JP4973689B2 - Organic semiconductor material, manufacturing method thereof, and organic electronic device - Google Patents

Description

  The present invention relates to organic semiconductor materials and organic electronic devices such as field effect transistors, and more particularly to an organic semiconductor material containing a porphyrin compound having a specific structure and an organic electronic device using the same.

  2. Description of the Related Art Conventionally, a field effect transistor (hereinafter, sometimes referred to as an FET) element that uses an inorganic semiconductor material such as silicon (Si) or gallium arsenide single crystal as a semiconductor layer has been widely used. However, in the case of inorganic materials, it is difficult to use a plastic (resin) for the substrate because it is processed at a high temperature of 300 ° C. or higher at the time of manufacturing, requires a lot of energy for manufacturing, and is used under vacuum such as vapor deposition, sputtering, and CVD. There are problems such that it is difficult to manufacture a large-area element due to the element manufacturing process, and that expensive equipment is required on the production line, resulting in high costs.

  Thus, organic electronic devices using organic semiconductor materials for semiconductor layers of electronic devices such as light-emitting diodes, nonlinear optical devices, as well as field effect transistors, have been proposed. According to this, since it can be manufactured by a process at a relatively low temperature, a plastic film can be used for the substrate, and there is an advantage that a lightweight and flexible device that is hard to break can be manufactured. Further, since it can be formed by a coating method or a printing method, there is an advantage that a large-area device can be manufactured at low cost without requiring expensive equipment. Furthermore, since organic materials have a wide variety of materials and can change the molecular characteristics by changing the molecular structure, there is a possibility that an element having a function not found in inorganic materials may be obtained.

Organic semiconductor materials are roughly classified into two types: polymer compound materials (polymer materials) and low-molecular compound materials. Devices using conductive polymer compounds and conjugated polymer compounds (Patent Document 1) and low-molecular compounds, respectively. A device using a compound (Patent Document 2) has been reported.
Typical polymer compound materials include conductive polymers and conjugated polymers. The method uses the conjugated polymer compound as a semiconductor as it is, and switches the ion (dopant) to and from the conjugated polymer compound by applying an electric field. Attempts have been made to do so. However, problems due to the polymer, that is, the solvent solubility is low and a uniform coating solution cannot be obtained, and the uniformity and stability of the film are low, and defects due to incomplete parts of the structure occur at the time of film formation. In addition, there are problems such as difficulty in purification, easy oxidation due to a decrease in oxidation potential, and no high-performance and high-stability material has yet been found.

Low-molecular compounds, on the other hand, have a nearly fixed structure as a result of synthesis, and can be used with various purification methods such as sublimation purification, recrystallization, and column chromatography. It is excellent in that it is easy to obtain a high-performance material.
Examples of low-molecular-weight compound materials include condensed aromatic hydrocarbon compounds such as pentacene and oligothiophenes in which four or more thiophene rings are connected, which are vapor-deposited and are as high as amorphous silicon (a-Si). There is a report showing mobility. However, there is a problem in terms of stability because it tends to be oxidized although it is not as high as a polymer compound. In other words, oxygen in the air is doped into the organic semiconductor film, the carrier density is increased, and there are cases where the leakage current increases or the mobility changes and stable characteristics cannot be obtained.

However, it is difficult to apply a coating process to low molecular weight compounds, and it is difficult to make full use of the characteristics of organic matter, such as the need to use a deposition method with high production costs. In general, when a film is formed by applying a low molecular weight compound from a solution, a granular structure is formed by crystallization, so that it is difficult to obtain a uniform film and there are many problems in film formation.

For example, although application of phthalocyanines to field effect transistors has been reported (Patent Documents 3 to 4, Non-Patent Document 1), phthalocyanines are generally insoluble in a solvent, and vacuum evaporation is required to produce these devices. It is necessary to form a film by the method.
Therefore, in recent years, a low-molecular compound with high solvent solubility is used as a precursor, and this is dissolved in a solvent and formed into a film by a coating process. After that, it is converted into a semiconductor to obtain an organic semiconductor film, thereby producing a field effect transistor. A method has been reported. For example, there are examples using pentacene or similar aromatic hydrocarbons (Non-Patent Documents 2 to 4).

  Here, the operational characteristics of the field-effect transistor are mainly the carrier mobility μ and conductivity σ of the semiconductor layer, the capacitance Ci of the insulating layer, the element configuration (source-drain electrode distance L and width W, insulating layer) , Etc.). In particular, it is important that the semiconductor material used for the semiconductor layer has a high carrier mobility μ (hereinafter sometimes simply referred to as mobility).

In pentacene, an example in which the mobility is 0.2 cm ² / Vs in the state of the film has been reported, but the mobility actually demonstrated by applying to the device is 10 ⁻² cm ^2.
/ Vs, the practical mobility is not yet high. In addition, tetrachlorobenzene molecules are eliminated from the pentacene precursor in this example, but tetrachlorobenzene has a high boiling point and is difficult to remove out of the reaction system, and its toxicity is a concern.

By the way, porphyrin compounds are studied as materials for optical devices for obtaining photocurrent and photovoltaic power, and an application example of benzoporphyrin to solar cells is described in Patent Document 5. However, the carrier mobility is low, and when the mobility is calculated from the carrier density and resistivity of the example, it remains at about 1.3 × 10 ⁻⁶ cm ² / Vs at the maximum. Because of such low mobility, application studies of porphyrin compounds are limited to optical devices, and application to organic electronic devices that positively utilize hole transportability and electron transportability has not been observed.

JP-A 61-202467 Japanese Patent No. 2984370 JP-A-11-251601 JP 2000-174277 A JP-A-9-18039

Appl. Phys. Lett. 69 (1996), p3086 Science, 270, 1995 (1995), p972. Optical Materials, Volume 12 (1999), p189 J. et al. Appl. Phys. 79 (1996), p2136

  As described above, the organic semiconductor material has various features not found in the inorganic semiconductor material. However, phthalocyanines, pentacene, oligothiophenes, and the like, which are relatively high-performance organic semiconductor materials, are all limited to costly vapor deposition processes. Therefore, there is a demand to obtain an organic electronic device that can be manufactured by an easier process and has practical characteristics.

  For this reason, there has been a demand for an organic semiconductor material having a high carrier mobility and stability and capable of forming a film by an easy manufacturing process such as a coating process, and an organic electronic device using the organic semiconductor material.

  In view of the above, as a result of various studies, it has been found that an organic electronic device using a compound having a specific porphyrin skeleton as a semiconductor material is useful, and has led to the present invention. Porphyrin is known to be applied to solar cells, but its mobility is still insufficient because of the insufficient purification of porphyrin itself. Thus, conventional porphyrin compounds are difficult to synthesize and purify, and have not received attention as materials for organic electronic devices.

However, as a result of studying the application of porphyrin compounds by the present inventors, surprisingly, compounds having a specific porphyrin skeleton can be formed into a film even in a solution process, exhibit high mobility, and other organic compounds. It has been found to have advantageous performance compared to semiconductor materials.
That is, the gist of the present invention is characterized by comprising a compound having a thiaporphyrin skeleton and having a molecular structure in which the distance from the thiaporphyrin ring plane to the center of the atoms forming the thiaporphyrin skeleton is within 1 km. And an organic semiconductor material comprising tetrabenzo-21-thiaporphyrin represented by the following formula and tetrabenzo-21,3-dithiaporphyrin represented by the following formula.

Another gist of the present invention is to convert a compound having a thiaporphyrin skeleton as a precursor having the following bicyclo structure into a compound having a thiaporphyrin skeleton by applying a solution in a solvent on a substrate and heating. It exists in the manufacturing method of the organic-semiconductor material characterized by doing.

  Still another subject matter of the present invention lies in an organic electronic device having a semiconductor layer and two or more electrodes, wherein the semiconductor layer contains the organic semiconductor material.

  According to the present invention, since an organic semiconductor material is used for an organic electronic device, it can be manufactured by a process at a relatively low temperature, so that a plastic film can be used for a substrate, and there is an advantage that a device that is lightweight and flexible and hardly breaks can be produced. Therefore, a thin field flexible field effect transistor can be manufactured. By using this as a switching element of each cell, a flexible active matrix liquid crystal display can be manufactured, and thus it can be widely applied.

  Moreover, the organic semiconductor material and organic electronic device containing the porphyrin compound according to the present invention have high carrier mobility and stability, and can be obtained by an easy manufacturing process. In addition, the field effect transistor according to the present invention has an advantage that the leakage current (leakage current) is small and the on / off ratio is large, the stability of the film and characteristics is high, and the lifetime is long. Furthermore, there is an advantage that the usable temperature range is wide, the film forming property is good, the large area is applicable, and it can be manufactured at low cost.

The schematic diagram of the field effect transistor (FET) of this invention is shown. The schematic diagram of the electrostatic induction transistor (SIT) of this invention is shown. The schematic diagram of the diode element of this invention is shown. It is a figure which shows the thermal-analysis result of the porphyrin compound obtained by the synthesis example 1. It is a figure which shows IR spectrum of the film | membrane which dried the solution of the porphyrin compound (1) obtained by the synthesis example 1. FIG. 6 is a diagram showing an IR spectrum of a film obtained by further heating the film of FIG. 5 obtained in Synthesis Example 1. FIG. It is a figure which shows the thin film absorption spectrum before and behind the heating in the synthesis example 1. It is a figure which shows the result of having observed the FET characteristic in the reference example 1. FIG. 10 is a diagram showing an X-ray diffraction pattern of a semiconductor film in Reference Example 5. FIG. It is a figure which shows the X-ray-diffraction pattern of the semiconductor film in Reference Examples 5 and 6. It is a figure which shows the hysteresis of the drain current by the scanning of gate voltage of the element of the reference examples 6 and 7. FIG.

Hereinafter, embodiments of the present invention will be described in detail.
First, the organic semiconductor material of the present invention will be described. In the present invention, a compound having a specific porphyrin skeleton is used.
(Compound having porphyrin skeleton)
In the present invention, the compound having a porphyrin skeleton refers to a compound having a porphyrin skeleton and an expanded porphyrin which is an analog obtained by increasing the number of pyrrole rings forming the porphyrin skeleton or replacing the pyrrole ring with a thiophene ring or a furan ring. (Expanded
porphyrin) is a generic name for compounds having a skeleton, and includes, for example, a porphyrin-based, thiaporphyrin-based, dithiaporphyrin-based, oxaporphyrin-based, dioxaporphyrin-based, thiaoxaporphyrin-based compound, and the like.

  Specifically, in the present invention, the compound having a porphyrin skeleton refers to a compound having a structure represented by the following general formula (A).

In the above formula, Y ^{1 to} Y ⁿ each independently represents a monocyclic ring composed of a π-conjugated hydrocarbon ring or heterocyclic ring, and Y ^{1 to} Y ⁿ may be substituted. X ^{1 to} X ⁿ each independently represent a direct bond or a linking group consisting of a linear hydrocarbon group, and X ^{1 to} X ⁿ may be substituted. Here, the following symbols represent single bonds or double bonds.

