All-solid-state electrochromic reflectance device for emittance modulation in the far-infrared spectral region

Abstract

All-solid-state electrochromic reflectance devices for thermal emittance modulation were designed for operation in the spectral region from mid- to far-infrared wavelengths (2–40 μm). All device constituent layers were grown by magnetron sputtering. The electrochromic (polycrystalline WO3), ion conductor (Ta2O5), and Li+ ion-storage layer (amorphous WO3), optimized for their infrared (IR) optical thicknesses, are sandwiched between a highly IR reflecting Al mirror, and a 90% IR transmissive Al grid top electrode, thereby meeting the requirements for a reversible Li+ ion insertion electrochromic device to operate within the 300 K blackbody emission range. Multicycle optical switching and emittance modulation is demonstrated. The measured change in emissivity of the device is to 20%.

Polaron and phonon properties in proton intercalated amorphous tungsten oxide thin films

“…33,35 Previous IRSE focused on uncolored amorphous tungsten oxide and electrochromic device performance for emittance modulation in the IR spectral region. 4,36 Elucidation of the phonon mode properties in connection with the polaron properties is still lacking. Accordingly, no conclusive statement about the source of the polaron cause had been made.…”

“…Electrochromic thin-film materials are employed in devices such as "smart windows," electrochromic rear view car mirrors, displays, emissivity modulation devices, and gas sensors, for example. [2][3][4][5] The sixfoldcoordinated tungsten oxide ͑WO 3 ͒ is among the most investigated electrochromic materials and can be found in many applications. [6][7][8] Despite large research efforts and numerous applications, the electronic mechanism responsible for the coloration process in WO 3 is still not fully understood.…”

Oxygen plasma effects on optical properties of ZnSe films

“…Theoretical device performance was evaluated based on previous experimental device results 33,34 and the optical data on degraded ZnSe layers presented in this article. Details of this performance study are being published elsewhere.…”

“…was recently developed that operates over the spectral range from 2 to 35 m. [32][33][34] The design of this electrochromic emissivity modulation device is shown in Fig. 1.…”

X-ray and Electron Spectroscopy Studies of Oxide Semiconductors for Photoelectrochemical Hydrogen Production

“…A detailed discussion of these effects and their origin can be found in, for example, [30][31][32]. One advantage of WO 3 is that the films can be deposited with a large variety of different techniques, including RF- [33,34] and DC-sputtering [33,35], screen-printing [36] and thermal evaporation [37]. The WO 3 films studied in this chapter were deposited by the group of E. Miller, University of Hawaii, using reactive sputtering from a W target under an argon and oxygen ambient.…”