KR20110060336A - Electrochromic device and method of manufacturing the same - Google Patents

Abstract

PURPOSE: An electrochromic device and manufacturing method thereof are provided to implement a flexible device including an electrode which is formed at low temperature. CONSTITUTION: First substrate and second substrates(10, 20) face with each other. A first electrode(12) is formed on the first substrate. A second electrode(22) is formed on the second substrate. An electricity change color layer is located between the first electrode and the second electrode. An electrolytic layer is located between the first electrode and the second electrode. The first electrode and the second electrode include the hole transport polymer material.

Description

Electrochromic device and its manufacturing method {ELECTROCHROMIC DEVICE AND METHOD OF MANUFACTURING THE SAME}

The present disclosure relates to an electrochromic device and a method of manufacturing the same.

Electrochromic refers to a phenomenon in which a color is reversibly changed by an electric field direction when a voltage is applied. An electrochromic material may reversibly change optical properties of a material by electrochemical oxidation and reduction reactions. That is, the electrochromic material may display color when the electric field is not applied when the electric field is not applied, or display color when the electric field is not applied, or on the contrary, color disappears when the electric field is applied. May have

As described above, the color change and the light transmission characteristics may be changed according to the electric field, and thus may be applied to a device using light transmission characteristics such as a smart window.

In addition, the electrochromic material with double stability has the characteristic of remembering the discoloration state, and it shows discoloration according to the oxidation or reduction state according to the direction of the electric field, and maintains discoloration even if the electric field is disconnected unless the direction of the electric field is changed. Has the property to As described above, due to the excellent lightness and portability along with the property of maintaining an image in the absence of power consumption, it can be applied to a display device such as an electronic paper.

One aspect of the present invention provides an electrochromic device capable of realizing a flexible device including an electrode which can be formed at a low temperature.

Another aspect of the present invention provides a method of manufacturing the electrochromic device.

An electrochromic device according to an aspect of the present invention includes a first substrate and a second substrate facing each other, a first electrode formed on the first substrate, a second electrode formed on the second substrate, and the first electrode. And an electrochromic layer positioned between the second electrode and an electrolyte layer positioned between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode comprises a hole transporting polymer. Include.

The hole transporting polymer may include a substituted or unsubstituted fluorene moiety, a substituted or unsubstituted arylene moiety, a substituted or unsubstituted arylenevinylene moiety, a substituted or unsubstituted aromatic amine moiety or a combination thereof. have.

The hole transporting polymer may include a substituted or unsubstituted triphenyl amine moiety represented by Formula 1, a substituted or unsubstituted fluorene moiety represented by Formula 2, or a combination thereof.

[Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ to R ₃ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 One selected from an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, and '*' indicates a linking moiety.

The hole transport polymer may include at least one part selected from the following Chemical Formulas 3 to 8.

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Formulas 3 to 8, R ₄ to R ₂₄ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 Is an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, n is an integer of 1 or more.

The electrochromic device may further include an auxiliary layer positioned between the first electrode and the electrochromic layer.

The auxiliary layer may include titanium oxide (TiO ₂ ), zinc oxide (ZnO), carbon nano bodies, or a combination thereof.

The second electrode may include the hole transport polymer, and may further include a common electrode positioned between the second substrate and the second electrode.

The second electrode may have a transmittance of at least 80% in the visible light region.

At least one of the first substrate and the second substrate may be a transparent plastic substrate.

In another embodiment, a method of manufacturing an electrochromic device includes forming a first electrode on a first substrate, forming a second electrode on a second substrate, and bonding the first substrate and the second substrate to each other. Forming an electrochromic layer on at least one of the first substrate and the second substrate, and filling an electrolyte between the first substrate and the second substrate, and forming the first electrode. At least one of the step and forming the second electrode includes forming a hole transporting polymer at a temperature lower than 200 ° C.

At least one of the forming of the first electrode and the forming of the second electrode may form a hole transporting polymer by a solution process.

Since the electrode can be formed at a low temperature, a flexible electrochromic device can be realized.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Unless otherwise defined below, "substituted" means that a hydrogen atom in a compound is a halogen atom (F, Cl, Br, I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group , Hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C1 to C20, C2 to C16 Alkynyl group, C6 to C20 aryl group, C7 to C13 arylalkyl group, C1 to C4 oxyalkyl group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C20 cycloalkyl group, C3 to C15 It means substituted with a substituent selected from a cycloalkenyl group of, a cycloalkynyl group of C6 to C15, a heterocycloalkyl group and a combination thereof.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Hereinafter, an electrochromic device according to an embodiment of the present invention will be described with reference to FIG. 1.

