Wide‐Band Reflection‐Type, All‐Solid‐State Switchable Mirror Composed of WO₃–Mg₄Ni Thin Films and Proton‐Conductive Polymer Electrolytes

Abstract

In all‐solid‐state devices based on WO3–NiO thin films, solid electrolytes such as Ta2O5 or Nb2O5 are usually used as the ion conducting layers. However, the thickness of the proton conducting layer of Ta2O5 or Nb2O5 is thicker, and the sputtering rate is low, which affects the cost and practical application of the devices. In this paper, a wide‐band reflection‐type all‐solid‐state WO3–Mg4Ni thin film switchable mirror was fabricated by using an assemble process and a proton‐conductive Nafion membrane was used as a solid electrolyte for the first time. WO3 is an ideal discoloration material in all‐solid‐state electrochromic devices, whereas Pd/Mg4Ni is a reflective switching material. WO3 and Pd/Mg4Ni thin films were deposited on ITO‐coated glass and glass substrates, respectively, by DC magnetron sputtering. The device was assembled by two separated thin films using a poly vinyl butyral (PVB) glue containing a proton‐conductive Nafion as the electrolyte. The fabricated all‐solid‐state mirror could be reversibly switched between the mirror and transparent state by applying different voltages. The influences of the Nafion concentration and applied power on the switching properties were investigated.

Infrared Gasochromic Devices Based on Metal Thin Films

“…[45,46] Early research in this area focused on using the resistivity change during the reaction between the rare earth metal and hydrogen to prepare hydrogen sensor, [47,48] while current research focuses on the areas of smart windows and plasmonic structural colors, whose spectral response characteristics correspond to the visible and near-infrared wavelengths of light (i.e., ≤2500 nm). [49,50] In contrast, no studies have examined the response characteristics in the mid-and long-wave infrared regions (i.e., the 2.5-25 µm region). We, therefore, considered that, in addition to the metal-insulator transition, the infrared optical properties of the material, such as the emissivity, could also undergo a substantial transition, thereby rendering such systems potentially suitable for use as hydrogen gasochromic materials for emissivity modulation.…”