JP2005093573A - Organic semiconductor laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor laser which is not required to form an organic thin film layer by a vacuum process and ensures an excellent film forming property without including any pin-hole or the like. <P>SOLUTION: On a substrate, an anode electrode layer, a light emitting layer, and a cathode electrode layer are laminated in this sequence. The light emitting layer includes a polymer material including a repetitive unit expressed by the following formula (I). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a current excitation type organic semiconductor laser using an organic polymer material.

  In order to realize an advanced information society, high-speed and large-capacity optical communication technology is indispensable, and one of the important devices that support this technology is a laser. At present, inorganic semiconductor lasers are used, but there is a problem of solving the high cost due to complicated manufacturing processes.

  On the other hand, recently, an organic electroluminescence (EL) element has been developed and is expected to be put to practical use for a color display panel of a mobile phone soon. Although organic EL has a simpler device structure than inorganic semiconductors, it can emit multicolor light. In particular, since light having a short wavelength (400 nm to 550 nm) can be obtained as compared with the wavelength of light (generally 620 nm to 800 nm) obtained with an inorganic semiconductor laser, for example, a large capacity (higher recording density) can be achieved. Since it can be expected to be applied in various fields, it is expected that it will be developed into an organic semiconductor laser in the future, and many studies and reports have been made so far.

  As this literature, the following nonpatent literature 1-3 is mentioned, for example.

However, since the organic semiconductor laser exemplified above uses a low-molecular compound as a light emitting material, film formation by a vacuum process is required, and a complicated manufacturing process is required as in the case of an inorganic semiconductor laser.
In addition, in the film formation process of these organic low molecular weight compounds by the vacuum evaporation method, a microcrystalline polycrystalline thin film is formed, and problems such as pinholes associated therewith cannot be avoided. It is difficult to obtain efficiently.

S. R. Forrest, et al. , Nature 389, 362 (1997) R. E. Slusher, et al. , Appl. Phys. Lett. 71,230 (1997) S. R. Forrest, et al. , Appl. Phys. Lett. 72, 144 (1998)

  In view of the above-described problems, an object of the present invention is to provide an organic semiconductor laser that does not need to form an organic thin film layer by a vacuum process and has excellent film forming properties without a pinhole or the like.

As a result of intensive studies, the present inventors have found that the above problem can be solved by using a specific organic polymer material for the light emitting layer, and have completed the present invention.
According to the present invention, the following organic semiconductor laser is provided.

  The invention of claim 1 is a polymer having at least a repeating unit represented by the following formula (I) in the light emitting layer in an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer and a negative electrode layer are laminated in this order. An organic semiconductor laser comprising a material.

(In the formula, R ¹ represents a group selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and Ar represents a substituted or unsubstituted aromatic hydrocarbon group.)

The invention according to claim 2 is the organic semiconductor laser according to claim 1, wherein R ¹ in the formula (I) is a substituted or unsubstituted alkyl group or alkoxy group having 1 to 18 carbon atoms. .

  According to a third aspect of the present invention, there is provided an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order, and a polymer having at least a repeating unit represented by the following formula (II) in the light emitting layer: An organic semiconductor laser comprising a material.

(In the formula, R ¹ represents a group selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group.)

  According to a fourth aspect of the present invention, there is provided an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order. An organic semiconductor laser comprising a material.

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 And when there are a plurality of R ¹ , R ² and R ³ , they may be the same or different, and Ar represents a substituted or unsubstituted aromatic hydrocarbon group.)

The invention of claim 5 is characterized in that, in the formula (III), at least one of R ¹ , R ² and R ³ is a substituted or unsubstituted alkyl group or alkoxy group having 1 to 18 carbon atoms. Item 5. An organic semiconductor laser according to Item 4.

