DE10197130B4 - Method for producing a photoelectric converter and photoelectric converter - Google Patents

Abstract

Process for producing a photoelectric converter (1), comprising the following steps:
Forming a blocking / separating film (7) comprising titanium oxide having an amorphous structure and having a mixing ratio of oxygen / titanium of 1.8 or more on a transparent electrode film (5) for preventing short-circuiting,
Forming a current / voltage generation layer film (9) of electron transport particles (9a) and a hole transport material (9c) on the blocking / separation film (7), and
Forming a counter electrode film (11) on the current / voltage generation layer film (9), wherein
the blocking / separating film (7) is produced on the basis of a vacuum film forming process.

Description

The invention relates to a photoelectric converter and a manufacturing method of such a converter. More particularly, the invention relates to a manufacturing method for a photoelectric converter usable as a solid-state solar cell.

Major efforts have been made in the field of solar cells to meet global energy needs. A photoelectric converter used as a solar cell must satisfy the requirements of (1) low manufacturing cost, (2) worldwide availability, and (3) environmentally friendly manufacturing, and must not rely on scarce resources.

Recently, silicon solar cells (single crystal or polycrystalline) have been widely used. Furthermore, it has become common practice to use amorphous silicon solar cells. However, these solar cells generally do not satisfy the above-mentioned requirements (1) to (3). An example of a solar cell satisfying the above-mentioned conditions (1) to (3) is a color-sensitizing solar cell. A representative example of this is a Graetzel cell. However, such a solar cell uses an electrolytic solution which evaporates in case of damage, etc., thus posing problems of long-term stability of the solar cell. Therefore, efforts have been made to stabilize color-sensitizing (hereinafter referred to as "color-sensitive" solar cells).

In order to stabilize a color-sensitive solar cell, it has been proposed to use, as an alternative to the electrolytic solution, amorphous hole transporting material to form a positive-charge transporting section. An example of a structure of such a color-sensitive solar cell will be described with reference to FIG 1 explained in more detail with reference to the production steps.

The solar cell 101 shown in this figure has a transparent electrode film 105 on that on a substrate surface 103 is designed with translucent properties. On the transparent electrode film 105 is a blocking film (hereinafter referred to as "blocking film") 107 for avoiding short circuits between the transparent electrode film 105 and a hole transport material 109c a current / voltage generation layer film 109 , which will be described below, formed. The blocking film 107 For example, it is made of titanium oxide and is formed by spray pyrolysis or the like. In this process, an alcoholic solution of an organically complex salt of titanium (Ti) is sprayed onto the substrate, which is heated to 600 ° C. On the trained blocking film 107 becomes the current / voltage generation layer film 109 applied, consisting of electron transport particles 109a for absorbing a sensitizing dye (hereinafter referred to as "sensitive") 109b , and a hole transport material 109c is formed. What the electron transport particles 109a the current / voltage generation layer film 109 As regards, for example, anatase type titanium oxide is used. Furthermore, the current / voltage generation layer film is 109 with a counter electrode film 110 coated.

The operation of a solar cell having such a construction will be described using an energy diagram 2 along with 1 explained. When light (sunlight) H through the substrate side 103 occurs, the sensitive dye 109b in the current / voltage generation layer film 109 excited by the light H, thus producing electrons e and holes h . Then electrons e from the excitation level into the electron transport particles 109a injected, wandering in it and pass the blocking film 107 , and arrive at the transparent electrode film 105 , and are extracted as stream. On the other hand, the holes h migrate from a ground level into the hole transport material 109c by means of a hopping line mechanism.

In a solar cell having the structure described above, the blocking film is used 107 to avoid physical contact between the hole transport material 109c including the current / voltage generation layer film 109 forms, and the transparent electrode film 105 , Therefore, the blocking film has to 107 have a good film quality and a certain thickness. If the hole transport layer 109c and the transparent electrode film 105 contact each other, the holes h (indicated by the dotted line in the figure) migrate from this contact portion to the transparent wiring film 105 , The holes h combine with the electrons e in the transparent conductive film 105 and disappear, so that the power source voltage performance (battery efficiency) deteriorates.

