WO2007036561A2

WO2007036561A2 - Electrochromic pastes comprising novel dyes

Info

Publication number: WO2007036561A2
Application number: PCT/EP2006/066877
Authority: WO
Inventors: Christoph Brabec; Hans-Dieter Feucht; Jens Hauch; Andreas Kanitz
Original assignee: Siemens Aktiengesellschaft
Priority date: 2005-09-30
Filing date: 2006-09-29
Publication date: 2007-04-05
Also published as: WO2007036561A3

Abstract

The invention relates to organic semiconductor components and especially electrochromic organic semiconductor components including novel electrochromic pH based pastes which comprise novel dyes. A redox system, a conducting salt and a dye are present in the paste in combined form and/or as a mixture. The invention also relates to the semiconductor components that comprise pastes of the aforementioned kind and/or in which the novel dyes are contained in the active layer. The dyes have a high bistability and have their long-wave absorption maximum in the near IR range.

Description

description

Electrochromic pastes with new dyes

The invention relates to organic semiconductor devices and more particularly to electrochromic organic semiconductor devices comprising electrochromic pastes comprising novel dyes wherein the pastes comprise a redox system, a conducting salt and a dye combined in a substance and / or as a mixture. Likewise, the invention relates to the semiconductor devices comprising such pastes and / or in which the new dyes are contained in the active layer.

The production of a flexible display with very low power consumption and / or high-resolution passive matrix displays based on electrochromic materials.

Electrochromic displays normally consist of 3 layers. One layer of this is the actual electrochromic material, a second layer has the function of an ion storage or dispenser and a third layer, which consists of an electrolyte and connects the first two layers together. When a voltage is applied between the electrochromic layer and the ion storage layer, the reflection and transmission properties of the electrochromic layer change and the material discolors. Materials are known, for example, from WO 02/0754411, which combines the function of the electrolyte and the color system in one layer. The layer consists of a redox system which is dissolved in an electrolyte. By applying a voltage, the concentration ratio of the redox partner is shifted to each other. In this reaction, protons and / or ions are released or bound, and thus the pH of the material is affected. Via a pH dye, the change in pH is then converted into a color change. When a voltage is applied to the system, the shift in the equilibrium of the redox partners on the two electrodes is in the opposite direction. As a result, the pH of one of the electrodes rises while it sinks on the counter electrode. When the voltage is removed, the system returns to its original state via diffusion and loses the assumed color again. This leads to a temporally limited bistability of the discoloration, which is determined by the diffusion rate of the reactants in the system. However, the bistability or the ratio of the discoloration time, ie of a defined contrast to the decolorization time, without applied voltage or shorted to 80% of the discoloration, is an important parameter for displays. The bistability determines how often a "refresh" pulse is needed to restore the discoloration, which has a direct effect on the power consumption, but also limits the maximum number of lines for pixelated passive matrix displays.

Classic pH dyes change color over a range of pH's, which is very useful for pH determination. However, in an electrochromic system, such as the electrochromic paste described above, this is not necessarily desirable because two positive effects can be achieved by a dye which has a very sharp color change over pH. On the one hand, a sharp color change leads to a optically faster turn-on behavior, since the basic pH value of the system can be set very close to the switching threshold. On the other hand, this leads to an increased visually perceivable bistability, since the color changes only slightly as the pH of the system approaches this switching point again. To be able to use the effect, however, new classes of dyes, which are fundamentally different from the classical pH dyes, necessary.

The object of the invention is therefore to provide electrochromic pastes that have a high bistability at the same time enable sharp color conversion in electrochromic systems. In addition, it is an object of the present invention to provide an organic component whose active layer comprises at least one dye with bistability improved according to the invention.

These objects are achieved by the subject matter of the claims in conjunction with the explanations in the description and examples.

According to an advantageous embodiment, electrochromic pastes comprise the following constituents a redox system, for example the quinone / hydroquinone or quinone / duroquinone redox system, preferably dissolved in an organic carbonate, particularly preferably in a propylene carbonate, a conducting salt or a mixture of several conducting salts and a dye.

