JP2002093584A - Conductive liquid crystal device, organic electroluminescence device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of current characteristics by impressing electric field, in an organic EL device. SOLUTION: The liquid crystal device has a π electron resonance structure in molecular structure, and is constituted of a bar-like conductive liquid crystal of negative inductive anisotropy or a discotheque conductive liquid crystal of positive inductive anisotropy, and a carrier transportation layer in which the face of the π electron resonance structure is arranged in parallel with an electrode surface by heat-treatment, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive liquid crystal device in which a carrier transport layer is formed using a conductive liquid crystal, an organic electroluminescence device using the liquid crystal device,
Further, the present invention relates to a method for manufacturing the element.

[0002]

2. Description of the Related Art As an organic electroluminescence device (hereinafter referred to as "organic EL device"), a carrier injection type EL device using an organic solid such as anthracene single crystal was studied in detail in the 1960s. Although these devices were of a single-layer type, Tang et al. Thereafter proposed a stacked organic EL device having a light emitting layer and a hole transport layer between a hole injection electrode and an electron injection electrode. The light emission mechanism of these injection-type EL devices is based on electron injection from the cathode and hole injection from the anode, migration of electrons and holes in the solid, recombination of electrons and holes, and generated singlet excitons. Luminescence,
It is common in that it goes through the stage of.

As a typical example of a stacked organic EL device, an ITO film is formed on a glass substrate as an anode, and a T
PD (N, N'-diphenyl-N, N'-di (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine) is formed to a thickness of about 50 nm, and Alq
3 (tris (8-quinolalit) aluminum) to about 50
A device is formed by forming the cathode with a thickness of nm and further depositing an Al or Li alloy as a cathode.

The work function of ITO used for the anode is 4.4 to
By setting it to 5.0 eV, holes are easily injected into the TPD, and a metal having a work function as small as possible and stable is selected as the cathode. For example, an alloy of Al and Li or Mg and A
g alloy. According to this configuration, 5V to 10V
Green light is obtained by applying a DC voltage of

A conductive liquid crystal is used as a carrier transport layer.
Examples of use are also known. For example, Nature, Vo
l. 371, p. 141, D. Adam et al
Is a long chain triphenylene compound,
The mobility of the liquid crystal phase (Dh phase) of the liquid crystal is 10^-3-10^-2c
m^Two/ Vsec and the mesophase (intermediate phase, liquid crystal phase)
Mobility is 10)^-1cm^Two/ Vsec
It has been reported. Furthermore, even in the rod-shaped liquid crystal,
Applied Physics, Vol. 68, No. 1, p. 26, by Junichi Hanna
Phenylnaphthalene-based smectic B phase
Mobility is 10 ^-3cm^Two/ Vsec or more
It has been tell.

Attempts to utilize such liquid crystals for electroluminescence include Liquid Crystal.
als, 1997, Vol. 23, no. 4, pp61
3-617, INGAH. STAFF et al report an organic EL device using a triphenylene-based discotic liquid crystal. In addition, POLYMER
S FOR ADVANCED TECHNOLOGI
ES, Vol. 9, p. 443-460, 1998,
ADVANCED MATERIALS 1997, V
ol. 9, No. 1, p. 48.

[0007]

In the conventional organic EL device, the organic layer is formed by using a low molecular weight compound, and the total thickness thereof is as thin as 100 nm to 200 nm. there were.

(1) Since the organic layer is thin, an electrical short circuit between electrodes is likely to occur. Unlike an inorganic EL element, an organic EL element cannot use an insulating film due to the necessity of injecting carriers. However, there was a problem in its driving characteristics.

(2) Since the organic layer is a thin film, the element capacity is large, the driving current is large, and the power consumption is increased.