Furthermore, the blocking film 107 Part of the conduction path for electrons e in the current / voltage generation layer film 109 be generated. Therefore, if the film thickness is unnecessarily large, the Internal resistance of the power source is high, degrading the power source voltage. Furthermore, the blocking film becomes 107 also part of the optical path for the incident light H, whereby the photoelectric conversion is deteriorated in their effectiveness when the optical absorption is large.

Therefore, it is desirable that the blocking film 107 has good film quality, can be made sufficiently thin, and at the same time shorts with the current / voltage generation layer film 109 avoids, without blocking the transport of the electron e , and that the blocking film 107 keep the optical absorption as small as possible.

The JP 2000-285974 A is concerned with avoiding short circuits of an electrical circuit between a charge transport layer and a transparent electrode and the separation of a transparent conductive layer from an n-type semiconductor electrode. Further, it is concerned with improving the long-term reliability by forming the n-type semiconductor electrode with a dense portion having a specific thickness and a porous portion. For this purpose, an n-type semiconductor electrode having a dense portion and a porous portion is formed, wherein the thickness of the dense portion is not smaller than 0.01 μm and not larger than 0.6 μm. In order to make the thickness of the dense portions so thin, depressions and protrusions existing on the surface must not be larger than 90 nm. As a result, a thin film having a thickness of less than 100 nm having no stress concentration is formed to provide a high-efficiency cell with long-term reliability. Since microstructures may vary depending on the raw material, the specific gravity of the dense portion is not less than 93% and not more than 100%. Pores in the dense section are closed. Moreover, a volume ratio of a polycrystalline phase contained in the dense portion is preferably not less than 5% and not more than 70%.

The JP 2001-156314 A is concerned with improving the productivity of elements by providing a dye-sensitizer photoelectric conversion element with improved durability while reducing failures such as short circuits. To this end, the photoelectric conversion element contains a conductive support, a semiconductor fine particle-containing layer adsorbing a dye applied to the conductive support, a positive hole transporting layer and a counter electrode, and is subjected to dye sensitization. The positive hole transporting layer contains a p-type inorganic compound semiconductor and an oxide semiconductor substrate is provided on the conductive support.

In a film production method such as the spray pyrolysis described above, there is also a drawback that the film thickness is extremely difficult to control and a reduction in the thickness of the blocking film is difficult as compared to the advantage that a relatively transparent film is obtained. Furthermore, it is necessary to use the substrate 103 To heat up to a high temperature, so that the process load is large. Furthermore, foreign matter can easily get into the film, so that a blocking film having stable properties is not obtained.

This problem is solved by a method and a photoelectric converter according to the independent claims.

In such a production method and in a photoelectric converter obtained thereby, by employing a device which produces the blocking film by means of a vacuum film forming process, a blocking film having a good quality and a good controllable thickness is obtained. Thus, there is obtained a photoelectric converter having a blocking film having a good film quality and a reduced thickness, suppressing light absorption in the blocking film, and reliably separating the hole transporting material constituting the current / voltage generating film film and the transparent electrode film by the blocking film.

In the following, the invention will be described in more detail by way of example with reference to the accompanying figures. Show it:

1 a sectional view for explaining the structure of a conventional photoelectric converter and the problems associated therewith.

2 a schematic diagram for explaining the operation of a photoelectric converter.

3 a schematic diagram of the structure of the photoelectric converter according to the invention.

4 a sectional view showing enlarged important parts of the photoelectric converter according to the invention.

5 a sectional view for explaining an example of the structure of an end portion of the photoelectric converter.

6 a sectional view for explaining another example of the structure of the end or end portion of the photoelectric converter.

7 a sectional view for explaining a still further example of the structure of the end or end portion of the photoelectric converter.