  The invention of claim 6 is the organic semiconductor laser according to claim 4 or 5, wherein the light emitting layer further contains a polymer material having a repeating unit represented by the following formula (IV).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 Represents an integer of ¹ to 4, and when there are a plurality of R ¹ , R ² and R ³ , these may be the same or different, and R ⁴ is selected from a substituted or unsubstituted alkyl group or an alkoxy group Represents a group to be

  The invention according to claim 7 is the organic semiconductor laser according to claim 4 or 5, wherein the light emitting layer further includes a polymer material having a repeating unit represented by the following formula (V).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 To R 4, when there are a plurality of R ¹ , R ² , and R ³ , these may be the same or different, and R ⁵ and R ⁶ may be substituted or unsubstituted alkyl groups or alkoxy Represents a group selected from a group.)

  The invention of claim 8 is the organic semiconductor laser according to claim 4 or 5, wherein the light emitting layer further contains a polymer material having a repeating unit represented by the following formula (VI).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 To R 4, when there are a plurality of R ¹ , R ² , and R ³ , these may be the same or different, and R ⁷ and R ⁸ are substituted or unsubstituted alkyl groups or alkoxy groups. Represents a group selected from

  The invention according to claim 9 is characterized in that a hole transport layer is provided between the positive electrode layer and the light emitting layer, and an electron transport layer is provided between the light emitting layer and the negative electrode layer. It is an organic-semiconductor laser of any one of Claims 1-8.

A tenth aspect of the present invention is the organic semiconductor laser according to the ninth aspect, wherein the hole transport layer has a thickness of 100 to 2000 nm.
The invention according to claim 11 is the organic semiconductor laser according to claim 9, wherein the electron transport layer has a thickness of 100 to 2000 nm.
A twelfth aspect of the present invention is the organic semiconductor laser according to any one of the first to ninth aspects, wherein a reflective layer is provided between the positive electrode layer and the light emitting layer.
A thirteenth aspect of the present invention is the organic semiconductor laser according to the twelfth aspect, wherein a reflective layer is provided between the light emitting layer and the negative electrode layer.
The invention of claim 14 is the organic semiconductor laser according to any one of claims 1 to 13, wherein a resonator is provided on one surface of the positive electrode layer.
The invention of claim 15 is characterized in that a positive electrode layer is provided on a substrate, a light emitting layer is provided on the positive electrode layer, and a negative electrode layer is provided on the light emitting layer. The organic semiconductor laser according to any one of 1 to 14.
The invention of claim 16 is the organic semiconductor laser according to any one of claims 1 to 15, wherein the light emitting layer contains a hole transport material.
The invention according to claim 17 is the organic semiconductor laser according to any one of claims 1 to 15, wherein the light emitting layer contains an electron transport material.
The invention according to claim 18 is the organic semiconductor laser according to any one of claims 1 to 15, wherein the light emitting layer contains a hole transport material and an electron transport material.
The invention according to claim 19 is the organic semiconductor laser according to any one of claims 1 to 18, wherein the light emitting layer is formed by a wet method.

  According to the present invention, it is not necessary to form an organic thin film layer by a vacuum process, and an organic semiconductor laser excellent in film forming properties without a pinhole or the like is provided.

Hereinafter, the present invention will be described in detail.
In the organic semiconductor laser of the present invention, at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order. An organic semiconductor laser having such a laminated structure is known, but the organic semiconductor laser of the present invention is characterized in that the light emitting layer includes a polymer material having at least a repeating unit represented by the above formula (I). To do. With this configuration, the organic semiconductor laser of the present invention can be easily manufactured even with a simple manufacturing process.

According to a further preferred embodiment, the light emitting layer includes at least a polymer material having a repeating unit represented by the formula (II).
According to another aspect of the present invention, the light emitting layer includes a polymer material having at least a repeating unit represented by the formula (III).

Of the polymer materials having a repeating unit represented by the above formula (III), a more preferred embodiment is a polymer material having a repeating unit represented by the above formula (IV).
Further, among the polymer materials having a repeating unit represented by the above formula (III), another more preferable embodiment is a polymer material having a repeating unit represented by the above formula (V).
Furthermore, among the polymer materials having a repeating unit represented by the above formula (III), another more preferable embodiment is a polymer material having a repeating unit represented by the above formula (VI).

