Method for preparing vertically aligned tungsten oxide nano structural electrochromic film

Abstract

The invention relates to a method for preparing a vertically aligned tungsten oxide nano structural electrochromic film. The method comprises the following steps of: 1) dissolving tungstic acid in a mixed solution of hydrogen peroxide and water, heating until tungstic acid is fully dissolved, and cooling to obtain transparent sol; 2) coating the obtained transparent sol on the surface of fluorine-doped tin oxide (FTO) conducting glass which is subjected to ultrasonic washing in a spinning way, and calcining to obtain the FTO conducting glass with a tungsten oxide crystal seed layer; and 3) preparing a reaction solution containing the transparent sol, hydrochloric acid, urea and solvent, immersing the obtained FTO conducting glass with the tungsten oxide crystal seed layer in a hydrothermal kettle in which the reaction solution is filled, preserving heat at the temperature of between 150 and 180 DEG C for 6 to 12 hours, naturally cooling to room temperature, washing and drying to obtain the vertically aligned tungsten oxide nano structural electrochromic film. A preparation process is simple and low in cost; by the method, the electrochromic properties such as color change speed, coloration efficiency, cycling stability and the like of the film are effectively improved; and the method has the industrial application prospect in the aspect of preparing the film on the surface of the glass.

Description

technical field [0001] The invention belongs to the field of preparation of electrochromic thin films, in particular to a preparation method of vertically aligned tungsten oxide nanostructure electrochromic thin films. Background technique [0002] Electrochromism refers to the phenomenon that materials produce stable and reversible changes under the action of electric field. When the material undergoes electrochemical injection and extraction of electrons and ions, its valence and chemical composition change, thereby changing the reflection and transmission properties of the material, and the appearance performance is manifested as a reversible change in color and transparency. . Electrochromic materials have been paid attention to because of their broad application prospects in display devices, smart windows, glare-free mirrors, and military anti-counterfeiting. Since S.K.Deb first reported the electrochromic effect of amorphous tungsten oxide film in 1969, electrochromi...

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Problems solved by technology

Although the electrochromic properties of these nanostructured tungsten oxide films have been greatly improved, there are still many problems in practical applications, such as: (1) the number of cycles is small, and it is difficult to meet the requirements of practical applications; (2) ) The coloring and fading time is long, and it cannot be used for fast response devices; (3) The modulation amplitude of visible light transmittance is low, which cannot meet the needs of practical applications

[0004] The reason is mainly in the following two aspects: First, these nanostructures are randomly attached to the surface of the glass substrate, so the bonding force between the tungsten oxide of these nanostructures and the transparent conductive substrate is relatively poor, especially at the top of the film. Tungsten oxide nanostructures, which will inevitably affect the contact between the ions in the electrolyte and the tungsten oxide nanostructures and the substrate, thereby affecting its electrochromic response speed; secondly, it is precisely because these randomly attached nanostructures are on the transparent conductive substrate The close packing of these nanostructures leads to the underutilization of the active surface of these nanostructures, which affects its coloring efficiency.

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