Moreover, n is an integer of 4-20. Further, in the entire structure represented by the general formula (A), the π electron system is conjugated in a ring shape.
That is, the structure represented by the above formula is a structure in which a π-conjugated ring represented by Y ^{1 to} Y ⁿ is π-conjugated as a whole via X ^{1 to} X ⁿ . Accordingly, Y ^{1 to} Y ⁿ are each a planar unit, and the entire structure represented by the general formula (A) has a very high planarity.

  In order for the organic semiconductor material to have high carrier mobility, it is desirable that adjacent molecules in the solid state overlap well. This is because the interaction between π electron orbitals is important when carriers, that is, electrons or holes are transferred between molecules. It is well known that π electrons play an important role in charge transport in organic semiconductors. However, few examples are known in which π electrons are conjugated to a macro scale and exhibit semiconductor characteristics.

In particular, in a molecular crystal, π-electron conjugation is limited within a molecule, and charge transport is performed by movement of charge between molecules. In that case, the greater the overlap of π orbitals conjugated within the molecule, the higher the efficiency of charge transfer. Therefore, the mobility of molecular crystals is also direction dependent. This is also reflected in the fact that materials having higher crystallinity generally exhibit higher mobility than amorphous materials.

In order to increase the overlap of π orbitals between molecules, it is desirable that the planarity of the π conjugated system of the molecules is high. As a measure of planarity, the deviation of atoms forming the porphyrin skeleton from the porphyrin ring plane can be used.
Therefore, the present invention is characterized in that it has a molecular structure in which the distance from the porphyrin ring plane to the center of the atoms forming the porphyrin skeleton is within 1 cm. If this distance is within 1 km, it has a high flatness and can satisfy the condition for increasing the mobility.

Here, the “porphyrin ring” refers to a structure represented by the general formula (A) including a π-conjugated ring represented by Y ^{1 to} Y ⁿ and X ^{1 to} X ⁿ . “Porphyrin ring plane” refers to a plane that minimizes the sum of the squares of the distances from the centers of all atoms forming the porphyrin ring. The “porphyrin skeleton” is a generic term for atoms or atomic groups that are bound to the porphyrin ring and that are restricted to free rotation with thermal energy at about room temperature, in addition to the atoms forming the porphyrin ring. Say.

In addition, “an atom or atomic group that is bonded to the porphyrin ring and limited in free rotation at a thermal energy of about room temperature” means between an atom of the porphyrin ring and an atom directly bonded thereto. The bond has an internal rotation energy barrier that is greater than the thermal energy at room temperature (usually 25 ° C.). For example, the energy barrier for internal rotation is 10 kcal / mol or more.
In general, the energy required for the rotation of the bond can be obtained by actual measurement, but can also be obtained by calculation by a molecular orbital method or the like. 6-311G (dp) and other non-empirical molecular orbital methods and MOPAC and other semi-empirical molecular orbital methods can be used. There is an advantage that the statistical calculation is simple.
When two or more porphyrin rings that can rotate freely in one molecule are included in the molecule, the above planarity of each porphyrin ring may be good, and the plurality of porphyrin skeletons are in the same plane. It is not necessary to take the structure in

  Next, the compound having a porphyrin skeleton of the present invention will be described in more detail. In the present invention, the compound having a porphyrin skeleton refers to a compound having a structure represented by the following general formula (A).

In the above formula, Y ^{1 to} Y ⁿ each independently represents a monocyclic ring composed of a π-conjugated hydrocarbon ring or heterocyclic ring, and Y ^{1 to} Y ⁿ may be substituted. X ^{1 to} X ⁿ each independently represent a direct bond or a linking group consisting of a linear hydrocarbon group, and X ^{1 to} X ⁿ may be substituted. Here, the following symbols represent single bonds or double bonds.

Moreover, n is an integer of 4-20. Further, in the entire structure represented by the general formula (A), the π electron system is conjugated in a ring shape.
Preferably, n is an integer from 4 to 10, more preferably n is an integer from 4 to 6, and most preferably n is 4. n represents the number of π-conjugated rings Y in the above structure, but if n is too large, the flatness tends to be poor, the electrical characteristics tend to be bad, and the synthesis becomes difficult. Because.

In the general formula (A), Y ^{1 to} Y ⁿ each independently represents a monocyclic ring composed of a π-conjugated hydrocarbon ring or heterocyclic ring, and an aromatic ring is preferable because of high planarity. Moreover, it is preferably a 5- to 8-membered ring, more preferably a 5- to 6-membered ring, and most preferably a 5-membered ring.
Y ¹ shows a preferred embodiment of to Y ⁿ in the following, but is not limited thereto. Examples of the 5-membered ring include a pyrrole ring, a thiophene ring, a furan ring, a thiazole ring, a dithiazole ring, an oxazole ring, an oxadiazole ring, a selenophene ring, and a cyclopentadiene ring. Examples of the 6-membered ring include a benzene ring, a pyridine ring, a pyrimidine ring, a naphthalene ring, an anthracene ring, and a pyrene ring.

Y ^{1 to} Y ⁿ may have a substituent. For example, Y ^{1 to} Y ⁿ may be condensed with other hydrocarbon rings or heterocyclic rings to form a condensed ring. It is preferable that the other ring is also an aromatic ring because the planarity is further improved. Moreover, it is preferably a 5- to 8-membered ring, more preferably a 5- to 6-membered ring. Hereinafter, a single ring composed of Y ^{1 to} Y ⁿ or a condensed ring composed of Y ^{1 to} Y ⁿ and another ring is collectively referred to as a ring including Y ¹ to Y ⁿ . Preferably, the ring containing Y ^{1 to} Y ⁿ is a monocyclic ring or a 2-8 condensed ring, more preferably a monocyclic ring or a 2-6 condensed ring, and most preferably a monocyclic ring or a 2-4 condensed ring. is there. In particular, it is desirable for enhancing the planarity that all of the rings including Y ^{1 to} Y ⁿ are aromatic rings.

Preferable examples of these other rings are π-conjugated rings such as benzene, naphthalene, anthracene, pyridine and quinoline. Specific examples of the condensed ring composed of Y ^{1 to} Y ⁿ and another ring include a benzopyrrole ring, a benzothiophene ring, and a benzofuran ring.
On the contrary, as an unpreferable example of another ring, it is typically a bicyclo ring.

The ring containing Y ^{1 to} Y ⁿ may have a substituent. Examples of the substituent that the ring containing Y ^{1 to} Y ⁿ may have include the following. A straight chain or branched chain having 1 to 18 carbon atoms which may be substituted such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-heptyl group, etc. An alkyl group; a C3-C18 cyclic alkyl group such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, and an adamantyl group; an optionally substituted carbon number such as a vinyl group, a propenyl group, and a hexenyl group -18 linear or branched alkenyl groups; cyclopentenyl groups, cyclohexenyl groups, etc., optionally substituted C3-C18 cyclic alkenyl groups; propynyl groups, hexynyl groups, etc., optionally substituted carbon atoms To 18 linear or branched alkynyl group; a heterocyclic group which may be substituted such as 2-thienyl group, 2-pyridyl group, 4-piperidyl group, morpholino group, etc. A phenyl group, a tolyl group, a xylyl group, a mesityl group and the like, an optionally substituted aryl group having 6 to 18 carbon atoms; a benzyl group, a phenethyl group and the like, an optionally substituted aralkyl group having 7 to 20 carbon atoms; A linear or branched alkoxy group having 1 to 18 carbon atoms which may be substituted, such as a group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group or a tert-butoxy group; A linear or branched alkenyloxy group having 3 to 18 carbon atoms which may be substituted, such as oxy group, butenyloxy group, pentenyloxy group; methylthio group, ethylthio group, n-propylthio group, n-butylthio group, sec-butylthio group And a linear or branched alkylthio group having 1 to 18 carbon atoms which may be substituted, such as a tert-butylthio group. .

Other specific examples include halogen atoms such as fluorine atom, chlorine atom, bromine atom; nitro group; nitroso group; cyano group; isocyano group; cyanato group; isocyanato group; thiocyanato group; isothiocyanato group; mercapto group; hydroxyamino group; a formyl group; a sulfonic group; a carboxyl group; an acyl group represented by -COR ^6, amino group represented by ^-NR 7 ^{R 8,} an acylamino group represented by -NHCOR ^9, in -NHCOOR ¹⁰ Carbamate group represented, Carboxylic ester group represented by -COOR ¹¹ , Acyloxy group represented by -OCOR ¹² , Carbamoyl group represented by -CONR ¹³ R ¹⁴ , Sulfonyl represented by -SO ₂ R ¹⁵ _group, Table with -SO ^{2 NR} 16 sulfamoyl group represented by ^{R _17,} -SO ^{3 R 18} It is the sulfonic acid ester group, a sulfonamide group represented by -NHSO ₂ R ^19, include sulfinyl group represented by -SOR ^20. Here, R ⁶ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁸ , R ¹⁹ , R ²⁰ each represents an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, R ⁷ , R ⁸ , R ¹³ , R ¹⁴ , R ¹⁶ , and R ¹⁷ represent any of a hydrogen atom, an optionally substituted hydrocarbon group, and an optionally substituted heterocyclic group.

The hydrocarbon group represented by R ^{6 to} R ²⁰ represents a linear or branched alkyl group, a cyclic alkyl group, a linear or branched alkenyl group, a cyclic alkenyl group, an aralkyl group, or an aryl group. Among these, a linear or branched alkyl group having 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and an n-heptyl group, a cyclopropyl group A cyclic alkyl group having 3 to 18 carbon atoms such as a cyclopentyl group, a cyclohexyl group and an adamantyl group, a linear or branched alkenyl group having 2 to 18 carbon atoms such as a vinyl group, a propenyl group and a hexenyl group, a cyclopentenyl group, a cyclo A C3-C18 cyclic alkenyl group such as a hexenyl group, a C7-C20 aralkyl group such as a benzyl group or a phenethyl group, a C6-C18 aryl such as a phenyl group, a tolyl group, a xylyl group, or a mesityl group Groups. The aryl group portion of these groups may be further substituted with the same substituent as the ring containing Y ¹ to Y ⁿ described above.

The heterocyclic group represented by R ^{6 to} R ²⁰ may be a saturated heterocyclic ring such as 4-piperidyl group, morpholino group, 2-morpholinyl group, piperazyl group, 2-furyl group, 2-pyridyl group, 2-thiazolyl. An aromatic heterocyclic ring such as a group or 2-quinolyl group may be used. These may contain a plurality of heteroatoms, may further have a substituent, and may have any bonding position. Preferred structures for the heterocyclic ring are a 5- or 6-membered saturated heterocyclic ring, a 5- or 6-membered monocyclic ring, and an aromatic heterocyclic ring thereof.

