JP2003264085A - Organic semiconductor element, organic electroluminescence element and organic solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor element higher in reliability and also high in yield without need of using a conventional ultrathin film by introducing a novel concept into the structure of a conventional organic semiconductor element, and to improve the efficiency of a photoelectronic device using an organic semiconductor in particular. <P>SOLUTION: An organic structure obtained by alternately laminating organic thin film layers (functional organic thin film layers) that develop various functions by passing SCLC through them and thin conductor film layers (omic thin conductor film layers) that develop dark conductivity by a technique such as doping of an acceptor or donner is provided between a positive electrode and a negative electrode. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electronic device using an organic semiconductor. In particular, it relates to photoelectronic devices such as photoelectric conversion elements and EL elements.

[0002]

2. Description of the Related Art Organic compounds have a variety of material systems as compared with inorganic compounds, and it is possible to synthesize materials having various functions by appropriate molecular design. In addition, the formed product such as a film is also highly flexible, and further has a feature that it is excellent in processability due to being polymerized. From these advantages,
In recent years, attention has been focused on photonics and electronics using functional organic materials.

Photonics utilizing the optical properties of organic materials have already played an important role in the current industrial technology. For example, a photosensitive material such as a photoresist is an essential material for the photolithography technique used for fine processing of semiconductors. In addition, the organic compound itself,
Since it has properties of absorbing light and emitting light (fluorescence or phosphorescence) accompanying it, it is also widely used as a light emitting material such as a laser dye.

On the other hand, since the organic compound itself is a material having no carrier, it essentially has an excellent insulating property. Therefore, with respect to electronics utilizing the electrical properties of organic materials, conventionally, the function as an insulator has been mainly used, and it has been used as an insulating material, a protective material, or a coating material.

However, there is a means for supplying a large amount of current to an organic material which is essentially an insulator, and it is being put to practical use in the field of electronics. This means can be roughly divided into two types.

One of them is, as represented by a conductive polymer, a π-conjugated organic compound by doping an π-conjugated organic compound with an acceptor (electron acceptor) or a donor (electron donor). It is a means for allowing a compound to have a carrier (see Non-Patent Document 1). Since the carriers increase to some extent by increasing the doping amount, the dark conductivity also increases accordingly and a large amount of current flows.

[0007]

[Non-Patent Document 1] Hideki Shirakawa, Edwin J. Louis,
Alan G. MacDiarmid, Chwan K. Chiang, and Alan J. He
eger, "Synthesis of Electrically Conducting Organi
c Polymers: Halogen Derivatives of Polyacetyrene,
(CH) _x ", Chem. Comm., 1977, 16, 578-580

Since the amount of electric current can reach a level of a normal semiconductor or higher, a group of materials exhibiting such a behavior is an organic semiconductor (or an organic conductor in some cases).
Can be called.

As described above, the means for improving the dark conductivity by doping the acceptor or the donor and passing an electric current through the organic material has already been partially applied in the field of electronics. For example, there are rechargeable secondary batteries using polyaniline or polyacene, and electrolytic capacitors using polypyrrole.

Another means of supplying a large amount of current to an organic material is Space Charge Limited Current (SCLC).
Current) is a means to use. SCLC is a current that flows by injecting and moving space charge from the outside, and its current density is represented by Child's law, that is, the following equation (1). J is current density, ε is relative permittivity, ε ₀
Is a vacuum permittivity, μ is a carrier mobility, V is a voltage, and d is a distance between electrodes to which V is applied (hereinafter referred to as “thickness”).

[0011]

[Equation 1] J = 9/8 · εε ₀ μ · V ² / d ³ (1)

The SCLC represented by the above formula (1) is SC
This formula does not assume any carrier trap when the LC flows. The current limited by the carrier trap is
It is called TCLC (Trap Charge Limited Current) and is proportional to the exponentiation of the voltage, but since both are bulk-controlled currents, they will be treated in the same way below.

For comparison, an equation representing the current density when an ohmic current according to Ohm's law flows is shown in the following equation (2). σ is conductivity and E is electric field strength.

[0014]

[Equation 2] J = σE = σ ・ V / d (2)

Since the conductivity σ in the equation (2) is represented by σ = neμ (n is carrier density and e is electric charge), it is included in the controlling factor of the amount of current flowing through the carrier density. Therefore,
For an organic material having a certain degree of carrier mobility, an ohmic current does not normally flow in an organic material in which almost no carriers exist unless the carrier density is increased by doping as described above.

However, as can be seen from the equation (1),
The factors that determine SCLC are the dielectric constant, carrier mobility, voltage, and thickness, and carrier density is irrelevant. That is, even with an organic material that is an insulator without carriers, it is possible to inject carriers from the outside and pass a current by making the thickness d sufficiently thin and selecting a material having a large carrier mobility μ. Of.

Even when this means is used, the amount of current can reach the level of an ordinary semiconductor or higher, so that an organic material having a high carrier mobility μ, in other words, an organic material which can potentially transport carriers. Can be called an organic semiconductor.

By the way, among such organic semiconductor devices utilizing SCLC, organic electroluminescence devices (hereinafter, referred to as "photoelectronic devices" utilizing both optical and electrical properties of functional organic materials)
"Organic EL element") has made remarkable progress in recent years.

The most basic structure of the organic EL device was reported by CW Tang et al. In 1987 (see Non-Patent Document 2). The element reported in Non-Patent Document 2 is a kind of diode element in which an organic thin film having a total thickness of about 100 nm in which a hole transporting organic compound and an electron transporting organic compound are laminated is sandwiched between electrodes. A light emitting material (fluorescent material) is used as the electron transporting compound. By applying a voltage to such an element, light emission can be extracted like a light emitting diode.

[0020]

[Non-Patent Document 2] CW Tang and SAVanslyke, "Organi
c electroluminescent diodes ", Applied Physics Lett
ers, Vol.51, No.12, 913-915 (1987)

The light emission mechanism is as follows. When a voltage is applied to an organic thin film sandwiched by electrodes, holes and electrons injected from the electrodes are recombined in the organic thin film and molecules in an excited state (hereinafter, "molecular exciton"). It is believed that light is emitted when the molecular excitons return to the ground state.

The types of molecular excitons formed by an organic compound can be a singlet excited state and a triplet excited state, and since the ground state is usually a singlet state, light emission from the singlet excited state does not occur. The light emission from the fluorescence and triplet excited states is called phosphorescence. In the present specification, includes the case where either excited state contributes to light emission.

In such an organic EL device, the organic thin film is usually formed as a thin film of about 100 to 200 nm. Further, since the organic EL element is a self-luminous element in which the organic thin film itself emits light, there is no need for a backlight as used in a conventional liquid crystal display. Therefore, it is a great advantage that the organic EL element can be manufactured to be extremely thin and lightweight.

Further, in an organic thin film of, for example, about 100 to 200 nm, the time from injection of carriers to recombination is about several tens of nanoseconds considering the carrier mobility of the organic thin film. Even if the process from binding to light emission is included, light emission is achieved within microsecond order. Therefore, one of the features is that the response speed is very fast.

Due to such characteristics of thinness, light weight and high-speed response, the organic EL element has been attracting attention as a next-generation flat panel display element. In addition, since it is a self-luminous type and has a wide viewing angle, it has relatively good visibility and is considered to be effective as an element used for a display screen of a mobile device.

In addition to the organic EL element, an organic solar cell is a typical example of an organic semiconductor element using an organic material (organic semiconductor) capable of potentially transporting carriers, that is, having a certain degree of carrier mobility. Can be mentioned.