In the above formulas (I) to (VI), the alkyl group or alkoxy group of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ is more soluble as the carbon number increases. However, since the carrier mobility is lowered, it is preferable to select a group that provides desired characteristics within a range where the solubility is not impaired. Examples of suitable groups in that case include alkyl groups or alkoxy groups having 1 to 25 carbon atoms. More preferably, it is an alkyl group or alkoxy group having 1 to 18 carbon atoms. A plurality of the same groups may be introduced, or a plurality of different groups may be introduced. In addition, these alkyl groups or alkoxy groups are further substituted with a halogen atom, a cyano group, a phenyl group, a hydroxyl group, a carboxyl group or a linear, branched or cyclic alkyl group or alkoxy group having 1 to 12 carbon atoms. It may contain a group.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, Heptyl group, octyl group, nonyl group, decyl group, 3,7-dimethyloctyl group, 2-ethylhexyl group, trifluoromethyl group, 2-cyanoethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, A cyclopentyl group, a cyclohexyl group, etc. can be mentioned as an example, As an alkoxy group, what inserted the oxygen atom or the sulfur atom in the bond position of the said alkyl group and made it an alkoxy group is mentioned as an example.

  The polymer material is further improved in solubility in a solvent due to the presence of an alkyl group or an alkoxy group. It is important to improve the solubility of these materials because the manufacturing tolerance of the film wet film forming process is increased. For example, the choice of coating solvent is expanded, the temperature range during solution preparation is expanded, the temperature and pressure range during solvent drying is expanded, and the high processability results in high purity and high uniformity. The possibility of obtaining a high-quality thin film increases.

The substituted or unsubstituted aromatic hydrocarbon group in the above formula may be a monocyclic group or a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group), and examples thereof include the following.
Examples thereof include a phenyl group, a naphthyl group, a pyrenyl group, a fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, a chrycenyl group, a biphenylyl group, and a terphenylyl group. Moreover, these aromatic hydrocarbon groups may have a substituent shown below.
(1) Halogen atom, trifluoromethyl group, cyano group, nitro group.
(2) An unsubstituted or substituted alkyl group or alkoxy group having 1 to 25 carbon atoms.
(3) Aryloxy group. (An aryloxy group having a phenyl group or a naphthyl group as the aryl group is exemplified. This includes an unsubstituted or substituted alkyl group having 1 to 25 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 25 carbon atoms, or A halogen atom may be contained as a substituent, specifically, a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methylphenoxy group, a 4-methoxyphenoxy group, a 4-chlorophenoxy group, And 6-methyl-2-naphthyloxy group.
(4) A substituted mercapto group or an aryl mercapto group. (Specific examples of the substituted mercapto group or aryl mercapto group include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.)
(5) An alkyl-substituted amino group. (Specifically, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (p-tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And a urolidyl group.)
(6) Acyl group. (Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.)

  Examples of the method for producing a polymer material having a repeating unit represented by the above formulas include a Yamamoto method using a halide, a Suzuki method using a halide and a boronic acid, and a Wittig-Horner reaction using an aldehyde and a phosphonate. In addition, a Wittig reaction using an aldehyde and a phosphonium salt, a Heck reaction using a vinyl substituent and a halide, a Ullmann reaction using an amine and a halide, and the like can be used, and they can be produced by a known method.

  The preferable molecular weight of the polymer material having a repeating unit represented by each of the above formulas is 1000 to 1000000 in terms of polystyrene-equivalent number average molecular weight, and more preferably 2000 to 500000. If the molecular weight is too small, it will be cracked during film formation and become less practical. On the other hand, when the molecular weight is too large, the solubility in a general solvent is deteriorated, the viscosity of the solution becomes high and coating becomes difficult, and the practicality is also poor.