The ring containing Y ^{1 to} Y ⁿ may have a linear or branched alkyl group, cyclic alkyl group, linear or branched alkenyl group, cyclic alkenyl group, linear or branched alkynyl group, linear or branched The alkoxy group, the linear or branched alkylthio group, and the alkyl chain portion of the alkyl group represented by R ^{6 to} R ²⁰ may further have a substituent. Examples of the substituent include the following. It is done. C1-C10 alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group; methoxymethoxy group, ethoxymethoxy group, propoxymethoxy group, ethoxyethoxy group An alkoxyalkoxy group having 2 to 12 carbon atoms, such as a propoxyethoxy group and a methoxybutoxy group; a methoxymethoxymethoxy group, a methoxymethoxyethoxy group, a methoxyethoxymethoxy group, a methoxymethoxyethoxy group, an ethoxyethoxymethoxy group, etc. 15 alkoxyalkoxyalkoxy groups; aryl groups having 6 to 12 carbon atoms such as phenyl group, tolyl group, xylyl group (these may be further substituted with any substituent); phenoxy group, tolyloxy group, xylyloxy Group, naphthyloxy Aryloxy group having 6 to 12 carbon atoms and the like; allyloxy group, an alkenyloxy group having 2 to 12 carbon atoms such as vinyloxy groups.

  Further, as other substituents, heterocyclic groups such as 2-thienyl group, 2-pyridyl group, 4-piperidyl group, morpholino group; cyano group; nitro group; hydroxyl group; amino group; N, N-dimethylamino group An alkylamino group having 1 to 10 carbon atoms such as N, N-diethylamino group; an alkylsulfonylamino group having 1 to 6 carbon atoms such as methylsulfonylamino group, ethylsulfonylamino group and n-propylsulfonylamino group; fluorine atom Halogen atoms such as chlorine atom and bromine atom; C2-C7 alkoxycarbonyl groups such as carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl; methyl Carbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyl group An alkylcarbonyloxy group having 2 to 7 carbon atoms such as a cis group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group; a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an isopropoxycarbonyloxy group, Examples thereof include an alkoxycarbonyloxy group having 2 to 7 carbon atoms such as an n-butoxycarbonyloxy group.

As the substituent that the ring containing Y ^{1 to} Y ⁿ may have, a hydroxyl group, an optionally substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group, a mercapto group, an acyl group, Furthermore, it may be substituted with an ester of a carboxyl group and its alcohol having 1 to 10 carbon atoms, a formyl group, a carbamoyl group, a halogen atom such as fluorine, chlorine, bromine or iodine, or an alkyl group having 1 to 10 carbon atoms. Examples thereof include a good amino group and nitro group, and these may further have a substituent.

Most preferably, the ring containing Y ^{1 to} Y ⁿ is unsubstituted or has a substituent composed of a single atom such as a halogen atom.
X ^{1 to} X ⁿ each independently represent a direct bond or a linking group consisting of a linear hydrocarbon group, and X ^{1 to} X ⁿ may each be substituted. The linear hydrocarbon group is preferably about 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably a linear unsaturated hydrocarbon group having 1 to 3 carbon atoms, In particular, an alkenylene group, an alkynylene group, an alkanediylidene group, and an alkenediylidene group are preferable.

Preferable specific examples of X ^{1 to} X ⁿ include, but are not limited to, a methine group, a vinylene group (ethenylene group), an ethynylene group, (= C = C =), and the like. Moreover, all of X ^{1 to} X ⁿ may have a substituent.
Examples of the substituent that X ^{1 to} X ⁿ may have include substantially the same substituents that the ring containing Y ^{1 to} Y ⁿ may have, but are bulky and free. Substituents that limit rotation are undesirable. More preferably, a linear alkyl group which may be substituted, a linear alkoxy group, a linear alkylthio group, an ester of a carboxyl group and a linear alcohol having 1 to 10 carbon atoms, or a halogen atom may be mentioned. . The substituents that X ^{1 to} X ⁿ may have may be bonded to each other to form a ring.

Of these, an unsubstituted linear alkyl group, a linear alkoxy group, a linear alkylthio group, an ester of a carboxyl group and a linear alcohol having 1 to 10 carbon atoms, and a halogen atom are preferable.
Most preferably, X ^{1 to} X ⁿ are unsubstituted or have a substituent composed of a single atom such as a halogen atom.

Conversely, a representative example of an undesirable substituent is a phenyl group.
Note that in the entire structure represented by the general formula (A), the π-electron system needs to be conjugated in a ring shape.
Further, in the compound having a porphyrin skeleton according to the present invention, various metals, cations, anions, salts, and the like may be coordinated with all or part of Y ¹ to Y ⁿ having the above structure. For example, it is a divalent metal atom, and specific examples are Zn, Cu, Fe, Ni, and Co. In addition, an atomic group in which a trivalent or higher-valent metal and other atoms are bonded, specifically Fe-B ¹ , Al-B ^2.
, Ti = O, Si—B ³ B ⁴ , and the like. Here, B ¹ , B ² , B ³ , and B ⁴ represent a monovalent group such as a halogen atom, an alkyl group, or an alkoxy group.

Examples of such porphyrin-based and extended porphyrin-based compounds are KARL M. et al. KADISH KEVIN M.K. By SMITH ROGER GUILARD, THE PORPHYRIN HANDBOOK VOL. Examples are 1 to 10, ACADEMIC PRESS (2000), and the like.
In addition, one atom is coordinated by two identical or different porphyrin rings, or two identical or different porphyrin rings share one or more atoms or atomic groups. And those in which three or more identical or different porphyrin rings are connected to each other on a long chain.

  Most preferably, the compound having a porphyrin skeleton according to the present invention specifically includes a structure represented by the following general formula (1) or (2).

In the above formulas (1) and (2), Z ^ia and Z ^ib (i = 1 to 4) represent a monovalent organic group, and Z ^ia and Z ^ib may be bonded to form a ring. Examples of the monovalent organic group include a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group, a mercapto group (alkylthio group), an acyl group, and a carboxyl group. An ester with an alcohol having 1 to 10 carbon atoms, a formyl group, a carbamoyl group, a halogen atom such as fluorine, chlorine, bromine and iodine, an amino group optionally substituted with an alkyl group having 1 to 10 carbon atoms, and a nitro group These may be further substituted. Examples of an organic group in which Z ^ia and Z ^ib are combined to form a ring include a ring formed by the structure of Z ^ia —CH═CH—Z ^ib , such as a benzene ring, a naphthalene ring, an anthracene ring, etc. Aromatic hydrocarbons such as pyridine ring, quinoline ring, furan ring, and thiophene ring, and non-aromatic cyclic hydrocarbons such as cyclohexene. R1 to R4 each represents a hydrogen atom or a monovalent organic group. Examples of the organic group include an optionally substituted alkyl group, aryl group, alkoxy group, mercapto group, ester of a carboxyl group and an alcohol having 1 to 10 carbon atoms, and a halogen atom.

M is a divalent metal atom, for example, Zn, Cu, Fe, Ni, Co, or an atomic group in which a trivalent or higher metal is bonded to another atom, for example, Fe-B ¹ , Al— ^{B 2, Ti = O, Si} -B 3 B 4, and the like. Here, B ¹ , B ² , B ³ , B ⁴
Represents a monovalent group such as a halogen atom, an alkyl group or an alkoxy group.
In addition, two porphyrin rings are coordinated by sharing one atom, two porphyrin rings are bonded by sharing one or more atoms or atomic groups, or three of them. It may be bonded to the long chain.

As described above, in order to increase the overlap of π orbitals between molecules, it is desirable that the porphyrin compound according to the present invention has high planarity of the π conjugated system of the molecule. It has a molecular structure in which the distance to the center is arranged within 1 km. The atoms forming the porphyrin skeleton are the atoms forming the porphyrin ring and the thermal energy at room temperature bonded to the substituents Z ^ia , Z ^ib and R ^{1 to} R ⁴ in (1) or (2). Indicates an atom or atomic group with limited free rotation.

  For example, the carbon atoms forming the four benzene rings of tetraphenylporphyrin having a benzene ring bonded to the four meso positions of the porphyrin ring are inhibited from free rotation due to steric hindrance between the benzene ring and the porphyrin ring. Included in the porphyrin skeleton. The presence of such a group at a position deviated from the plane of the porphyrin ring is not preferable because the steric hindrance prevents the porphyrin rings from overlapping. On the other hand, when the rotation of the bond is free, such as an alkyl group or an alkoxy group, particularly a straight chain alkyl group or an alkoxy group, the structure can be freely adjusted so that the porphyrin rings overlap so that it does not become an obstacle. , Not included in the porphyrin skeleton.

The porphyrin ring plane can be defined as a plane that minimizes the sum of the squares of the distances from the centers of all atoms forming the porphyrin ring. If the distance from this plane to the center of the atom forming the porphyrin skeleton is within 1 km, the condition for high planarity and high mobility can be satisfied.
Typical examples of porphyrin compounds having high flatness include the following tetraphenylporphyrins, which are the most well-known porphyrins, and porphyrins having a bicyclo structure.

Accordingly, Z ^ia and Z ^{ib in the} general formula (1) or (2) are preferably single atoms such as a hydrogen atom and a halogen atom. In addition, a group that forms a ring with high planarity that has no substituent, and at least one of Z ^ia —CH═CH—Z ^ib (i = 1 to 4) forms an aromatic ring such as benzene, naphthalene, and anthracene. What is a group and more preferably all Z ^ia —CH═CH—Z ^ib (i = 1 to 4) are aromatic rings are preferred. R ^{1 to} R ⁴ are also preferably single atoms such as a hydrogen atom or a halogen atom.

The present invention is also characterized by containing a compound having a porphyrin skeleton and having a carrier mobility (mobility: μ) of 1 × 10 ⁻⁵ cm ² / Vs or more. The carrier mobility necessary for application to an electronic device is determined by the magnitude of the current to be controlled, the switching speed, and the element structure. By using the porphyrin compound of the present invention, an organic device having a carrier mobility of 1 × 10 ⁻⁵ cm ² / Vs or more, preferably 1 × 10 ⁻³ cm ² / Vs or more can be provided. So far, the mobility of organic semiconductors in molecular crystals is a single crystal of condensed aromatic hydrocarbon such as pentacene,
The value is about m ² / Vs. Porphyrin molecules have a large π-orbital, which may increase the intermolecular interaction. Furthermore, since the porphyrin molecule has a central metal, it can be expected that the metal-mediated interaction can be used, and the mobility is 10 cm ^2. / Vs to 100cm ²
It is considered that even / Vs can be achieved.

  Another condition for exhibiting high mobility is the purity of the semiconductor material constituting the semiconductor layer. Impurities that trap carriers cause a large decrease in mobility even in trace amounts. Such impurities that easily become traps are those in which the level of accepting carriers is in the energy gap of the semiconductor. When the carrier is a hole, it has the highest occupied level (HOMO) higher than that of the semiconductor, and when the carrier is an electron, it has the LUMO level lower than that of the semiconductor.

  Such an impurity that does not give an energy level also causes a decrease in mobility because the impurity has a defect in the semiconductor crystal structure when the concentration is high. Therefore, the impurity concentration is desirably low, preferably 10% or less, and more preferably 1% or less. According to the manufacturing method using a highly soluble precursor described later, there is an advantage that a high-purity semiconductor layer can be formed.

In porphyrin compounds, holes are usually carriers, but they can exhibit electron transport properties by a substituent or a central metal, and can also use electrons as carriers.
When charge injection from the electrode needs to occur smoothly as in a field effect transistor, there is a preferred position in the energy level of carriers. In the case of holes, if HOMO is too low, the barrier for charge injection becomes large, which is not preferable. However, if the HOMO is too high, it is easily oxidized by air and becomes unstable. Therefore, the ionization potential in the solid state corresponding to the HOMO level is preferably 5.6 eV or less, and more preferably 5.3 eV or less. The ionization potential is preferably 4.5 eV or more, and more preferably 4.8 eV or more.

