JPH05259434A - Organic rectifying element - Google Patents

Abstract

PURPOSE:To provide an organic rectifying element with excellent rectifying function. CONSTITUTION:A glass board 1 is provided with a gold electrode 2 thereon through a sputtering method, etc., and a poly-3-methylthiophene layer is piled up thereon through electrolytic oxidation polymerization. Then it is electrochemically applied with a dedoping treatment to form a high molecular conductive layer 3, a 5-methyl-10-(p-methylbenzyl)-5,10-dihydrophenazine film 4 is deposited on the layer 3 through a vacuum deposition method, and further aluminum 18 vacuum-deposited on the film 4 to form an electrode 5, and thereby an organic rectifying element in realized finally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new organic rectifying device, which is used as an electric rectifier, a transistor, a rectifying diode, a photodiode, a light emitting diode, a switch or the like for electronics or optoelectronics. It is generally widely applicable in the relevant industries.

[0002]

2. Description of the Related Art As an organic rectifying element, a Schottky junction type element in which a p-type organic semiconductor and a metal thin film having a small work function are combined is known, and a combination of Al / metal-free phthalocyanine / Au, Al / poly The 3-methylthiophene / Au combination has been investigated. The present inventors have already developed an organic two-layer type photoelectric conversion element as shown in JP-A-59-28388 and JP-A-3-91269, and have clarified the results. It was necessary to develop the device.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have focused on the fact that they exhibit a rectifying action, which is a drawback of the prior art, but have a low efficiency, and have searched for an organic compound that surely and efficiently enhances the rectifying action. The present invention has been carried out, the structure thereof has been repeatedly investigated, and then the synthesis, the properties thereof, and the applications thereof have been advanced to finally complete the present invention which should be conspicuous.

[0004]

The present inventors have found that 5- (electron-donating group) -substituted-10- (aralkyl or nuclear-substituted aralkyl) -5,
It has been clarified that an element having a constituent part in which a 10-dihydrophenazine film (hereinafter abbreviated as phenazine film) and a polymer conductor material layer or a metal material layer are laminated has an excellent organic rectifying action. .. The polymer conductor material layer referred to here is a layer made of at least one polymer conductor material selected from the group consisting of organic synthetic materials, organic pyrolysis materials, and carbon materials, and a metal material layer. Is a layer made of at least one metal-based material selected from the group consisting of metals, alloys, metal oxides, metal sulfides and alloy oxides.

The electron-donating group in 5- (electron-donating group) -substituted-10- (aralkyl or nucleus-substituted aralkyl) -5,10-dihydrophenazine (hereinafter abbreviated as phenazine) means an alkyl group or an aralkyl group. , An amino group, an alkylamino group, a dialkylamino group, an acylamino group, an alkylacylamino group, a pyrrolidinyl group, a pepyridyl group, a morpholino group, and the like. Typical examples are a methyl group, an ethyl group, a propyl group, and an isopropyl group. , N-butyl group, isobutyl group, t-butyl group, cyclohexyl group, methylamino group, acetylamino group, aralkyl group shown below and the like.

The 10- (aralkyl or nucleus-substituted aralkyl) group in phenazine is a benzyl group, a phenylethyl group, a p-alkylbenzyl group (for example, a p-methylbenzyl group, a p-ethylbenzyl group), a p-alkoxybenzyl group ( For example, p-methoxybenzyl group), p-aminobenzyl group, p- (N-substituted amino) benzyl group (eg p-methylaminobenzyl group, p-acetylaminobenzyl group), p-cyanobenzyl group, p-nitro Benzyl group, p-fluorobenzyl group, p-fluoromethylbenzyl group, p-chlorobenzyl group, p-bromobenzyl group, p-iodobenzyl group, m-dialkylbenzyl group (for example, 3,5-dimethylbenzyl group), m-dialkoxybenzyl group (eg 3,5-dimethoxybenzyl group, m-diaminobenzyl group, m-di (N-substituted amino) benzyl group, m-bis (trifluoromethyl group) ) Benzyl group, m-dinitrobenzyl group, m-difluorobenzyl group, o-dichlorobenzyl group (for example, 2,3-dichlorobenzyl group, 3,4-dichlorobenzyl group), m-dichlorobenzyl group (for example, 2, 4-dichlorobenzyl group, 3,5-dichlorobenzyl group), m-dibromobenzyl group, m-diiodobenzyl group, etc. The alkyl group of the aralkyl group bonded to the 10-position of phenazine has a carbon number of 1 to 4 pieces,
Of course, they may be linear or branched.