This is, so to speak, utilizing a mechanism reverse to that of the organic EL element. That is, the most basic structure is organic
Similar to an EL element, it has a structure in which an organic thin film having a two-layer structure is sandwiched by electrodes (see Non-Patent Document 3). An electromotive force can be obtained by utilizing a photocurrent generated by absorbing light in the organic thin film. It can be considered that the current flowing at this time is that carriers generated by light flow by utilizing the carrier mobility of the organic material.

[0028]

[Non-Patent Document 3] CWTang, "Two-layer organic photo
voltaic cell ", Applied Physics Letters, vol.48, No.
2, 183-185 (1986)

As described above, in the field of electronics, the organic material, which originally had only been considered to be used as an insulator, is
Organic semiconductors are currently being actively researched because they can play a central role in various electronic devices and photoelectronic devices.

In the above, two methods using an organic semiconductor have been described above as means for passing a current through an organic material which is essentially an insulator. However, each of the two methods has different drawbacks.

First, when the carrier density is increased by doping an organic semiconductor with an acceptor or a donor, although the conductivity is certainly improved, the physical properties (light absorption characteristics, fluorescence, etc.) inherent to the organic semiconductor itself are originally obtained. Properties, etc.) are lost. For example, when an acceptor or a donor is doped into a π-conjugated polymer material that emits fluorescence, the conductivity is increased but no light is emitted. Therefore, instead of obtaining the function of conductivity, various other functions of the organic material are sacrificed.

Further, although there is an advantage that various conductivity can be achieved by adjusting the doping amount of the acceptor or the donor, no matter how much the acceptor or the donor is doped to increase the carriers, a metal or an inorganic compound similar to the metal is obtained. It is difficult to obtain a carrier density as stable as (inorganic compound conductor such as titanium nitride). In other words, it is extremely difficult to exceed the electric conductivity of the inorganic material with respect to the electric conductivity except for some examples, and the merit remains only when the workability and flexibility are rich.

On the other hand, when SCLC (hereinafter also including photocurrent) is passed through the organic semiconductor, the inherent physical properties of the organic semiconductor itself are not lost. A typical example is an organic EL element, which utilizes the light emission of a fluorescent material (or a phosphorescent material) while passing an electric current. Organic solar cells also utilize the function of light absorption of organic semiconductors.

However, as can be seen from the equation (1),
Since SCLC is inversely proportional to the cube of the thickness d, it can only flow with a structure in which electrodes are sandwiched on both sides of an extremely thin film. More specifically, considering the general carrier mobility of organic materials, it is necessary to form an ultrathin film of about 100 nm to 200 nm.

Certainly, by using the ultra-thin film as described above, many SCLCs can flow at a low voltage. Non-patent document 2
In the organic EL device as described in the section 1, the thickness of the organic thin film is 100 nm
One of the factors of success is that the ultra-thin film of uniform degree is used.

However, the fact that the thickness d must be made extremely thin is the biggest problem in flowing the SCLC. First, in a thin film with a thickness of about 100 nm, defects such as pinholes are likely to occur, and defects such as short circuits may occur starting from such defects, resulting in poor yield. In addition, the mechanical strength of the thin film is lowered, and since it is an ultrathin film, the manufacturing process is naturally limited.

When SCLC is used as an electric current, it is advantageous that the organic semiconductor itself does not lose its original physical properties and various functions can be exhibited. Deterioration of the function of the semiconductor is accelerated. For example, taking an organic EL element as an example, the element life is almost inversely proportional to the initial luminance, in other words, the element life (half-life of emission luminance) in inverse proportion to the amount of current flowing.
Is known to deteriorate (see Non-Patent Document 4).

[0038]

[Non-Patent Document 4] Yoshiharu Sato, "Journal of the Organic Physics and Bioelectronics Subcommittee of the Japan Society of Applied Physics", Vol. 11, No. 1
(2000), 86-99

As described above, in a device that exhibits conductivity by doping an acceptor or a donor, functions other than conductivity are lost. In addition, devices that develop conductivity using SCLC have problems in device reliability and the like due to the large amount of current flowing through the ultrathin film.

By the way, a photoelectronic device using an organic semiconductor such as an organic EL element or an organic solar cell has a problem in its efficiency.

Take an organic EL element as an example. Organic
As described above, the light emitting mechanism of the EL element is converted into light by recombining the injected holes and electrons. Therefore, theoretically, a maximum of one photon can be extracted from the recombination of one hole and one electron,
You cannot extract multiple photons. That is, the internal quantum efficiency (the number of photons emitted with respect to the number of injected carriers) is 1 at the maximum.

However, in reality, it is difficult to bring the internal quantum efficiency close to 1. For example, in the case of an organic EL device using a fluorescent material as a light-emitting body, the statistical production ratio of singlet excited state (S ^* ) and triplet excited state (T ^* ) is
Since it is considered that S ^* : T ^* = 1: 3 (see Non-Patent Document 5), the theoretical limit of the internal quantum efficiency is 0.25. Furthermore, unless the fluorescence quantum yield φ _f of the fluorescent material is 1, the internal quantum efficiency is even lower than 0.25.

[0043]

[Non-Patent Document 5] Tetsuo Tsutsui, “Organic Molecule of Applied Physics,
Bioelectronics Subcommittee, 3rd Workshop Text ”, P.31 (1993)

In recent years, it has been attempted to bring the theoretical limit of internal quantum efficiency closer to 0.75 to 1 by utilizing the light emission from the triplet excited state by using a phosphorescent material, which actually exceeds that of a fluorescent material. Efficiency has been achieved. However, this also requires the use of a material having a high phosphorescence quantum yield φ _p of the phosphorescent material, so that the selection range of the material is inevitably limited. This is because organic compounds that can emit phosphorescence at room temperature are extremely rare.

In other words, if a means for improving the current efficiency of the organic EL element (luminance generated with respect to the flowing current) can be taken, it will be a great innovation. If the current efficiency is improved, more brightness can be produced with less current. In other words, since the amount of current flowing to achieve a certain brightness can be reduced, the deterioration caused by passing a large amount of current through the ultrathin film as described above is also small.

The current situation is that the mechanism opposite to that of the organic EL element, that is, photoelectric conversion such as in an organic solar cell, is inefficient. In the case of a conventional organic solar cell using an organic semiconductor, an electric current does not flow unless an ultrathin film is used as described above, and therefore, no electromotive force is generated. However, the use of an ultrathin film causes a problem that the light absorption efficiency is not good (the light cannot be completely absorbed). This seems to be a major cause of poor efficiency.

[0047]

From the above, in an electronic device using an organic semiconductor, if a large amount of current is applied while making use of the physical properties peculiar to organic materials, the reliability and the yield will be adversely affected. There is a drawback that. Moreover, especially in photoelectronic devices, the efficiency of the device is also poor. It can be said that these problems are basically derived from the “ultra thin film” structure of the conventional organic semiconductor device.

Therefore, in the present invention, by introducing a new concept into the structure of the conventional organic semiconductor element, an organic semiconductor element having higher reliability and higher yield can be provided without using the conventional ultrathin film. This is an issue. Another object is to improve the efficiency of a photoelectronic device using an organic semiconductor.

[0049]

Means for Solving the Problems As a result of extensive studies, the present inventor has conducted an organic semiconductor that expresses conductivity by doping an acceptor or a donor, and an organic semiconductor that expresses conductivity by using SCLC. By combining
Means for solving the above problems have been devised. The most basic structure is shown in FIG.

FIG. 1 shows an organic thin film layer (in this specification, referred to as “functional organic thin film layer”) which exhibits various functions by flowing SCLC, and a method of doping an acceptor or a donor. An organic structure in which floating conductive thin film layers expressing dark conductivity are alternately laminated,
It is an organic semiconductor element provided between an anode and a cathode.