  As the compound having a porphyrin skeleton of the present invention, a compound in a solid state at room temperature is preferable for application to a device. Depending on the substituent in the general formula (1) or (2), a compound exhibiting liquid crystallinity can be obtained, but it can be used as an organic semiconductor even in a liquid crystalline state. In particular, since the porphyrin compounds of the present invention have a structure with good planarity, it is expected that a discotic liquid crystal is obtained. Such a structure is convenient for transporting carriers. Since it is not preferable to cause a large change in characteristics in the operating temperature range, a compound whose phase transition temperature such as melting point or freezing point is not in the range of 5 ° C. to 40 ° C. is preferable. The compound that takes a solid state at room temperature preferably has a melting point or glass transition temperature of 50 ° C. or higher, and more preferably 100 ° C. or higher.

Moreover, as an on-off ratio of the organic-semiconductor material containing the porphyrin compound of this invention, it is so desirable that it is high, However, Preferably it is 800 or more, More preferably, it is 1000 or more.
Examples of preferred porphyrin compounds of the present invention are given below. Here, the structure of a metal-free body is illustrated, but a metal salt corresponding to the following examples and a molecule having a substituent can be used as preferred examples as well. In addition, molecular structures with good symmetry are mainly exemplified, but an asymmetric structure based on a combination of partial structures can also be used. Of course, the porphyrin compound of the present invention is not limited to these exemplified compounds. In the following, Me represents a methyl group, and Et represents an ethyl group.

(Method for synthesizing porphyrin compounds)
The porphyrin compounds of the present invention can be synthesized using a corresponding pyrrole compound, thiophene compound, furan compound or the like as a starting material. For methods for synthesizing porphyrin compounds, see, for example, KARL M. et al. KADIS H KEVIN M. By SMITH ROGER GUILARD, THE PORPHYRIN HANDBOOK VOL. 1. A method described in ACADEMIC PRESS (2000) can be used.

  For example, the condensation of pyrrole and aldehyde is often used as a method for synthesizing tetraphenylporphyrin.

(In the above formula, Q ¹ and Q ² correspond to Z ^ia and Z ^ib of the general formula (1) or (2), and Q ³ corresponds to R ^{1 to} R ⁴ ).
It can also be obtained by a condensation reaction of a carboxylic acid ester or a pyrrole having a methyl group at the α-position.

(In the above formula, Q ¹ and Q ² correspond to Z ^ia and Z ^ib in the general formula (1) or (2). R ⁵ represents an alkyl group.)
Among the porphyrin compounds of the present invention, benzoporphyrins in which a benzene ring is condensed with one or more pyrrole ring, thiophene ring, and furan ring can be derived using a corresponding bicyclo compound as a precursor. Since this precursor does not have a planar structure, it has high solubility in a solvent and is difficult to crystallize. Therefore, application from a solution gives an amorphous or a good film close to amorphous. A benzoporphyrin film having high planarity can be obtained by heat-treating this film and removing ethylene. The structure of the unsubstituted and metal-free body is represented by the following chemical reaction. This reaction proceeds quantitatively by heating to 100 ° C. or higher, preferably 150 ° C. or higher. In addition, since it is an ethylene molecule that desorbs, it hardly remains in the system, and there is no problem in terms of toxicity and safety. Next, an example of tetrabenzoporphyrin in which four benzene rings are condensed is shown.

  Examples of the synthesis method of this bicyclo compound include the following route.

また、途中のピロール中間体までの合成ルートは別のルートでも取ることができる。

Moreover, the synthetic route to the intermediate pyrrole intermediate can be taken by another route.

The precursor metal complex can be obtained by mixing the compound and the metal salt in an organic solvent. A metal salt can be used as long as it is soluble in an organic solvent, but acetate is a typical example. Any solvent may be used as long as it dissolves the metal salt and the bicyclo compound. Preferred examples include chloroform, alcohol, dimethylformamide, tetrahydrofuran, acetonitrile, N-methylpyrrolidone, and a mixed solvent thereof.
(Device type)
(1) Definition of electronic device The electronic device of the present invention has two or more electrodes, and the current flowing between the electrodes and the generated voltage are controlled by, for example, electricity, magnetism, or chemical substances other than light. It is a device. For example, an element that controls current and voltage by applying a voltage, an element that controls voltage and current by applying a magnetic field, and an element that controls voltage and current by applying a chemical substance. Examples of this control include rectification, switching, amplification, and oscillation. The corresponding devices currently implemented in silicon and the like include resistors, rectifiers (diodes), switching elements (transistors, thyristors), amplifier elements (transistors), memory elements, chemical sensors, etc., or combinations of these elements. Examples include integrated devices. Since the porphyrin compound according to the present invention has a high carrier mobility μ, it is highly effective when applied to a switching element (transistor, thyristor).

Also for devices controlled by light or controlling light emission, the porphyrin materials are used for applications other than those that operate by directly absorbing light or emitting light, such as wiring, voltage and current control. Devices are also included.
More specific examples of electronic devices are described in S.A. M.M. Examples include those described in Sze, Physics of Semiconductor Devices, 2nd Edition (Wiley-Interscience 1981).
(2) Field Effect Transistor An example of the organic device of the present invention is a field effect transistor (FET). This is because there are two electrodes (source electrode and drain electrode) in contact with the semiconductor, and the current flowing between the electrodes (called the channel) is controlled by the voltage applied to another electrode called the gate. is there. The gate electrode has a structure in which an electric field is basically applied only to the semiconductor layer and no current flows, and it is called a field effect transistor.

  According to the present invention, since an organic semiconductor material is used, it can be manufactured by a process at a relatively low temperature, so that a plastic film can be used for a substrate, and there is an advantage that a lightweight and flexible device that is hard to break can be manufactured. Therefore, a thin film flexible field effect transistor can be manufactured, and by using this as a switching element of each cell, a flexible active matrix liquid crystal display can be manufactured and widely applied.

  The operational characteristics of the field effect transistor are as follows: carrier mobility μ of semiconductor layer, conductivity σ, electrostatic capacity Ci of insulating layer, element configuration (distance L and width W between source and drain electrodes, film thickness of insulating layer) d) and the like. The higher the carrier mobility μ is, the better the semiconductor material used for the field effect transistor. However, since the porphyrin compounds according to the present invention have a high carrier mobility μ, the effect is high when used for the field effect transistor. In addition, the field effect transistor according to the present invention has an advantage that the leakage current (leakage current) is small and the on / off ratio is large, the stability of the film and characteristics is high, and the lifetime is long. Furthermore, there is an advantage that the usable temperature range is wide, the film formability is good, the large area is applicable, and it can be manufactured at low cost.

In general, a structure in which a gate electrode is insulated by an insulating film (Metal-Insulator-Semiconductor: MIS structure) is often used. Others have a structure in which a gate electrode is formed through a Schottky barrier, but in the case of an FET using an organic semiconductor material, a MIS structure is often used.
Hereinafter, the field effect transistor of the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to these structures.

1A to 1D show some structural examples of field effect transistor elements. 1 is a semiconductor layer, 2 is an insulator layer, 3 and 4 are source and drain electrodes, 5 is a gate electrode, and 6 is a substrate. In addition, arrangement | positioning of each layer and an electrode can be suitably selected according to the use of an element. Since current flows in a direction parallel to the substrate, it is called a lateral FET.
The substrate 6 needs to be able to be held without peeling off each layer formed thereon. Such materials include, for example, insulating plates such as plates and films made of resin, paper, glass, ceramics, etc., and insulating layers formed by coating on conductive substrates such as metals and alloys. Examples thereof include composite materials composed of various combinations such as materials. Use of a resin film or paper is preferable because the element can have flexibility.

A material having conductivity can be used for the electrodes 3, 4, and 5. For example, metals such as platinum, gold, aluminum, chromium, nickel, cobalt, copper, titanium, magnesium, calcium, barium, sodium and alloys containing them, conductive oxides such as InO ₂ , SnO ₂ , ITO, polyaniline , Conductive polymer compounds such as polypyrrole, polythiophene, polyacetylene, and polydiacetylene; semiconductors such as silicon, germanium, and gallium arsenide; and carbon materials such as carbon black, fullerene, carbon nanotube, and graphite. Further, the conductive polymer compound or the semiconductor may be doped. Examples of the dopant include acids such as hydrochloric acid, sulfuric acid, and sulfonic acid, Lewis acids such as PF ₆ , AsF ₅ , and FeCl ₃ , halogen atoms such as iodine, metal atoms such as sodium and potassium, and the like. Alternatively, a conductive composite material in which carbon black, metal particles, or the like is dispersed in the above material can be used.

In addition, although wiring (not shown) is connected to the electrodes 3, 4, and 5, the wiring can be manufactured using substantially the same material as the electrodes.
The insulator layer 2 can be made of an insulating material. For example, polymers such as polymethyl methacrylate, polystyrene, polyvinyl phenol, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, phenol resin, and copolymers of these, silicon dioxide, aluminum oxide , Oxides such as titanium oxide, ferroelectric oxides such as SrTiO ₃ and BaTiO ₃ , dielectrics such as nitrides such as silicon nitride, sulfides and fluorides, or polymers in which particles of these dielectrics are dispersed , Etc.

As described above, the thickness of the insulator layer 2 is preferably as thin as possible within a range in which a necessary function can be performed. Usually, the film thickness is 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more. However, the film thickness is usually 10 μm or less, preferably 1 μm or less, and more preferably 500 nm or less.
As a material of the semiconductor layer 1, a semiconductor layer containing the above porphyrin compound as a main component is preferably used. A main component means containing 50 weight% or more. More preferably, it contains 80% by weight or more. In order to improve the characteristics or to impart other characteristics, it may be used by mixing with other organic semiconductor materials as necessary, or various additives may be added. The semiconductor layer 1 may be composed of a plurality of layers.

  The thickness of the semiconductor layer 1 is preferably as thin as possible within a range in which a necessary function can be performed. In the lateral field effect transistor element as illustrated in FIG. 1 (the source electrode and the drain electrode are arranged almost horizontally), the characteristics of the element do not depend on the film thickness if the film thickness exceeds a predetermined value. This is because the leakage current often increases as the film thickness increases. In order to perform a necessary function, the film thickness is usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more. However, the film thickness is usually 10 μm or less, preferably 1 μm or less, and more preferably 500 nm or less.

  In the organic electronic device of the present invention, other layers can be provided between the layers or on the outer surface of the element as necessary. For example, when the protective layer is formed directly on the semiconductor layer or via another layer, there is an advantage that the influence of outside air such as humidity can be minimized. In addition, there is an advantage that the electrical characteristics can be stabilized, such as increasing the ON / OFF ratio of the device.

  The material of the protective layer is not particularly limited. For example, films made of various resins such as acrylic resin such as epoxy resin and polymethyl methacrylate, polyurethane, polyimide, polyvinyl alcohol, fluororesin, polyolefin, silicon oxide, aluminum oxide, and nitride A film made of a dielectric such as silicon or an inorganic oxide film or a nitride film is preferably used. In particular, a resin (polymer) having a low oxygen and moisture permeability and a low water absorption rate is desirable.