3 shows the construction of a photoelectric converter according to the invention, during 4 a sectional view of important parts of the photoelectric converter shows. The photoelectric converter 1 in these figures, it is preferably used as a solid-state solar cell. The photoelectric converter 1 points, starting from below, on: A substrate 3 , a transparent electrode film 5 , a blocking film 7 , a current / voltage generation layer film 9 , and a counter electrode film 11 which are stacked in this order. In particular, the current / voltage generation layer film becomes 9 by filling a hole transport material 9c around the electron transport particles 9a for absorbing a sensitive dye 9b educated. This becomes the photoelectric converter 1 of the type of sensitive / sensitizing dye. Described below are details of the elements in the order of respective manufacturing steps.

First, a substrate 3 made of a material that is permeable to light (sunlight) H. The substrate 3 For example, it can be made of glass, PET (polyethylene terephthalate), PEN, polyimide, polyamide, polycarbonate, or other types of plastic. Note that when the light H enters from the side of the counter substrate 11 the substrate 3 does not have to be transparent to the light H and can be made on a ceramic basis, for example of zirconia or a metal such as steel or copper. It should be noted that when manufacturing the substrate 3 from a metal an insulation treatment, for example covering the surface of the substrate 3 by a silicon oxide film.

Such a substrate 3 when the photoelectric converter 1 is used as a solar cell, with a transparent Elekrodenfilm 5 provided, which acts as a negative electrode of the solar cell. This transparent electrode film 5 It must have a low resistance to form a series resistance in the power source, and must have a low optical absorption because it becomes the optical path for the light H, and further should have excellent chemical resistance and weather resistance properties. To meet these criteria, a transparent electrode film is formed 5 through a layer of ZnO, SnO ₂ , InO ₃ , ITO (Sn-doped In ₂ O ₃ ), IFO (F-doped InO ₂ O ₃ ), ATO (Sb-doped SnO ₂ ), FTO (F-doped SnO ₂ ), CTO (Cd-doped SnO ₂ ) or the like, and used alone or in the form of a complex layer. As a complex layer, for example, SnO ₂ / ITO, ZnO / ITO, or the like can serve. Among them, preferably ITO, FTO, SnO ₂ / ITO, and ZnO / ITO are usable. For producing such a transparent Elekrodenfilms 5 can sputter, vacuum evaporation. CVD (Chemical Vapor Deposition), IP (ion implantation), spray, dip and the like are used.

Now, the transparent electrode film becomes 5 with a blocking film 7 provided to short circuits between the transparent electrode film 5 and the hole transport material 9c the current / voltage generation layer film 9 to avoid. The blocking film 7 is preferably made of an insulating material having a light transmissive property or a semiconductor material having a light transmissive property and has a large energy gap (Gap) such as titanium oxide, Nb ₂ O ₅ and WO ₃ . When electron transport particles 9a of titanium oxide in the current / voltage generation layer film 9 near the blocking layer 7 are attached, the blocking film becomes 7 preferably formed by titanium oxide, whereby the bonding of the electron transport particles 9a and the blocking film 7 secured or fixed.

The blocking film 7 serves to avoid short circuits (contacts) between the transparent electrode film 5 and the hole transport material 9c and must be of high quality. If the blocking film 7 is realized on the basis of titanium oxide, vozugsweise preferably titanium oxide with an amorphous (non-crystalline) structure into consideration. When the crystal grain size of the titanium oxide is large, a large grain boundary portion becomes in the blocking film 7 formed, so that the hole transport material 9c that's made of an amorphous one organic substance having a cube size of up to 1 nm and a low viscosity passes through the grain boundary portion and the transparent electrode film 5 contacted. Furthermore, in a heat treatment step (about 500 ° C) to promote a bonding process among the electron transport particles 9a the blocking film 7 preferably as an amorphous structure at the time of film formation, since the crystals of the blocking film 7 also grow. In another example useful for understanding the invention, it may have a microcrystalline structure and is formed, for example, as an anatase type crystal.

