Inorganic-alone solid-state electrochromic device for application as visible near infrared region electronic curtain

A prototype inorganic material-based solid-state electrochromic device (ECD) using an active WO${}_3$ layer has been demonstrated followed by testing its potential application in blocking infrared (IR) radiation. A cost-effective hydrothermal method has been used for fabricating WO${}_3$-based electrodes. Prior to application, the structural and morphological characterization of the WO${}_3$ has been done using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. A solid-state ECD has been fabricated in a sandwiched geometry with a supporting gel electrolyte. The solid-state inorganic ECD displays a color contrast of more than 40% at 600 nm wavelength while toggling between transparent (OFF state) and blue (ON state) colors under a bias of as low as 2.5 V making it a power-efficient device. The device is capable of maintaining its absorbance switching for longer than 2400 s without altering its absorbance rate. The device is capable of blocking IR radiation with more than 100% in its ON state as compared to its OFF state. A power-efficient electrochromic performance has been reported from an inorganic-alone solid state ECD while displaying its potential as an electronic curtain. (© 2022 The Authors. physica status solidi (a) applications and materials science published by Wiley‐VCH GmbH)