What is important here is that the conductive thin film layer preferably has a structure capable of being almost ohmic-connected to the functional organic thin film layer (in this case, the conductive thin film layer is particularly referred to as "ohmic conductive film"). Body thin film layer "). In other words, the barrier between the conductor thin film layer and the functional organic thin film layer is eliminated or made extremely small.

With this structure, holes and electrons are easily injected from each ohmic conductor thin film layer into each functional organic thin film layer. For example, a conceptual diagram of an element in which n = 2 in FIG. 1 is shown in FIG. In FIG. 2, when a voltage is applied between the anode and the cathode, electrons are emitted from the first ohmic conductor thin film layer to the first functional organic thin film layer from the first ohmic conductor thin film layer. Holes are easily injected into the second functional organic thin film layer. Seen from the external circuit, holes flow from the anode to the cathode and holes flow from the cathode to the anode (Fig. 2 (a)). However, both electrons and holes flow from the ohmic conductor thin film layer. It can be seen that the water flows in the opposite direction (Fig. 2 (b)).

Here, each functional organic thin film layer is 100 nm to 200 nm thick.
By setting the thickness to nm or less, the carriers injected into each functional organic thin film layer can flow as SCLC. That is, in each functional organic thin film layer, a function (e.g., light emission) derived from the physical properties peculiar to the organic material can be exhibited.

Moreover, if the basic structure of the present invention is applied,
This is extremely useful because the organic structure can be made as thick as desired. That is, conventional elements (anode 301 and cathode 3
It is assumed that a device in which the functional organic thin film layer 303 is sandwiched between 02 and 02) can obtain a current density of J by applying a certain voltage V to a film thickness of d (FIG. 3 (a)). Where the film thickness is d
In the case of the present invention in which n functional organic thin film layers 303 and n-1 ohmic conductor thin film layers 304 are alternately laminated (see FIG. 3).
(b)), so far the film thickness of d (100nm-200n
Although the SCLC could only flow to m), apparently nd
It is as if a SCLC with a current density of J is flowing for the film thickness of 3 as in Fig. 3 (a). In other words, it looks like Figure 3
Although it becomes like (c), this is not possible with conventional devices (no matter how much voltage is applied, SCLC suddenly stops flowing as the film thickness increases).

Of course, in this case, simply thinking, a voltage of nV is required. However, in an electronic device using an organic semiconductor, it is possible to easily overcome the drawback that reliability and yield are adversely affected if a large amount of current is applied while making use of the physical properties inherent to organic materials.

As described above, by providing the organic structure in which the functional organic thin film layers and the conductive thin film layers are alternately laminated between the anode and the cathode, the SCLC in the organic semiconductor element is thicker than the conventional one. The concept of being able to flush has never existed. This concept can be widely applied not only to organic EL elements that emit light by flowing SCLC and organic solar cells that utilize photocurrent, which is the reverse mechanism, but also to other organic semiconductor elements. .

Therefore, in the present invention, between the anode and the cathode,
In an organic semiconductor device provided with an organic structure formed by sequentially stacking n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more), the kth (k is 1 ≦ k ≤
A floating conductor thin film layer is provided between the functional organic thin film layer (n-1) and the (k + 1) th functional organic thin film layer. It is characterized in that it is in ohmic contact with the functional organic thin film layer.

In this case, it is preferable to use an organic compound as the conductor thin film layer instead of using a metal or a conductive inorganic compound. Particularly in the case of a photoelectronic device that requires transparency, organic compounds are more suitable.

Therefore, in the present invention, between the anode and the cathode,
In an organic semiconductor device provided with an organic structure formed by sequentially stacking n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more), the kth (k is 1 ≦ k ≤
A floating conductor thin film layer containing an organic compound is provided between the (n-1) integer functional organic thin film layer and the (k + 1) th functional organic thin film layer. The thin film layer is in ohmic contact with the functional organic thin film layer.

In order to make ohmic contact between the conductor thin film layer and the functional organic thin film layer or a contact close thereto, as described above, the conductor thin film layer is formed of an organic compound, and an acceptor or a donor is formed. Doping is an important means.

Therefore, in the present invention, between the anode and the cathode,
In an organic semiconductor device provided with an organic structure formed by sequentially stacking n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more), the kth (k is 1 ≦ k ≤
A floating conductor thin film layer containing an organic compound is provided between the (n-1) integer functional organic thin film layer and the (k + 1) th functional organic thin film layer. It is characterized in that the thin film layer contains at least one of an acceptor and a donor for the organic compound.

Further, in the present invention, 1 is provided between the anode and the cathode.
In an organic semiconductor element provided with an organic structure formed by sequentially stacking n functional organic thin film layers from the nth to the nth (n is an integer of 2 or more), the kth (k is 1 ≦ k ≦ (N
-1) integer)), and a floating conductor thin film layer containing an organic compound is provided between the functional organic thin film layer and the (k + 1) th functional organic thin film layer. Contains both an acceptor and a donor for the organic compound.

When the conductor thin film layer is doped with an acceptor or a donor, the same organic compound used for the functional organic thin film layer and the organic compound used for the conductor thin film layer are connected. (That is, by incorporating the organic compound used in the functional organic thin film layer into the conductive thin film layer and doping the conductive thin film layer with an acceptor or a donor), a device can be manufactured by a simpler process. You can

By the way, when the conductor thin film layer contains both an acceptor and a donor, the conductor thin film layer includes a first layer in which an acceptor is added to an organic compound and a donor in the same organic compound as the organic compound. A second layer to which is added is laminated, and a structure in which the first layer is located closer to the cathode than the second layer is preferable.

Also in such a case, it is preferable to connect the organic compound used in the functional organic thin film layer and the organic compound used in the conductor thin film layer with the same one.

By the way, when both the acceptor and the donor are contained in the conductor thin film layer, the conductor thin film layer includes the first layer obtained by adding the acceptor to the first organic compound, and the first organic compound. Is a structure in which a second layer obtained by adding a donor to a different second organic compound is laminated, and a structure in which the first layer is located closer to the cathode than the second layer is also suitable. .

Also in this case, it is preferable to connect the organic compound used in the functional organic thin film layer and the organic compound used in the first layer by the same one. In addition, an organic compound used in the functional organic thin film layer,
It is preferable to connect the same organic compound as that used in the second layer.

The functional organic thin film layer may be formed using a bipolar organic compound, or may be used in combination with a monopolar organic compound such as stacking a hole transport layer and an electron transport layer. Good.

The device structure as described above is extremely useful because it can improve the efficiency particularly in the field of photoelectronics related to light emission and light absorption among organic semiconductor devices. That is, by forming the functional organic thin film layer with an organic compound that emits light when an electric current is applied, a highly reliable and efficient organic EL element can be obtained. In addition, by forming the functional organic thin film layer with an organic compound that produces photocurrent (produces electromotive force) by absorbing light, a highly reliable and efficient organic solar cell can be obtained.

Therefore, in the present invention, all of the functional organic thin film layers described above are also included in an organic semiconductor element having a structure capable of exhibiting the function of an organic EL element or the function of an organic solar cell.

In particular, in the organic EL element, when the functional organic thin film layer is composed of a bipolar organic compound,
The bipolar organic compound preferably includes a polymer compound having a π-conjugated system. At that time, it is preferable to use a polymer compound having the π-conjugated system for the conductor thin film layer and dope an acceptor or a donor to improve the dark conductivity. Alternatively, a conductive polymer compound to which an acceptor or a donor is added may be used as the conductor thin film layer.

In the organic EL element, a functional organic thin film layer is formed by combining monopolar organic compounds such as stacking a hole transport layer made of a hole transport material and an electron transport layer made of an electron transport material. In this case, it is preferable to use at least one of the hole transport material and the electron transport material for the conductor thin film layer and dope an acceptor or a donor to improve the dark conductivity. Alternatively, both the hole transport material and the electron transport material may be used. Specifically, a structure in which a layer in which an electron transporting material used in a functional organic thin film layer is doped with a donor and a layer in which a hole transporting material used in a functional organic thin film layer is doped with an acceptor are stacked is laminated. , A thin film conductor layer is used.

