JPS6249331A - Thin high-polymer film elememt having photoresponsiveness - Google Patents

Abstract

PURPOSE:To provide the title element which is stable, has excellent repetitive characteristics and exhibits a large spectrum change particularly in a near IR region from 600nm by forming a photodissociative or decomposable electrolyte contg. a dopant between a pair of electrode substrates and providing the thin high-polymer film which generates a change of the reflected or transmitted spectra when doped with the dopant in the electrolyte. CONSTITUTION:The photodissociative or decomposable ion conductive layer is held in place between a pair of the electrode substrates and the thin high-polymer film which generates a change of the reflected or transmitted spectra when doped with the molecules or ions formed in said ion conductive layer by irradiation of light thereon to one of a pair of the electrode substrates. The dedoping of the molecules and ions doped into the thin high-polymer film and the restoration of the original state are efficiently realized particularly when the thin high-polymer film formed by electrochemically converting the same to the thin polymerized high-polymer film in an electrolyte contg. a monomer material for polymn. is used and if a voltage is impressed between a pair of the electrode substrates. The thin film element which is stable, has the excellent repetitive characteristic and exhibits the large spectrum change particularly in 600nm- near IR region is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a photoresponsive polymer thin film element whose light transmission and reflection spectra can be changed by light irradiation.

(Prior Art and Problems) Photoresponsive polymers that exhibit a reversible hue change upon interaction with light are attracting attention from the viewpoint of application to display elements, optical recording media, and the like. Conventionally, organic photochromic materials have been well-known as photoresponsive polymer materials as described above, and a number of studies have been conducted on them. As organic photochromic materials, materials such as hydrazones, semicarbazones, triphenylmethanes, spiro compounds represented by various spiropyrans, and P-aminoazobenzene derivatives are known. The problems faced in the practical application of organic 7-otochromic materials include low reversibility of repeated operations, low light resistance, excitation light sources ranging from near-ultraviolet light to short-wave visible light, and hue changes (transmission and reflection spectrum changes). ) is small. Particularly from the viewpoint of optical storage medium applications, a stable photoresponsive polymer thin film that exhibits large spectral changes in the near-infrared wavelength region from 600 nm or more is strongly desired.

(Objectives of the Invention) 1 The present invention solves the above problems and provides a device using a novel photoresponsive polymer thin film that is stable and has excellent repeatability, and exhibits large spectral changes in the near-infrared region from 600 nm. It is about providing.

(Specific means for solving the problem) The photoresponsive polymer thin film of the present invention has a photo-dissociable or degradable ion conductive layer sandwiched between a pair of electrode substrates, and On one side, a polymer thin film is formed which causes reflection and transmission spectrum changes by doping with molecules or ions generated in the ion conductive layer by light irradiation.

In particular, when a polymer thin film is electrochemically polymerized into a thin polymer film in an electrolytic solution containing a monomer material for polymerization, and a voltage is applied between the pair of electrode substrates, the polymer thin film is doped. It is possible to efficiently dedoble molecules and ions and return them to their original state.

The polymer thin film used in the present invention can be one that exhibits a spectrum change due to ion or molecular doping. In particular, a thin polymer film produced by electrochemically polymerizing in an electrolytic solution containing a monomer material for polymerization is excellent in terms of reversibility and stability of doping and dedoping of ions or molecules.

The above monomer materials include thiophene, pyrrole, etc.
There are heterocyclic compounds containing N, aniline derivatives, benzene derivatives having a hydroxyl group, and derivatives having a vinyl group.

An electrolytic solution containing 0605 to 0.1 mol/7 of these materials, such as an alkali metal, tetraalkylammonium and C1o4-, BF4-, PF6- or 5o4-, c
In an organic solvent such as water or acetonitrile or propylene carbonate, 0.1 to 1.0 mol/l of a salt consisting of perchlorate ion, fluporolate ion, fluorophosphate ion, sulfate ion, chloride ion, etc. By electrolyzing with an appropriate potential and current, the polymer is polymerized onto the electrode. The polymer thin film formed as described above exhibits a color change due to doping and dedoping of ions in the electrolyte into the polymer thin film by applying a voltage in the electrolyte.

