High-Vacuum Annealed Al-Doped ZnO Nanorods for Fast-Switching Electrochromic Windows with High-Optical Contrast and Long-Term Stability

Abstract

We report an effective approach for improving the switching performance in a Ag-based electrochromic (EC) window by using one-dimensional (1D) aluminum-doped zinc oxide (AZO) nanorods (NRs). Conventional Ag-based EC windows reversibly switch between transparent, mirror, and black states. However, it is a limit to extensive commercialization due to problems of poor optical contrast and slow switching speed. Here, we exhibit a simultaneous fast switching speed and high optical contrast by introducing high-vacuum annealing on the AZO NRs electrode to improve surface conductivitiy and to lower the Schottky barrier height (SBH) at the interface. The high-vacuum annealing on AZO NRs significantly shortened the switching time (21.2 s) by 40% for bleaching between black and transparent states compared to the switching time in the EC windows without annealing (35.3 s). In the visible wavelengths, the EC windows had excellent optical transmittance of 76.87% in the transparent state and 1.56% in the black state and a reflectance of 80.19% in the mirror state. They also have long-term stability that works for ∼10 000 cycles without degradation.

Progress in the Synthesis and Application of Transparent Conducting Film of AZO (ZnO:Al)

“…Combining AZO films with other materials and coating the obtained composite films onto glass can solve this problem. Song et al [ 75 ] presented a highly effective method for enhancing the switching performance of silver-based electrochromic (EC) windows, utilizing one-dimensional (1D) aluminum-doped nanorods (NRs). In Figure 11 , they achieved this by subjecting AZO NR electrodes to high-vacuum annealing, resulting in improved surface conductivity and reduced Schottky barrier height (SBH) at the interface.…”

“…The wavelength range for transmittance and reflectance spans from 400 to 700 nm. ( f ) Switching time comparison of EC windows incorporating AZO nanorod 2h [ 75 ]. From American Chemical Society, Copyright 2022.…”

Gel polymer electrolyte for reversible metal electrodeposition dynamic windows enables dual-working electrodes for faster switching and reflectivity control

“…Currently there are many technologies using electrochromic oxides and organic molecules to tune the color and transmission of the window (Barile et al, 2017). Compared with these technologies, dynamic windows based on reversible metal deposition (RME) have the advantage of potential low cost, neutral color, and great contrast ratio (Barile et al, 2017;Jeong et al, 2017;Hernandez et al, 2018;Strand et al, 2018;Hernandez et al, 2020;Eh et al, 2020;Kimura et al, 2020;Poh et al, 2021;Guo et al, 2022;Kimura et al, 2022;Song et al, 2022;Tao et al, 2022). These windows operate by the reversible electrodeposition of metals ions, e.g., Bi 3+ and Cu 2+ , to their metallic form on a Ptcoated indium tin oxide (ITO) transparent electrode.…”