The phenazine may be a single compound or a mixture of two or more compounds as long as it is the above compound. Some amount of antioxidant, UV stabilizer, spacer powder (plastics powder, silica powder, silicone rubber powder, etc.) as a film thickness control material for long-term stabilization when these phenazines are formed into a film. It may be added, or a small amount of a dye (coloring agent, fluorescent agent) may be contained as a material for confirming the thickness of the film.

Among the polymer conductor materials, organic synthetic materials include polypyrrole, poly-3-methylpyrrole and poly-
3,4-dimethylpyrrole, polythiophene, poly-3-methylthiophene, poly-3,4-dimethylthiophene, poly-p-
Phenine, polyacetylene, poly-p-phenylene sulfide, poly-m-phenylene, poly-p-phenylene oxide, polycyanoacetylene, polyphenylacetylene,
Polyvinylcarbazole, polydiacetylene, polypyridine, poly (N-methylpyrrole), polypicoline, etc. can be used, either undoped or doped, and conductive rubber or resin containing them is also used. it can.

Among the polymer conductor materials, organic pyrolysis materials include synthetic graphite, conductive carbon fiber, pyrolysis polyimide, pyrolysis polyoxadiazole, pyrolysis polyolefin, pyrolysis polyamide, pyrolysis polyacrylonitrile, Pyrolysis polyvinyl chloride, pyrolysis polyvinyl alcohol, pyrolysis epoxy resin, pyrolysis phenol resin,
There are pyrolyzed crosslinked polystyrene, pyrolyzed polyisocyanurate, and pyrolyzed polypeptide, which can be used either as undoped material or doped material, and also as a conductive rubber or resin containing them.

Among the polymer conductor materials, carbonaceous materials include graphite, glass carbon, furnace black, Ketjen black, acetylene black, petroleum pitch carbide, coal tar pitch carbide, and the like.
These may be either undoped or doped, and conductive rubber or resin containing them may also be used.

Metal-based materials include metals such as gold,
Silver, platinum, palladium, nickel, aluminum, indium, magnesium, calcium, silicon, titanium, zirconium, etc.), alloy (for example, palladium alloy, aluminum alloy, titanium alloy, magnesium alloy, tin alloy, indium alloy, antimony alloy),
Metal oxides (for example, aluminum oxide, indium oxide, silicon oxide, titanium oxide, tin oxide, zinc oxide, copper oxide, antimony oxide, zirconium oxide, etc., which have been made conductive by forming lattice defects with a dopant), metal sulfide (For example, iron sulfide, cobalt sulfide, nickel sulfide, copper sulfide, etc. having lattice defects to provide conductivity), alloy oxides (oxides of the above alloys or mixtures of the above metal oxides), etc. In addition, conductive rubber or resin containing these can also be used.

The phenazine film referred to in the present invention is provided between the polymer conductor material layer and the polymer conductor material layer, or between the polymer conductor material layer and the metal material layer, or between the metal material layer and the metal material layer. It is provided between the system material layers. The simplest one may be a single layer of any combination, but to further enhance the effect, for example, a polymer conductor material layer,
It is preferable that a phenazine film, a polymer conductive material layer, a phenazine film, a metal-based material layer, and the like have a multilayer structure or a multilayer structure. In this case, it goes without saying that the polymer conductor material layer and the metal-based material layer may be appropriately replaced with each other.

The above laminate is usually provided on a substrate (glass, plastics, film, metal sheet, ceramic plate, plastics molded product, etc.), and after suitable electrode parts are attached, it is a film if necessary. Although it is coated, it may be laminated between the substrates depending on the purpose. Therefore, the thickness of this laminate can be arbitrarily changed according to the thickness of the substrate, the thickness of the polymer conductor material layer or the thickness of the metal-based material layer. However, the phenazine film is preferably a single layer with a thickness of 200 to 5000Å.
Therefore, when the phenazine film is overlaid, the total thickness will increase according to the number of times it is overlaid, but the thickness of each phenazine film is reduced within the range of 200 to 5000Å, It is preferable to pay attention to the range of 200 to 2000Å. Care should be taken to ensure that the film thickness is uniform.

As a method for forming the phenazine film of the present invention, any one of the following methods is adopted. (1) Vacuum evaporation method or sputtering method (2) Method of coating solution (including casting method) and drying (3) Placing a film in advance (pressurization method, adhesion method,
Electrostatic sticking method) The phenazine film is not only formed on the entire surface of the laminated surface, but it may be patterned into a predetermined shape according to the purpose, or the unnecessary portion is partially removed by etching to form a pattern. May be.