The blocking film 7 has a high resistance according to its function, whereby the thicker the film is, the larger the internal resistance of the current / voltage source (battery). This is a factor that affects the deterioration of battery performance. Therefore, the blocking film becomes 7 preferably formed as a thin film. When it is made of titanium oxide, the thickness of the film is preferably not more than 100 nm. The film thickness of the transparent electrode film 5 When it is made of titanium oxide, it is set to 15 nm or more, preferably 20 nm or more, to reliably provide physical contact between the transparent electrode film 5 and the hole transport material 9c to avoid through the blocking film.

If the blocking film 7 to the optical path of the light (sunlight) H from the substrate side 3 is desirable, the optical absorption is as small as possible, and the blocking film 7 is made as thin as possible. Therefore, when making the blocking film 7 made of titanium oxide titanium oxide with a mixing ratio of oxygen to titanium (O / Ti mixing ratio) of 1.8 or more.

Here is the blocking film 7 is preferably formed in a shape that reliably covers the surface on the transparent electrode film to the corner portions, so that the transparent electrode film 5 and the hole transport material 9c can be separated. That's why, as in 5 is shown, the blocking film 7 preferably, such that it not only the surface of the transparent electrode film 5 but also the entire surface of an exposed surface including the portions exposed at the ends.

A blocking film 7 with such a structure is produced by sputtering, vacuum evaporation, IP, CVD, or other vacuum film forming processes. The method is not limited to these vacuum film forming processes. Preferably, sputtering is used because the control of the quality of the film to be formed is easy. In particular, RF sputtering is used using titanium oxide as the target or sputtering in an oxygen environment using titanium as the target. In this case, it is possible to form a titanium film in vacuum, and then heat-treat the titanium film in an air or oxygen environment to form titanium oxide therewith.

If the blocking film 7 is formed by RF sputtering using titanium oxide as a target to obtain titanium oxide having a high film quality and an amorphous or microcrystalline structure, the applied power is preferably 0.01 to 0.10 W / mm ² , the film forming temperature (substrate temperature ) is 350 ° C or less, and the partial pressure of oxygen in the film forming environment is 5.3 cm ^-3 Pa or more. In particular, when the film-forming temperature is too low, the bonding strength and the film thickness of the blocking film become 7 weak, so that it becomes impossible to achieve a well-defined film structure. Therefore, the film-forming temperature is preferably set to 200 ° C to 350 ° C. The higher the partial pressure of oxygen in the film forming environment, the lower the film forming speed, so that preferably the upper limit of the partial pressure of oxygen in the film forming environment is 8.0 × 10 ^-3 Pa. Therefore, the partial pressure of oxygen in the film forming environment is preferably set to 5.3 × 10 ^-3 Pa to 8.0 × 10 ^-3 Pa.

After the above-described formation of the blocking film 7 On this, the current / voltage generation layer film becomes 9 educated.

At this time, first the electron transport particles 9a on the blocking film 7 applied or pinned. The electron transport particles 9a are preferably anatase titanium dioxide particles. The electron transport particles 9a can be obtained by doping a different type of element in anatase type titanium oxide particles or by surface treatment. The particle size of the electron transport particles 9a is 5 to 50 nm, is preferably set to 10 to 30 nm, taking into account the photoelectric conversion efficiency.

To cause the surface or surface of the electron transport particles 9a the sensitive dye 9b In the following steps, the electron transport particles become absorbed 9a on the blocking film 7 so applied or pinned that many columns around the electron transport particles 9a occur, that is, in a state in which the porosity is largely maintained. Furthermore, the thickness of the layer is the electron transport particle 9a on the blocking layer 7 about 0.1 to 40 μm.