For example, polythiophene formed by oxidative polymerization of thiophene has a clear color change of red when undoped and blue when doped.
A color change with a clear spectrum change occurs in the 00 nm to near infrared region. Polypyrrole obtained by oxidative polymerization of pyrrole also causes a spectral change that causes a clear color change from 600 nm to near infrared, similar to the orange-dark line.

In the present invention, the spectrum change of a polymer thin film due to the above-mentioned ion or molecule doping is carried out not electrochemically but by light irradiation. Ions or molecules to be doped into the polymer thin film are generated by light irradiation.

Ions or molecules decomposed or dissociated by light irradiation are doped into the polymer thin film by diffusion, causing a spectrum change. If the dissociated or decomposed substance is an ion, it is necessary to apply a voltage at the same time, but if the dissociated or decomposed substance is an oxidizing or reducing molecule, no voltage application is necessary.

As the photodegradable or dissociable ionic conductor,
AgBr, AgI as molecules that are generated.

Silver halides such as AgCl, RbAg4I, and further silver halides such as Ag2SO4, Ag2CrO4,
Ag2CrO4, Ag2WOAg2WO41A bay g3A
SO4,Ag2Cr207. A mixture of Ag oxyacid salts such as AgBO2 and a dye sensitizer that shifts the photosensitive wavelength to longer wavelengths can be used.

On the other hand, AsF6-,
PF6-, BF4-, ClO4-, 5o42-, C1-
, I-, Br-, etc. can be used. Ions and molecules doped by light irradiation are easily dedoped by applying a reverse voltage and return to their original state.

The figure is a schematic cross-sectional view of the photoresponsive polymer thin film element of the present invention. 1 is a substrate made of plastic, glass, etc.;
2 is a transparent electrode such as ITO, 3 is a polymer thin film, and 4 is an electrolyte layer, which is an ion conductive layer in the examples described below. 5 is a counter electrode made of metal such as Pt, Au, Ag, Ni, carbon, ITO, etc., and 6 is a substrate made of plastic, glass, etc.

(Example) An ITO transparent electrode was formed on a glass substrate, and a polythiophene film was formed as a polymer thin film on the electrode by electrolytic oxidation polymerization. On the other hand, an Ag film was formed as a counter electrode on the other glass substrate, and AgBr+0.3
An ion conductive layer of wt%AgI was sandwiched between the layers.

The above element was irradiated with an argon laser at a power of several meters to 100 mW in a spot diameter of 10 pm. The area illuminated by light changed from red to blue.

On the other hand, when a voltage of -3 to -10V was applied, the blue color returned to red.

This phenomenon is thought to be due to the decomposition of 2AgBr-2Ag+Br2 by light irradiation, and the doping of Br2 molecules into the ECP (polythiophene) film, resulting in a color change of 2ECP (red) + Br2-2, ECP+, Br- (dark blue). It was done.

The above-mentioned repeatability characteristics were very excellent, and no deterioration was observed even after repeating the test 104 times or more.

(Effects of the invention) As described above based on the embodiments, the present invention has the following effects:
It has now become possible to provide a novel photoresponsive polymer thin film element that is stable and has excellent repeatability, and exhibits large spectral changes, particularly in the 600 nm to near-infrared wavelength range.

[Brief explanation of the drawing]

The figure is a schematic cross-sectional view of an element showing one embodiment of the present invention. In the figure

Claims (1)

[Claims] (1) A photo-dissociable or decomposable electrolyte containing a dopant is provided between a pair of electrode substrates, and the dopant in the electrolyte is doped between at least one electrode substrate and the electrolyte to obtain a reflection or transmission spectrum. 1. A polymer thin film element characterized by comprising a polymer thin film that causes a change in .