Moreover, since some porphyrin compounds absorb light and generate charges, the electronic device portion can be shielded from light if necessary. For example, it can be realized by forming a pattern with a low light transmittance (a so-called black matrix) in a desired region. For this pattern, a metal film such as chromium, aluminum, silver, or gold, a resin film in which a pigment such as carbon black is dispersed, an organic dye film, or the like can be used.
(3) Static induction transistor (SIT)
Another type of field effect transistor is an electrostatic induction transistor (SIT). The structure of SIT will be described.

In the lateral FET, the source electrode and the drain electrode are arranged side by side on the substrate, and the direction of current flow is perpendicular to the electric field induced by the gate, whereas in the SIT, at an appropriate position between the source and drain, It is characterized in that the gate electrode is arranged on a grid and the direction of the current is parallel to the electric field induced by the gate.
FIG. 2 is a schematic diagram of an electrostatic induction transistor (SIT). 7 is a source electrode, 8 is a drain electrode, 9 is a gate electrode, and 10 is a semiconductor layer. These are provided on a substrate (not shown). According to the SIT structure, the flow of carriers spreads in a plane, so that a large amount of carriers can be moved at one time. Further, since the source electrode and the drain electrode are arranged vertically, the distance between the electrodes can be reduced, so that the response is fast. Therefore, it can be preferably applied to applications in which a large current flows or high-speed switching is performed.

The description regarding the semiconductor layer 10 is the same as that of the semiconductor layer 1, and the description regarding the electrodes 7 and 8 is the same as that of the electrodes 3, 4 and 5.
The gate electrode 9 has a mesh or stripe structure in which carriers pass between the electrodes. The distance between the meshes of the gate electrode is preferably smaller than the distance between the source and the drain (corresponding to the thickness of the element). Moreover, the thickness of an electrode is 10 nm or more normally, Preferably it is 20 nm or more. However, it is usually 10 μm or less, preferably 1 μm or less.

The material of the gate electrode 9 can be the same as that of the above-described electrodes 3, 4, and 5. Preferably, an island-shaped thin film made of a conductive material such as a metal, an alloy, or a conductive polymer is used. For example, a semi-transparent aluminum electrode having a thickness of 50 nm or less can be used.
In general, an insulating layer or an energy barrier is provided between the gate electrode 9 and the semiconductor layer 10 so as to suppress the entry and exit of carriers from the electrode. For example, an insulating layer may be patterned around the electrode. Further, as the electrode material, a metal that can form an energy barrier with the semiconductor may be selected to suppress the entry and exit of carriers between the semiconductor layer. For example, by selecting aluminum, a so-called Schottky barrier can be formed with the p-type semiconductor.

Moreover, you may provide another layer between each layer and the outer surface of an element as needed.
The electrostatic induction transistor according to the present invention has advantages in that the carrier mobility μ is high, the leakage current is small, the on / off ratio is large, the stability of the film and characteristics is high, and the life is long. Furthermore, there is an advantage that the usable temperature range is wide, the film formability is good, the large area is applicable, and it can be manufactured at low cost.
(4) Diode element Another example is a diode element. This is a two-terminal element having an asymmetric structure. E and F of FIG. 3 are schematic diagrams of diode elements. These are provided on a substrate (not shown).

  The structural example E has a structure in which a semiconductor layer 13 containing a porphyrin compound is sandwiched between two metal electrodes 11 and 12 having different work functions. The description regarding the semiconductor layer 13 is the same as that of the semiconductor layer 1. At least one of the electrodes 11 and 12 forms an energy barrier with the semiconductor material. In order to form an energy barrier, a material having a work function different between an electrode and a semiconductor may be selected. For example, aluminum is often used as a metal that forms an energy barrier with a p-type semiconductor. As other electrode materials, the same materials as those of the above-mentioned electrodes 3, 4 and 5 can be used, but metals and alloys are preferable. When a voltage is applied to this element, a so-called rectifying action is observed in which the value of the current flowing varies depending on the polarity of the voltage. Therefore, an application example of such a diode element is a rectifier element.

  Structure example F is a structure in which semiconductor layers 16 and 17 having work functions greatly different from each other are sandwiched between electrodes 14 and 15. The description regarding the semiconductor layer 16 is the same as that of the semiconductor layer 1. The semiconductor layer 17 may have a work function greatly different from that of the semiconductor layer 16, and examples of such a material include perylene pigments, phthalocyanine materials, fullerenes, and conjugated polymers.

The electrodes 14 and 15 may be the same material or different materials, and the same materials as the electrodes 3, 4 and 5 described above can be used.
Moreover, you may provide another layer between each layer and the outer surface of an element as needed.
(5) Resistor etc. Moreover, a resistive element is mentioned as another application example. This is a two-terminal element having a symmetric structure provided on a substrate with a semiconductor layer sandwiched between two electrodes. The resistance element can be used as a resistor for adjusting the resistance between the electrodes, or as a capacitor for adjusting the electric capacity between the electrodes by increasing the resistance.

The explanation about the semiconductor layer is the same as that of the semiconductor layer 1, and the explanation about the electrode is the same as that of the electrodes 3, 4, and 5.
Moreover, you may provide another layer between each layer and the outer surface of an element as needed.
Such a diode element or resistance element has an advantage that device parameters such as a resistance value can be widely controlled by using the organic semiconductor material of the present invention exhibiting high carrier mobility, which is convenient for integration.
(6) Application of organic electronic device of the present invention [6-1] Active matrix The organic electronic device of the present invention can be used as a switching element of an active matrix of a display. This utilizes the fact that the current between the source and drain can be switched by the voltage applied to the gate, so that the switch is turned on only when the voltage is applied to the display element or the current is supplied, and the circuit is disconnected at other times. Thus, high-speed and high-contrast display is performed.

Examples of the display element to be applied include a liquid crystal display element, a polymer dispersed liquid crystal display element, an electrophoretic display element, an electroluminescent element, and an electrochromic element.
In particular, the organic electronic device of the present invention can be manufactured by a low-temperature process, and a substrate that cannot withstand high-temperature processing, such as a plastic plate, a plastic film, or paper, can be used. In addition, since the device can be manufactured by a coating or printing process, it is suitable for application to a large area display. Further, as an alternative to the conventional active matrix, it is advantageous as an element capable of an energy saving process and a low cost process.

[6-2] IC
Further, by integrating transistors, a digital element or an analog element can be realized. Examples of these include logic circuits such as AND, OR, NAND, NOT, memory elements, oscillation elements, amplification elements, and the like. Furthermore, by combining these, IC cards and IC tags can be produced. [6-3] Sensors Organic semiconductors change their characteristics greatly due to external stimuli such as gases, chemical substances, and temperatures. Application to sensors is also conceivable. For example, by measuring the amount by which the characteristics of the organic electronic device of the present invention change due to contact with gas or liquid, it is possible to detect the chemical substances contained in it qualitatively or quantitatively.
(Method for producing organic electronic device of the present invention)
A preferred method for manufacturing an organic electronic device according to the present invention will be described below by taking the field effect transistor (FET) shown in Structural Example A in FIG. 1 as an example, but these are also applied to other organic electronic devices in the same manner. sell.
(1) Substrate and Substrate Processing Generally, an organic electronic device such as a field effect transistor is manufactured by providing necessary layers and electrodes on the substrate 1. As the substrate, those described above can be used.

  By performing a predetermined surface treatment on the substrate, device characteristics may be improved. For example, by adjusting the degree of hydrophilicity / hydrophobicity of the substrate surface, the film quality of the film formed thereon can be improved. In particular, the characteristics of organic semiconductor materials vary greatly depending on the state of the film, such as the orientation of the molecules. However, the substrate surface treatment can control the molecular orientation at the interface between the substrate and the semiconductor film that is subsequently formed, thereby improving the characteristics. It is estimated to be.

Examples of such substrate treatment include hydrophobization treatment with hexamethyldisilazane, cyclohexene, octadecyltrichlorosilane, acid treatment with hydrochloric acid, sulfuric acid, acetic acid, sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc. Alkali treatment with ozone, ozone treatment, fluorination treatment, plasma treatment with oxygen, argon, etc., Langmuir Blodget film formation treatment, other insulator and semiconductor thin film formation treatment, mechanical treatment, electrical treatment such as corona discharge , Etc.
(2) Electrode formation Next, the gate electrode 5 is formed. As the electrode material, those described above can be used.

Various known methods can be used for forming the electrode film, and for example, a vacuum deposition method, a sputtering method, a coating method, a printing method, a sol-gel method, or the like can be used.
After film formation, patterning is performed as necessary to obtain a desired shape. As the patterning method, various known methods can be used. For example, a photolithographic method combining photoresist patterning and etching (wet etching with an etchant or dry etching with reactive plasma), inkjet printing, screen printing, offset printing, A printing method such as letterpress printing, a soft lithography method such as a microcontact printing method, and a method combining a plurality of these methods can be used. Alternatively, the pattern may be directly formed by irradiating an energy beam such as a laser or an electron beam to remove the material or change the conductivity of the material.
(3) Insulating layer Next, the insulating layer 2 is formed. The insulator material described in [3] above can be used.

Various methods known in the art can be used to form the insulator layer 2. For example, a coating method such as spin coating or blade coating, a printing method such as screen printing or ink jet, a vacuum deposition method, a sputtering method, or the like. For example, a method of forming an oxide film on a metal such as alumite can be used.
In the embodiment in which the semiconductor layer is formed on the insulator layer, a predetermined surface treatment can be performed on the insulator layer in order to favorably align the semiconductor molecules at the interface between the two layers. As the surface treatment method, the same surface treatment as that of the substrate can be used.

Further, the source electrode 3 and the drain electrode 4 are formed, and the formation method and the like are the same as those of the gate electrode 5.
(4) Semiconductor layer Subsequently, the organic semiconductor layer 1 is formed. As the organic semiconductor material, those described above can be used. Various methods known in the art can be used for forming the semiconductor layer. For example, the semiconductor layer is roughly divided into a formation method in a vacuum process such as a sputtering method and a vapor deposition method and a formation method in a solution process such as a coating method and a printing method. The
(5) Vacuum process A method for obtaining an organic semiconductor layer by forming an organic semiconductor material by a vacuum process will be described in detail. For example, it is possible to use a vacuum deposition method in which a material is put in a crucible or a metal boat, heated in a vacuum, evaporated and attached to a substrate. At this time, the degree of vacuum is usually 1 × 10 ⁻³ Torr (1.3 × 10 ⁻¹ Pa) or less, preferably 1 × 10 ⁻⁶ Torr (1.3 × 10 ⁻⁴ Pa) or less. In addition, since the characteristics of the semiconductor film and thus the device change depending on the substrate temperature, an optimum substrate temperature is selected. Usually, the range of 0 ° C to 200 ° C is preferable. The deposition rate is usually 0.001 nm / second or more, preferably 0.01 nm / second or more. However, it is usually 10 nm / second or less, preferably 1 nm / second or less. Instead of the method of evaporating the material by heating, a sputtering method in which accelerated ions such as argon collide with the material target to knock out material atoms and adhere to the substrate may be used.

