All-Solid-State Infrared Electrochromic Devices Based on Thin Metal Films.

Infrared electrochromic devices (IR-ECDs) are pivotal for dynamic thermal regulation. However, the quest for all-solid-state IR-ECDs with high stability and a broadly tunable range of emissivity remains a challenge. This study presents the development of an all-solid-state infrared electrochromic device (IR-ECD) with the structure of ITO/HWO/TaO/Pd/MgNi based on the hydrogen-induced metal-insulator transition of Mg-Ni alloy films. The emissivity modulation is improved by film stack optimization, with changes of 0.32 and 0.47 in the 3-5 and 7.5-14 μm bands, respectively. The introduction of an ultrathin Ti isolation layer between the catalytic and electrolyte layers enhances the cyclic stability. Our findings offer a novel strategy for the design and fabrication of all-solid-state IR electrochromic devices and highlight the potential of Mg-Ni alloy-based all-solid-state IR-ECDs in advanced energy and information fields.