Next, the layer structure of the organic semiconductor laser of the present invention will be described with reference to FIGS. 1 to 4 are sectional views of the organic semiconductor laser of the present invention.
As shown in FIG. 1, the organic semiconductor laser of the present invention includes at least a positive electrode layer 2, a light emitting layer 3, and a negative electrode layer 4 laminated in this order, and the positive electrode layer 2, the light emitting layer 3, and the negative electrode layer. 4 is usually formed on the substrate 1 so that the positive electrode layer 2 is in contact with the substrate 1 (with the negative electrode layer 4 side facing away from the substrate 1). Since the organic semiconductor laser of the present invention is configured in this way, holes are injected from the positive electrode layer 2 provided on the substrate 1 to the light emitting layer 3, and electrons are injected from the negative electrode layer 4 to the light emitting layer 3. Is injected and light is obtained by recombination of the holes and the electrons in the light emitting layer 3. This light is amplified by repeatedly reflecting between the reflective layers (specifically, the contact surface between the positive electrode layer 2 and the light emitting layer 3 and / or the contact surface between the light emitting layer 3 and the negative electrode layer 4). And emitted as laser light.

  As the substrate 1, glass, plastic film or the like can be generally used.

In the present invention, the positive electrode layer 2 has a function of injecting holes into the light emitting layer 3 (when a hole transport layer is provided, the light emitting layer 3 is passed through the hole transport layer as described later). The positive electrode layer 2 is preferably formed of a metal having a high work function (4 eV or more), an alloy thereof, an electrically conductive compound, and a mixture thereof. Specific examples of such electrode materials include metals such as Au, and conductive materials such as CuI, ITO (indium tin oxide), SnO ₂ , and ZnO. The thickness of the positive electrode layer 2 is usually 10 nm to 1 μm, preferably 50 to 200 nm. As a method for forming the positive electrode layer 2, a conventionally known method such as vapor deposition or sputtering can be used.

In the present invention, the negative electrode layer 4 has an action of injecting electrons into the light emitting layer 3 (as will be described later, when an electron transport layer is provided, through the electron transport layer into the light emitting layer 3). The negative electrode layer 4 is preferably formed of a metal having a small work function (4 eV or less) or an alloy thereof, an electrically conductive compound, and a mixture thereof. Specific examples of such electrode materials include Na, Na · K alloy, Mg, Li, Mg / Cu mixture, Mg · Ag alloy, Al·Li alloy, Al / Al ₂ O ₃ mixture, In, rare earth metal, etc. Is mentioned. The thickness of the negative electrode layer 3 is usually 10 nm to 1 μm, preferably 50 to 200 nm. As a method for forming the negative electrode layer, a conventionally known method such as vapor deposition or sputtering can be used.

In the present invention, the light emitting layer 3 has a function of generating light by recombining holes injected from the positive electrode layer 2 and electrons injected from the negative electrode layer 4. The light emitting layer 3 of the present invention contains the polymer material described above. Moreover, when the light emitting layer 3 is formed for the purpose of improving electrical characteristics, an electron transport material and / or a hole transport material described later may be included together with the polymer material.
There is no restriction | limiting in particular in the film thickness of a light emitting layer, Although it can select suitably, Usually, it is preferable to set it as the range of 5-500 nm.

  In the present invention, the light emitting layer 3 can be easily formed into a thin film by a known method such as a spin coating method, a casting method, an inkjet method, a dipping coating method, for example, a wet method. The polymer material used in the present invention is easily dissolved in an organic solvent such as dichloromethane, tetrahydrofuran, chloroform, toluene, dichlorobenzene and xylene. Therefore, the light emitting layer 2 can be easily produced by preparing a solution having an appropriate concentration with an appropriate solvent capable of dissolving the polymer material and applying the solution by the above-described method or the like.

  In the organic semiconductor laser of the present invention, as shown in FIG. 2, a hole transport layer 5 is provided between the positive electrode layer 2 and the light emitting layer 3, and electrons are disposed between the light emitting layer 3 and the negative electrode layer 4. A transport layer 6 is preferably provided. With this configuration, light is generated in the light emitting layer 3 by applying a voltage between the positive electrode layer 2 and the negative electrode layer 4, and the light is transmitted to the hole transport layer 5, the light emitting layer 3, and the like. The light can be emitted from the end of the light emitting layer 3 after being amplified by repeating total reflection on the contact surface of the light emitting layer 3 and / or the contact surface of the electron transport layer 6 and the light emitting layer 3.