Since the organic semiconductor material of the present invention is a relatively low molecular weight compound, such a vacuum process can be used. Although the vacuum process requires expensive equipment, there is an advantage that a uniform film can be easily obtained with good film formability.
(6) Solution process A method for obtaining an organic semiconductor layer by forming a film of an organic semiconductor material by a solution process will be described in detail. First, an organic semiconductor material is dissolved in a solvent and applied onto a substrate.
As a method of application, casting methods such as dripping a solution, spin coating, dipping, blade coating, wire bar coating, spray coating, etc., and printing methods such as inkjet printing, screen printing, offset printing, letterpress printing, A soft lithography technique such as a micro contact printing method, or a combination of these techniques can be used. Furthermore, as a technique similar to coating, a Langmuir-Blodgett method in which a monomolecular film formed on a water surface is transferred to a substrate and laminated, a liquid crystal or a melt state is sandwiched between two substrates, or introduced between substrates by capillary action A method etc. are also mentioned.

When the solution process is used, there is an advantage that a large-area organic electronic device can be easily manufactured with relatively inexpensive equipment.
The porphyrin compound of the present invention can also be produced by dissolving and applying in a solvent. At this time, it is possible to directly apply the porphyrin compound used finally in the device, but by applying a highly soluble compound (hereinafter referred to as a precursor) and changing its chemical structure, It is also possible to convert to a final porphyrin compound. In particular, it is useful for forming a film of a material hardly soluble in a solvent by a coating method.

  As this precursor, those having a bicyclo structure shown below are preferred examples.

このビシクロ構造は、加熱によりエチレン分子が解離してベンゼン環に変化する。

This bicyclo structure is transformed into a benzene ring by dissociation of ethylene molecules by heating.

ビシクロ構造は立体的にかさ高いため、結晶性が悪く、この構造を有する分子は溶解性が良好でかつ溶液から塗布した際に、結晶性の低い、あるいは無定型の膜が得やすい性質を有することが多い。加熱工程によりベンゼン環に変化すると、平面性の良好な分子構造になるために、結晶性の良好な分子に変化する。従って、この前駆体からの化学変化を利用することにより、結晶性の良好な膜を塗布により得ることが出来る。この加熱工程は、塗布溶媒を留去するなど他の目的を兼ねても良い。

Since the bicyclo structure is three-dimensionally bulky, the crystallinity is poor, and molecules having this structure have good solubility and have the property of being easy to obtain an amorphous film with low crystallinity when applied from a solution. There are many cases. When it is changed to a benzene ring by the heating process, it has a molecular structure with good planarity, so that it changes into a molecule with good crystallinity. Therefore, a film having good crystallinity can be obtained by coating by utilizing the chemical change from this precursor. This heating step may also serve other purposes such as distilling off the coating solvent.

In particular, among the porphyrin compounds of the present invention, a compound in which a benzene ring is condensed with a pyrrole ring, a thiophene ring, or a furan ring, called benzoporphyrins, can be obtained from a bicyclo structure as a precursor. It is advantageous to obtain an element.
Further, in the solution process, the semiconductor layer can be made thick by repeating the coating-drying step as necessary. When the semiconductor film is formed by conversion from the precursor, by repeating the coating-semiconductor conversion step, the thick film can be formed by utilizing the difference in solubility between the precursor and the semiconductor.

Further, different film forming methods such as coating and vapor deposition can be combined, or different materials can be laminated by the same or different film forming methods.
In general, solution processes do not have high film formability and it is difficult to obtain organic semiconductor films with high crystallinity. However, according to this method, organic semiconductor films with high crystallinity and good characteristics can be obtained by simple solution processes. Is obtained and is very preferable. The film thus formed has desirable characteristics such as high carrier mobility, low leakage current, and high on / off ratio. This production method is not limited to the organic semiconductor material according to the present invention, and is an excellent method that can be widely applied to general organic semiconductor materials.
(7) Post-treatment of the semiconductor layer The organic semiconductor layer thus produced can be further improved in characteristics by post-treatment. For example, the heat treatment can relieve distortion in the film generated during film formation, and can improve and stabilize characteristics. Furthermore, a change in characteristics due to oxidation or reduction can be induced by exposure to an oxidizing or reducing gas or liquid such as oxygen or hydrogen. This can be used for the purpose of increasing or decreasing the carrier density in the film, for example.
(8) Doping treatment Further, by adding a trace amount of element, atomic group, molecule, or polymer called doping, the characteristics can be changed to make it desirable. For example, doping with an acid such as oxygen, hydrogen, hydrochloric acid, sulfuric acid or sulfonic acid, a Lewis acid such as PF ₆ , AsF ₅ or FeCl ₃ , a halogen atom such as iodine, a metal atom such as sodium potassium or the like can be mentioned. This can be achieved by contact with these gases, immersion in a solution, or electrochemical doping treatment. These dopings can be added at the time of synthesizing the material, after the formation of the film, or can be added to the solution in the production process from the solution, or added at the stage of the precursor film. It is also possible to co-deposit materials to be added at the time of vapor deposition, to mix them in the atmosphere at the time of film formation, or to perform doping by accelerating ions in a vacuum and colliding with the film.

These doping effects include a change in electrical conductivity due to an increase or decrease in carrier density, a change in carrier polarity (p-type, n-type), a change in Fermi level, etc., which are often used in semiconductor devices. It is what. The doping process can also be used in the organic electronic device of the present invention.
(9) Protective layer In the organic electronic device of the present invention, other layers can be provided between the layers or on the outer surface of the element as necessary. For example, when the protective layer is formed directly on the semiconductor layer or via another layer, there is an advantage that the influence of outside air can be minimized. There is also an advantage that the electrical characteristics of the device can be stabilized. The above-mentioned materials can be used as the protective layer material.

  In forming the protective layer, various known methods can be used. When the protective layer is made of a resin, for example, a method of applying a resin solution followed by drying to form a resin film, or applying or depositing a resin monomer The method of polymerizing after that is mentioned. Cross-linking treatment may be performed after film formation. When the protective layer is made of an inorganic material, for example, a formation method in a vacuum process such as a sputtering method or a vapor deposition method, or a formation method in a solution process typified by a sol-gel method can be used.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
As a method for synthesizing the thia / oxaporphyrin compound, the method described in Japanese Patent Application No. 2003-049561 can be used.
Synthesis example 1
The bicyclo compound (1) was synthesized by the following synthesis route.

  53.5 ml of thiophenol and 51.25 g of potassium hydroxide were dissolved in 600 ml of ethanol. To this solution, 19.4 ml of cis-1,2-dichloroethylene was slowly added dropwise. Thereafter, the mixture was stirred at room temperature for 30 minutes, and further heated and stirred at 80 to 90 ° C. for 23 hours. The solvent was concentrated under reduced pressure, water was added thereto, and the mixture was extracted with chloroform. The organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain cis-1,2-phenylthioethylene.

This cis-1,2-phenylthioethylene and 750 mg of diphenyl diselenide were dissolved in 100 ml of methylene chloride. The solution was cooled in an ice bath and 175 ml of 30% aqueous hydrogen peroxide was slowly added. The crystals precipitated by vigorous stirring overnight at room temperature were filtered off, dissolved in chloroform, washed with water, saturated aqueous sodium hydrogen carbonate, and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. Further, this was dissolved in 500 ml of chloroform and cooled in an ice bath.
Slowly add 84 g of chloroperbenzoic acid and stir overnight at room temperature. The precipitated solid was filtered through Celite, and the organic layer was washed with water, saturated aqueous sodium hydrogen carbonate and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. This solid was rinsed with ether to obtain 67.06 g of cis-1,2-diphenylsulfonylethylene (yield 87%). Colorless crystals, mp 100-101 ° C.

This cis isomer and a catalytic amount of iodine were dissolved in methylene chloride, and those that precipitated as a solid by irradiation with sunlight were filtered to obtain trans-1,2-diphenylsulfonylethylene. Colorless crystals, mp 219.5 ° C.
By dissolving 29.33 g of trans-1,2-diphenylsulfonylethylene in 200 ml of toluene and then adding 11.4 ml of 1,3-cyclohexadiene, followed by dry distillation for 21 hours and then recrystallization, 5,6-diphenylsulfonyl 35.66 g (yield 96.5%) of -bicyclo- [2,2,2] oct-2-ene were obtained.

  7.76 g of this was placed in a reaction vessel, purged with nitrogen, and 50 ml of anhydrous tetrahydrofuran (THF) was added and dissolved. Thereto was added 2.43 ml of ethyl isocyanoacetate, the reaction solution was cooled in an ice bath, and 50 ml of a 1M solution of t-BuOK / THF was slowly added dropwise. Thereafter, the reaction solution was returned to room temperature and stirred overnight. Quenched with 1N hydrochloric acid, extracted with chloroform, washed with water and saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel chromatography to obtain 4,7-dihydro-4. , 7-ethano-2H-isoindole-1-carboxylate 3.49 g (yield 80.4%). Colorless crystals, mp 129-130 ° C.

A solution obtained by dissolving 0.109 g of the obtained crystal in 15 ml of THF was added dropwise with stirring at 0.14 g of LiAlH ₄ at 0 ° C, and the mixture was stirred at 0 ° C for 2 hours. The reaction solution was poured into 25 mL of saturated water and extracted three times with 50 mL of chloroform. To the combined extracts, 0.010 g of p-toluenesulfonic acid was added and stirred at room temperature for 12 hours. After adding 0.150 g of p-chloranil and stirring at room temperature for 12 hours, the reaction solution was poured into water. The organic phase was separated, washed 5 times with 250 mL of aqueous sodium bicarbonate, once with 250 mL of water, and 100 mL of saturated brine, and then dried over magnesium sulfate. The residue obtained by distilling off the solvent was purified by column chromatography (chloroform, alumina) to obtain 0.094 g of a porphyrin compound (1) containing the target bicyclo structure.

A main peak of m / Z = 622 (M ⁻ ) was observed in the negative ion mode of the MALDI-TOF mass spectrum.
The thermal analysis result (DTA-TG) of this compound is shown in FIG.
Weight loss and exotherm are seen in the temperature range of 146 ° C to 198 ° C. This weight loss (about 18%) corresponds to the elimination of four ethylene molecules from the bicyclo compound and conversion to tetrabenzoporphyrin.

  FIG. 5 shows an IR spectrum of a film obtained by dropping a chloroform solution of the porphyrin compound (1) on the gold vapor-deposited film and drying the solvent. FIG. 6 shows the IR spectrum of the film heated at 210 ° C. for 2 minutes. A change in the IR spectrum reflecting the change in the molecular structure accompanying the elimination of the ethylene molecule is observed, and it can be seen that tetrabenzoporphyrin is generated by heating the film.

A mass obtained by heating the bicyclo compound (1) at 210 ° C. for 10 minutes was measured by the MALDI-TOF method in the negative ion mode similarly to the bicyclo compound. Then, a molecular ion peak of tetrabenzoporphyrin of m / z = 510 (M ⁻ ) was observed, and conversion to tetrabenzoporphyrin by heating was confirmed. Further, since the IR spectrum of the heated product almost coincided with the IR spectrum after heating measured on the substrate, it was confirmed that what was purified by heating was tetrabenzoporphyrin.