1 is a cross-sectional view showing an electrochromic device according to an embodiment of the present invention.

An electrochromic device according to an embodiment of the present invention may include a display electrode formed on a pair of first and second substrates 10 and 20 facing each other and on the first and second substrates 10 and 20, respectively. 12) and counter electrode 22.

The first and second substrates 10 and 20 may be made of glass, plastic, or metal, and at least one of the first and second substrates 10 and 20 may be transparent. When the first and second substrates 10 and 20 are made of plastic, a flexible electrochromic device can be implemented. The plastic here may comprise, for example, one or more selected from polyacrylates, polyethyleneetherphthalates, polyethylenenaphthalates, polycarbonates, polyarylates, polyetherimides, polyethersulfones and polyimides.

The display electrode 12 may be made of a transparent conductive material, for example, an inorganic conductive material such as indium tin oxide ITO or fluorine tin oxide (FTO) or polyacetylene or polythiophene. It may include an organic conductive material such as.

The counter electrode 22 may be made of a hole transport polymer.

The hole transporting polymer is a material capable of transporting holes injected from an anode, and may be, for example, a conjugated polymer having π and σ bonds or a polymer containing an amine compound. Among the structures of such polymers may include, for example, substituted or unsubstituted fluorene moieties, substituted or unsubstituted arylene moieties, substituted or unsubstituted arylenevinylene moieties, substituted or unsubstituted aromatic amine moieties or combinations thereof. Can be.

The hole transporting polymer may include, for example, a substituted or unsubstituted triphenyl amine moiety represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, R ₁ is hydrogen, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C3 to C30 cycloalkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted One selected from C2 to C30 heteroaryl groups and combinations thereof, and '*' indicates a linking moiety.

The hole transporting polymer may also include substituted or unsubstituted fluorene moieties, for example represented by the following formula (2).

[Formula 2]

In Formula 2, R ₂ and R ₃ are each independently hydrogen, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C3 to C30 cycloalkyl group, substituted or unsubstituted C6 to C30 aryl group , A substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, and '*' indicates a linking moiety.

The substituted or unsubstituted triphenyl amine moiety represented by Chemical Formula 1, the substituted or unsubstituted fluorene moiety represented by Chemical Formula 2, or a combination thereof may be a compound represented by the following Chemical Formulas 3 to 8.

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Formulas 3 to 8, R ₄ to R ₂₄ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 May be one selected from an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, and n is an integer of 1 or more. The compound may be in monomeric, oligomeric or polymeric form.

The moiety represented by Chemical Formula 3 is, for example, N, N-bis [4-butylphenyl] -N, N-bis [phenyl] benzidine ([N, N-bis [4-butylphenyl) represented by the following Chemical Formula 3A. ] -N, N-bis [phenyl] benzidine]).

[Formula 3A]

The moiety represented by Formula 4 is, for example, [9,9-dioctylfluorenyl-2,7-diyl] -co- [N, N-bis [4-butylphenyl- represented by Formula 4A 1,1-biphenylene-4,4-diamine] ([9,9-dioctylfluorenyl-2,7-dyil] -co- [N, N-bis [4-butylphenyl-1,1-biphenylene-4, 4-diamine]).

[Formula 4A]

The moiety represented by Chemical Formula 5 is, for example, [9,9-dihexylfluorenyl-2,7-diyl] -co- [N, N-bis {p-butylphenyl} represented by Chemical Formula 5A -1,4-diaminophenylene] ([9,9-dihexylfluorenyl-2,7-diyl] -co- [N, N-bis {p-butylphenyl} -1,4-diamino-phenylene]) Can be.

[Formula 5A]

The moiety represented by Chemical Formula 6 may be, for example represented by one of Chemical Formulas 6A to 6C.

[Formula 6A]

[Formula 6B]

[Formula 6C]

The moiety represented by Chemical Formula 7 may be, for example represented by Chemical Formula 7A.

[Formula 7A]

The moiety represented by Chemical Formula 8 may be, for example represented by Chemical Formula 8A.

[Formula 8A]

These hole transporting polymers may exhibit conductivity when voltage is applied. In particular, the ionization potential can be adjusted according to the structure of the hole transporting polymer to control the driving voltage. The control of the driving voltage according to the structure of the hole transporting polymer may be determined according to the ratio of the hole transport moiety in the hole transporting polymer. For example, in the case of the hole transport polymer including the triphenyl amine moiety described above, the ionization potential may vary depending on the proportion of the triphenyl amine addition in the hole transport polymer. Therefore, the driving voltage can be controlled by adjusting the structure of the hole transporting polymer.

The counter electrode 23 made of the hole transporting polymer may have a transmittance of at least 80% in the visible light region.