  Examples of hole transport materials used for the hole transport layer 5 include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, Arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds , Conductive polymer oligomers such as polyvinylcarbazole derivatives, aniline copolymers, thiophene oligomers, and polythiophenes.

  Examples of the electron transport material used for the electron transport layer 6 include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthalene perylene, carbodiimides, fluorenylidenemethane derivatives, Andraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Also, a series of electron transport compounds described in JP-A-59-194393 can be used as an electron transport material. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material. In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum. , Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc and the like, and the central metals of these metal complexes are In, Mg, Cu, Ca Metal complexes replaced with Sn, Ga or Pb can also be used as the electron transport material. In addition, metal-free or metal phthalocyanine, or those having a terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material. Distyrylpyrazine derivatives can also be used as an electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as an electron transport material. The electron transport layer 6 made of the above electron transport material has an electron donating donor made of a compound such as an alkali metal or alkaline earth metal and a fluoride, chloride or iodide of the alkali metal or alkaline earth metal. It is preferable to dope by 1 to 30 mol%.

  In the present invention, the electron transport layer 5 and the hole transport layer 6 exemplified above can be formed by a conventionally known method such as a spin coating method, a casting method, a vapor deposition method, or a sputtering method. It is preferable to use a vapor deposition method.

  The thickness of the hole transport layer 5 is preferably 100 to 2000 nm, and more preferably 200 to 500 nm. The thickness of the electron transport layer 6 is preferably 100 to 2000 nm, and more preferably 200 to 500 nm. If the thickness of the hole transport layer 5 and the thickness of the electron transport layer 6 are within such ranges, the light emitted from the light emitting layer 3 is totally reflected at the contact surface between the hole transport layer 5 and the light emitting layer 3, and the laser light is reflected. Can be obtained. If the thickness of the hole transport layer 5 or the electron transport layer 6 is too thin, there is a possibility that the light emitted from the contact surface is totally reflected and laser light cannot be obtained. There is a risk of doing.

  In the organic semiconductor laser of the present invention, it is preferable that a reflective layer 7 is provided between the positive electrode layer 2 and the light emitting layer 3 as shown in FIG. With this configuration, light is repeatedly reflected and amplified between the reflective layer 7 and the negative electrode layer 4 (waveguide effect), so that the amplified laser light is extracted from the end face of the organic semiconductor laser. be able to. From this viewpoint, it is preferable that a reflective layer (not shown) is also provided between the light emitting layer 3 and the negative electrode layer 4.

  As an example of a material that can be used for the reflective layer 7, it is preferable to use a metal having a high reflectance. Examples of the metal include those similar to those used for the negative electrode layer 4 shown above.

  In the organic semiconductor laser of the present invention, it is preferable that the resonator 8 is provided on one surface of the positive electrode layer 3 in order to obtain laser light amplified more efficiently. Specifically, as shown in FIG. 4, it is preferable that the resonator 8 is provided on the substrate 1, and the positive electrode layer 2, the light emitting layer 3, and the negative electrode layer 4 are laminated on the resonator 8 in this order. . The resonator may be provided on the positive electrode layer 3 (between the positive electrode layer 2 and the light emitting layer 3). Thereby, the light generated in the light emitting layer 3 is amplified and reflected in the diffraction grating waveguide in the resonator, and is efficiently extracted as laser light.

  As an example of the resonator structure used in the present invention, it is preferable to use a distributed feedback resonator such as DFB (Distributed Feedback) or DBR (Distributed Bragg Reflector). The diffraction grating for obtaining these resonators can be manufactured by a conventionally known lithography technique.

  2 to 4, the laminate composed of the positive electrode layer 2 and the like is placed on the substrate 1 with the positive electrode layer 2 side facing the substrate 1 (the negative electrode layer 4 side is opposite to the substrate 1). 1 is preferably used, and as the material constituting the substrate 1, those described in the embodiment of FIG. 1 are preferably used.

  The present invention will be described in detail by the following examples, but the present invention is not limited thereto.

