JP2019121669A - Photoelectric conversion element using dye, and electronic device using same - Google Patents

Abstract

To provide a photoelectric conversion element capable of sufficiently suppressing a decrease in power generation performance, and an electronic device using the same.SOLUTION: In a photoelectric conversion element provided with a photoelectric conversion cell, the photoelectric conversion cell includes an electrode substrate, an opposing substrate facing the electrode substrate, an oxide semiconductor layer provided on the electrode substrate, an electrolyte provided between the electrode substrate and the opposing substrate, a sealing portion which connects the electrode substrate and the opposing substrate and surrounds the electrolyte together with the electrode substrate and the opposing substrate, and a dye supported on the oxide semiconductor layer. The electrode substrate has a conductive layer in contact with the electrolyte, and the electrolyte contains platinum ions, and the concentration of platinum ions in the electrolyte is 1 to 9 mM.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a photoelectric conversion element using a dye, and an electronic device using the same.

  BACKGROUND A photoelectric conversion element such as a solar cell may be used as a power source in an electronic device such as a calculator. For example, Patent Document 1 below discloses an electronic device in which a solar cell and a primary cell connected in parallel to each other are incorporated as a power supply. In this electronic device, the switching frequency of the primary battery is reduced by switching the power supply so that the solar battery is driven under illumination and the primary battery is driven in a dark place by the power switch. .

Unexamined-Japanese-Patent No. 8-171433

  However, the electronic device described in Patent Document 1 has the following problems when a photoelectric conversion element using a dye is used as a solar cell.

  That is, in the electronic device described in Patent Document 1, when a high voltage primary battery is used as the primary battery, the electronic device moves from under high illuminance to under low illuminance, and the power is switched by the power switch. When switching from a solar cell to a primary cell, a high voltage of the primary cell may be applied to the solar cell, and a large reverse current may flow in the solar cell. In this case, there is a possibility that the dye is deteriorated due to the large reverse current to lower the power generation performance of the solar cell.

  This invention is made in view of the said situation, and it aims at providing the photoelectric conversion element which can fully suppress the fall of electric power generation performance, and the electronic device using the same.

  In order to solve the above-mentioned subject, the present inventors repeated earnestly research paying attention to an electrolyte. As a result, the inventors have found that the above problems can be solved by setting the concentration of platinum in the electrolyte to a specific range, and the present invention has been completed.

  That is, the present invention is a photoelectric conversion element provided with a photoelectric conversion cell, wherein the photoelectric conversion cell includes an electrode substrate, an opposing substrate facing the electrode substrate, an oxide semiconductor layer provided on the electrode substrate, and An electrode substrate and an electrolyte provided between the opposing substrate, the electrode substrate and the opposing substrate are connected, and a sealing portion surrounding the electrolyte together with the electrode substrate and the opposing substrate, supported on the oxide semiconductor layer And a dye, the electrolyte includes platinum ions, and the concentration of platinum ions in the electrolyte is 1 to 9 mM.

  According to the photoelectric conversion element of the present invention, even if a high voltage is applied to the photoelectric conversion element and a large current flows immediately after the photoelectric conversion element moves from under high illuminance to under low illuminance, the electrolyte is platinum ion 1 By including in the range of -9mM, the resistance of the interface between the electrolyte and the conductive layer of the electrode substrate is sufficiently reduced. It is considered that this is because platinum ions dissolved in the electrolyte are deposited as platinum on the surface of the conductive layer while the photoelectric conversion element is placed under high illuminance. For this reason, even when a large reverse current flows in the photoelectric conversion element immediately after the photoelectric conversion element moves from high illuminance to low illuminance, current flows not only between the conductive layer and the oxide semiconductor layer but also conductively. It is also possible to pass well between the layer and the electrolyte. That is, even when a large reverse current flows in the photoelectric conversion element immediately after the photoelectric conversion element moves from high illuminance to low illuminance, not only between the conductive layer and the oxide semiconductor layer but also the conductive layer and the electrolyte It is also possible to disperse the current during the Therefore, a large current is sufficiently suppressed from flowing to the dye supported on the oxide semiconductor layer. Therefore, according to the photoelectric conversion element of this invention, the fall of the electric power generation performance by degradation of pigment | dye can fully be suppressed.

In the photoelectric conversion element, the oxygen transmission rate ratio r represented by the following formula (1) is preferably 0.0004 to 0.0015 cm ³ (STP) / (day · mL) in the sealing portion. .
Oxygen transmission rate ratio r = v / m (1)
(In said formula (1), v represents the oxygen transmission rate (cm < ³ > (STP) / day) of the said sealing part, m represents the quantity (mL) of the said electrolyte.)

