Assessing AlN||VO₂||AlN Multilayer Architectures Deposited by Ion-Beam Sputtering for Smart Window Applications

Abstract

Thermochromic (TC) smart windows regulate building temperature by adjusting their transmittance depending on ambient conditions. Vanadium dioxide (VO2) is a leading TC material due to its insulator-to-metal transition close to, but above, room temperature, which modulates its transmittance in the near-infrared (NIR) region. Implementing TC windows faces challenges such as lowering the phase transition temperature of the TC material, ensuring high visible-light transmittance, or enabling scalable fabrication. Multilayer structures with buffer and antireflective (AR) layers address these challenges by improving crystallinity and enhancing the transmittance properties. We use ion-beam sputtering to deposit multilayer architectures of the type AlN||VO2||AlN on quartz glass substrates. AlN is chosen for its refractive index and protective qualities. The TC properties of corresponding multilayer films with AlN as the buffer and AR layer are explored, and structure–property relationships are established. The results demonstrate promising advancements in TC smart window technologies.