(3) In some cases, the efficiency of injecting electrons and holes from an electrode such as ITO into an organic layer is low. This is because, when the organic compound molecule is in a crystalline state, the fine crystal grain boundaries cause carrier conduction damage, and thus the organic compound molecule is usually used in an amorphous state. It was a major cause that the quantity could not be secured. Since the electronic structure of the organic EL element has a large energy gap of about 3 eV, there is no thermally excited free carrier, and carriers injected from the electrode form a current (space charge limited current). Carrier injection efficiency has become a serious problem. Since the injection efficiency is low, the applied voltage must be increased in order to secure the amount of current, which in turn leads to thinning of the element layer thickness, which causes an electrical short between electrodes and an increase in capacitive load. Had become.

(4) Poor durability such as deterioration of light emission characteristics and drive deterioration due to the invasion of water and the influence of moisture. Normal organic E
In the L element, a cathode is formed by depositing a metal film after laminating an organic material, but a metal having a small work function suitable for the cathode is easily oxidized and has low durability. Also, when a protective film is formed by sputtering, when the forming temperature is high (generally, 100 ° C. is a limit), the organic layer is deteriorated, and the element structure is broken due to the stress of the film. Was.

(5) In addition to the above, another problem unique to the case where an electric field is applied to a liquid crystal material to flow a current is that the interaction between the dielectric anisotropy of the liquid crystal material and the external electric field causes the liquid crystal molecules to react with each other. There is a problem that reorientation (electric field reorientation) occurs and injection of carriers from the electrode surface is deteriorated. In such a material, a current flows immediately after application of an electric field, but the amount of current decreases with the passage of time, so that a stable current cannot flow.

An object of the present invention is to provide an organic EL device which solves the above-mentioned problems, and constitutes a highly reliable liquid crystal device without deterioration of current characteristics, and uses the liquid crystal device to improve reliability. And to provide an organic EL element having high luminous efficiency.

[0014]

A first aspect of the present invention is to form a liquid crystal phase having a π electron resonance structure in its molecular structure and a negative dielectric anisotropy between two opposing electrodes. It is a conductive liquid crystal element characterized by sandwiching a carrier transport layer made of a rod-shaped conductive liquid crystal material having a temperature range shown,
In the carrier transport layer, it is desirable that the π electron resonance structure plane is oriented parallel to the electrode surface.

In the second aspect of the present invention, at least a light-emitting organic layer and a liquid crystal phase having a π-electron resonance structure in its molecular structure and having a negative dielectric anisotropy are provided between two opposing electrodes. An organic electroluminescence device comprising a rod-shaped conductive liquid crystal material having a temperature range as shown, and sandwiching a carrier transport layer in which the π-electron resonance structure plane is oriented in parallel to the electrode surface.

According to a third aspect of the present invention, there is provided a disco having at least a temperature region showing a liquid crystal phase having a π electron resonance structure in its molecular structure and a positive dielectric anisotropy between two opposing electrodes. It is a conductive liquid crystal device characterized by sandwiching a carrier transport layer made of a tick conductive liquid crystal material, wherein in the carrier transport layer, the π electron resonance structure surface is desirably oriented parallel to an electrode surface. .

A fourth aspect of the present invention is that at least a light-emitting organic layer and a liquid crystal phase having a π-electron resonance structure in its molecular structure and having a positive dielectric anisotropy are provided between two opposing electrodes. An organic electroluminescence device comprising a discotic conductive liquid crystal material having a temperature range as shown, and sandwiching a carrier transport layer in which the π-electron resonance structure plane is oriented parallel to the electrode surface.

In the organic electroluminescence device according to the second or fourth aspect of the present invention, the carrier transport layer has the π-electron resonance structure plane oriented in parallel with the electrode surface by heat treatment. And that the light-emitting organic layer is in an amorphous state as a preferred embodiment.