  FIG. 7 shows a comparison of UV-visible absorption spectra of a film obtained by spin-coating a chloroform solution of the bicyclo compound (1) on a quartz glass substrate and drying the solvent, and a film obtained by heating the film at 210 ° C. for 10 minutes. Shown in It is observed that a change from a bicyclo compound to tetrabenzoporphyrin (690 nm) is observed as an increase in Q band intensity and a long wavelength shift in the porphyrin absorption spectrum.

Synthesis example 2
0.02 g of the bicyclo compound (1) of Synthesis Example 1 and 0.1 g of zinc acetate dihydrate were stirred in a mixed solvent of 30 mL of chloroform and 3 mL of methanol for 3 hours at room temperature. The reaction solution was washed twice with 100 mL of water and once with 40 mL of saturated brine, and the organic phase was dried over sodium sulfate. The solid obtained by concentrating the solvent was recrystallized with a mixed solvent of chloroform / methanol to obtain 0.022 g of a zinc complex of the bicyclo compound (1). Furthermore, only a single peak was fractionated and purified by gel permeation chromatography (Nippon Analytical Industry JAIGEL-1H, 2H, chloroform).

Mass spectra were measured and molecular peaks were confirmed.
Synthesis Example 3: Synthesis of 21,23-dithiaporphyrin 5 A dithiaporphyrin compound having the following bicyclo ring structure was synthesized by the following synthesis route.

The starting material diformylthiophene 1 was prepared according to Tetrahedron Letters, vol. 43, 8485 (2002).
(1) Synthesis of 1,3-bis- (dihydroxymethyl) -4,7-dihydro-4,7-ethano-2-benzo [c] thiophene 2

Diformylthiophene 1 (0.437 g, 2.0 mmol) was placed in a 50 ml eggplant-shaped flask and dissolved in 10 ml of dichloromethane and 10 ml of methanol. The vessel was cooled to 0 ° C., NaBH ₄ (0.277 g, 6.0 mmol) was added, and the mixture was stirred for 30 minutes. After the reaction solution was quenched with water, the organic layer was extracted with dichloromethane. The organic layer was washed with water and saturated brine, dried over sodium sulfate and concentrated. The obtained oil was crystallized in a freezer and then purified by recrystallization (CHCl ₃ / hexane) to obtain the target product, dihydroxymethylthiophene 2 in a yield of 78%.

Appearance: colorless crystals mp: 143-145 ° C
¹ H NMR (400 MHz, CDCl ₃ ): 1.51-1.60 (m, 4H), 3.90 (m, 2H), 4.69-4.75 (m, 4H), 6.46-6.52 (m, 2H)
¹³ C NMR (100 MHz, CDCl ₃ ): 26.0, 34.8, 57.5, 129.4, 135.3, 144.5
m / z (EI): 222 (87), 194 (100), 177 (100)
IR (KBr): 3130-3380 cm ^-1 (OH)
C ₁₂ H ₁₄ O ₂ S Elemental analysis Calculated values: C = 64.83%, H = 6.35%
Actual value: C = 64.73%, H = 6.37%
(2) Synthesis of thiatripyran diethyl ester 3

Dihydroxymethylthiophene 2 (0.888 g, 4.0 mmol) and bicyclopyrrole ethyl ester (1.737 g, 8.0 mmol) were placed in a 200 ml eggplant-shaped flask, the inside of the container was purged with argon, and dissolved in 60 ml of chloroform. . The container was cooled to 0 ° C., 1 ml of TFA was added, and the mixture was stirred for 1 hour and then refluxed for 5 hours. The reaction solution was poured into water and quenched, and then the organic layer was extracted with chloroform. The organic layer was washed with water, aqueous sodium bicarbonate, and saturated brine, dried over sodium sulfate, and concentrated. The obtained crude product was washed with a mixed solvent of ether and hexane, and then purified by recrystallization (CHCl ₃ / hexane) to obtain thiatripyran diethyl ester 3 as a target product in a yield of 90%. It was.

Appearance: Light brown powder (including stereoisomers)
mp:> 180 ° C. (decomposition)
¹ H NMR (400 MHz, CDCl ₃ ): 1.34 (t, J7.3, 6H), 1.39-1.61 (m, 12H), 3.62 (m, 2H), 3.68 (m, 2H), 3.95-4.01 (m, 4H), 4.26 (q, J7.3,4H), 4.31 (m, 2H), 6.40-6.51 (m, 6H), 8.09 (brs, 2H)
m / z (EI): 620 (24), 592 (100), 564 (49), 546 (8), 518 (18)
IR (KBr): 3180-3310 cm ^-1 (NH), 1666 cm ^-1 (CO)
C ₃₈ H ₄₀ O ₄ S Elemental analysis Calculated values: C = 73.52%, H = 6.49%, N = 4.51%
Actual value: C = 73.31%, H = 6.52%, N = 4.43%
(3) Synthesis of thiatripyrandicarboxylic acid 4

Thiatripyran diethyl ester 3 (0.620 g, 1.0 mmol) was placed in a 100 ml eggplant-shaped flask and dissolved in 10 ml of tetrahydrofuran (THF), 8 ml of ethanol, and 12 ml of water. LiOH.H ₂ O (0.840 g, 20 mmol) was added and refluxed for 20 hours. The reaction solution was cooled to room temperature, 1N HCl aqueous solution was slowly added to bring the pH of the solution to 1, and the organic layer was extracted with ethyl acetate. The organic layer was washed with water and saturated brine, dried over sodium sulfate and concentrated. The obtained crude product was washed with a mixed solvent of ether and hexane to obtain the target product thiatripyrandicarboxylic acid 4 in a yield of 98%. This product was used for the next reaction without purification.

Appearance: Light brown powder (including stereoisomers)
¹ H NMR (400 MHz, Acetone-d ⁶ ): 1.30-1.58 (m, 12H), 3.64-3.70 (m, 2H), 3.80-3.85 (m, 2H), 3.99-4.08 (m, 4H), 4.30 ( m, 2H), 6.32-6.49 (m, 6H), 9.68 (brs, 2H)
IR (KBr): 2820-3460 cm ^-1 (OH), 1670 cm ^-1 (CO)
(4) Synthesis of 21,23-dithiaporphyrin 5

Thiatripyrandicarboxylic acid 4 (0.508 g, 0.9 mmol) was placed in a 500 ml eggplant-shaped flask protected from light, and the inside of the container was purged with argon, and 2.5 ml of TFA was added at room temperature and stirred for 5 minutes. After adding 200 ml of dry CH ₂ Cl ₂ , diformylthiophene (0.196 g, 0.9 mmol) was quickly added and stirred at room temperature for 16 hours. Thereafter, triethylamine was slowly added to neutralize the solution, DDQ (0.227 g, 1.0 mmol) was added, and the mixture was further stirred for 2 hours. The resulting solution was washed with water, saturated aqueous sodium hydrogen carbonate, and saturated brine, dried over sodium sulfate, and concentrated. The obtained crude crystals were treated with column chromatography (alumina, 50% ethyl acetate / hexane) and then purified by recrystallization (CH ₂ Cl ₂ / MeOH) to obtain dithiaporphyrin 5 as the target product. Obtained in 37% yield.

Appearance: Green-brown solid (including stereoisomers)
mp:> 130 ° C. (decomposition)
¹ H NMR (400 MHz, CDCl ₃ ): 1.83 to 2.02 (m, 8H), 2.13 (m, 4H), 2.29 (m, 4H), 5.55 (m, 4H), 6.04 (m, 4H), 7.03-7.06 (m, 4H), 7.26 (m, 4H), 10.94 (m, meso-H, 4H)
m / z (FAB): 657 (M ^{+ 1} , 35), 629 (11), 601 (9), 573 (29), 545 (100)
C ₄₄ H ₃₆ N ₂ S ₂ elemental analysis (0.25CH ₂ Cl ₂ +0.25 MeOH)
Calculated values: C = 77.64%, H = 5.80%, N = 4.08%
Actual value: C = 77.90%, H = 5.51%, N = 4.01%
As described above, it was confirmed to be the target product by elemental analysis, NMR, and mass spectrum.

Synthesis Example 4: Synthesis of 21-thiaporphyrin 6 Synthesis example except that thiatripyrandicarboxylic acid 4 was synthesized in the same manner as synthesis example 3, and a pyrrole derivative was used instead of thiophene for this thiatripyrandicarboxylic acid 4. In the same manner as in 3, a thiaporphyrin compound having the following bicyclo structure was synthesized by the following synthesis route.

Thiatripyrandicarboxylic acid 4 (0.508 g, 0.9 mmol) was placed in a 500 ml eggplant type flask protected from light, and the inside of the container was purged with argon, and 2.5 ml of TFA was added at room temperature and stirred for 5 minutes. After adding 200 ml of dry CH ₂ Cl ₂ , diformylpyrrole (0.181 g, 0.9 mmol) was quickly added and stirred at room temperature for 16 hours. Thereafter, triethylamine was slowly added to neutralize the solution, DDQ (0.227 g, 1.0 mmol) was added, and the mixture was further stirred for 2 hours. The resulting solution was washed with water, saturated aqueous sodium hydrogen carbonate, and saturated brine, dried over sodium sulfate, and concentrated. The crude crystals were treated with column chromatography (alumina, 50% ethyl acetate / hexane) and then purified by recrystallization (CH ₂ Cl ₂ / MeOH) to obtain 42% yield of thiaporphyrin 6 as the target product. Obtained at a rate.

Appearance: Green-purple solid (including stereoisomers)
mp:> 130 ° C. (decomposition)
¹ H NMR (400 MHz, CDCl ₃ ): 1.82-2.00 (m, 8H), 2.13 (m, 4H), 2.28 (m, 4H), 5.57 (m, 4H), 5.87 (m, 2H), 6.04 (m , 2H), 7.06 (m, 4H), 7.21-7.25 (m, 4H), 10.39 (m, meso-H, 2H), 10.90 (m, meso-H, 2H)
m / z (FAB): 640 (M ^{+ 1} , 44), 612 (10), 584 (9), 556 (32), 528 (100)
C ₄₄ H ₃₇ N ₃ S (0.25CH ₂ Cl ₂ ) Elemental analysis Calculated values: C = 80.39%, H = 5.72%, N = 6.36%
Actual value: C = 80.30%, H = 6.00%, N = 6.17%
As described above, it was confirmed to be the target product by elemental analysis, NMR, and mass spectrum.

Reference example 1
On an N-type silicon substrate (Sb-doped, resistivity 0.02 Ωcm or less, manufactured by Sumitomo Metal Industries, Ltd.) on which an oxide film of 300 nm is formed, length (L) 2.5-50 μm, width (W) by photolithography Gold electrodes (source and drain electrodes) having a gap of 250 μm or 1000 μm were formed. In addition, an oxide film at a position different from this electrode is etched with a hydrofluoric acid / ammonium fluoride solution, gold is deposited on the exposed Si portion, and an electrode for applying a voltage to the silicon substrate (gate electrode) It was.

