Reduced Transition Temperature in Al:ZnO/VO2 Based Multi-Layered Device for low Powered Smart Window Application

Abstract

The metal-to-insulator transition (MIT) closest to room temperature of 68-70 °C as shown by vanadium oxide (Vo 2), compared with other transition metal oxides, makes it a potential candidate for smart window coating. We have successfully fabricated a potential smart window device after the optimum design of a multilayered thin film structure made out of transparent conducting oxide (aluminum doped zinc oxide) and pure Vo 2 using pulsed laser deposition technique. This comprehensive study is based on two different configurations for multi-layered structure approach, with the intention to reduce the transition temperature, as well as to maintain the Mit properties that would strengthen the potential of the structure to be used for a smart window device. By creating a multi-layered structure, we were able to create a low powered device that can operate less than 15 V that leads to significant decline in the infrared transmission by a magnitude of over 40% and provided sufficient heat to trigger the MIT at a temperature around 60 °C, which is almost 10 °C lower than its bulk counterpart. This finding would positively impact the research on Vo 2 thin films, not only as smart windows but also for numerous other applications like bolometers, infrared detectors, Mott transistors and many more.

Thermochromic Energy Efficient Windows: Fundamentals, Recent Advances, and Perspectives

“…Transparent conductive (TC) materials, including Ag, − Cu, − F:SnO 2 (FTO), Al:ZnO (AZO), − and other doped oxides and nitrides, − are commonly applied as low emissivity coating materials, they have enough free electrons to reflect MIR light and are transparent in the visible region. Investigations have been conducted on VO 2 -based thermochromic smart windows to achieve thermochromic and low-emissivity bifunctionalities.…”

Structural, Optical, and Magnetic Properties of Pure and Ni–Fe-Codoped Zinc Oxide Nanoparticles Synthesized by a Sol–Gel Autocombustion Method

“…Major properties that distinguish ZnO among others are the wide and direct band gap of 3.39 eV and its piezoelectricity . Due to these remarkable properties, it has several applications in different fields such as optoelectronics, electromechanical devices, light-emitting diodes, photocatalysis, piezoelectricity, nanogenerators, solar cells, smart windows, transistors, gas sensors, and much more. − It is a multifunctional semiconductor that can also be used as a magnetic storage device or optical/electrical switching device. ,− ZnO is low cost, abundant, biosafe, and biocompatible, thereby it is used in various medical applications . Interestingly, the optical and electrical properties of ZnO can be easily tuned by transition metal doping and specifically by varying the dopant concentrations.…”

“…Interestingly, the optical and electrical properties of ZnO can be easily tuned by transition metal doping and specifically by varying the dopant concentrations. As a result, doped ZnO nanoparticles (NPs) have gained huge interest in the past decade. − Significantly improved magnetic, electrical, optical, and structural properties have been reported by many researchers. − Fabrication of transition metal-doped ZnO can be achieved by several different techniques, − microemulsion process, − microwave hydrothermal process, sol–gel synthesis, precipitation method, chemical vapor, solvothermal synthesis, , chemical method, , and autocombustion method . The autocombustion method, however, is a short, time-saving, and homogeneous method.…”

Role of Hafnium Doping on Wetting Transition Tuning the Wettability Properties of ZnO and Doped Thin Films: Self-Cleaning Coating for Solar Application

“…Metal oxides (TiO 2 , ZnO, WO 3 , Fe 2 O 3 , V 2 O 5 , etc.) have attracted special consideration, owing to their extensive variety of tunable properties, as seen in photocatalysts, sensors, transparent electrodes, and other energy applications. − Among them, ZnO is a widely studied semiconductor with high electron mobility, improved processability, and superior optical and electronic properties , coupled with reversible wettability properties, therefore possessing great prospective in energy harvesting, smart windows, and environmental purification . Additionally, an important feature of ZnO is its intrinsic hydrophilic nature, owing to the presence of hydroxyl groups attached to its surface.…”