A fifth aspect of the present invention is a step of forming a carrier transport layer by heat treatment so that the π electron resonance structure plane is oriented parallel to the surface of the first electrode; Forming a luminescent organic layer on the luminescent organic layer and forming a second electrode on the luminescent organic layer to form the luminescent organic layer and the carrier transport layer on the first electrode and the second electrode. The carrier transport layer has a π-electron resonance structure in its molecular structure, and has a dielectric constant anisotropy. A method for manufacturing an organic electroluminescent element, wherein

A sixth aspect of the present invention is a step of forming a carrier transporting layer by heat treatment so that the π-electron resonance structure plane is oriented parallel to the surface of the first electrode;
Forming a luminescent organic layer on the carrier transport layer;
Forming a second electrode on the light emitting organic layer to provide the light emitting organic layer and the carrier transport layer between the first electrode and the second electrode; The organic layer, wherein the transport layer is a layer made of a discotic conductive liquid crystal material having a temperature range showing a liquid crystal phase having a positive dielectric anisotropy having a π electron resonance structure in a molecular structure. This is a method for manufacturing an electroluminescence element.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal device of the present invention has a structure in which a rod-shaped conductive liquid crystal having a negative dielectric anisotropy is oriented parallel to an electrode surface, or a discotic conductive liquid crystal having a positive dielectric anisotropy. Is characterized in that the director is vertically oriented on the electrode surface to form a carrier transport layer in which the current characteristics are prevented from deteriorating due to the application of an electric field. And a carrier transport layer comprising a crystalline liquid crystal and having a π-electron resonance structure plane oriented parallel to the electrode surface.

The present invention mainly solves the above-mentioned problem of the prior art, particularly, the problem (3).
By using the liquid crystal layer as the carrier transport layer, other problems such as an increase in the thickness of the organic layer can be solved.

A high electric field (10 V / 1
(00 nm) is required because the mobility of carriers (holes and electrons) in the organic layer is low and the efficiency of carrier injection from the electrode to the organic layer is low.

The organic compound used for the organic EL device has a conduction band (LUM) because of its wide band gap of about 0.3 eV.
O; Lowest Unoccupied Molec
(Ultra Orbital) has no thermally excited free electrons, and the current is exclusively provided by the tunnel current injected from the electrode. The injection efficiency from this electrode depends on the work function of the electrode and the LUMO, HOMO (Hig
Hest Occupied Molecular O
It is known that there is a surface that largely depends on not only the level gap of rbital) but also the molecular arrangement and structure of the organic compound. However, organic compounds (for example, TPD, α-NPD ( Bis [N- (1-naphthyl) -N-phenyl] benzidine), TAZ-01
(3- (4-biphenylyl) -4-phenyl-5-
(4-tert-butylphenyl) -1,2,4-triazole), Alq3, etc.), it is necessary to apply a high electric field of about 10 V / 100 nm to the organic layer-electrode junction interface in order to obtain a current amount. Was. Further, since the mobility of the organic compound is about 10 ⁻³ to 10 ⁻⁵ cm ² / Vsec,
In order to secure a current, a high electric field has been required for the electric field applied to the element. Further, since the conventional monomer amorphous type organic layer is formed by a vacuum evaporation method, it is difficult to form a thick film exceeding 1 μm at least in terms of productivity.

In the present invention, the above problem is improved by using a conductive liquid crystal layer as a carrier transport layer. The function will be described below.

[1] The conductive liquid crystal has a mobility of 10 ^-2.
cm ² / Vsec (Reference: Na
cure, vol. 371, p. 141, D. Adam
et al).

[2] The conductive liquid crystal has an alignment property because it undergoes a phase transition depending on the temperature and has a smectic phase, a nematic phase or an isotropic phase at a high temperature, and is used by being oriented between electrodes as in a normal liquid crystal element. Can be. At this time, if the dielectric constant anisotropy is a rod-shaped liquid crystal, the reorientation effect by the electric field exerts a force in the direction of pressing the long axis of the liquid crystal molecules against the electrode substrate. There is no.

On the other hand, a rod-shaped liquid crystal having a positive dielectric anisotropy undergoes a change in the direction in which the long axis of the liquid crystal molecules is separated by the application of an electric field, so that the current characteristics deteriorate. In the case of discotic liquid crystal, since the π-electron resonance structure plane is orthogonal to the director direction, it is desirable that the dielectric anisotropy is positive.