• (1) Lösen der Elektrontransportpartikel 9a in einem Binder oder einem viskositätserhöhenden Mittel, und Aufsprühen bzw. Aufbringen des Ergebnisses auf den Blockierfilm 7, dann Trocknen und Sintern bei einer Temperatur von 150 bis 600°C.
• (2) Abdecken des Blockierfilms 7 mit einer Lösung aus Titanium-Alkoxid oder Titanium-Acetonat, dann Trocknen und bei Bedarf Sintern bei einer Temperatur von 150 bis 600°C.
• (3) Gelieren von Titaniumoxid-Sol auf den Blockierfilm 7.
• (4) Besprühen bzw. Bedecken des Blockierfilms 7 mit Titaniumoxidpartikeln, die durch Hydrolyse einer Titaniumverbindung erhalten werden, in Anwesenheit von nuklearen Spezies, dann Trocknen, und anschließend Sintern bei einer Temperatur von 150 bis 600°C je nach Bedarf.

In this sense, if the electron transport particles 9a on the blocking film 7 applied, for example, the following methods (1) to (4) are applied:

• (1) dissolving the electron transport particles 9a in a binder or viscosifier, and spraying the result onto the blocking film 7 , then drying and sintering at a temperature of 150 to 600 ° C.
• (2) Cover the blocking film 7 with a solution of titanium alkoxide or titanium acetonate, then drying and, if necessary, sintering at a temperature of 150 to 600 ° C.
• (3) Gelling titanium oxide sol on the blocking film 7 ,
• (4) spraying or covering the blocking film 7 with titanium oxide particles obtained by hydrolysis of a titanium compound in the presence of nuclear species, then drying, and then sintering at a temperature of 150 to 600 ° C as occasion demands.

Then it causes the electron transport particles 9a on the blocking film 7 are applied, the sensitive dye 9b absorb. Here is the sensitive dye 9b an absorption which is in the region of visible radiation. It can find a metal complex or an organic dye use.

As for the metal complex, copper phthalocyanine, titanyl phthalocyanine, or another metal phthalocyanine, chlorophyll or derivatives thereof, hemin, and metal complexes of ruthenium, osmium, iron, zinc and the like can be used as disclosed in Japanese Unexamined Patent Publication JP H01-220380 A and Japanese Unexamined Patent Publication JP H05-504023 A is described. Among them, as far as the ruthenium complex is concerned, Ru (II) (bipyridine dicarboxyl) 2 (isothiocyanate) 2 can be used in concrete ruthenium 505, ruthenium 535, ruthenium 353B to TBA, and ruthenium 620 manufactured by Solaronix / Switzerland. As for the organic dye, metal-free phthalocyanine, a melocyanine-based dye, a xanthene-based dye and a triphenylmethane-based dye can be used as the cyanine-based dye.

According to the invention, from the standpoint of sensitive efficiency, it is preferable to use a metal complex as a sensitive dye 9b used.

Here you can absorb the sensitive dye 9b through the electron transport particles 9a on the blocking film 7 are applied, find a method in which a layer of electron transport particles 9a , which has dried well, in a solution of the sensitive dye 9b is immersed, or find a method in which the layer of electron transport particles 9a with the solution of the sensitive dye 9b is coated.

Now the layer of electrotransport particles 9a through which the sensitive dye 9b was absorbed with the hole transport material 9c refilled. The hole transport material 9c For example, an arylamine-based positive charge transport material such as N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-biphenylamine (TPD) or amorphous 2,2 ', 7,7'- Tetrakis [N, N'-di (4-methoxypenyl) amine] -9,9'-spirobifluorene: OMeTAD with an elevated transition point (Tg) to extend the lifetime of the positive charge transport function and stabilize it.

As a dopant for improving the electron injection efficiency of the sensitive dye 9b into the electron transport particles 9a or to improve the space charge effect, a salt of tri (bromophenyl) amine and SbCl ₆ , Li [(CF ₃ SO ₂ ) ₂ N], LiClO ₄ or CaClO ₄ may also be added.

As for the material properties, the viscosity is preferably very low, the Tg point is high, and the structure is amorphous.