An organic semiconductor device according to the invention comprises a substrate, a lower electrode, an upper electrode and in between an active organic layer in which at least one dye according to the invention is contained.

The invention is based on known redox systems and conductive salts and the further development of the dyes according to the invention in these systems is described.

The new electrochromic dye classes are in particular types of methine dyes in which the longest wavelength absorption maximum is in the NIR range of the electromagnetic spectrum. Since the human eye is particularly insensitive in this area, the formation of a visible dye, due to a change in pH, perceived much sharper. Therefore, such layers with common methine dye concentrations appear colorless or almost colorless. If, by protonation or deprotonation, a conversion of the methine structure of the dye occurs, a new chromophore structure forms, which has its long-wavelength absorption maximum in the visible spectral range of the electromagnetic spectrum and which is easily perceptible to humans.

Structure type A: Deprotonatable methine substances

An ^"

Methine dye (cationic) merocyanine

For the following applies:

R1 can be H, alkyl (branched or unbranched Cl to ClO) or

Aryl (preferably phenyl),

R 2 and R 2 * independently of one another are alkyl (branched or unbranched Cl to ClO), aryl (preferably phenyl) or an alkylene structure bridged with Y 1 and / or Y 2

[(CH 2) 3, (CH 2) 4 or -C (CH 3) 2 -CH = C (CH 3) -],

R 3 and R 3 * independently of one another are H, alkyl (branched or unbranched C 1 to C 10), aryl (preferably phenyl) or both are bonded via an oxygen atom or sulfur atom,

X1 and X2 are each, independently of one another, -O-, -S-, -Se-, a vinylene grouping (-CH =CH-) or a benzanelated vinylene grouping, Y1 and Y2 independently of one another are -CH =, -C-alkyl =

(branched or unbranched Cl to ClO), -C-aryl = (preferably phenyl) or -N =,

Z is a) a monomethine grouping, for example -N = or -CH = b) a trimethine grouping, for example -CH = CH-CH = or

(Quadrainat;

c) a Pentamethingruppierung, for example

with R equal to Cl or substituted by an organic one

Rest; and An ^" represents any anion, preferably the perchlorate anion

Structure type B: Anionic methine dyes

r

Oxonol type methine dye (anionic)

For the following applies:

X1 and X2 independently of one another are -O-, -S-, -Se-, a vinylene grouping (-CH = CH-) or a benzanelated vinylene grouping,

Y 1 and Y 2 are each, independently of one another, -CH =, -C-alkyl = (branched or unbranched Cl to ClO), -C-aryl = (preferably phenyl) or -N =,

Z is a) a monomethine grouping, for example -N = or -CH = b) a trimethine grouping, for example -CH = CH-CH = o-

of the

(Quadrainat)

a Pentamethingruppierung, for example

or with R equal to Cl or substituted by an organic one

Rest; and K ⁺ is any cation, preferably that

triethylammonium,

Structure type C: Protonatable methine dyes

Methine dye (cationic) methine dye (dicationsch)

For the following applies:

Alk = alkyl groups (branched or unbranched Cl to

ClO), n = 2, 3 or 4;

An ^" = any anion, preferably the perchlorate anion Structure type D: Protonable Michler's ketone type

Dyes with weakly basic amine functions

-If ₊ H ^T

for the following applies:

Ar is aromatic radical, preferably phenyl and 1-

Naphthyl, n can be 0 or 1, for the case n = 1, the substituents Rl form a chemical bond and the

Substituents R 2 are H or phenyl

X is -O-, -S-, -Se-, a vinylene grouping (-CH = CH- or a benzanelated vinylene grouping,

Y is -CH =, -C-alkyl = (branched or unbranched Cl to ClO), -C-aryl = (preferably phenyl) or -N =,

Structure type E: barbituric acid-derived merocyanine

For the time:

R 1 is alkyl (branched or unbranched C 1 to C 10), R 2 is alkyl (branched or unbranched C 1 to C 10) or aryl (preferably phenyl and 1-naphthyl), n is 2, 3 and 4 X is O or S. ,

The dyes of the invention are characterized by a high bistability, which reduces the power consumption of a single electrochromic element, and makes possible the production of high-resolution passive matrix displays. The use of the dyes described and illustrated by way of example in organic semiconductor technology is likewise part of the invention.