[3] However, the discotic liquid crystal exhibits liquid crystallinity by forming side chains around a core such as triphenylene, and the side chains are formed on the surface of the metal substrate (I
(Including TO)), and in the liquid crystal state, the core of triphenylene or the like is oriented with respect to the electrode surface.
This has the effect of facilitating delivery of carriers from the electrodes. This makes it possible to increase the injection efficiency as compared with a normal amorphous organic compound. in this way,
By aligning a discotic liquid crystal having a hydrophobic side chain on a metal surface (including ITO), the efficiency of carrier injection from the electrode to the organic layer can be improved.

This effect is improved even in a normal rod-like liquid crystal by improving the interaction of the electrode atoms with the electron cloud by the orientation of the π-electron resonance structure surface in the molecular structure such as phenyl group and naphthalene group. It can be similarly expected that the efficiency of injection from the substrate improves.

In addition to such a static alignment effect, a rod-shaped liquid crystal having a negative dielectric anisotropy or a discotic liquid crystal having a positive dielectric anisotropy when an electric field is applied has a π-electron resonance structure surface in the direction of the electric field. The injection efficiency at the electrode interface can be further increased because the electric field orientation torque is received orthogonally.

[4] Molecules having liquid crystallinity can be rearranged on the electrode surface by reorientation treatment (post-treatment), so that injection efficiency is easily improved.

As described above, a conductive liquid crystal material having a π-electron resonance structure in the molecular structure and having a temperature region showing a liquid crystal phase is sandwiched between two opposing electrodes. Such a torque forms a carrier transport layer in which the π-electron resonance structure plane is oriented parallel to the electrode surface, whereby an organic EL device having high carrier injection efficiency can be formed.

In the present invention, the orientation of the π-electron resonance structure plane parallel to the electrode surface means not only when the π-electron resonance structure plane is completely parallel to the electrode surface, but also when the structure surface and the electrode surface are parallel to each other. Means that they are oriented so that the angle between them is less than 45 ° at the maximum.

The liquid crystal device of the present invention having the above-described carrier transporting layer made of a conductive liquid crystal is provided by the above organic E
In addition to the L element, it can be applied to various uses such as an optical sensor, a photoconductor (copier), an organic semiconductor element (organic TFT), a temperature sensor, and a spatial modulation element.

The π-electron resonance structure of the conductive liquid crystal used in the present invention may be, for example, pyridine ring, pyrimidine ring,
Pyridazine ring, pyrazine ring, tropolone ring, azulene ring, benzofuran ring, indole ring, indazole ring,
Examples include a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phenanthrene ring, and an anthracene ring.

The core structure of the discotic liquid crystal used as the conductive liquid crystal in the present invention includes a triphenylene structure and the above structure,
Examples include a metal-phthalocyanine skeleton, a phthalocyanine skeleton, a dibenzopyrene skeleton, a metal-naphthalocyanine skeleton, a dibenzopyrene skeleton, and a hexabenzocoronene skeleton.

As an electrode material used in the present invention, in addition to ITO, indium, indium oxide, tin oxide,
Cd ₂ SnO ₄ , zinc oxide, copper iodide, gold, platinum and the like, and the cathode is an alkali metal, an alkaline earth metal and its alloys such as sodium, potassium, magnesium,
Examples include lithium, sodium potassium alloy, magnesium indium alloy, magnesium silver alloy, aluminum, aluminum lithium alloy, aluminum copper alloy, aluminum copper silicon alloy and the like.

The material used for the luminescent organic layer in the organic EL device of the present invention includes, in addition to Alq3,
BeBq (bis (benzoquinolinolato) beryllium complex), DTVBi (4,4'-bis- (2,2-di-p
-Tolyl-vinyl) -biphenyl), Eu (DBM) 3
(Phen) (tris (1,3-diphenyl-1,3-
Propane diono) (monophenanthroline) Eu (II)
I)), further, diphenylethylene derivatives, triphenylamine derivatives, diaminocarbazole derivatives, bisstyryl derivatives, benzothiazole derivatives, benzoxazole derivatives, aromatic diamine derivatives, quinacridone compounds, perylene compounds, oxadiazole derivatives, coumarins Series compounds and anthraquinone derivatives. These materials are preferably laminated in an amorphous state by a vacuum deposition method.