Here is the hole transport material 9c around the electron transport particles 9a filled the sensitive dye 9b absorb by performing a coating process, such as a spin-coating process. This becomes the current / voltage generation layer film 9 formed from the electron transport particles 9a containing the sensitive dye 9b absorb, and the hole transport material 9c is formed.

Furthermore, it is possible to form the corners of the current / voltage generating layer film 9 within the corners of the blocking film 7 to put, such as in 6 and 7 is shown, so that the current / voltage generating layer film 9 and the transparent electrode film 5 reliably through the blocking film 7 be separated from each other. When a current / voltage generation layer film 9 is made with such a shape, the blocking film 7 formed, and then the above-mentioned step sequences for forming the current / voltage generating layer film 9 performed in a state in which a part, for example, an outer strip / circumference of the blocking film 7 is masked.

After that, when the photoelectric converter 1 is used as a solar cell, the current / voltage generating layer film 9 with a counter electrode film 11 coated, which serves as the anode of the solar cell. This counter electrode film 11 preferably contains Au, Pt, Pd or the like with a work function of about 5.0 eV and a high catalytic activity. Because when using the photoelectric converter 1 the counter electrode film 11 forms an internal resistance in the solar cell, the thicker one of the film is good for the purpose of resistance reduction. In the case of a photoelectric converter in which light from the side of the counter electrode film 11 However, the light absorption is suppressed by reducing the thickness of the counter electrode film 11 is reduced, whereby battery efficiency can be obtained. Therefore, for example, in forming the counter electrode film 11 by Au, Pt, Pd, or the like, preferably the thickness of the counter electrode film 11 set to 300 nm or less, in a particularly preferred embodiment to 200 nm or less.

The counter electrode film 11 is preferably prepared by sputtering, vacuum evaporation, IP, CVD and other vacuum film forming processes. The substrate temperature at the time of film formation becomes the decomposition temperature of the hole transport material 9c including the current / voltage generation layer film 9 forms or less.

As explained above, a photoelectric converter 1 obtained from the solid-state type. When such a photoelectric converter 1 is used as a solar cell, it is used in a state where the transparent electrode film and the counter electrode film 11 with an external circuit 20 are connected.

In the manufacturing method described above, by employing a device comprising the blocking film 7 formed by vacuum film formation, a blocking film 7 with a good controllable thickness and quality, and a film without entry of foreign matter or the like can be obtained. This will make it possible to get a blocking film 7 form, which has a good film quality and is thin. That is, a blocking film 7 with a high film quality can be made so thin that a photoelectric converter 1 is obtained in which the light absorption in the blocking film 7 is suppressed and the current / voltage generating layer film 9 and the transparent electrode film 5 reliably separated by the blocking film. This becomes a photoelectric converter 1 With a high conversion efficiency, it becomes possible to realize a solid-type solar cell having a high battery efficiency.

It should be noted that in the described embodiment, the structure of a dye-sensitive type photoelectric converter described by the electron transporting particles has been described 9a in the current / voltage generation layer film 9 containing the sensitive dye 9b absorb, is formed. However, the photoelectric converter of the present invention can be generally applied to a solid state type photoelectric converter in which the current / voltage generating layer film 9 through the electron transport particles 9a and the hole transport material 9c is formed, and the blocking film 7 between the current / voltage generation layer film 9 and the transparent electrode film 5 is provided.

Among such photoelectric transducers, it is possible to use electron transport particles 9a to use titanium oxide with oxygen defects causing long-wave absorption of the excitation type. Such a photoelectric converter can without the sensitive dye absorbing electron transport particles 9a be realized. Also in this case, the required properties with respect to the blocking film are similar to those of a sensitive dye film, with which similar effects are obtained using the invention.

