanding EC performances of wide transmittance modulation (49.1 % at 750 nm), fast switching speeds (1.6 s for coloration speed and 1.7 s for bleaching speed) and a high CE value (68.0 cm 2 /C) as the result of low charge transfer and ion diffusion resistances, together with superb electrical conductivity of Ti-doped WO 3 . In a previous study, we developed a novel approach of tunneled phosphorus (P)-doped WO 3 films using the ignition reaction of the red P. [22] The ignited red P generated the critical exothermic reaction on the WO 3 surface, which resulted in a partial surface deformation and vaporization of red P (see Figure 3b).…”

“…Commercial success in smart windows for architectural buildings is fundamental for the development of electrochromic devices (ECDs) that can adjust solar radiation or incident visible light and thus improve human comfort and energy efficiency by changing transmittance levels according to the dynamic needs . Furthermore, owing to their unique ability to reversibly vary optical properties (color and reflection) depending on applied potential, ECDs have been extensively used in various applications such as electronic displays, military camouflage, and satellite thermal control . A typical ECD presents a multi‐layered structure consisting of cathodic and anodic electrochromic (EC) layers, two transparent conducting layers, and an electrolyte layer, in which the EC reaction is generated when the ions are moved into and out of the EC layers by the electrochemical redox processes .…”

“…There performances concern the number of electrical, optical, electronic, and electrochemical behaviors of the ECDs mainly determined by nanostructuring of EC materials. In particular, in the ECDs, the interfacial interactions of the EC materials with the electrolyte provide unobstructed ion channels, improve electron conduction, and shorten ion diffusion distance, all of which significantly affect the EC performances . Recently, several papers using quantum dots (QDs) as next‐generation EC materials have been published .…”

“…[1,2] Furthermore, owing to their unique ability to reversibly vary optical properties (color and reflection) depending on applied potential, ECDs have been extensively used in various applications such as electronic displays, military camouflage, and satellite thermal control. [2][3][4] A typical ECD presents a multi-layered structure consisting of cathodic and anodic electrochromic (EC) layers, two transparent conducting layers, and an electrolyte layer, in which the EC reaction is generated when the ions are moved into and out of the EC layers by the electrochemical redox processes. [5] Therefore, the performances of the ECDs, such as transmittance modulation, switching speed, coloration efficiency (CE), and cycling retention, are determined by the degree of reaction capacity and kinetics that occur in the EC layers.…”

“…In particular, in the ECDs, the interfacial interactions of the EC materials with the electrolyte provide unobstructed ion channels, improve electron conduction, and shorten ion diffusion distance, all of which significantly affect the EC performances. [3] Recently, several papers using quantum dots (QDs) as next-generation EC materials have been published. [9] The EC behavior of QDs can be attributed to size-dependent optoelectronic properties to cause the collection of electrons in the conduction band and electron injection and optical transitions of surface energy states during the electrochemical reaction.…”