[0040]

(Example 1) Organic EL having a sectional structure shown in FIG.
An element was manufactured. In the figure, 1 is an anode, 2 is a cathode, 3 is a carrier transport layer, 4a to 4c are luminescent organic layers, and 5 is a glass substrate. The manufacturing process is described below.

As a hole injection anode 1 on a glass substrate,
The ITO film was formed by setting the substrate temperature to 200 ° C.
200 scc Ar gas using a 10% target
m, O ₂ gas was introduced at 3 sccm to form a film by sputtering.
The work function after sputter deposition was about 4.5 eV. The ITO film was irradiated with UV light using a low-pressure mercury lamp to increase the work function. The thickness was set to 70 nm.

The above substrate was placed in a vacuum chamber having a reduced pressure of 2.66 × 10 ⁻³ Pa or less, and the following liquid crystal A was deposited to a thickness of about 50 nm by resistance heating evaporation. The deposition pressure is 1.
Vapor deposition was performed at 33 × 10 ⁻³ Pa at a vapor deposition rate of about 0.1 nm / sec.

Liquid crystal A: C ₅ H ₁₁ —COO— (Ph) — (Ph) —Br Ph is a phenylene group

[0044]

Embedded image Cry. : Crystalline phase, SmE: smectic E phase, Sm
B: Smectic B phase, Iso. : Isotropic phase

The light-emitting organic layers 4a to 4c were formed with different organic layers by mask evaporation so as to have different emission wavelengths. As a host material of the organic layer, Alq3
And a layer in which the emission wavelength is shifted to the shorter wavelength side using 5 wt% of perylene as a doping material, and an emission wavelength using DCM (a styryl dye) of 5 wt%. Were shifted to the longer wavelength side. These luminescent organic layers 4a to 4c
Was formed on the carrier transport layer 3 made of the liquid crystal A by vacuum evaporation. The deposition pressure is 1.
Deposition was performed at 33 × 10 ⁻³ Pa at a deposition rate of about 0.1 nm / sec. The structural formulas of Alq3, perylene, and DCM are shown below.

[0046]

Embedded image

Further, an AlLi alloy (Li 1.8% by weight) film was vacuum-deposited to a thickness of 50 nm as a cathode 2 on the luminescent organic layers 4a to 4c, and an Al layer was formed to a thickness of 150 nm.
Vacuum deposited to a thickness of 3 to obtain a device.

By raising the temperature of the device to 70 ° C.,
By increasing the amount of current flowing through the device, it was possible to realize electroluminescence light emission. The amount of current (injection amount of carrier) from the ITO electrode is increased by the orientation of the liquid crystal A. At this time, the long axis of the liquid crystal molecules was aligned almost parallel to the electrode surface on the ITO electrode (reorientation effect: a sample in which a cathode metal was deposited at 10 nm was observed under a polarizing microscope having an orthogonal polarizer). The same was true when the layer thickness of the liquid crystal A was 150 nm.)

In the liquid crystal A, since the dielectric anisotropy is negative due to the presence of the carbonyl group attached to the tail portion,
There is little deterioration in current density after applying an electric field. In particular, the smectic B phase, which is a low-order liquid crystal phase, has a remarkable effect of improving deterioration.

By adopting such an element configuration,
A carrier transport layer in which a conductive liquid crystal material (liquid crystal A) having a π-electron resonance structure in a molecular structure and having a temperature region showing a liquid crystal phase is sandwiched, and the π-electron resonance structure plane is oriented parallel to the electrode surface. Thus, a light-emitting device was manufactured. At this time, the liquid crystal A has a homogeneous orientation in which the director direction is parallel to the ITO electrode surface and randomly oriented between the ITO electrode and Alq3. In the case of a rod-shaped liquid crystal such as liquid crystal A, the director is parallel to the molecular long axis, and the director is arranged parallel to the electrode surface when an electric field is applied.
An organic EL device having a carrier transport layer in which the π-electron resonance structure plane was oriented parallel to the electrode plane could be constructed.