In the following, specific examples 1 to 4 of the invention, a comparative example and corresponding evaluation results will be described. In Examples 1 to 4 and the comparison result, photoelectric converters were prepared by changing the formation conditions with respect to the blocking film 7 and varying the thickness of the blocking film 7 during the training conditions. Then the photoelectric conversion efficiency, the composition of the blocking film 7 and the crystal structure measured in the produced photoelectric converters.

production method

The photoelectric converters of Examples 1 to 4 and Comparative Example were prepared by the following method.
First, the entire surface of a 25 mm x 25 mm substrate 3 made of glass with a transparent electrode film 5 from ITO coated by sputtering.

Then, the transparent electrode film became 5 masked to a blocking film 7 of titanium oxide in a 20 mm x 25 mm area on the transparent electrode film 5 applied.

Here, five evaluation samples for Examples 1 to 4 and the comparative example were prepared. There were blocking films with five thickness types of 10 nm, 20 nm, 60 nm, 100 nm and 150 nm in areas of 20 mm × 25 mm on the transparent electrode film 5 the evaluation samples trained.

The blocking films 7 were formed by RF sputtering. The partial pressures of oxygen (O ₂ ) and substrate temperatures at the time of film formation were set in Table 1 below. Further, for this film formation, TiO ₂ (99.99%) was used as the target, the general film forming conditions being set so that the applied power was 0.44 W / mm ² , and the partial pressure of Ar used as the sputtering gas , 13.3 Pa. Table 1 Conditions for the formation of the blocking film substrate temperature Partial pressure of oxygen (O ₂ ) Comparative example 200 ° C 0 Pa example 1 200 ° C 5.3 × 10 ^-3 Pa Example 2 200 ° C 13.3 × 10 ^-3 Pa Example 3 350 ° C 5.3 × 10 ^-3 Pa Example 4 400 ° C 5.3 × 10 ^-3 Pa

Then the blocking film became 7 coated and by means of a screen printing process with electron transport particles 9a Mistake. What the electron transport particles 9a As such, use was made of anatase type titanium oxide sol produced by Solaronix (particle size in about 13 nm, specific surface area in about 120 m ² / g), mark: Ti nanooxide T. Then, this became in the atmosphere 300 ° C sintered to a layer of electron transport particles 9a of anatase type titanium oxide crystal having a thickness of about 5 μm.

Then a sample was placed on the electron transport particles 9a were dipped into a solution of sensitive dye (ruthenium 535- to TBA solution to cause the electron transport particles 9a the sensitive dye 9b absorb. Then the hole transport material solution (the OMeTAD solution) was spin coated to form the hole transport material 9c into the gaps of the electron transport particles 9a to fill. Then that became with the transparent electrode film 5 connected positive transport material 9c Wipe thoroughly with a rag or brush, and the solution in the positive transport material 9c was evaporated to form the current / voltage generation layer film 9 to obtain.

Then, Au was sputtered on the current / voltage generation layer film 9 deposited with a thickness of 150 nm to form a counter electrode film 11 train. Thus, a photoelectric converter 1 made with a optically effective area of 5 cm ² as a solar cell.

evaluation results

The photoelectric converters prepared in Examples 1 to 4 and Comparative Example were examined for the photoelectric conversion efficiency (battery property). Furthermore, the The blocking film of each photoelectric converter was examined for the content of the titanium oxide using an X-ray microanalyzer (XMA), the crystal structure was analyzed by using an X-ray diffraction apparatus (MRD), and the light absorption rate for light having a wavelength of 550 nm was measured. It should be noted that the light absorption rate for a blocking film of 100 nm was measured.

The following Table 2 shows the evaluation results for the comparative example. The light absorption rate for the blocking film (film thickness of 100 nm) of the comparative example was 11%. Table 2 Comparative Example film thickness conversion efficiency O / Ti mixing ratio crystal structure 10 nm 0,107 1.6 Amorphous 20 nm 0,128 1.6 Amorphous 60 nm 0.138 1.6 Amorphous 100 nm 0.206 1.6 Amorphous 150 nm 0,190 1.6 Amorphous

