JPS61214200A - Record display element - Google Patents

Abstract

PURPOSE:To enable to repeat coloring-erasing by using a layer of semiconductor that generates electromotive force by light, an electrochromic layer that makes coloring-erasing electrochemically by generated electrons or positive holes and a recording element provided with an electrode necessary for erasing. CONSTITUTION:An ITO electrode z2 is provided on a glass substrate and semiconductor layers 3 are laminated on it in the order of P-i-n. Conductive bodies 4 are islanded on the surface n-layer and an EC layer 5 is laminated on it. Then, a recording element is assembled by bringing the substrate and a counter electrode 7 of ITO into contact with an electrolyte 6. External light is shaded, and the electrode 2 and the counter electrode 7 are made to a closed circuit, and under this condition, He-Ne laser is irradiated. Color is formed efficiently in spotlike form in the part irradiated by the laser beam. DC1V is applied between the electrode 2 and the electrode 7 making the electrode 2 side a positive pole. The spotlike coloring irradiating a fluorescent lamp on the element is erased perfectly. Thus, information storage by photowriting becomes possible and can be erased electrically, and writing and erasing can be made repeatedly.

Description

[Detailed description of the invention] Industrial applications The present invention records and reproduces audio, 6 images, and electrical signals.

The present invention relates to a recording/display element for erasing.

BACKGROUND OF THE INVENTION Magnetic and optical storage systems have traditionally been used to store, reproduce, and erase audio, video, and electrical signals. Optical storage systems are attracting attention because they can achieve higher storage densities than magnetic storage systems. Optical storage systems record information by irradiating a TeC recording film formed on an acrylic substrate with a laser beam in response to a signal and making holes in the recording film in thermal mode; A common method is to use a TK anti-film or the like to change the crystalline state to the amorphous state in a thermal mode by irradiating laser light to create states with different light reflectances. All of these optical recording methods utilize state changes due to thermal mode, and have drawbacks in reliability, especially in terms of heat resistance.Also, in order to display a single image character or pattern, Display elements include CRT, EL, FL, and LED.

Light-emitting devices such as PDP and light-receiving devices such as LCD and ECD are used. Light-receiving type elements are easier to see in bright places than light-emitting types, and they are less irritating and less tiring on the eyes when used for long periods of time.
rface), it is logical. Among them E
CDs have attracted attention in recent years because of their characteristics such as having a display memory function and being independent of viewing angle.

Conventional ECDs apply a voltage between a display electrode and a counter electrode to electrochemically form an electrochromic layer (hereinafter referred to as E) on the display electrode.
C layer) was colored to display a pattern, which was then erased by applying a reverse voltage between the electrodes.

Problems to be Solved by the Invention The present invention improves heat resistance, which is a problem of conventional optical recording materials, and also improves heat resistance, which is a problem of conventional optical recording materials.
The purpose of the present invention is to provide a new recording element capable of displaying a fine arbitrary pattern in addition to the need for a book lead. A function that uses an electrochromic layer that electrochemically develops and erases color using generated electrons or holes and a recording element equipped with the electrodes necessary for erasing to perform optical recording and erasing in a method that is completely different from the thermal mode. This is what you get.

An electrochromic layer (hereinafter abbreviated as EC layer) is provided in the active semiconductor layer, the EC layer and a counter electrode are brought into contact with an electrolyte, and electrons and holes are generated in the portion of the semiconductor layer provided on the opposite side of the EC layer. is generated, electrons (or holes) are injected into the EC layer side, and the holes (or electrons) flow through the electrode to the counter electrode. The injection of electrons (or holes) into the EC layer is largely influenced by the state of the interface, but it can be improved by providing a conductor that makes ohmic contact with the semiconductor layer between the semiconductor layer and the 1i:0 layer. It can be done easily. In addition, by forming the conductor into an island shape, in-plane diffusion of electrons (or holes) can be prevented. When irradiated with zero or spot-shaped light, the EC layer will form a spot-like shape depending on the amount of charge generated and injected. Develops color. Next, when the light irradiation is stopped or the electrode and the opposing electrode are brought into an open circuit state, the coloring reaction stops and the coloring state is retained in the memory. Furthermore, in order to erase a spot-shaped colored part, it is possible to apply a constant erasing voltage between the electrodes, irradiate the colored part with light, and force a current opposite to that during coloring to flow.

The above coloring and erasing can be repeated.

Example [Example 1] As shown in FIG. 1, an ITO electrode 2 (In2O3+5n0
2 + AI-y Au + Cr + ML etc.) is provided by a vapor deposition method, and a semiconductor layer 3 of amorphous silicon (hereinafter abbreviated as a-s i) is formed on it by a glow discharge decomposition method. Stack them in this order. Next, on the n layer on the surface is an island shape (area is from 100 people φ to so
o person φ) and conductor 4 (Aj!.