(Example 2) An organic EL device was manufactured in the same manner as in Example 1 except that the following liquid crystal B, which is a discotic liquid crystal, was vacuum-deposited to a thickness of 50 nm instead of the liquid crystal A. The deposition pressure is about 0.1 nm at 1.33 × 10 ⁻³ Pa.
/ Sec at a deposition rate of / sec.

[0052]

Embedded image

The liquid crystal B has a phase transition of 75.0% when the temperature is raised.
Crystalline phase to discotic phase (D phase, liquid crystal phase) at ℃
Phase transition from phase D to isotropic phase at 138.0 ° C. Since this liquid crystal has a carbonyl group in the side chain, the dielectric anisotropy is positive, and the director is oriented in a direction perpendicular to the electrode surface when an electric field is applied.

The obtained device was heated to 75 ° C. to produce an organic EL device using a conductive liquid crystal. At this time, the discotic column was oriented almost perpendicularly to the electrode surface on the ITO electrode (reorientation effect: confirmed by observing a sample in which a cathode metal was deposited at 10 nm under a polarizing microscope having an orthogonal polarizer. The layer thickness of the liquid crystal B is 1.
The same was true for 50 nm).

(Example 3) An organic EL device was prepared in the same manner as in Example 1 except that the liquid crystal A was replaced with the following liquid crystal C in which a rod-shaped liquid crystal core had a biphenyl structure and a tail structure had an alkoxy structure. Was prepared. LCD _{C: C 6 H 13 -O- (} Ph) - (Ph) -COO-
C ₃ H ₇

[0056]

Embedded image SmA: smectic A

The obtained organic EL device emitted good light as in Example 1.

(Example 4) An organic EL device was prepared in the same manner as in Example 1 except that the liquid crystal A was replaced with the following liquid crystal D having a rod-shaped liquid crystal core having a biphenyl structure and a tail structure having an alkoxy structure. Was prepared. LCD _{D: -O- C 9 H 19 (} Ph) - (Ph) -COO-
CH ₃

[0059]

Embedded image

The obtained organic EL device emitted good light as in Example 1.

Example 5 An organic EL was prepared in the same manner as in Example 1 except that the liquid crystal A was replaced with the following liquid crystal E having a rod-shaped liquid crystal core having a triphenyl structure and a tail structure having an alkoxy structure. An element was manufactured. LCD _{E: C 6 H 13 -CO- (} Ph) - (Ph) - (P
h) -Br

[0062]

Embedded image N: Nematic phase

The obtained organic EL device emitted good light as in Example 1.

(Example 6) An organic EL device was prepared in the same manner as in Example 2 except that hexaphenyl-n-heptyloxybenzoate of triphenylene was used instead of the liquid crystal B. In the obtained organic EL element, good light emission was obtained as in Example 2.

The liquid crystal used in this example has six ester bonds.
The permanent dipole of the molecule group has a positive strength on dielectric anisotropy (Δε)
The dielectric anisotropy is positive in order to provide a significant contribution.
In the present invention, undesirable discotic liquid crystal
Examples are hexakis ((4-O) having a negative dielectric anisotropy.
Octylphenyl) -ethynyl) benzene. Other hope
A preferred example of the liquid crystal is hexa-n-dodecanoyl oxo.
Sirksen (C₁₃H ₂₇COO)₆Is mentioned. Further
Preferred examples of 1-nitro-2,3,6,7,
10,11-hexaalkoxytriphenylene (OC_n
H_{2n + 1})₆There are 4- and 5-position homologues. for n = 5
Dielectric anisotropy is 1.2 at 35 ° C and 0.9 as positive even at 50 ° C
, There is no characteristic change when an electric field is applied.