A basic example of the structure of the organic rectifier according to the present invention will be described. As shown in FIG. 1, the organic rectifying device includes a substrate 1, an electrode 2 formed on the substrate 1, a polymer conductor layer 3 formed on the electrode 2, and a polymer conductor layer 3 formed on the polymer conductor layer 3. Formed phenazine film 4 and phenazine film 4
It is composed of the electrode 5 formed above.

It is preferable from a laboratory point of view that the electrode 2 provided on the substrate 1 is a transparent electrode which substantially covers the entire surface of the substrate 1. The transparent electrode is formed by depositing gold, silver, aluminum, indium, indium tin oxide (ITO) on the substrate 1 such as a glass plate, a transparent plastic sheet or a film.
Film) and tin oxide (nesa film) can be formed by vapor deposition. Further, the electrode 5 can be formed by depositing gold, silver, copper, aluminum or nickel. The polymer conductor layer 3 can be omitted particularly when used as a single layer type.

The manufacturing procedure of the organic rectifying device differs depending on the type of the electrode 2 formed on the substrate 1. When aluminum is used as one of the electrodes, first, the phenazine film of the present invention is vacuumed on the aluminum electrode. It is preferable that the layer is formed by a method such as a vapor deposition method, a coating method, a casting method, a spin coating method, and a polymer conductor layer is laminated thereon. Then, if necessary, a counter electrode such as a gold electrode may be vacuum-deposited thereon.

On the other hand, when a substrate having a transparent electrode formed by a sputtering method or the like, for example, a gold electrode is used, a polymer conductor layer is laminated on the gold electrode by an electrolytic oxidation polymerization method or the like, and electromechanically After the dedoping treatment, it is convenient to stack a phenazine film on it by vacuum evaporation or the like.
Further, an electrode such as aluminum may be vacuum-deposited if necessary.

[0019]

In the organic rectifying device of the present invention, an effective rectifying action is performed, for example, at the interface barrier between the polymer conductor layer and the phenazine film. Further, since the rectifying action is performed also at the interface between the phenazine film and the metal-based material layer, it becomes possible to manufacture an element having a far superior rectifying action than the conventionally known organic rectifying element.

In the organic rectifying device of the present invention, a Schottky type or heterojunction type barrier is formed at the interface between the polymer conductor layer and the phenazine film, and the forward direction is generated according to the potential gradient formed spontaneously. When a voltage is applied, injection of charges and transport of charges across both layers occur, but when a voltage is applied in the opposite direction, a current does not flow because it opposes the potential gradient, and it functions as a diode. In addition, the light irradiation causes charge separation at the interface, which causes charge transport along the potential gradient. Therefore, a photocurrent is obtained by applying a load between both electrodes of the organic rectifying element and short-circuiting the electrodes externally, and it also functions as a photodiode. Further, it can be made to function as a light emitting diode by utilizing the fact that the electric charge injected by the forward voltage application recombines with the opposite electric charge in the bulk and emits light.

[0021]

EXAMPLES Regarding the organic rectifying device of the present invention, a number of experiments were conducted on its manufacturing method and its performance, and a typical example extracted from them will be described. The present invention should not be construed as being limited to the following examples, and it goes without saying that the embodiments can be arbitrarily modified and implemented without departing from the spirit and spirit of the present invention. is there.

Example 1 First, a gold electrode was vapor-deposited on a glass substrate by a sputtering method, and poly-3-methylthiophene (hereinafter abbreviated as PMeT) was formed thereon by electrolytic oxidation polymerization. Then this PM
After electro-chemically dedoping the eT film, a 5-methyl-10- (p-methylbenzyl) -5,10-dihydrophenazine film (hereinafter abbreviated as MMDP) was laminated by a vacuum deposition method.
Finally, vacuum-deposit aluminum on top of it and add Au / PM
A sandwich cell with a structure of eT / MMDP / Al was manufactured.

A current-voltage curve was examined by continuously applying a DC voltage to the sandwich cell while changing the DC voltage in the dark. 2 and 3 are graphs showing current changes when the DC applied voltage is continuously changed. As a result, it was confirmed that there was a stable rectifying action in which the forward direction was when a positive voltage was applied to the gold electrode side. For gold electrode +
The current value when a voltage of 4 V was applied was +14.0 mA, the current value when a voltage of -4 V was applied was -0.117 μA, and the rectification ratio was 120,000 (see Fig. 2). At an applied voltage of ± 2 V, the rectification ratio is 18000 at current values of +1.05 mA and -0.058 μA, respectively.
Was (see FIG. 3).