In the following, the individual structural types will be explained in more detail on the basis of exemplary embodiments.

i) Electrochromic paste with a quinone / hydroquinone redox system dissolved in propylene carbonate with conductive salt, polyethylene oxide and dye

Dye examples:

Structure type A:

Structure type B:

Structure type C

Structure type D

Structure type E:

According to the invention, dyes are used for the first time in electrochromic systems whose longest wavelength absorption maximum is in the near IR range and which are characterized by high bistability.

Claims

claims

1. Electrochromic paste comprising a redox system, a conductive salt and a dye, wherein the dye is selected from the series of dyes whose longest wavelength absorption maximum in the range of about 800 nm of the electromagnetic spectrum.

2. Electrochromic paste according to claim 1, wherein the dye is a methine dye.

3. An electrochromic paste as claimed in claim 1 or 2, wherein the dye is selected from the group of deprotonatable methine dyes, protonatable methine dyes, anionic methine dyes, protonatable dyes of Michler's ketone type and / or merocyanine derived from barbituric acid. Dyes.

4. Electrochromic paste according to one of the preceding claims, wherein the dye is selected from the group of the following general structures A to E.

Structure type A:

An ^"

Methine dye (cationic) merocyanine

With

Rl is H, alkyl (branched or unbranched Cl to ClO ^', or aryl, preferably phenyl,

R2 and R2 * are each independently alkyl (branched or unbranched Cl to ClO), aryl, preferably phenyl or an alkylene structure bridged with Y 1 and / or Y 2 [(CH ₂ ) 3, (CH ₂ ) ₄ or -C (CH ₂ ) ₂ -CH = C (CH ₃ ) -],

R 3 and R 3 * independently of one another are H, alkyl (branched or unbranched Cl to ClO), aryl, preferably phenyl, or both are linked via an oxygen atom or sulfur atom,

Y 1 and Y 2 independently of one another represent -CH =, -C-alkyl = (branched or unbranched Cl to ClO), -C-aryl =, preferably phenyl or -N =,

Z stands for a monomethine grouping, for example -N = or -CH =

a trimethine grouping, for example -CH = CH-CH = or

(Quadrainat)

a Pentamethingruppierung, for example

or with R equal to Cl or substituted by an organic one

Rest; and An ^" represents any anion, preferably the perchlorate anion Structure type B:

K ⁺

oxonol

Methine dye (anionic)

With

R 3 and R 3 * independently of one another are H, alkyl (branched or unbranched C 1 to C 10), aryl, preferably phenyl, or both are bonded via an oxygen atom or sulfur atom,

Y 1 and Y 2 independently of one another represent -CH =, -C-alkyl = (branched or unbranched Cl to ClO), -C-aryl =, preferably phenyl, or -N =,

Z stands for a monomethine grouping, for example -N = or -CH =

a trimethine grouping, for example -CH = CH-CH = or

(Quadrainat)

a Pentamethingruppierung, for example

with R equal to Cl or substituted by an organic radical;

and K ⁺ is any cation, preferably the triethylammonium cation,

Structure type C:

Methine dye (cationic) methine dye (dicationsch)

With

Alk = alkyl groups (branched or unbranched Cl to

ClO), n = 2, 3 or 4;

An ^" = any anion, preferably the perchlorate anion

Structure type D:

- H + lf

With

Ar is aromatic radical, preferably phenyl and 1-

Substituents R 2 are H or phenyl,

Structure type E:

For the time:

R1 is alkyl (branched or unbranched Cl to ClO ^' R2 is alkyl (branched or unbranched Cl to ClO) or aryl (preferably phenyl and 1-naphthyl), n is 2, 3 and 4 X is O or S.

5. Use of one of the dyes of claim 4 in an organic semiconductor device.

An organic semiconductor device comprising a substrate, at least one lower electrode, an upper electrode and at least one active layer therebetween, wherein a dye according to any one of claims 1 to 4 is contained in at least one active layer.