The structure of the functional organic thin film layer is the same as that of the organic EL element in the organic solar cell. That is,
In the organic solar cell, when the functional organic thin film layer is composed of a bipolar organic compound, the bipolar organic compound preferably contains a polymer compound having a π-conjugated system. At that time, it is preferable to use a polymer compound having the π-conjugated system for the conductor thin film layer and dope an acceptor or a donor to improve the dark conductivity. Alternatively, a conductive polymer compound to which an acceptor or a donor is added may be used as the conductor thin film layer.

In the organic solar cell, when a functional organic thin film layer is formed by combining a monopolar organic compound such as stacking a layer made of a hole transport material and a layer made of an electron transport material, a conductive thin film is formed. Also for the layer, a method of using at least one of the hole transport material and the electron transport material and doping an acceptor or a donor to improve the dark conductivity is preferable. Alternatively, both the hole transport material and the electron transport material may be used.
Specifically, a structure in which a layer in which an electron transporting material used in a functional organic thin film layer is doped with a donor and a layer in which a hole transporting material used in a functional organic thin film layer is doped with an acceptor are stacked is laminated. , A thin film conductor layer is used.

It is not necessary to reduce the sheet resistance of all the above-mentioned conductor thin film layers (ohmic conductor thin film layers) as long as carriers can be injected. Therefore, it is sufficient that the conductivity is about 10 ^-10 S / m ² or more.

[0076]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail by taking an organic EL element or an organic solar cell as an example. Note that in the organic EL element, at least one of the anode and the cathode is transparent in order to extract light emission, but in this embodiment, a transparent anode is formed on the substrate and light is extracted from the anode side. Describe the device structure. Actually, it is also applicable to a structure in which a cathode is formed on a substrate to take out light from the cathode, a structure to take out light from the side opposite to the substrate, and a structure to take out light from both sides of the electrode. As for the organic solar cell, in order to absorb light, either one of both sides of the element may be transparent.

First, in the organic EL element, a simple device is used as a means for overcoming the poor reliability derived from the ultrathin film and for improving the ratio of the light emitted to the flowing current (that is, the current efficiency). From the viewpoint of structure, for example, organic EL elements may be connected in series. This is explained as follows.

As shown in FIG. 4 (a), when a certain voltage V ₁ is applied, a current having a current density of J ₁ flows, and light energy of L ₁ per unit area (photons having a certain energy are emitted. Then, it is assumed that there is an organic EL element D ₁ that emits light with the energy multiplied by the number of photons. The power efficiency φe ₁ at this time (which is the energy of light emission for a given electric energy (electric power) and is synonymous with the energy conversion efficiency) is given by the following formula.

[0079]

[Equation 3] φe ₁ = L ₁ / (J ₁ · V ₁ ) (3)

Next, an organic EL element D _{2 which} is completely equivalent to this D ₁
Consider the case where is connected in series with D ₁ (Fig. 4 (b)). Note that the contact C ₁ at this time is assumed to be an ohmic connection between D ₁ and D ₂ .

Here, a voltage V ₂ (= 2V ₁ ) twice as high as the voltage applied in FIG. 4A is applied to the entire device (that is, the device D _all having a structure in which D ₁ and D ₂ are connected). ) Is applied. Then, since D ₁ and D ₂ are equivalent, as shown in FIG. 4 (b), a voltage of V ₁ is applied to each of D ₁ and D ₂ , and a current of common current density J ₁ is generated. Flowing. Therefore, D ₁ and D ₂ emit light with the light energy of L _1, respectively, and thus double the light energy 2L ₁ can be obtained from the entire device D _all .

The power efficiency φe ₂ at this time is given by the following equation.

[Equation 4] φe ₂ = 2L ₁ / (J ₁・ 2V ₁ ) = L 1 / (J ₁・ V ₁ ) (4)

As can be seen by comparing the above equations (3) and (4), there is no change between FIG. 4 (a) and FIG. 4 (b) in terms of power efficiency, and V ₁ and J ₁ to L ₁ The energy conservation law of being converted into is protected. However, the current efficiency is
Apparently doubled, that is, increased from L ₁ / J ₁ to 2 L ₁ / J ₁ . This has an important meaning for the organic EL device. In other words, the current efficiency can be increased by increasing the number of organic EL elements connected in series, applying more voltage by the increased number, and keeping the current density constant.

If this concept is further generalized, when n completely equivalent organic EL elements are ohmic-connected in series, n times the luminance is obtained by increasing the voltage by n times while keeping the current density constant. be able to. This property is due to the fact that the luminance and the current density are in a proportional relationship in the organic EL element.

Of course, even when different organic EL elements are connected in series, the brightness emitted from each organic EL element is different, but one organic EL element can be obtained by applying a large voltage.
It is possible to extract more luminance than the L element. The conceptual diagram is shown in FIG.

As shown in FIG. 5, different organic EL devices
D ₁ and D ₂ are connected in series, and the voltage (V ₁ or D ₁ ) required to flow the current of J ₁ to one organic EL element (D ₁ or D ₂ ).
Applying a voltage V ₁ + V ₂ higher than V ₂ ), the current in J ₁ is L ₁ +
The brightness of L ₂ (> L ₁ , L ₂ ) can be extracted.

At this time, for example, a blue light emitting element is used for D ₁ and a yellow light emitting element is used for D ₂ , so that white light emission is obtained if the colors can be mixed. Will also be possible.

As described above, by ohmic-connecting the elements in series, the apparent current efficiency can be improved and a large luminance can be obtained with a smaller current. This means that the current required to emit light of the same brightness is
This means that it can be made smaller than before. Moreover, as long as a large voltage can be applied, any number of organic EL elements can be connected, and the overall film thickness can be increased.

However, there is a problem even when the organic EL elements are simply connected in series as described above. This is a problem caused by the electrodes and element structure of the organic EL element, which will be described with reference to FIG. FIG. 6A is a cross-sectional view of the organic EL element D ₁ of FIG. 4A, and FIG. 6B is a schematic cross-sectional view of the entire element D _all of FIG. 4B.

The basic structure of an ordinary organic EL device (see FIG. 6)
(a)) is a functional organic thin film layer (hereinafter referred to as “organic organic thin film layer”) which is provided with a transparent electrode 602 (here, an anode, generally ITO is used) on a substrate 601, and emits light when an electric current is applied.
(Hereinafter referred to as “EL layer”) 604, and the cathode 603 is formed. In this case, the light is transparent electrode (anode) 602.
Taken from. As the cathode 603, a metal electrode having a low work function is usually used, or a cathode buffer layer for assisting electron injection and a metal conductive film (such as aluminum) are used together.

When two such organic EL elements are simply connected in series (FIG. 6 (b)), the first transparent electrode (anode) 6
On 02a, the first organic EL layer 604a, the first cathode 603a, the second transparent electrode (anode) 602b, the second organic EL layer 604b,
The structure is such that the second cathode 603b is sequentially stacked. Then, the light emitted from the second organic EL layer 604b cannot be transmitted because the first cathode 603a is a metal, and cannot be taken out of the device. Therefore, it is impossible to mix the light emission of the upper and lower organic EL elements to obtain white light.

For example, transparent electrodes are used for both the anode and the cathode.
Techniques using ITO have also been reported (Non-Patent Document 6: G.
Parthasarathy, PE Burrows, V. Khalfin, VG Ko
zlov, and SR Forrest, "A metal-free cathode for
organic semiconductor devices ", J. Appl. Phys., 7
2, 2138-2140 (1998)). With this, the first cathode 603
Since a can be made transparent, the light emitted from the second organic EL layer 604b can also be extracted. However, since ITO is mainly formed by sputtering,
There is concern about damage to the EL layer 604a. Further, in terms of process, the film formation of the organic EL layer by vapor deposition and the film formation of ITO by sputtering must be repeated, which is complicated.

Therefore, a more preferable form in which the current efficiency can be improved similarly to the concept that the current efficiency can be improved by connecting the elements in series and the transparency of the element can be cleared without any problem is, for example, as shown in FIG. It is a simple structure.

In FIG. 7, a first organic EL layer 704a, a first conductor thin film layer 705a, a second organic EL layer 704b, and a cathode 703 are sequentially arranged on a transparent electrode (anode) 702 provided on a substrate 701. It is a laminated structure. In this case, the first conductor thin film layer
By applying an acceptor or a donor doped to an organic semiconductor, the 705a can be almost ohmic-connected to the organic EL layer (can inject both hole and electron carriers), and can also substantially maintain transparency. Therefore, the light emission generated in the second organic EL layer 703b can also be extracted, and the current efficiency can be doubled simply by doubling the voltage.

Moreover, since all the processes can be manufactured by a consistent process (for example, a dry process such as vacuum deposition when a low molecular weight is used, a wet process such as spin coating when a high molecular weight is used), it is not complicated. not exist.

Although FIG. 7 shows a structure in which two organic EL layers are provided, as described above, a multi-layer structure can be used as long as even a large voltage can be applied (of course, each organic A conductive thin film layer is inserted between the EL layer and the organic EL layer). Therefore, it is possible to overcome the poor reliability of the organic semiconductor element derived from the ultrathin film.

This idea naturally applies to an organic solar cell which can be said to have a mechanism reverse to that of an organic EL element. This is explained as follows.

It is assumed that there is an organic solar cell S ₁ in which a photocurrent having a current density J ₁ is generated by a certain light energy L _{1 and} an electromotive force of V ₁ is generated. When n pieces of this S ₁ are ohmic-connected in series and the light energy of nL ₁ is applied to them, if, for example, all n pieces of solar cells S ₁ have equivalent light energy (= nL ₁ / n =
If L ₁ ) can be supplied, electromotive force n times (= nV ₁ )
Can be obtained. In short, if all the organic solar cells connected in series can absorb light, the electromotive force will increase accordingly.

For example, there is a report that electromotive force is improved by connecting two organic solar cells in series (Non-Patent Document 7:
Masahiro HIRAMOTO, Minoru SUEZAKI, and Masaaki YOK
OYAMA, "Effect of Thin Gold Interstitial-layer on
the Photovoltaic Properties of Tandem Organic Sola
r Cell ", Chemistry Letters, pp.327-330, 1990). In Non-Patent Document 7, by inserting a thin film of gold between two organic solar cells (front cell and back cell),
The result is that the electromotive force due to light irradiation is improved.

However, even in Non-Patent Document 7,
From the viewpoint of light transmission, the thickness of the gold thin film is set to 3 nm or less. In other words, gold must be designed as an ultrathin film that allows light to pass therethrough, and designed so that light can reach the back cell. In addition, the reproducibility of ultra-thin films of the order of several nm has a problem.

Such a problem can also be solved by applying the present invention. That is, in the structure of the organic solar cell as in Non-Patent Document 7, the present invention may be applied to the gold thin film portion. By doing so, rather than connecting two elements in series, it can be used as one organic solar cell having a larger film thickness and higher efficiency than conventional ones.

In the above, the basic concept and constitution of the present invention have been described by taking the organic EL element and the organic solar cell as an example. Below, preferable examples of the constitution of the conductor thin film layer used in the present invention are listed. However, the present invention is not limited to these.

First, from the viewpoint of having conductivity, that is, having a large number of carriers, various metal thin films can be used. Specifically, Au, Al, Pt, Cu, Ni and the like can be mentioned. When these metals are used as the conductor thin film layer, it is preferably an ultrathin film (several nm to several tens of nm) that can transmit visible light.

Various metal oxide thin films can be used, particularly from the viewpoint of visible light transmittance. Specifically, ITO, ZnO, CuO, SnO ₂ , BeO, cobalt oxide, zirconium oxide, titanium oxide, niobium oxide, nickel oxide,
Examples thereof include neodymium oxide, vanadium oxide, bismuth oxide, beryllium aluminum oxide, boron oxide, magnesium oxide, molybdenum oxide, lanthanum oxide, lithium oxide, and ruthenium oxide. It is also possible to use a compound semiconductor thin film, and ZnS, ZnSe, GaN, AlGa
N, CdS, etc.

The present invention is particularly characterized in that the conductor thin film layer can be composed of an organic compound. For example, there is a method of forming a conductor thin film layer by mixing a p-type organic semiconductor and an n-type organic semiconductor.

Typical examples of the p-type organic semiconductor include CuPc represented by the following formula (1), other metal phthalocyanines and metal-free phthalocyanines (the following formula (2)).
In addition, TTF (the following formula (3)), TTT (the following formula (4)), methylphenothiazine (the following formula (5)), N-isopropylcarbazole (the following formula (6)), etc. can also be used as p-type organic semiconductors. Is. Furthermore, hole transport materials used in organic EL or the like, such as TPD (the following formula (7)), α-NPD (the following formula (8)), and CBP (the following formula (9)), may be applied. .

[0107]

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

Typical examples of the n-type organic semiconductor include F ₁₆ -CuPc represented by the following formula (10) and PV (the following formula (1
1)), Me-PTC (the following formula (12)), PTCDA (the following formula (13)), a 3,4,9,10-perylenetetracarboxylic acid derivative, or a naphthalenecarboxylic acid anhydride (the following formula (12)). 14)), naphthenenecarboxylic acid imide (the following formula (15)), and the like. In addition, TCNQ (the following formula (16), TCE (the following formula (17)), benzoquinone (the following formula (18)), 2,6-naphthoquinone (the following formula (1
9)), DDQ (the following formula (20)), p-fluoranil (the following formula (21)), tetrachlorodiphenoquinone (the following formula (22)), nickel bisdiphenylguloxime (the following formula (23)), etc. Can also be used as an n-type organic semiconductor. Further, an electron transport material used in an organic EL or the like such as Alq ₃ (the following formula (24)), BCP (the following formula (25)), PBD (the following formula (26)) may be applied.

[0109]

[Chemical 10]

[Chemical 11]

[Chemical 12]

[Chemical 13]

[Chemical 14]

[Chemical 15]

[Chemical 16]

[Chemical 17]

[Chemical 18]

[Chemical 19]

[Chemical 20]

[Chemical 21]

[Chemical formula 22]

[Chemical formula 23]

[Chemical formula 24]

[Chemical 25]

[Chemical formula 26]

Further, in particular, a method in which an acceptor (electron acceptor) of an organic compound and a donor (electron donor) of an organic compound are mixed and a charge transfer complex is formed so as to have conductivity to form a conductive thin film layer. Is preferred. Although some charge transfer complexes are likely to crystallize and have poor film-forming properties, the conductor thin film layer of the present invention may be formed in a thin layer or in a cluster shape (if carriers can be injected), so that a big problem occurs. Absent.

Examples of the combination of charge transfer complexes include TTF-TCNQ represented by the following formula (27), K-TCNQ and Cu-
A metal-organic acceptor system such as TCNQ is typical. In addition, [BEDT-TTF] -TCNQ (the following formula (28)), (Me) ₂ P-
C ₁₈ TCNQ (the following formula (29)), BIPA-TCNQ (the following formula (3)
0)), Q-TCNQ (the following formula (31)) and the like. Note that these charge transfer complex thin films are vapor-deposited films, spin-coated films, LB films, films dispersed in polymer binders, etc.
Either can be used.

[0112]

[Chemical 27]

[Chemical 28]

[Chemical 29]

[Chemical 30]

[Chemical 31]

Further, as a constitutional example of the conductor thin film layer, a method of doping an organic semiconductor with an acceptor or a donor so as to have dark conductivity is preferable. As the organic semiconductor, an organic compound having a π-conjugated system such as a conductive polymer may be used. Examples of the conductive polymer include commercially available materials such as poly (ethylenedioxythiophene) (abbreviation: PEDOT), polyaniline, and polypyrrole, as well as polyphenylene derivatives, polythiophene derivatives, and poly (paraphenylenevinylene) derivatives. and so on.

When the acceptor is doped, it is preferable to use a p-type material as the organic semiconductor. Examples of the p-type organic semiconductor include the chemical formulas (1) to (9) described above. At this time, FeCl ₃ (II
A Lewis acid (strongly acidic dopant) such as I), AlCl ₃ , AlBr ₃ , AsF ₆ or a halogen compound may be used (the Lewis acid can act as an acceptor).

When the donor is doped, it is preferable to use an n-type material as the organic semiconductor. Examples of the n-type organic semiconductor include the chemical formulas (10) to (26) described above. At this time, as donors, Li, K, Ca, Cs
A Lewis base such as an alkali metal or an alkaline earth metal represented by, for example, may be used (the Lewis base can act as a donor).

As a more preferable form, a conductor thin film layer may be formed by combining some of the above-mentioned constitutions. That is, for example, on one or both sides of an inorganic thin film such as the above-mentioned metal thin film, metal oxide thin film, compound semiconductor thin film, a thin film in which a p-type organic semiconductor and an n-type organic semiconductor are mixed, a charge transfer complex thin film, or a doped film. A conductive polymer thin film, a p-type organic semiconductor thin film doped with an acceptor, or an n-type organic semiconductor thin film doped with a donor is preferably formed.
At this time, it is also effective to use a charge transfer complex thin film instead of the inorganic thin film.

In particular, by stacking a donor-doped n-type organic semiconductor thin film and an acceptor-doped p-type organic semiconductor thin film to form a conductor thin film layer,
This is very effective because both holes and electrons can be efficiently injected into the functional organic thin film layer. Moreover,
An n-type organic semiconductor thin film doped with a donor or a p-type organic semiconductor thin film doped with an acceptor is laminated on one side or both sides of a thin film in which a p-type organic semiconductor and an n-type organic semiconductor are mixed to form a conductor thin film layer. A method of doing is also possible.

It is not necessary to form all the thin films mentioned above as the structure of the conductor thin film layer into a film shape.
It may be formed in an island shape.

By applying the above-described conductor thin film layer to the present invention, an organic semiconductor element having high reliability and high yield can be manufactured.

For example, when the organic thin film layer in the present invention is configured to emit light by passing an electric current, the organic EL
Although an element can be obtained, the organic EL element of the present invention is effective because it can also improve efficiency.

Organic thin film layer (that is, organic EL layer) in that case
As the structure of, the structure and constituent materials of the organic EL layer of a commonly used organic EL element may be used. Specifically, as described in Non-Patent Document 2, a laminated structure of a hole transport layer and an electron transport layer, a single layer structure using a polymer compound, and a high level utilizing light emission from a triplet excited state. There are many variations such as efficiency elements. Further, as described above, by mixing the respective organic EL layers with different emission colors, a white light emitting device having high efficiency and a long device life can be applied.

Regarding the anode of the organic EL element, ITO (indium tin oxide) or I
Transparent conductive inorganic compounds such as ZO (indium zinc oxide) are often used. Ultra thin films such as gold are also possible. When nontransparent is acceptable (when light is extracted from the cathode side), a metal / alloy or a conductor which does not transmit light but has a large work function to some extent may be used, and examples thereof include W, Ti, and TiN.

For the cathode of the organic EL element, a metal or alloy having a small work function is usually used, an alkali metal, an alkaline earth metal or a rare earth metal is used, and an alloy containing these metal elements is also used. For example, Mg: A
g alloy, Al: Li alloy, Ba, Ca, Yb, Er, etc. can be used.
Further, when extracting light from the cathode, an ultrathin film of these metals / alloys may be applied.

Further, for example, an organic solar cell can be obtained by forming the organic thin film layer in the present invention so as to generate electromotive force by absorbing light, but the organic solar cell of the present invention also improves efficiency. It is effective because it can

As the structure of the functional organic thin film layer at that time, the structure and constituent materials of the functional organic thin film layer of the generally used organic solar cell may be used. Specific examples include a laminated structure of a p-type organic semiconductor and an n-type organic semiconductor as described in Non-Patent Document 3.

[0126]

EXAMPLES Example 1 In this example, an organic EL device of the present invention using a charge transfer complex as a conductor thin film layer will be specifically illustrated. The element structure is shown in FIG.

First, a glass substrate 801 on which ITO, which is an anode 802, is formed to a thickness of about 100 nm is formed on a glass substrate 801 which is a hole-transporting material by N, N′-bis (3-methylphenyl) -N, N′-diphenyl-benzidine ( Abbreviation: TPD) is vapor-deposited with a thickness of 50 nm to form the hole transport layer 804a. Next, tris (8-quinolinolato) aluminum (abbreviation: Alq), which is an electron-transporting light-emitting material, is deposited to a thickness of 50 nm,
The electron-transporting and light-emitting layer 805a is used.

After the first organic EL layer 810a is formed in this manner, TTF and TCNQ are made 1: 2 as the conductor thin film layer 806.
Co-evaporate to a ratio of 1 and make this layer 10 nm.

After that, as the hole transport layer 804b, TPD 5
0 nm is vapor-deposited, and Al is used as an electron transport layer and a light emitting layer 805b on it.
q is deposited to 50 nm. Thus, the second organic EL layer 810b is formed.

Finally, as the cathode 803, the atomic ratio of Mg and Ag is 1
The organic EL device of the present invention is obtained by performing co-evaporation so that the ratio becomes 0: 1 and forming a film of the cathode 803 with a thickness of 150 nm.

Example 2 In this example, the same organic semiconductor used in the organic EL layer was contained in the conductive thin film layer, and the organic compound of the present invention was made conductive by doping the acceptor and the donor. The EL element will be specifically exemplified. The element structure is shown in FIG.

First, TPD, which is a hole transporting material, is deposited to 50 nm on a glass substrate 901 on which ITO, which is an anode 902, is deposited to a thickness of about 100 nm.
Evaporation is performed to form a hole transport layer 904a. Next, 50 nm of Alq, which is an electron-transporting light-emitting material, is deposited to form an electron-transporting layer / light-emitting layer 905a.
And

After forming the first organic EL layer 910a in this manner, a layer 906 co-deposited with Alq is vapor-deposited with a thickness of 5 nm so that the donor TTF has a ratio of 2 mol%. afterwards,
TPD is adjusted so that the acceptor TCNQ has a ratio of 2 mol%.
The conductive thin film layer 911 is obtained by vapor-depositing the layer 907 co-deposited with

After that, as the hole transport layer 904b, TPD 5
Evaporated to a thickness of 0 nm, and formed Al as the electron transport layer and light emitting layer 905b on it.
q is deposited to 50 nm. Thus, the second organic EL layer 910b is formed.

Finally, as the cathode 903, Mg and Ag have an atomic ratio of 1
The organic EL element of the present invention is obtained by performing co-evaporation so that the ratio becomes 0: 1 and forming a film of the cathode 903 with a thickness of 150 nm. This element is very simple and effective because it can be manufactured by simply applying the organic semiconductor used for the organic EL layer as a constituent material of the conductor thin film layer and mixing a donor and an acceptor.

Example 3 In this example, a wet method organic EL element in which an electroluminescent polymer is used for an organic EL layer and a conductive thin film layer is formed of a conductive polymer is specifically exemplified. To do. The device structure is shown in FIG.

First, a mixed solution of polyethylenedioxythiophene / polystyrenesulfonic acid (abbreviation: PEDOT / PSS) was applied by spin coating to a glass substrate 1001 on which ITO, which was the anode 1002, was formed to a thickness of about 100 nm, and water was evaporated By doing so, the hole injection layer 1004 is formed in a thickness of 30 nm. next,
Poly (2-methoxy-5- (2'-ethyl-hexoxy) -1,4-phenylenevinylene) (abbreviation: MEH-PP
V) is spin-coated to a thickness of 100 nm to form a light emitting layer 1005a.

After the first organic EL layer 1010a is formed in this way, PEDOT / PSS is spin-coated to a thickness of 30 nm as the conductor thin film layer 1006.

After that, MEH-PPV was used as the light emitting layer 1005b.
Is spin-coated to form a 100 nm film. Since the conductor thin film layer is made of the same material as the hole injection layer,
The EL layer 1010b does not need to form a hole injection layer. Therefore, even if the 3rd and 4th layers and the organic EL layer are stacked, the PEDOT / PSS of the conductor thin film layer can be performed with a very simple operation.
And the MEH-PPV of the light emitting layer are alternately stacked.

Finally, Ca was deposited to a thickness of 150 nm as a cathode,
On top of that, 150 nm of Al is used as a cap to prevent Ca oxidation.
Vapor deposition.

Example 4 In this example, an organic solar cell of the present invention to which a mixture of a p-type organic semiconductor and an n-type organic semiconductor is applied as a conductor thin film layer will be specifically exemplified.

First, on a glass substrate on which ITO, which is a transparent electrode, is deposited to a thickness of about 100 nm, CuPc, which is a p-type organic semiconductor, is deposited on the glass substrate.
nm vapor deposition. Next, PV, which is an n-type organic semiconductor, is evaporated to a thickness of 50 nm, and a pn junction is formed in the organic semiconductor by using CuPc and PV. This is the first functional organic thin film layer.

Then, CuPc and PV were used as a conductor thin film layer.
Co-deposit at a ratio of 1: 1 to form 10 nm. Furthermore, CuPc is vapor-deposited with a thickness of 30 nm and PV is vapor-deposited with a thickness of 50 nm to form a second functional organic thin film layer.

Finally, Au is deposited to a thickness of 150 nm as an electrode. The organic solar cell configured in this manner is extremely effective because the present invention can be realized by finally using two kinds of organic compounds.

[0145]

By implementing the present invention, it is possible to provide an organic semiconductor device having higher reliability and higher yield without using a conventional ultrathin film. Further, especially in a photoelectronic device using an organic semiconductor, its efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram showing the concept of the present invention.

FIG. 3 is a diagram showing an effect of the present invention.

FIG. 4 is a diagram showing a theory of improving current efficiency.

FIG. 5 is a diagram showing a theory of improving current efficiency.

FIG. 6 is a diagram showing a conventional organic EL element.

FIG. 7 is a diagram showing an organic EL element of the present invention.

FIG. 8 is a diagram showing a specific example of the organic EL element of the present invention.

FIG. 9 is a diagram showing a specific example of the organic EL element of the present invention.

FIG. 10 is a diagram showing a specific example of the organic EL element of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/22 H01L 29/28 33/26 31/04 DF term (reference) 3K007 AB03 AB04 AB11 DA06 DB03 FA01 5F051 AA11 BA17 CB13 CB18 DA03 DA17 FA04 FA06

Claims (47)

[Claims] 1. An organic semiconductor in which an organic structure formed by sequentially stacking n functional organic thin film layers from the first to the n-th (n is an integer of 2 or more) is provided between two electrodes. In the device, all the floating conductive thin film layers are located between the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer. Is provided, and the conductor thin film layer is in ohmic contact with the functional organic thin film layer. 2. An organic semiconductor having an organic structure in which n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more) are sequentially laminated between two electrodes. In the element, all of the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer are in a floating state containing an organic compound. An organic semiconductor element, wherein a conductor thin film layer is provided, and the conductor thin film layer is in ohmic contact with the functional organic thin film layer. 3. An organic semiconductor in which an organic structure is provided between two electrodes, in which n functional organic thin film layers from 1st to nth (n is an integer of 2 or more) are sequentially stacked. In the element, all of the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer are in a floating state containing an organic compound. An organic semiconductor element, wherein a conductor thin film layer is provided, and the conductor thin film layer contains at least one of an acceptor and a donor for the organic compound. 4. The first to nth electrodes (n is 2) between two electrodes.
In the organic semiconductor element provided with the organic structure formed by sequentially stacking n functional organic thin film layers up to the above integer), k-th (k is an integer 1 ≦ k ≦ (n−1)) Between the functional organic thin film layer and the (k + 1) th functional organic thin film layer, a floating conductor thin film layer containing an organic compound is provided, and the conductor thin film layer includes the organic compound. An organic semiconductor device characterized by containing both an acceptor or a donor. 5. The organic semiconductor element according to claim 3, wherein a region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. An organic semiconductor device characterized by: 6. The organic semiconductor device according to claim 4, wherein the conductor thin film layer includes a first layer obtained by adding an acceptor to the organic compound and a donor added to the same organic compound as the organic compound. An organic semiconductor device having a structure in which a second layer is laminated, wherein the first layer is located closer to the cathode than the second layer. 7. The organic semiconductor device according to claim 6, wherein the region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. Organic semiconductor device. 8. The organic semiconductor element according to claim 4, wherein the conductor thin film layer is different from the first layer in which an acceptor is added to the first organic compound and the second layer different from the first organic compound. A second layer in which a donor is added to the organic compound of
An organic semiconductor device having a structure in which the first layer is located closer to the cathode than the second layer. 9. The organic semiconductor device according to claim 8, wherein the region of the functional organic thin film layer in contact with the first layer contains the same organic compound as the first organic compound. Characteristic organic semiconductor device. 10. The organic semiconductor device according to claim 8, wherein a region of the functional organic thin film layer in contact with the second layer contains the same organic compound as the second organic compound. Characteristic organic semiconductor device. 11. The organic semiconductor device according to claim 1, wherein the functional organic thin film layer is made of a bipolar organic compound. 12. The organic semiconductor device according to claim 1, wherein the functional organic thin film layer is at least one hole transport layer made of a hole transport material and an electron transport material. 2. An organic semiconductor device having at least one electron-transporting layer consisting of, wherein the hole-transporting layer is located closer to the anode than the electron-transporting layer. 13. An n-th functional organic thin film layer from the 1st to the n-th (n is an integer of 2 or more) which emits light when an electric current is passed between the anode and the cathode. In the organic electroluminescence element provided with the organic structure, between the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer. Are all provided with a floating conductive thin film layer, and the conductive thin film layer is in ohmic contact with the functional organic thin film layer. 14. An n-th functional organic thin film layer from the first to the n-th (n is an integer of 2 or more), which emits light when a current is applied, is sequentially laminated between an anode and a cathode. In the organic electroluminescence element provided with the organic structure, between the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer. Are provided with a floating conductor thin film layer containing an organic compound, and the conductor thin film layer is in ohmic contact with the functional organic thin film layer. . 15. An n-th functional organic thin film layer from the first to the n-th (n is an integer of 2 or more) that emits light when an electric current is applied is sequentially laminated between an anode and a cathode. In the organic electroluminescent element provided with the organic structure, all are provided between the k-th (k is an integer of 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th organic thin film layer. An organic electroluminescence device is characterized in that a floating conductor thin film layer containing an organic compound is provided, and the conductor thin film layer contains at least one of an acceptor or a donor for the organic compound. . 16. An n-th functional organic thin film layer from the 1st to the nth (n is an integer of 2 or more) which emits light when an electric current is applied is sequentially laminated between an anode and a cathode. In the organic electroluminescence element provided with the organic structure, between the k-th (k is an integer 1 ≦ k ≦ (n−1)) functional organic thin film layer and the k + 1-th functional organic thin film layer. Are all provided with a floating conductor thin film layer containing an organic compound, wherein the conductor thin film layer contains both an acceptor or a donor for the organic compound. element. 17. The organic electroluminescent element according to claim 15 or 16, wherein the region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. An organic electroluminescence device characterized by the above. 18. The organic electroluminescence device according to claim 16, wherein the conductive thin film layer is a first layer in which an acceptor is added to the organic compound, and a donor is added to the same organic compound as the organic compound. And a second layer formed by stacking the second layer, wherein the first layer is located closer to the cathode than the second layer is. 19. The organic electroluminescence device according to claim 18, wherein the region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. An organic electroluminescence device that does. 20. The organic electroluminescence device according to claim 16, wherein the conductive thin film layer is different from the first layer in which an acceptor is added to the first organic compound and the first organic compound. A second layer in which a donor is added to the second organic compound, and a structure formed by stacking, wherein the first layer is located on the cathode side of the second layer, the organic electroluminescence. element. 21. The organic electroluminescence device according to claim 20, wherein the region of the functional organic thin film layer in contact with the first layer contains the same organic compound as the first organic compound. An organic electroluminescence device characterized by: 22. The organic electroluminescence device according to claim 20, wherein the region of the functional organic thin film layer in contact with the second layer contains the same organic compound as the second organic compound. An organic electroluminescence device characterized by: 23. The organic electroluminescence device according to claim 13, wherein the functional organic thin film layer is made of a bipolar organic compound. 24. The organic electroluminescence device according to claim 13, wherein the functional organic thin film layer comprises at least one hole transport layer made of a hole transport material and an electron transport layer. An organic electroluminescence device comprising at least one electron transport layer made of a material, wherein the hole transport layer is located closer to the anode than the electron transport layer. 25. The organic electroluminescent device according to claim 23, wherein the bipolar organic compound includes a polymer compound having a π-conjugated system. 26. The organic electroluminescent device according to claim 23, wherein the bipolar organic compound includes a polymer compound having a π-conjugated system, and the conductor thin film layer has a high π-conjugated system. An organic electroluminescence device comprising a molecular compound. 27. The organic electroluminescent device according to claim 23, wherein the bipolar organic compound contains a polymer compound having a π-conjugated system, and the conductor thin film layer is doped with an acceptor or a donor. An organic electroluminescence device comprising a conductive polymer compound. 28. The organic electroluminescent device according to claim 24, wherein the conductor thin film layer contains at least one of the hole transport material and the electron transport material. 29. The organic electroluminescence device according to claim 24, wherein the conductor thin film layer contains both the hole transport material and the electron transport material. 30. Between the two electrodes, n functional organic thin film layers from 1st to nth (n is an integer of 2 or more) sequentially generating electromotive force by absorbing light are sequentially laminated. In the organic solar cell provided with the organic structure
Is an integer of 1 ≦ k ≦ (n−1)), and a floating conductor thin film layer is provided between the functional organic thin film layer and the (k + 1) th functional organic thin film layer. An organic solar cell, wherein the conductor thin film layer is in ohmic contact with the functional organic thin film layer. 31. Between the two electrodes, n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more) sequentially generating electromotive force by absorbing light are sequentially laminated. In the organic solar cell provided with the organic structure
Is an integer of 1≤k≤ (n-1)) and a floating conductor thin film layer containing an organic compound is provided between the functional organic thin film layer and the (k + 1) th functional organic thin film layer. The organic thin film layer is characterized in that the conductive thin film layer is in ohmic contact with the functional organic thin film layer. 32. Between the two electrodes, n functional organic thin film layers from the 1st to the nth (n is an integer of 2 or more) sequentially generating electromotive force by absorbing light are sequentially laminated. In the organic solar cell provided with the organic structure
Is an integer of 1≤k≤ (n-1)) and a floating conductor thin film layer containing an organic compound is provided between the functional organic thin film layer and the (k + 1) th functional organic thin film layer. In the organic solar cell, the conductor thin film layer contains at least one of an acceptor and a donor for the organic compound. 33. Between the two electrodes, n functional organic thin film layers from 1st to nth (n is an integer of 2 or more) sequentially generating electromotive force by absorbing light are sequentially laminated. In the organic solar cell provided with the organic structure
Is an integer of 1≤k≤ (n-1)) and a floating conductor thin film layer containing an organic compound is provided between the functional organic thin film layer and the (k + 1) th functional organic thin film layer. In addition, the conductor thin film layer contains both an acceptor and a donor for the organic compound. 34. The organic solar cell according to claim 32 or 33, wherein a region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. An organic solar cell characterized by. 35. The organic solar cell according to claim 33, wherein the conductor thin film layer comprises a first layer obtained by adding an acceptor to the organic compound, and a donor added to the same organic compound as the organic compound. An organic solar cell having a structure in which a second layer is laminated, wherein the first layer is located closer to the cathode than the second layer. 36. The organic solar cell according to claim 35, wherein a region of the functional organic thin film layer in contact with the conductor thin film layer contains the same organic compound as the organic compound. Organic solar cells. 37. The organic solar cell according to claim 33, wherein the conductor thin film layer is different from the first organic compound in the first layer and the second layer different from the first organic compound. A second layer in which a donor is added to the organic compound of
An organic solar cell having a structure in which the first layer is located closer to the cathode than the second layer. 38. The organic solar cell according to claim 37, wherein the region of the functional organic thin film layer in contact with the first layer contains the same organic compound as the first organic compound. Characteristic organic solar cell. 39. The organic solar cell according to claim 37, wherein the region of the functional organic thin film layer in contact with the second layer contains the same organic compound as the second organic compound. Characteristic organic solar cell. 40. The organic solar cell according to any one of claims 30 to 39, wherein the functional organic thin film layer is made of a bipolar organic compound. 41. The organic solar cell according to any one of claims 30 to 39, wherein the functional organic thin film layer has at least one hole transport layer and at least one electron transport layer. The organic solar cell, wherein the hole transport layer is located closer to the anode than the electron transport layer. 42. The organic solar cell according to claim 40, wherein the bipolar organic compound includes a polymer compound having a π-conjugated system. 43. The organic solar cell according to claim 40, wherein the bipolar organic compound includes a polymer compound having a π-conjugated system, and the conductor thin film layer has the π-conjugated system.
An organic solar cell comprising a polymer compound having a conjugated system. 44. The organic solar cell according to claim 40, wherein the bipolar organic compound includes a polymer compound having a π-conjugated system, and the conductive thin film layer is a conductive layer containing an acceptor or a donor. An organic solar cell comprising a high-molecular compound. 45. The organic solar cell according to claim 41, wherein the conductor thin film layer contains at least one of the hole transport material and the electron transport material. 46. The organic solar cell according to claim 41, wherein the conductor thin film layer contains both the hole transport material and the electron transport material. 47. The organic semiconductor device, the organic electroluminescence device or the organic solar cell according to claim 1, wherein the electric conductivity of the conductor thin film layer is 10 ⁻¹⁰ S / m. An organic semiconductor element, an organic electroluminescence element, or an organic solar cell, which is characterized by being ² or more.