Next, when this element was irradiated with light, a photoelectromotive force was generated in the direction in which the gold electrode side was positive. At this time, the change in photocurrent when the wavelength of the irradiation light was changed was measured. FIG. 4 is a graph of an action spectrum showing the relationship between light wavelength and photocurrent. From this graph, when light is irradiated from the gold electrode side (●), the photocurrent value becomes the minimum at the absorption maximum of PMeT, so the filter effect by PMeT is shown,
It can be seen that the active surface is at the back of the PMeT layer, not at the interface between the gold electrode and the PMeT layer. In addition, when the light is irradiated from the aluminum electrode side (○), the photocurrent value becomes maximum near the absorption skirt of the MMDP, which shows the filter effect by the MMDP. The main active surface is the back of the MMDP layer, that is, PMeT and MMDP. It can be seen that this is the interface with. Since the single-layer element in which only MMDP is sandwiched between the gold electrode and aluminum has a rectifying action and a photoelectric conversion action in the same direction as the two-layer element, the interface between aluminum and MMDP also functions as an active surface. I understand.

Example 2 Instead of MMDP in Example 1, 5-methyl-10- (p-methoxybenzyl) -5,10-dihydrophenazine (hereinafter referred to as MMODP
Abbreviated), 5-methyl-10- (p-cyanobenzyl) -5,10-
Dihydrophenazine (hereinafter abbreviated as MCDP), or
A similar sandwich cell was prepared using 5-methyl-10- (m-dinitrobenzyl) -5,10-dihydrophenazine (hereinafter abbreviated as MDNDP). It was confirmed that when these sandwich cells were applied in the dark while continuously changing the DC applied voltage, a current change similar to that shown in FIG. The rectification ratio is 12000 (± 2v) for the element using MMODP and 10000 for the element using MCDP.
(± 4v), and 1200 (± 4v) with the device using MDNDP
It was found that all have excellent rectifying action.

Example 3 In Example 1, a remarkable rectifying effect was observed in the case of using another polymer conductive material layer instead of the PMeT layer.
The name of the layer material and the rectification ratio (± 2V) were as follows. That is, polypyrrole (rectification ratio 16000), poly-3,
4-dimethylpyrrole (rectification ratio 18000), poly p-phenylene (rectification ratio 15000), polythiophene (rectification ratio 1200),
Polyacetylene (rectification ratio 1000), polycyanoacetylene (rectification ratio 2000), polyvinylcarbazole (rectification ratio 100)
0), pyrolysis polyimide (rectification ratio 8000), pyrolysis polyacrylonitrile (rectification ratio 5000), graphite (rectification ratio)
6000). Similarly, when a metal material is used, indium (rectification ratio 12000), aluminum / magnesium (rectification ratio 15000), zinc chloride-doped aluminum oxide (rectification ratio 4000), antimony pentachloride-doped tin oxide (rectification ratio) 14000), conductive copper sulfide (rectification ratio 100
00) was obtained.

[0027]

The organic rectifying device of the present invention efficiently rectifies by using both the interface barrier between the polymer conductor material layer and the phenazine film and the interface barrier between the phenazine film and the metal-based material layer. Therefore, it has become possible to manufacture an element that gives a rectification ratio far superior to that of a conventionally known organic rectification element. Photoelectric charge separation is performed using this barrier, and as a result, the separated electrons and holes are transported in opposite directions, so that they also function as a photoelectric conversion element. Further, it also functions as an electroluminescence device by utilizing the fact that the charges injected by the voltage application recombine with the opposite charges to emit light while moving in the bulk along the potential gradient of the barrier. Therefore, it is believed that the superiority of the application of the present invention in industry is enormous.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an organic rectifying device of the present invention.

FIG. 2 is a graph showing current-voltage characteristics of the organic rectifier of the present invention.

FIG. 3 is a graph showing current-voltage characteristics of the organic rectifier of the present invention.

FIG. 4 is a graph showing a photocurrent action spectrum and an absorption spectrum of PMeT and MMDP of the organic rectifier of the present invention.

[Explanation of symbols]

 1 substrate 2 electrode 3 polymer conductor layer 4 phenazine film 5 electrode

Claims (3)

[Claims] 1. A 5- (electron-donating group) -substituted-10- (aralkyl or nucleus-substituted aralkyl) -5,10-dihydrophenazine film and a polymer conductor material layer or a metal-based material layer are laminated. An organic rectifying device characterized by the above. 2. The polymer conductor material layer is a layer made of at least one polymer conductor material selected from the group consisting of organic synthetic materials, organic pyrolysis materials and carbon materials. The organic rectifying element described. 3. The organic material according to claim 1, wherein the metal-based material layer is a layer made of at least one metal-based material selected from the group consisting of metals, alloys, metal oxides, metal sulfides and alloy oxides. Rectifying element.