Facile Fabrication of Trimodal Switchable Mirror Device with Zero Transmittance in the Black State

Abstract

The electrochromic mirror device (ECD) demonstrating transparent, mirror, and black states with zero transmittance in the black state is fabricated using facile dry deposition method. The device is capable of achieving both a highly reflective mirror and a complete black state. ECD is fabricated using a WO3 film deposited by nanoparticle deposition system (NPDS) and optical characteristics of its transparent, mirror, and black states are evaluated. Notably, the device demonstrates the mirror state with high reflectance over 80% and a black state that completely blocks the entire visible light, resulting in nearly zero transmittance. Device durability is evaluated over 100 cycles; the transmittance of the black and transparent states is measured to be 9.61%, 79.6% at its wavelength of 680 nm, respectively. Moreover, the reflectance of the mirror state at the same wavelength is measured to be 73.1% and 72.7% for the first and 100th cycles, respectively. Microstructural observations suggest that the visible light‐blocking effect is a consequence of the rough surface obtained using NPDS, which leads to uneven electrodeposition of Ag ions to produce localized surface plasmon resonance. Dry deposition method of the electrochromic layer is an excellent method for fabricating high‐contrast three‐mode electrochromic mirrors.

High Optical Contrast of Quartet Dual-Band Electrochromic Device for Energy-Efficient Smart Window

“…NPDS is a dry deposition method for depositing various ceramic or metal powders on a substrate at supersonic speed using the pressure difference generated by an air compressor and vacuum pump, as explained in detail in the Supporting Information (Figure S1). − When powders collide with the substrate, their particles break and stick to the substrate, resulting in the formation of a thin film with high surface roughness. Previously, a smart mirror device using a WO 3 thin film fabricated by NPDS has been reported; this device exhibited 0% transmittance at 300–900 nm after the electrodeposition of Ag + ions onto the rough surface of the WO 3 film . Therefore, in the present study, NPDS was used to deposit WO 3 and ATO films with highly rough surfaces to demonstrate quartet dual-band ECDs.…”

Transparent, High‐Charge Capacity Metal Mesh Electrode for Reversible Metal Electrodeposition Dynamic Windows with Dark‐State Transmission <0.1%

“…[14] A robust counter electrode must have enough capacity to charge balance the working electrode reaction while maintaining desired window properties (high transparency and low haze). Some RME systems use redox shuttles in the electrolyte [15,20,21] (e.g., 3 Br − ⇆ Br 3 − , Figure 1a) or ion intercalation materials as the counter electrode material [22][23][24][25] (e.g., NiO x and various hexacyanoferrates, Figure 1b) for the counter reactions. Redox shuttles are not ideal for RME as the 3 Br − ⇆ Br 3 − reaction is colored.…”

A black energy-saving electrochromic device based on a dye copolymer–metal complex

“…Compared with commercial display technology such as liquid crystal display (LCD), bistable electrochromic displays could retain information without energy consumption. 13,14 Due to the advantages of ultra-low energy consumption and long-term maintenance of expected color/transmittance, bistable electrochromic devices have broad application prospects [15][16][17] in smart windows, [18][19][20][21] non-emission displays, 22 etc. As one of the most important parts of optical model and display technology, bistable black electrochromic devices can adjust the intensity and spectrum of the entire visible region of solar light and has been expected by many research groups.…”

“…In recent years, organic molecules 23 or polymers, [24][25][26] metal oxides 27,28 and hybrid materials 29,30 have been used to fabricate electrochromic black devices. The related reaction mechanisms can be attributed to color-mixing, 31,32 electrodeposition, [33][34][35] the designing of new materials, etc. For example, black electrochromic devices were prepared by mixing three different colored functionalized POSSs, namely octaviologen (OHV-POSS), thiophene (OTxHV-POSS) and phenyl (OphHV-POSS).…”