  Dissolving 2 mg of the bicyclo compound (1) obtained in Synthesis Example 1 in 1 mL of chloroform and evaporating the solvent between the source and drain electrodes was repeated several times to obtain a good film. When X-ray diffraction of this film was observed, no sharp peak was observed. When the film was observed under a crossed Nicol microscope, an image with a dark surface was obtained, and the film was isotropic. Therefore, it can be seen that the obtained film is amorphous.

  The substrate was heated at 210 ° C. for 10 minutes. When X-ray diffraction of the obtained film was observed, a sharp peak was observed. In addition, when the film was observed under a crossed Nicol microscope, a colored domain structure was observed. Therefore, it can be seen that the obtained film is crystalline. This is because the bicyclo compound changed to tetrabenzoporphyrin and became crystalline. Further, the obtained film had low solubility in a solvent and was hardly soluble in an organic solvent.

The characteristics of the field effect transistor thus obtained were measured using a semiconductor parameter analyzer 4155C manufactured by Agilent Technologies. The measurement results are shown in FIG.
The current flowing with respect to the voltage Vd applied between the source and the drain is Id, the voltage applied to the source and the gate is Vg, the threshold voltage is Vt, the capacitance per unit area of the insulating film is Ci, and the source electrode When the interval between the drain electrodes is L, the width is W, and the mobility of the semiconductor layer is μ, the operation can be expressed as follows.

  When Vd <Vg−Vt,

  When Vd> Vg,

Therefore, the mobility μ is an important material parameter that governs the characteristics of the element (transistor), and a high μ material is required to obtain a high-performance element.
Conversely, μ can be obtained from the current-voltage characteristics of the element. Equation (1) or (2) is used to determine μ, but there are several definitions of mobility μ, and Id for a certain Vg
Effective mobility μeff obtained from the slope of −Vd, field effect mobility μFE obtained from the slope of Id−Vg with respect to a certain Vd, and saturation movement obtained from the slope of Id ^1/2 −Vg of the saturation current portion of equation (2). There is a degree μsat. The effective mobility μeff, the field effect mobility μFE, and the saturation mobility μsat should be the same values in the model for obtaining the above formula, and the same is true for semiconductor materials that can actually obtain ideal FET characteristics. It becomes a value of the degree. However, these values may be different due to the difference between the characteristics of the actual semiconductor material and the model.

When each mobility is obtained from FIG. 8, the effective mobility μeff is 1 × 10 ⁻³ cm ² / Vs, the field effect mobility μFE is 1.6 × 10 ⁻³ cm ² / Vs, and the saturation mobility μsat is 0. It was 7 × 10 ⁻³ cm ² / Vs.
Reference example 2
Using chlorobenzene as a solvent, a bicyclo compound film was prepared in the same manner as in Reference Example 1, and converted to benzoporphyrin by heating.

The characteristics of the field effect transistor thus obtained were measured using a semiconductor parameter analyzer 4155C manufactured by Agilent Technologies. The effective mobility μeff was 1.6 × 10 ⁻² cm ² / Vs, and the saturation mobility μsat was 1.3 × 10 ⁻² cm ² / Vs.
Reference example 3
A solution obtained by dissolving oxydianiline and benzophenonetetracarboxylic anhydride in dimethylformamide at a molar ratio of 1: 1 is spin-coated on a slide glass on which aluminum is vapor-deposited, and heated at 250 ° C. to form a 500 nm polyimide film. Produced. A bicyclo compound film was prepared on this film in the same manner as in Reference Example 1, and converted to benzoporphyrin by heating.

On top of this, gold was vapor-deposited through a shadow mask prepared using a tungsten wire with a diameter of 25 μm as a gap portion, and source and drain electrodes having a gap with a width (W) of 250 μm and a length (L) of 25 μm were prepared. The characteristics of the field effect transistor thus obtained were measured using a semiconductor parameter analyzer 4155C manufactured by Agilent Technologies. The effective mobility μeff was 3.7 × 10 ⁻² cm ² / Vs, and the saturation mobility μsat was 1.4 × 10 ⁻² cm ² / Vs.

Reference example 4
An FET was produced in the same manner as in Reference Example 1 using the zinc complex synthesized in Synthesis Example 2. When the FET characteristics were measured, the effective mobility μeff was 1.9 × 10 ⁻⁴ cm ² / Vs, and the saturation mobility μsat was 1.3 × 10 ⁻⁴ cm ² / Vs.
Reference Example 5
The bicyclo compound (1) obtained in Synthesis Example 1 was converted to tetrabenzoporphyrin by heating at 210 ° C. for 30 minutes. This was vacuum-deposited on the same electrode substrate as in Reference Example 1 at a vacuum degree of 2 × 10 ⁻⁶ Torr (2.6 × 10 ⁻³ Pa) to produce a field effect transistor. The relationship between the substrate temperature and the transistor mobility (saturation mobility) during vacuum deposition is shown in the following table. This shows that the mobility varies depending on the substrate temperature.

Substrate temperature Saturation mobility μsat
Room temperature 2.9 × 10 ⁻⁴ cm ² / Vs
80 ° C. 2.3 × 10 ⁻⁶ cm ² / Vs
150 ° C. 5.6 × 10 ⁻⁷ cm ² / Vs
200 ° C. 2.8 × 10 ⁻⁸ cm ² / Vs

Moreover, the X-ray-diffraction pattern about what was vapor-deposited at 80 to 200 degreeC in FIG. 9 is shown. Comparing these, it can be inferred that the films are strongly oriented with respect to the substrate because they show different crystal forms at 150 ° C. or higher and 80 ° C. or lower and both have few peaks. For this reason, it is considered that a large difference appears in the observed mobility.

Reference Example 6
The bicyclo compound (1) obtained in Synthesis Example 1 was prepared by repeating column chromatography of chloroform-silica gel and reprecipitation with chloroform-methanol to improve the purity. In Synthesis Example 1, the purity at an absorbance at 254 nm by liquid chromatography was 99.0%, whereas this high-purity product was 99.7%.

Using this, a field effect transistor was fabricated in the same manner as in Reference Example 1 except that a precursor film was prepared by spin coating in dry nitrogen and heated at 210 ° C. for 5 minutes in nitrogen on a hot plate. Produced.
As an evaluation, when the saturation mobility μsat calculated from the slope of the plot of the square root of the drain current Id and the gate voltage is obtained from the relationship between the current in the saturation region and the gate voltage, the saturation mobility μsat is 0.016 cm ² / Vs. The above was observed. Further, when the on / off ratio was determined from the ratio of the drain current when the gate voltage was 0V and −30V at the drain voltage of −30V, the on / off ratio was at least 10 ³ or more, and the best value of 10 ⁵ was observed. It was.

  FIG. 10 shows an X-ray diffraction pattern of the semiconductor layer obtained in Reference Example 6 and the semiconductor layer produced by vapor deposition at a substrate temperature of 150 ° C. in Reference Example 5. Since the low-angle peaks coincide with each other, they are considered to be similar crystals, but the diffraction patterns are greatly different, and it is presumed that the film states such as orientation and crystallinity are different. For this reason, it is thought that the semiconductor layer obtained by application | coating-heating shows a favorable characteristic.

Reference Example 7
A toluene solution of polymethyl methacrylate (PMMA) was spin-coated on the element produced in Reference Example 6 and dried at 120 ° C. to form a 2 μm film.
With respect to this element and the element manufactured in Reference Example 6, the drain voltage was measured while the drain voltage was fixed at −30 V and the gate voltage was changed from 50 V → −50 V → 50 V. The results are shown in FIG. Off ratio even without the PMMA film shows good properties have 10 ³ or more, small hysteresis of a drain current by the scanning of the gate voltage when providing a PMMA film, and it is understood that the improved on-off ratio.

Example 1
Using the dithiaporphyrin synthesized in Synthesis Example 3, a FET was produced in the same manner as in Reference Example 1. That is, a tetrabenzodithiaporphyrin film was prepared by applying a precursor having the following bicyclo structure to a substrate on which an electrode was formed in the same manner as in Reference Example 1 and then performing heat treatment. When the electrical characteristics of the FET element thus obtained were measured, it showed FET characteristics, a saturation mobility of 1.1 × 10 ⁻⁴ cm ² / Vs, and an on / off ratio of 1000.

Example 2
An FET was produced in the same manner as in Reference Example 1 using thiaporphyrin synthesized in Synthesis Example 4. That is, a tetrabenzothiaporphyrin film was prepared by applying a precursor having the following bicyclo structure on a substrate on which an electrode was formed in the same manner as in Reference Example 1 and then performing heat treatment. When the electrical characteristics of the FET element thus obtained were measured, it showed FET characteristics, a saturation mobility of 2.5 × 10 ⁻⁵ cm ² / Vs, and an on / off ratio of 38.

Reference Example 8
An FET was produced in the same manner as in Reference Example 1 using the following zinc complex. That is, as in Reference Example 1, a precursor having a bicyclo structure was applied on a substrate on which an electrode was formed, followed by heat treatment to produce a semiconductor film, thereby obtaining a field effect transistor. When the electrical characteristics of the FET element thus obtained were measured, the saturation mobility μsat was 0.7 × 10 ⁻⁴ cm ² / Vs, and the effective mobility μeff was 1 × 10 ⁻⁴ cm ² / Vs.

Comparative Example 1
A field effect transistor was prepared using the porphyrin compounds shown in the following structural formulas and the electrical characteristics were evaluated, but none of the FET characteristics appeared.

  When the molecular structures of these porphyrin compounds were determined by molecular orbital methods (MOPAC, etc.) and molecular dynamics methods (MM2), etc., the atoms constituting the porphyrin skeleton were located at a position 1 mm or more away from the porphyrin ring plane. Confirmed that it exists.

DESCRIPTION OF SYMBOLS 1 Semiconductor layer 2 Insulator layer 3 Source electrode 4 Drain electrode 5 Gate electrode 6 Substrate 7 Source electrode 8 Drain electrode 9 Gate electrode 10 Semiconductor layer 11 Metal electrode 12 Metal electrode 13 Semiconductor layer 14 Electrode 15 Electrode 16 Semiconductor layer 17 Semiconductor layer

Claims (8)

  An organic semiconductor material comprising a compound having a thiaporphyrin skeleton and having a molecular structure in which the distance from the plane of the thiaporphyrin ring to the center of an atom forming the thiaporphyrin skeleton is within 1 mm. The organic semiconductor material according to claim 1, wherein the compound having a thiaporphyrin skeleton has a mobility of 1 × 10 ⁻⁵ cm ² / Vs or higher. An organic semiconductor material comprising tetrabenzo-21-thiaporphyrin represented by the following formula.

An organic semiconductor material comprising tetrabenzo-21,23-dithiaporphyrin represented by the following formula.

The compound which has the thiaporphyrin skeleton in any one of Claims 1 thru | or 4 by apply | coating the solution which melt | dissolved the compound which has the thiaporphyrin skeleton as a precursor which has the following bicyclo structure in the solvent on a board | substrate, and heating. A method for producing an organic semiconductor material, which is converted into

  An organic electronic device having a semiconductor layer and two or more electrodes, wherein the semiconductor layer contains the organic semiconductor material according to any one of claims 1 to 4.   The organic electronic device according to claim 6, wherein the organic electronic device is a switching element.   The organic electronic device according to claim 6 or 7, wherein the organic electronic device is a field effect transistor.

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