[0066]

As described above, the liquid crystal device of the present invention has a carrier transporting layer made of a conductive liquid crystal which has excellent carrier transporting ability and does not deteriorate even when an electric field is applied. A highly reliable organic EL element in which deterioration is prevented is realized. Further, since the film can be made thicker, electric short-circuit and deterioration due to moisture, which have been caused by the thinner organic layer, can be prevented, and a highly reliable electronic device can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of an organic EL device manufactured in an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode 2 Cathode 3 Carrier transport layer 4a-4c Luminescent organic layer 5 Glass substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Moriyama, Inventor 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Naoya Nishida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term in the company (reference) 3K007 AB08 AB13 DA01 DB03 EA02 EB00 FA03 5C094 AA31 AA38 BA29 BA43 CA19 CA24 EA04 EA07 FB01

Claims (12)

[Claims] 1. At least between two opposing electrodes,
A conductive liquid crystal device comprising a carrier transport layer made of a rod-shaped conductive liquid crystal material having a temperature region exhibiting a liquid crystal phase having a negative dielectric anisotropy having a π electron resonance structure in a molecular structure. . 2. The carrier transport layer, wherein the π-electron resonance structure plane is oriented parallel to an electrode surface.
3. The conductive liquid crystal device according to item 1. 3. At least between two opposing electrodes,
A light-emitting organic layer and a rod-shaped conductive liquid crystal material having a temperature region exhibiting a liquid crystal phase having a negative dielectric anisotropy having a π-electron resonance structure in a molecular structure, wherein the π-electron resonance structure surface is an electrode. An organic electroluminescence device comprising a carrier transport layer oriented parallel to the surface thereof. 4. The organic electroluminescence device according to claim 3, wherein the carrier transport layer has the π-electron resonance structure plane oriented parallel to the electrode surface by a heat treatment. 5. The organic electroluminescence device according to claim 3, wherein the light-emitting organic layer is in an amorphous state. 6. At least between two opposing electrodes,
A conductive liquid crystal comprising a carrier transport layer made of a discotic conductive liquid crystal material having a temperature region exhibiting a liquid crystal phase having a π electron resonance structure and a positive dielectric anisotropy in a molecular structure. element. 7. The carrier transport layer, wherein the π-electron resonance structure plane is oriented parallel to an electrode surface.
3. The conductive liquid crystal device according to item 1. 8. At least between two opposing electrodes,
A light-emitting organic layer, and a discotic conductive liquid crystal material layer having a temperature region exhibiting a liquid crystal phase having a π electron resonance structure in the molecular structure and having a positive dielectric anisotropy. An organic electroluminescence device characterized in that a carrier transport layer in which is oriented in parallel with the electrode surface is sandwiched. 9. The organic electroluminescence device according to claim 8, wherein the carrier transport layer has the π-electron resonance structure plane oriented in parallel with the electrode surface by heat treatment. 10. The organic electroluminescence device according to claim 8, wherein the light emitting organic layer is in an amorphous state. 11. A step of forming a carrier transport layer by heat treatment so that a π-electron resonance structure plane is oriented parallel to a surface of the first electrode, and forming a light-emitting organic layer on the carrier transport layer. And forming a second electrode on the luminescent organic layer to provide the luminescent organic layer and the carrier transport layer between the first electrode and the second electrode. The carrier transport layer has a π-electron resonance structure in its molecular structure and is a layer made of a rod-shaped conductive liquid crystal material having a temperature region showing a liquid crystal phase having a negative dielectric anisotropy. A method for producing an organic electroluminescence element. 12. A step of forming a carrier transport layer by heat treatment so that a π electron resonance structure plane is oriented parallel to a surface of the first electrode, and forming a light-emitting organic layer on the carrier transport layer. And forming a second electrode on the luminescent organic layer to provide the luminescent organic layer and the carrier transport layer between the first electrode and the second electrode. The carrier transport layer has a π-electron resonance structure in its molecular structure, and is a layer made of a discotic conductive liquid crystal material having a temperature region indicating a liquid crystal phase having a positive dielectric anisotropy. A method for producing an organic electroluminescent device, characterized by: