JPH0282656A - Manufacture of optoelectric transducer - Google Patents

Abstract

PURPOSE:To obtain an optoelectric transducer excellent in optoelectric conversion efficiency, closed-circuit photocurrents, and fill-factor by solubilizing a porphyrin compound or a metallic complex thereof by using a micell formation agent composed of a ferrocene derivative, electrolyzing the micell solution and forming a thin film. CONSTITUTION:A micell formation agent consisting of a ferrocene derivative, a supporting electrolyte and a porphyrin compound as a thin-film material or a metallic complex thereof are introduced into an aqueous medium, and dispersed sufficiently by ultrasonic waves or an agitator or the like, thus forming a micell. A micell solution acquired is electrolytically treated by using electrodes 2, 4 as it is left at rest or while being slightly agitated. Consequently, Fe<2+> is changed into Fe<3+> at an anode in Fe ions in the ferrocene derivative, the micell is broken, and the particles of the porphyrin compound and the metallic complex thereof precipitate on the anode. Fe<3+> oxidized at the anode is reduced to Fe<2+> at a cathode and returned to an original micell. The thin-film 1 of the desired porphyrin compound or the metallic complex thereof is formed onto the electrode 2 through such an electrolytic treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a photoelectric conversion element, and more specifically, a method for manufacturing a photoelectric conversion element, and more specifically, a method for manufacturing a photoelectric conversion element, which has a photoactive layer made of a thin film of a porphyrin compound or a metal complex thereof, and has a high photoelectric conversion efficiency. The present invention relates to a method of manufacturing an FL conversion element.

(Prior Art and Problems to be Solved by the Invention) It has not been known that porphyrin compounds or metal complexes thereof can be formed into illll-types by casting methods, CVD methods, PVD methods (vacuum evaporation methods), sputtering methods, etc. However, photoelectric conversion elements using thin films formed in this manner have low light conversion efficiency, closed-circuit photocurrent, fill factor, etc., and have not been practically satisfactory.

Therefore, the present inventors have made extensive research in order to eliminate the drawbacks of conventional porphyrin-based light conversion elements and to manufacture a porphyrin-based charge conversion element with high photoelectric conversion efficiency.

[Means to solve the problem]

As a result, m
It was discovered that H can be used as an excellent photoelectric conversion element. The present invention was completed based on this knowledge.

That is, in producing a photoelectric conversion element in which a photoactive layer made of a porphyrin compound or its metal complex FJDQ is formed as an electrode material, the present invention provides a micelle-forming agent made of a ferrocene derivative of a porphyrin compound or its metal complex in an aqueous medium. The present invention provides a method for producing a photoelectric conversion element, which comprises solubilizing the micelle solution in a step and electrolyzing the obtained micellar solution.

In the present invention, various porphyrin compounds and metal complexes thereof can be used as raw materials for the thin film. Specifically, tetraphenylporphyrin (H, -TP P
), its metal complex (M-TPP; M represents a metal such as iron, cobalt, nickel, copper, zinc, magnesium, manganese, etc.), tetrabenzoporphyrin (R2-TBP)
), its metal complex (M-TBP; M represents the same metal as above), tetrapyridylporphyrin (Hz T
P y P ), its metal complex (M-TPyP; M represents the same metal as above), and the like.

To produce a thin film of this porphyrin compound or its metal complex, as described above, the porphyrin compound or its metal complex as a raw material is solubilized in an aqueous medium using a micellizing agent made of a ferrocene derivative. The solution is electrolyzed to form a thin film. The micellizing agent used in forming this thin film is made of a ferrocene derivative, and there are various types of micellar agent, as long as it can solubilize the raw material porphyrin compound and its metal complex in an aqueous medium. . Specifically, the following (1), (
There are three types: 2) and (3).

First, (1) a ferrocene compound (
Examples include ferrocene or ferrocene to which an appropriate substituent (alkyl group, acetyl group, etc.) is bonded.

If the number of carbon atoms in the main chain is too small, it will not form micelles, and if the number of carbon atoms is too large, it will not dissolve in water.

There are various ways in which the ferrocene compound is bonded to this surfactant, and can be roughly divided into those bonded to the end of the main chain of the surfactant, those bonded directly or through an alkyl group in the middle of the main chain, and those bonded within the main chain. Examples include those incorporated into.

Such ammonium-type ferrocene derivatives include the general formula e (wherein R1 and R2 are each hydrogen or a carbon number of 1 to 4
represents an alkyl group (not exceeding the integer m described below), z and z' each represent hydrogen or a substituent (such as a methyl group, ethyl group, methoxy group, or carbomethoxy group), and X represents a halogen. . Also, m and n are m≧O
, n≧0 and represents an integer satisfying 4≦m+n≦16. ).

(In the formula, R, R2, ≧0.j≧Ok≧1 and 3≦h+j+ does not satisfy ≦15 and indicates an integer, and p is 0
Indicates an integer that satisfies -1 where ≦p≦. )5 General formula (wherein R', R'', X, Y, Z, Z' are the same as above (
However, the number of carbon atoms in R+ and Rz does not exceed the integer r described below.

). Furthermore, r, s, and t are r≧0. s≧0゜L≧1
and represents an integer satisfying 4≦r+s+t≦16.

) or the general formula (wherein R', R'', X, Y, Z, Z', r, s, and t are the same as above).

Specific examples of ferrocene derivatives as micellization agents include:

Next, (2) other types of ferrocene derivatives include the ether type ferrocene derivative R represented by the general formula. Here, a represents an integer from 2 to 18, and b represents 2.
It is a real number between 0 and 50.0. Since a is an integer of 2 to 18 as described above, an alkylene group having 2 to 18 carbon atoms such as an ethylene group or a propylene group is interposed between the ring member carbon atom and Y.

In addition, b means not only an integer between 2.0 and 50.0 but also a real number including these, and this represents the average number of repeating oxyethylene groups (-CH2CH20-) constituting the ferrocene derivative. It shows. Furthermore, Y in the above general formula is oxygen (-0-)
Alternatively, it represents an oxycarbonyl group (-○C-), and z and z' each represent hydrogen or a substituent as described above.

These ether type ferrocene derivatives are
It can be produced by the method described in Japanese Patent No. 212718.

Furthermore, (3) other types of ferrocene derivatives include pyridinium-type ferrocene derivatives represented by the general formula. In this formula, Z, Z", and X are the same as above, and R3 is an alkyl group having 1 to 4 carbon atoms, and
an alkoxy group, a carbalkoxy group having 1 to 5 carbon atoms,
It represents a hydroxyl group, a carboxyl group, a sulfonic acid group, etc., and C and R2 represent a straight chain or branched alkylene group having 1 to 16 carbon atoms. Specifically, this C-Hz- is a direct group including polymethylene groups (CH,) such as a tetramethylene group, a pentamethylene group, an octamethylene group, an undecamethylene group, a dodecamethylene group, and a hexadecamethylene group. Examples include chain alkylene groups and branched alkylene groups such as 2-methylundecamethylene groups and 4-ethylundecamethylene groups.

These pyridinium type ferrocene derivatives are
It can be produced by the method described in No. 3-52696.

As the micellizing agent used in the method of the present invention, the above-mentioned (
The ferrocene derivatives 1), (2), or (3) are preferably used.

In the method of the present invention, first, a micellar agent made of the above-mentioned ferrocene derivative, a supporting salt, and a porphyrin compound or a metal complex thereof as a thin film raw material are placed in an aqueous medium.
Disperse thoroughly using ultrasonic waves, a homogenizer, a stirrer, etc. to form micelles, then remove excess porphyrin compounds and their metal complexes as necessary, and leave the resulting micelle solution standing still or stir it slightly. Electrolytic treatment is performed using an electrode while adding . Additionally, the porphyrin compound or its metal complex may be supplemented and added to the micelle solution during the electrolytic treatment, or the micelle solution near the anode may be extracted from the system and the porphyrin compound or its metal complex may be added to the extracted micelle solution. A circulation circuit may also be installed in which the liquid is mixed and stirred and then returned to the vicinity of the cathode. The concentration of the micelle agent at this time is higher than the limit micelle concentration,
Specifically, it may be about 0.1 mM or more. The electrolytic conditions may be selected appropriately depending on various situations, but usually the liquid temperature is 0 to 70°C, preferably 20 to 30°C, and the voltage is 0.
．． 03-t, oov, preferably 0.1-0.5V, current density 10mA/cI11 or less, preferably 1-3
00μA/c+11.

When this electrolytic treatment is performed, a reaction proceeds according to the principle of micellar electrolysis. Focusing on the behavior of Fe ions in ferrocene derivatives, we can see that at the anode, Fe'' of ferrocene
+ becomes Fe3+, the micelles collapse, and particles of the porphyrin compound and its metal complex are deposited on the anode. On the other hand, at the cathode, the Fe'' oxidized at the anode is reduced to Fe'' and returns to the original micelles, so the film forming operation can be repeated using the same solution.

Through such electrolytic treatment, a thin film of a desired porphyrin compound or its metal complex is formed on the electrode (anode).

The supporting salt (supporting electrolyte) used in the method of the present invention is added as necessary to adjust the electrical conductivity of the aqueous medium. The amount of this supporting salt to be added may be within a range that does not interfere with the precipitation of the solubilized porphyrin compound or its metal complex, and is usually 10 to 300% of the micellar agent.
The target concentration is about twice as high, preferably about 50 to 200 times. Although electrolysis can be carried out without adding this supporting salt, in this case a highly pure thin film containing no supporting salt can be obtained. In addition, when using a supporting salt, the type of supporting salt should be one that can adjust the electrical conductivity of the aqueous medium without interfering with the formation of micelles or the precipitation of the porphyrin compound or its metal complex onto the electrode. There are no particular restrictions.

Specifically, sulfates (lithium, potassium, strium, etc.) are commonly used as supporting salts.

salts of rubidium, aluminum, etc.), acetate salts (lithium, potassium, sodium, rubidium, etc.).

salts of beryllium, magnesium, calcium, strontium, barium, aluminum, etc.) halide salts (salts of lithium, potassium, sodium, rubidium, calcium 1 magnesium, aluminum, etc.), water-soluble oxide salts (lithium, potassium, sodium, rubidium, etc.) , calcium, magnesium, aluminum, etc.) are preferred.

Further, the electrode material used in the method of the present invention may be any metal or conductor that has a higher oxidation potential than ferrocene (+0.15 V vs. saturated electrode). Specifically, fTo(
Examples include mixed oxides of indium oxide and tin oxide), platinum, gold, silver, grady carbon 3 conductive metal oxides, and organic polymer conductors.

In the method of the present invention, the thus obtained thin film of the porphyrin compound or its metal complex is used as a photoactive layer to form a photoelectric conversion element. There are various types of photoelectric conversion elements that use a thin film of the above-mentioned porphyrin compound or its metal complex as a photoactive layer.Specifically, they are roughly divided into two types: wet type and dry type. be able to. Among these, the wet type is usually configured as a system as shown in FIG. In other words, a porphyrin compound or its metal complex thin film 1 is added to the redox solution 5.
A configuration in which the electrode 2 (which is usually installed on a transparent or translucent substrate 3 (glass, etc.)) and its counter electrode 4 are immersed and electrically connected, that is, the electrode/porphyrin compound A photoelectric conversion element is constructed by a system consisting of a metal complex thin film/redox system/electrode (counter electrode).

Here, the redox system is one that has been known for a long time, specifically 13−−←2e−←→ 3■ (Fe(CN)&) 3− + e−← (Fe(C
N) 6)' etc. can be mentioned.

By the way, the photoelectric conversion element consisting of the above system allows
The principle by which light energy is converted into electrical energy is as follows. First, when a thin film 1 of a porphyrin compound or its metal complex is irradiated with light energy (light source: xenon lamp, argon lamp, helium lamp, argon laser, semiconductor laser, etc.), electrons jump out from the thin film 1, which is a photoactive layer. , the redox system stops this from happening. At this time, holes are generated in the thin film 1 after the electrons have jumped out. On the other hand, the redox system that has stopped receiving electrons is itself reduced and changes to, for example, I:l-+ 2 e--→31-, and further Nico's 31- is connected to the counter electrode 4 (e.g., platinum, gold, Graseeker
(such as phon), it is oxidized and returns to ■□−. The electrons from the counter electrode 4 pass through a lead wire or the like to the electrode 2 on which the thin film 1 is formed, and the electrons pass through the lead wire or the like to the electrode 2 where the thin film 1 is formed.
It combines with the hole inside and disappears. In this process, light energy is converted into electrical energy.

Note that in the above system, the direction of irradiation of light energy may be from the thin film 1 side or from the substrate 3 side.

Furthermore, the dry type is usually configured as a system as shown in FIG. That is, on the porphyrin compound or its metal complex thin film 1 formed on the electrode 2 on the substrate 3, a counter electrode 4 made of aluminum, copper, all-platinum, etc. is formed by vapor deposition or the like. Depending on the type of porphyrin compound, it is desirable to ensure that the electrode 2 or counter electrode 4 and the porphyrin compound or its metal complex thin film 1 are in blocking contact. A dry photoelectric conversion element is constructed by sandwiching a thin film of a porphyrin compound or its metal complex between two electrodes 2.4 and electrically connecting each electrode with a lead wire or the like. be done.

The photoelectric conversion device of the present invention may be any device having a photoactive layer made of a thin film of a porphyrin compound or its metal complex formed by the method of the present invention, and is not limited to the above-mentioned system examples, but can be used in various systems. can be configured.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Example 1 0.198 g of Fe as a nonionic micellizing agent was added to 100 ml of water, 0.15 g of tetraphenylporphyrin zinc complex (ZnTPP) was added, and the mixture was stirred with ultrasonic waves for 10 minutes. The obtained micelle solution was
Centrifugation was performed at 0 rpm for 10 minutes. 20 cc of this supernatant was collected, and 0.208 g of LiBr was added thereto to prepare an electrolyte.

Next, while using the above electrolyte solution, ITO/
Using glass as the cathode, platinum as the cathode, and a saturated electrode as the reference electrode (SCE), constant potential electrolysis treatment was performed at 25°C with an applied voltage of +0.5μ (potentiostat: manufactured by Hokuto Denko, HA211). I did it. The amount of current applied at this time was 13 millicoulombs/c+fl.

By the above operation, a thin film of ZnTPP was obtained on the ITO electrode. The visible absorption spectrum of this thin film is shown in Figure 3, and an electron micrograph of the thin film surface (magnification: 30,000 times 1
S-800, manufactured by Hitachi, Ltd.) is shown in Fig. 4.

The ZnTPP thin film/ITO/glass thus obtained was used as a photoelectric conversion electrode, and the following operations were performed.

That is, potassium iodide (Kl) 0.1M, iodine (I
z) 0.5 mM, sodium sulfate (Na2So4
) 0, 1 M solution (redox solution; acetate buffer).

50 cc of a solution (pH=4.8) was prepared, the photoelectric conversion electrode was placed in this solution, and a photoelectric conversion element was constructed using platinum as a counter electrode.

Light from a 500 watt xenon lamp (manufactured by Ushio Electric) was passed through an IQR-80 filter (800 nm) to this element.
The transmitted light was applied from the TTO side by cutting off the area larger than m. At this time, the light intensity was 6 mW/cul. In addition, the photoelectric conversion efficiency at this time is 0.01%, the fill factor is 0.42°, and the closed circuit photocurrent is 17.05.
It was μA. These are summarized in Table 1.

Further, the voltage-current characteristics at this time are shown in FIG. 5(a).

The voltage-current characteristics were measured at a potential scanning rate of 10 mV/sec.

Furthermore, the action spectrum (relationship between photocurrent and irradiation light wavelength) of this photoelectric conversion element is shown in FIG.

Comparative Example 1 Vacuum evaporation (PVD) was applied on ITO installed on a glass substrate.
) method to form a ZnTPP thin film (thickness: 1000),
Using this as a photoelectric conversion electrode, the same operations as in Example 1 were performed.

The visible absorption spectrum of the formed ZnTPP thin film is shown in the third
As shown in the figure. Further, the voltage-current characteristics of the photoelectric conversion element are shown in FIG. 5(b), and the action spectrum is shown in FIG. 6.

Furthermore, the photoelectric conversion efficiency, fill factor, and closed circuit photocurrent are shown in Table 1.

Example 2 Except that the pH of the redox was 1.2,
The same operation as in Example 1 was performed. The results are shown in Table 1.

Example 3 The same operation as in Example 1 was performed except that the photoelectric conversion element was irradiated with light from a xenon lamp from the ZnT P thin film side. The results are shown in Table 1.

Example 4 The amount of current applied during the formation of the ZnTPP thin film was set to 13 millicoulombs/
Changed from crl to 5 millicoulombs/cffl and added benzoquinone/hydroquinone 1 as a redox solution.
The same operation as in Example 1 was carried out, except that a solution (pH=2.1) consisting of 0 mM NazS Oa O, IM and sulfuric acid at 5 μf/roomA was used. The results are shown in Table 1.

Comparative Example 2 The same operation as in Comparative Example 1 was performed except that the solution of Example 4 was used as the redox solution. The results are shown in Table 1.

[Effects of the Invention] As described above, according to the method of the present invention, a photoelectric conversion element having a good photoelectric conversion efficiency of 5, a closed circuit photocurrent, and a fill factor can be obtained.

Therefore, the photoelectric conversion element obtained by the method of the present invention is
It can be used for various purposes including solar cells, CGL elements of photosensitive materials, and gas sensors.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one example of the photoelectric conversion element of the present invention, and FIG. 2 is a schematic diagram showing another example of the photoelectric conversion element of the present invention. Figure 3 shows ZnTP obtained in Example 1 and Comparative Example 1.
The visible absorption spectrum of the P%l film is shown, and FIG. 4 shows an electron micrograph of the surface of the ZnTPP)W film obtained in Example 1. FIG. 5(a) shows the voltage-current characteristics of the photoelectric conversion element formed in Example 1, and FIG. 5(b) shows the voltage-current characteristics of the photoelectric conversion element formed in Comparative Example 1. 6th
The figure shows the action spectrum of the photoelectric conversion element. In FIGS. 1 and 2, 1 is a porphyrin compound or its metal complex thin film, 2 is an electrode 53, a substrate, 4 is a counter-PiA electrode, 5 is a redox solution, and 6 is an electrometer, respectively. Figure 1 Figure 3 Wavelength (nm) Figure 2)

Claims (1)

[Claims] (1) When producing a photoelectric conversion element in which a photoactive layer made of a thin film of a porphyrin compound or its metal complex is formed as an electrode material, the porphyrin compound or its metal complex is mixed with a micellizing agent made of a ferrocene derivative in an aqueous medium. A method for producing a photoelectric conversion element, which comprises solubilizing and electrolyzing the obtained micelle solution.