Example 1
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. An organic positive photoresist was applied onto this substrate, and a diffraction grating (resonator) with a pitch of 500 nm was produced by lithography. On top of this, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (TPD) was deposited to a thickness of 250 nm as a hole transport layer. did. Subsequently, as a polymer material, a 1.5% by mass dichloromethane solution of a polymer material having a repeating unit represented by the following formula (1) (number average molecular weight 13200) was prepared, and a membrane filter having a pore size of 0.1 μm was used. Filtered. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, An MgAg alloy was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted.

Example 2
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. After depositing 10 nm of Au as a reflective layer and 250 nm of TPD as a hole transport layer on this substrate, a polymer material (number average molecular weight 31400) having a repeating unit represented by the following formula (2) is used. A 1.5 mass% dichloromethane solution was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, An MgAg alloy was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

Example 3
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. On this substrate, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (TPD) was used as a hole transport layer with a thickness of 250 nm. After vapor deposition, a 1.5% by mass dichloromethane solution of a polymer material having a repeating unit represented by the above formula (1) was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, an MgAg alloy as a cathode Was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

Example 4
A glass substrate provided with an ITO film having a thickness of 150 nm was washed with boiling alcohol, and the surface was surface-treated with oxygen plasma. After depositing TPD with a thickness of 250 nm as a hole transport layer on this substrate, 1.5% by mass of a polymer material having a repeating unit represented by the above formula (1), 5% by mass of Alq, and 5% by mass. A dichloromethane mixed solution containing% TPD was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficient drying, 250 nm of Alq was deposited as an electron transport layer, and then 200 nm of an MgAg alloy was formed as a cathode. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

Example 5
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. An organic positive photoresist was applied onto this substrate, and a diffraction grating (resonator) with a pitch of 500 nm was produced by lithography. On top of this, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (TPD) was deposited to a thickness of 250 nm as a hole transport layer. After that, a 1.5% by mass dichloromethane solution of a polymer material (number average molecular weight 27100) having a repeating unit represented by the following formula (3) was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, An MgAg alloy was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted.

Example 6
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. On this substrate, Au was deposited as a reflective layer with a thickness of 10 nm, followed by TPD as a hole transport layer with a thickness of 250 nm, and then a polymer material having a repeating unit represented by the following formula (4) (number average molecular weight 39200). 1.5 mass% dichloromethane solution was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, An MgAg alloy was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

Example 7
A glass substrate provided with an ITO film (positive electrode layer) having a thickness of 150 nm was washed with boiling alcohol, and the surface was further treated with oxygen plasma. On this substrate, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (TPD) was used as a hole transport layer with a thickness of 250 nm. After vapor deposition, a 1.5 mass% dichloromethane solution of a polymer material (number average molecular weight 44500) having a repeating unit represented by the following formula (5) was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, after depositing 250 nm of 2- (4-tert.-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole as an electron transport layer, an MgAg alloy as a cathode Was formed to 200 nm. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

Example 8
A glass substrate provided with an ITO film having a thickness of 150 nm was washed with boiling alcohol, and the surface was surface-treated with oxygen plasma. After depositing TPD as a hole transport layer with a thickness of 250 nm on this substrate, 1.5% by mass of a polymer material having a repeating unit represented by the above formula (3), 5% by mass of Alq3, and 5% by mass. A dichloromethane mixed solution containing% TPD was prepared and filtered through a membrane filter having a pore size of 0.1 μm. Using this solution, a light emitting layer was formed on the TPD film by spin coating to a thickness of 100 nm. After sufficiently drying, Alq3 was deposited to 250 nm as an electron transport layer, and then an MgAg alloy was formed to 200 nm as a cathode. When a voltage of 30 V was applied to the organic semiconductor laser produced in this way, it was confirmed that laser light was emitted from the edge of the light emitting layer.

  As described above, since a specific polymer material is used for the light emitting layer in the present invention, it is not necessary to form an organic thin film layer by a vacuum process, and the production is easy, and there is no production of a pinhole or the like. An organic semiconductor laser excellent in film properties and practicality can be provided.

