Electrochromism of gold-vanadium pentoxide composite thin films prepared by alternating thermal deposition

Abstract

The composite thin films of Au-V2O5 were prepared by means of an alternating thermal deposition technique. The electrochromic properties of the films were dependent on Au contents and calcination temperature. The composite film containing 26 at. % Au calcined at 400 °C gave clear electrochromism of reddish-violet (cathodic polarization) ↔ green (anodic). The film had a strong optical absorption peak ascribable to the dispersed Au particles at 615 nm (cathodic) or 555 nm (anodic). The shift of this absorption peak, coupled with that of the absorption edge of the V2O5 matrix, was responsible for the new electrochromism.

Recent advances in vanadium pentoxide (V2O5) towards related applications in chromogenics and beyond: fundamentals, progress, and perspectives

“…238 Similarly, the new coloration of reddish-violet 2 green due to the effective dielectric constant of Au grains was observed in Au-V 2 O 5 . 234 There are fewer reports on the response time and CE of a compact V 2 O 5 film at this stage. The compact granular morphology of a V 2 O 5 film with grains, 80-100 nm in size, produced a low CE value of approximately 13 cm 2 C À1 at 630 nm with a slow response time of approximately 60 s and an unsatisfactory reversibility of approximately 70%.…”

“…Other important key figures of merit to evaluate the performance of ECDs, such as the coloration efficiency, cycling life, and switching time, have attracted less attention. Classical V 2 O 5 films for ECDs are usually fabricated by RF magnetron sputtering, 229,231,232 DC magnetron sputtering, 158,233 thermal evaporation, 225,226,234,235 and sol-gel [236][237][238] methods. The advantage of these techniques is the good adhesion of the film to the substrate.…”

“…240 Nagase et al introduced a new coloration using V 2 O 5 -based composites, such as Au-V 2 O 5 and V 2 O 5 -TiO 2 . 234,238 Fig. 17 compares the coloration of pure V 2 O 5 and V 2 O 5 -based composites.…”

“…17 compares the coloration of pure V 2 O 5 and V 2 O 5 -based composites. 234,238 In the V 2 O 5 -TiO 2 system (x-TiO 2 , x = 0 for pure V 2 O 5 and x = 1 for pure TiO 2 ), the pristine film color and EC coloration are affected by the x value. The color change of blue 2 green 2 yellow (x = 0-0.3), gray 2 yellow (x = 0.5), and reddish-brown 2 gray 2 green 2 yellow (x = 0.7) occurred as the films were polarized while only a color change of dark-blue 2 transparent (x = 1) was observed.…”

All-solid-state electrochromic device of electrodeposited WO3 and prussian blue film with PVC gel electrolyte

“…Intensified research efforts to develop electrochromic devices have spread worldwide in recent years. [1][2][3][4][5][6][7] The focus of these research programs is on large-area window applications. For such applications, an all-solid-state electrochromic device have unique advantages (such as reliability and safety) when compared to conventional liquidbased devices.…”