It is formed by Au, Cr-Au)'&G#-(+Raider-Ji-Sakigaku precipitation method (c)), and an EC layer es CWO3 or Mo5s) is laminated on the entire surface by vapor deposition method. Next, the substrate and ITO facing electrode 7 (I
n203. SnO! , Au, pd, etc.) was brought into contact with the electrolyte (L1 salt-based electrolyte) 6 to assemble the recording element. Note that 8 is the back substrate (glass).Now, with external light shielded and the electrode 2 and the counter electrode 7 in a closed circuit, a He-Ne laser (632.8 nm) is applied.

8 mw), the electrodes were placed in an open circuit state, and the electrochromic layer 6 was observed from the opposite electrode side, and it was found that the laser beam irradiated area was efficiently colored in a spot shape. This coloring state could be retained in memory for a long time at room temperature. Next, electrode 2
DCl is applied between the electrodes and the counter electrode 7 with the electrode 2 side as the positive electrode.
When V was applied and the element was irradiated with external light (fluorescent lamp), the spot-like color development was completely eradicated.

Furthermore, in a high temperature storage test at 70″C17c,
It was confirmed that there was almost no deterioration in characteristics. Note that reproduction could be performed using visible light on the longer wavelength side in an open circuit state.

As in Example 1, experiments were conducted using various electrochromic layers and electrolytes, and it was found that the following materials could be used.

(Electrochromic layer) WO3, MoO2, Tt02, V2O,, Cr2O
3°Nb2o6. Fe-cyano complexes, phthalocyanine complexes, viologens, such as phosphorus blue and Berlin blue.

Organic electrochromic materials such as polypyrrole and polythiophore.

(Electrolyte) Organic electrolyte such as propylene carbonate or γ-butyrolactone in which Li salt such as L z BF4 t Li C4!04 is dissolved, KBr, KCj! An aqueous solution in which etc. are dissolved.

Li3N, LtAj! F4. β-AI! 203.
SiOX(H2O).

Ta206x(H2O), Li2SiO3-L13PO
4th class solid electrolyte. In addition, when the coloring efficiency of the electrochromic layer was low, this could be achieved by doubling the p-1-n junction and doubling the electromotive force voltage. In addition, when the electrolyte is solid, the back substrate 7 is unnecessary0 [Example 2] When an electrode active material layer was provided on the counter electrode in the same recording element as in Example 1, color development and erasing speed were improved. Did 0
The active material that was effective was I r (C)
I) xr Ni (OH)X, WO3 (polycrystalline)
.

Li2Wo4. V2O6, iron cyano complex, etc. are evaporated thin films.

[Example 3] A similar experiment was conducted in Example 1 using CdS and CdSe as the semiconductor layer instead of the a-8L photovoltaic layer. As a result, the same effect as in Example 1 was observed, although the semiconductor layer had strong light absorption and it was difficult to confirm the coloring state.

[Example 4] In Example 1, an n layer (a, -5t) was formed on the electrode 2 side, and an electrochromic layer 5 was formed on the p layer (a-5iC).
(I r (OH)X , Nl (OH)X I
7 talocyanine complex, iron cyano complex), and the functions of binding and electrical elimination of other structures were confirmed.

[Example 6] As shown in FIG. 2, P
An electrode 2 was deposited on the layer side, a conductor 4 was formed in an island shape on the n-layer side, and further an electrochromic layer 6 was formed, and combined with a counter electrode 7 and an electrolyte 6 to create a recording element. However, each constituent material used was each material of Examples-1 and -2.

When optical writing, memory retention, and electrical erasing experiments were conducted in the same manner as in Example 1, it was confirmed that the colored spots were slightly blurred, but similar effects were observed.

In addition to St, as a semiconductor substrate, Ga As
.

It has been found that compound semiconductors such as InP can also be used.

Effects of the Invention By using the present invention, it is possible to provide a completely new recording/display element that enables information storage by optical writing, is electrically erasable, and has excellent heat resistance and can be repeatedly written and erased.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the basic structure of different embodiments of the recording/display element of the present invention. 1...Substrate, 2...Electrode, 3...
...Semiconductor layer, 4...Electric conductor, 6...
Electrochromic layer, 6... Electrolyte, 7.
. . . Counter electrode, 8 . . . Back base material.

Claims (3)

[Claims] (1) An electrode is provided on one side of a semiconductor layer having photovoltaic force,
A recording/display element characterized in that an island-shaped conductor is provided on the back surface, an electrochromic layer is laminated on top of the island-shaped conductor, and the electrochromic layer and a counter electrode are in contact with an electrolyte. (2) The recording/display element according to claim 1, wherein the semiconductor layer is made of amorphous silicon. (3) The semiconductor layer made of amorphous silicon is p-i
The recording/display element according to claim 2, characterized in that it has a two-type structure: -n/p-i-n.