It is sectional drawing for showing an example of the organic-semiconductor laser of this invention. It is sectional drawing for showing another example of the organic-semiconductor laser of this invention. It is sectional drawing for showing another example of the organic-semiconductor laser of this invention. It is sectional drawing for showing another example of the organic-semiconductor laser of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Positive electrode layer 3 Light emitting layer 4 Negative electrode layer 5 Hole transport layer 6 Electron transport layer 7 Reflective layer 8 Resonator

Claims (19)

In an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order, the light emitting layer includes a polymer material having at least a repeating unit represented by the following formula (I) An organic semiconductor laser.

(In the formula, R ¹ represents a group selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and Ar represents a substituted or unsubstituted aromatic hydrocarbon group.) 2. The organic semiconductor laser according to claim 1, wherein R ¹ in the formula (I) is a substituted or unsubstituted alkyl group or alkoxy group having 1 to 18 carbon atoms. In an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order, the light emitting layer includes a polymer material having at least a repeating unit represented by the following formula (II) An organic semiconductor laser.

(In the formula, R ¹ represents a group selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group.) In an organic semiconductor laser in which at least a positive electrode layer, a light emitting layer, and a negative electrode layer are laminated in this order, the light emitting layer includes a polymer material having at least a repeating unit represented by the following formula (III) An organic semiconductor laser.

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 And when there are a plurality of R ¹ , R ² and R ³ , they may be the same or different, and Ar represents a substituted or unsubstituted aromatic hydrocarbon group.) In the formula ^{(III), R 1, R} 2 and at least one organic semiconductor laser according to claim 4, wherein the substituted or unsubstituted alkyl group or alkoxy group having 1 to 18 carbon atoms R ³ . 6. The organic semiconductor laser according to claim 4, wherein the light emitting layer further includes a polymer material having a repeating unit represented by the following formula (IV).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 Represents an integer of ¹ to 4, and when there are a plurality of R ¹ , R ² and R ³ , these may be the same or different, and R ⁴ is selected from a substituted or unsubstituted alkyl group or an alkoxy group Represents a group to be 6. The organic semiconductor laser according to claim 4, wherein the light emitting layer further includes a polymer material having a repeating unit represented by the following formula (V).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 To R 4, when there are a plurality of R ¹ , R ² , and R ³ , these may be the same or different, and R ⁵ and R ⁶ may be substituted or unsubstituted alkyl groups or alkoxy Represents a group selected from a group.) 6. The organic semiconductor laser according to claim 4, wherein the light emitting layer further includes a polymer material having a repeating unit represented by the following formula (VI).

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x, y and z are each independently 0 To R 4, when there are a plurality of R ¹ , R ² , and R ³ , these may be the same or different, and R ⁷ and R ⁸ are substituted or unsubstituted alkyl groups or alkoxy groups. Represents a group selected from   9. A hole transporting layer is provided between the positive electrode layer and the light emitting layer, and an electron transporting layer is provided between the light emitting layer and the negative electrode layer. 2. The organic semiconductor laser according to item 1.   The organic semiconductor laser according to claim 9, wherein the hole transport layer has a thickness of 100 to 2000 nm.   The organic semiconductor laser according to claim 9, wherein the electron transport layer has a thickness of 100 to 2000 nm.   The organic semiconductor laser according to claim 1, wherein a reflective layer is provided between the positive electrode layer and the light emitting layer.   The organic semiconductor laser according to claim 12, wherein a reflective layer is provided between the light emitting layer and the negative electrode layer.   The organic semiconductor laser according to claim 1, wherein a resonator is provided on one surface of the positive electrode layer.   15. The method according to claim 1, wherein a positive electrode layer is provided on the substrate, a light emitting layer is provided on the positive electrode layer, and a negative electrode layer is provided on the light emitting layer. The organic semiconductor laser according to item.   The organic semiconductor laser according to claim 1, wherein the light emitting layer contains a hole transport material.   The organic semiconductor laser according to claim 1, wherein the light emitting layer contains an electron transport material.   The organic semiconductor laser according to claim 1, wherein the light emitting layer includes a hole transport material and an electron transport material. The organic semiconductor laser according to claim 1, wherein the light emitting layer is formed by a wet method.

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