The following Table 3 shows the evaluation results of Example 1. The light absorption rate of the blocking film (film thickness of 100 nm) of Example 1 was 1%. Table 3 Example 1 film thickness conversion efficiency O / Ti mixing ratio crystal structure 10 nm 0,122 1.8 Amorphous 20 nm 0.215 1.8 Amorphous 60 nm 0,220 1.8 Amorphous 100 nm 0.215 1.8 Amorphous 150 nm 0,180 1.8 Amorphous

The following Table 4 shows the evaluation result regarding Example 2. The light absorption rate of the blocking film (film thickness of 100 nm) of Example 2 was 1%. Table 4 Example 2 film thickness conversion efficiency O / Ti mixing ratio crystal structure 10 nm 0,119 1.8 Amorphous 20 nm 0.209 1.8 Amorphous 60 nm 0.217 1.8 Amorphous 100 nm 0.215 1.8 Amorphous 150 nm 0,187 1.8 Amorphous

The following Table 5 shows the evaluation result of Example 3. The light absorption rate of the blocking film (film thickness of 100 nm) of Example 3 was 1%. Table 5 Example 3 film thickness conversion efficiency O / Ti mixing ratio crystal structure 10 nm 0,120 1.9 Anastas 20 nm 0.213 1.9 Anastas 60 nm 0.219 1.9 Anastas 100 nm 0.217 1.9 Anastas 150 nm 0.177 1.9 Anastas

The following Table 6 shows the evaluation result regarding Example 5. The light absorption rate of the blocking film (film thickness of 100 nm) of Example 3 was 1%. Table 6 Example 4 film thickness conversion efficiency O / Ti mixing ratio crystal structure 10 nm 0,100 1.9 Anastas 20 nm 0.195 1.9 Anastas 60 nm 0,199 1.9 Anastas 100 nm 0,200 1.9 Anastas 150 nm 0,151 1.9 Anastas

From the above results, it can be seen that when using titanium oxide in the blocking film 7 the light absorption rate in the blocking film 7 was kept low in Examples 1 to 4 when the mixing ratio of oxygen / titanium was 1.8 or more. In this case, it was confirmed that at a thickness of the blocking film 7 in a range of 20 nm to 100 nm, the conversion efficiency became 0.195 or more. Furthermore, it was found that in the presence of a blocking film 7 from an amorphous structure, the above-described conversion efficiencies and light absorption rates were obtained when the film thickness fell within the range of 20 nm to 100 nm.

As described above, according to the invention, by using a structure for producing the blocking film between the current / voltage generating layer film and the transparent electrode film by vacuum film formation, a thin blocking film having a high film quality can be obtained, thus resulting in a photoelectric converter having a high conversion efficiency. With this, it becomes possible to realize a solid-state type solar cell having good battery efficiency by using such a photoelectric converter.

Claims (2)

Method for producing a photoelectric converter ( 1 ), comprising the steps of: forming a blocking / separation film ( 7 ) comprising titanium oxide having an amorphous structure and having a mixing ratio of oxygen / titanium of 1.8 or more on a transparent electrode film ( 5 ) for preventing short circuits, forming a current / voltage generation layer film ( 9 ) from electron transport particles ( 9a ) and a hole transport material ( 9c ) on the blocking / separating film ( 7 ), and forming a counter electrode film ( 11 ) on the current / voltage generation layer film ( 9 ), wherein the blocking / separation film ( 7 ) is manufactured on the basis of a vacuum film forming process. Photoelectric converter ( 1 ), comprising: a transparent electrode film ( 5 ) and a counter electrode film ( 11 ), between them a current / voltage generation layer film ( 9 ) from electron transport particles ( 9a ) and from hole transport material ( 9c ) and a blocking / separating film ( 7 ) comprising titanium oxide having an amorphous structure and having a mixing ratio of oxygen / titanium of 1.8 or more for avoiding short-circuits between the transparent electrode film ( 5 ) and the current / voltage generation layer film ( 9 ), wherein the blocking / separation film ( 7 ) is made on the basis of a vacuum film forming process.

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