Electrochromic Thin Film of Prussian Blue Nanoparticles Fabricated using Wet Process

Abstract

Electrochromic thin films of Prussian blue nanoparticles were developed using wet processing. The resultant alkyl-ligand covered nanoparticles disperse well in organic solvents. Consequently, various conventional coating and printing methods can be used in high-quality micro-fabrication to prepare electronic devices. We examined electrochromic properties of the thin film fabricated using spin-coating method. Electrochromism of the thin film on an indium tin oxide (ITO) electrode was observed. The color changes from blue to colorlessness reversibly at potentials between +0.6 to -0.4 V. Furthermore, various patterns were printed on ITO substrates using photolithography, indicating potential application of this approach to information displays and smart windows.

Electronic Structure of Hole-Doped Transition Metal Cyanides

“…wH 2 O (M and A are a transition metal and an alkaline metal, respectively), are attracting increasing interest from material scientists because they are ubiquitous materials with potential use in electrochromic devices, [1][2][3][4] gas storage devices, and material sensors. [5][6][7][8] In particular, the color of the transition metal cyanides can be changed to red (M ¼ Co), blue (M ¼ Fe), or yellow (M ¼ Ni).…”

A fast-switching light-writable and electric-erasable negative photoelectrochromic cell based on Prussian blue films

“…Prussian blue [PB, iron (III) hexacyanoferrate (II)] is a well known synthetic coordination-compounded transition metal hexacyanometallate, which has attracted considerable attention owing to its various applications in electrochromic [24][25][26], sensors [27], catalysts [28], and batteries [29]. Different from WO 3 , PB is an anodically coloring electrochromic material with promising electrochromic properties.…”

Color-Switchable Glass and Display Devices Fabricated by Liquid Processes with Electrochromic Nanoparticle “Ink”

“…12) With the ''ink'', dispersion liquid of the nanoparticles, various conventional coating and printing methods can be used in high-quality micro-fabrication of PB and PBA films, e.g., flat thin film with very small roughness and patterned thin film. 13) For example, the information display devices can be easily fabricated as shown in Fig. 1(b) with patterned EC layers.…”

“…12,13) The diameters of 90% of nanoparticles of the PB and Ni-PBA were less than 10 and 25 nm, respectively, estimated by the dynamic light-scattering method. The PB nanoparticle is stably dispersed in toluene, e.g., the PB ink with the concentration of 0.1 g/ml exhibited no precipitate even after 8 weeks.…”

“…The EC properties of the nanoparticle thin films are similar to that of the electrodeposited ones. 13,14) For the electrode with Ni-PBA nanoparticles, the clear color change requires larger potential than that with PB nanoparticles. This is due to the difference of the thickness of the nanoparticle thin film, 250 and 1000 nm for PB and Ni-PBA, respectively.…”