An auxiliary electrode 22 is formed between the substrate 20 and the counter electrode 23 made of a hole transporting polymer. The auxiliary electrode 22 may be made of a transparent conductive material, for example, indium tin oxide (ITO), fluorine-containing tin oxide (FTO), a metal such as Al, antimony-containing tin oxide (ATO) and these It can include a combination of.

An electrochromic layer 14 including an electrochromic material is formed on the display electrode 12. The electrochromic material is a material capable of reversibly changing color due to oxidation and reduction reactions depending on voltage, for example, a compound including a viologen group.

An auxiliary layer 13 may be formed between the display electrode 12 and the electrochromic layer 14 to improve adhesion of the electrochromic layer 14. The auxiliary layer 13 may include, for example, titanium oxide (TiO ₂ ) or the like, and may be omitted in some cases.

A reflector (not shown) may be formed under the counter electrode 23.

The first substrate 10 and the second substrate 20 are fixed by the spacer 15, and an electrolyte 30 is filled between the first substrate 10 and the second substrate 20. The electrolyte 30 supplies an oxidation / reduction material that reacts with the electrochromic material, and may be a liquid electrolyte or a solid polymer electrolyte. As the liquid electrolyte, a solution in which a lithium salt such as LiOH or LiClO ₄ , a potassium salt such as KOH, and a sodium salt such as NaOH is dissolved in a solvent may be used, but is not limited thereto. As the solid electrolyte, for example, poly (2-acrylamino-2-methylpropane sulfonic acid) or polyethylene oxide may be used, but is not limited thereto. It is not.

In the above description, only the counter electrode 23 is made of a hole transport polymer, but the present invention is not limited thereto, and the display electrode 12 may also be made of a hole transport polymer.

Hereinafter, a method of manufacturing an electrochromic device according to an embodiment of the present invention described above will be described with reference to FIG. 1.

The display electrode 12 is formed on the first substrate 10, and the auxiliary layer 13 is formed thereon. Subsequently, an electrochromic material 14 is applied on the auxiliary layer 13.

After the auxiliary electrode 22 is formed on the second substrate 20, the hole transporting polymer is coated on the second substrate 20 and dried to form the counter electrode 23. The counter electrode 23 may form the hole transporting polymer in a solution process, and the solution process may be, for example, spin coating, slit coating, inkjet printing, spraying or dipping. The forming of the counter electrode 23 may be performed at a temperature lower than about 200 ° C. without a high temperature heat treatment and / or vacuum treatment. Therefore, the process can be simplified and can be formed on a plastic substrate, thereby manufacturing a flexible electrochromic device.

Subsequently, after the first substrate 10 and the second substrate 20 are bonded together, an electrolyte is filled between the first substrate 10 and the second substrate 20.

As such, the electrochromic device according to the embodiment of the present invention includes an electrode made of a hole transporting polymer to control driving voltage and capacitance according to the polymer structure. Therefore, the performance of the transparent electrochromic device can be improved, and in the case of the reflective electrochromic device, the visibility can be improved.

In addition, by forming the hole transporting polymer in a solution process, the process may be simplified and a low temperature process may be performed to implement a flexible display device.

The present invention will be described in more detail with reference to the following Examples. However, the following examples are merely for illustrative purposes and do not limit the scope of the present invention.

[ Example  One]

An ITO electrode is formed on the plastic substrate, and then titanium oxide and electrochromic material are coated on it. On another plastic substrate, a polymer including the moiety represented by Formula 3A is applied by spin coating and dried at about 60 ° C. Subsequently, the two plastic substrates are sealed using spacers, and then 0,05 mmol of LiClO 4 as an electrolyte is dissolved in gamma butyrolactone and injected between the substrates.

[ Example  2]

An electrochromic device was manufactured in the same manner as in Example 1, except that the polymer including the moiety represented by Chemical Formula 6A was used instead of the polymer represented by Chemical Formula 3A as the hole transporting polymer.

[ Example  3]

An electrochromic device was manufactured in the same manner as in Example 1, except that the polymer including the moiety represented by Chemical Formula 6B was used instead of the polymer represented by Chemical Formula 3A as the hole transporting polymer.

[ Example  4]

An electrochromic device was manufactured in the same manner as in Example 1, except that a polymer including a moiety represented by Chemical Formula 6C was used instead of the polymer represented by Chemical Formula 3A as a hole transporting polymer.

[ Example  5]

An electrochromic device was manufactured in the same manner as in Example 1, except that the polymer including the moiety represented by Chemical Formula 7A was used instead of the polymer represented by Chemical Formula 3A as the hole transporting polymer.

[ Example  6]

An electrochromic device was manufactured in the same manner as in Example 1, except that a polymer including a moiety represented by Chemical Formula 8A was used instead of the polymer represented by Chemical Formula 3A as a hole transporting polymer.

Check ionization potential

The ionization potential of the electrochromic device prepared according to Examples 2 to 6 is measured. In the polymers used in Examples 2 to 6, the proportion of triphenylamine addition in the polymer and the ionization potential measurement results thereof are shown in Table 1.

TABLE 1

Polymer Triphenylamine
Fraction (wt%) Ionization potential
(eV) Example 2 57 5.09 Example 3 44 5.30 Example 4 61 5.26 Example 5 53 5.04 Example 6 55 4.98

As shown in Table 1, it can be seen that the ionization potential changes depending on the proportion of triphenylamine in the hole transport polymer. Accordingly, it can be seen that the ionization potential is controlled by adjusting the structure of the hole transporting polymer.

Electrical Characteristics of Electrochromic Devices

The electrochromic device manufactured according to Example 1 was checked for electrical characteristics by using a periodic current voltage method.

2 and 3 are graphs showing cyclic volatmetry of an electrochromic device according to Example 1;

Referring to FIG. 2, when the electrochromic device manufactured according to Example 1 is circulated in a certain voltage range, it can be seen that the electrochromic material changes in current while repeating oxidation and reduction. It can also be seen that the current characteristic does not change significantly even after 5,000 repetitions. It can be seen from this excellent electrical properties and stability.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

1 is a cross-sectional view showing an electrochromic device according to an embodiment of the present invention,

2 and 3 are graphs showing a cyclic voltammetry of the electrochromic device according to Example 1;

Claims (13)

A first substrate and a second substrate facing each other, A first electrode formed on the first substrate, A second electrode formed on the second substrate, An electrochromic layer positioned between the first electrode and the second electrode, and An electrolyte layer positioned between the first electrode and the second electrode Including, At least one of the first electrode and the second electrode is an electrochromic device comprising a hole transport polymer material. In claim 1, The hole transport polymer material includes a substituted or unsubstituted fluorene moiety, a substituted or unsubstituted arylene moiety, a substituted or unsubstituted arylenevinylene moiety, a substituted or unsubstituted aromatic amine moiety, and combinations thereof Electrochromic device. 3. The method of claim 2, The hole transport polymer is an electrochromic device comprising a substituted or unsubstituted triphenyl amine moiety represented by Formula 1, a substituted or unsubstituted fluorene moiety represented by Formula 2, or a combination thereof. [Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ to R ₃ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 One selected from an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, and '*' indicates a linking moiety. 4. The method of claim 3, The hole transport polymer is an electrochromic device comprising at least one part selected from the formula (3) to (8). (3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Formulas 3 to 8, R ₄ to R ₂₄ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 Is an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, n is an integer of 1 or more. In claim 1, Electrochromic device further comprising an auxiliary layer positioned between the first electrode and the electrochromic layer. The method of claim 5, The auxiliary layer is an electrochromic device comprising titanium oxide (TiO ₂ ), zinc oxide (ZnO), carbon nano-body or a combination thereof. In claim 1, The second electrode includes the hole transport polymer, An electrochromic device further comprising an auxiliary electrode positioned between the second substrate and the second electrode. 8. The method of claim 7, And the second electrode has a transmittance of at least 80% in the visible region. In claim 1, At least one of the first substrate and the second substrate is a transparent plastic substrate. Forming a first electrode on the first substrate, Forming a second electrode on the second substrate, Bonding the first substrate and the second substrate to each other, Forming an electrochromic layer on at least one of the first substrate and the second substrate, and Filling an electrolyte between the first substrate and the second substrate Including, At least one of the step of forming the first electrode and the step of forming the second electrode comprises the step of forming a hole transporting polymer at a temperature lower than 200 ℃. In claim 10, At least one of the step of forming the first electrode and the step of forming the second electrode is a method of manufacturing an electrochromic device to form a hole transporting polymer by a solution process. In claim 10, The hole transport polymer is a method of manufacturing an electrochromic device comprising a substituted or unsubstituted triphenyl amine moiety represented by the following formula (1), a substituted or unsubstituted fluorene moiety represented by the following formula (2) or a combination thereof. [Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ to R ₃ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 One selected from an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, and '*' indicates a linking moiety. The method of claim 12, The hole transport polymer is a method of manufacturing an electrochromic device comprising at least one part selected from the formula (3) to (8). (3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Formulas 3 to 8, R ₄ to R ₂₄ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 Is an aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and a combination thereof, n is an integer of 1 or more.

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