In this case, when the oxygen permeation rate ratio r is that is ^{0.0015cm 3 (STP) / (day} · mL) below, the oxygen transmission rate ratio r is greater than the ^{0.0015cm 3 (STP) / (day} · mL) In comparison with the above, the permeation of oxygen in the sealing portion is more sufficiently suppressed, and the oxidation of platinum deposited under high illuminance is more sufficiently suppressed. As a result, platinum deposited under high illuminance is less likely to be dissolved in the electrolyte, and the resistance of the interface between the electrolyte and the conductive layer immediately after the transition from high illuminance to low illuminance is more sufficiently reduced. In addition, when the oxygen transmission rate ratio r is 0.0004 cm ³ (STP) / (day · mL) or more, the oxygen transmission rate ratio r is less than 0.0004 cm ³ (STP) / (day · mL) The amount of oxygen transmission when standing in a dark place is much higher than that in the dark, and the platinum that is deposited is more sufficiently dissolved by the permeated oxygen, so precipitation of platinum under high illuminance The temporarily increasing leak current can be more sufficiently eliminated by standing in the dark.

In the photoelectric conversion element, the resistance R1 (Ω · cm ² ) of the interface between the conductive layer and the electrolyte immediately after being placed under irradiation of pseudosun light for 1 sun corresponds to 1 sun of the photoelectric conversion element. The resistance R2 (Ω · cm ² ) of the interface between the conductive layer and the electrolyte after standing for 12 hours under pseudo-sunlight irradiation and then standing for 100 hours in the dark Is preferred.

  In this case, a large reverse current flows when a high voltage is applied to the photoelectric conversion element immediately after the photoelectric conversion element is transferred from the high illuminance state to the low illuminance state as compared to the case where R1 is R2 or more. By being dispersed not only between the conductive layer and the oxide semiconductor layer but also between the conductive layer and the electrolyte, it is possible to more sufficiently suppress the decrease in the power generation performance due to the deterioration of the dye.

In the photoelectric conversion element, it is preferable that the R1 satisfies the following formula (2) and the R2 satisfies the following formula (3).
R1 <1.5 × 10 ⁵ (2)
R2 ≧ 1.5 × 10 ⁵ (3)

In this case, compared to the case where R2 is less than 1.5 × 10 ⁵ Ω · cm ² , the leakage current after being placed in the dark after the photoelectric conversion element is placed under high illuminance is small. Power generation performance.

  The present invention also provides a power supply having a first power supply and a second power supply connected in parallel to the first power supply, a power consumption unit that consumes the power supplied from the power supply, and the power supply. (1) An electronic device comprising: a power switch capable of switching to a power source or the second power source, wherein the first power source is configured of the photoelectric conversion element described above, and the second power source is a primary battery. It is an electronic device comprised by at least 1 sort (s) selected from the group which consists of a secondary battery and a capacitor.

  According to the electronic device of the present invention, for example, when the illuminance of light irradiated to the first power source in the power source is high, the power source is switched to the first power source by the power source switching switch. At this time, according to the first power source, when the electrolyte contains platinum ions in the range of 1 to 9 mM, the resistance of the interface between the electrolyte and the conductive layer of the electrode substrate is sufficiently reduced. In this state, the first power source moves from under high illuminance to under low illuminance, the power switch switches the power source from the first power source to the second power source, and the first power source shifts from under high illuminance to under low illuminance Immediately after the high voltage from the second power supply is applied to the first power supply and a large reverse current flows to the first power supply, the current flows not only between the conductive layer and the oxide semiconductor layer but also the conductive layer and the electrolyte. It will be possible to pass through well. That is, even when a large reverse current flows in the first power supply immediately after the first power supply moves from high illuminance to low illuminance, the current is not only between the conductive layer and the oxide semiconductor layer, but also the conductive layer. It is also possible to disperse between the electrolyte and the electrolyte. Therefore, the flow of a large current to the dye supported in the oxide semiconductor layer is sufficiently suppressed. Therefore, in the first power supply, it is possible to sufficiently suppress the decrease in the power generation performance due to the deterioration of the dye. Therefore, according to the electronic device of the present invention, even when the power supply is switched to the first power supply by the power supply changeover switch, it is possible to sufficiently suppress the reduction of the power supplied to the power consumption unit.

  In the present invention, the "concentration of platinum ion" refers to a photoelectric conversion element being allowed to stand in a dark room for 100 hours, and then the photoelectric conversion element is disassembled to collect electrolyte, and inductively coupled plasma emission spectrometry (ICP) It refers to the concentration measured by-OES).

Furthermore, in the present invention, “cm ³ (STP)” indicates that the volume of oxygen that permeates through the sealing portion is a volume measured under the standard condition, that is, at 0 ° C. and 1 atm.

  ADVANTAGE OF THE INVENTION According to this invention, the photoelectric conversion element which can fully suppress the fall of electric power generation performance, and the electronic device using the same are provided.

It is the schematic which shows one Embodiment of the electronic device of this invention. It is sectional drawing which shows the 1st power supply of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the electronic device of the present invention.

  As shown in FIG. 1, the electronic device 200 includes a first power supply 101 and a power supply 100 having a second power supply 102 connected in parallel to the first power supply 101, and power that consumes the power supplied from the power supply 100. A consumption unit 110 and a power supply switching switch 120 capable of switching the power supply 100 to the first power supply 101 or the second power supply 102 are provided.

  The power consumption unit 110 is not particularly limited as long as it consumes the power supplied from the first power supply 101 or the second power supply 102. When the electronic device 200 is configured by, for example, a calculator, the power consumption unit 110 outputs, for example, the output result calculated by the calculation unit based on the calculation unit, the input unit for inputting information to the calculation unit, and the input unit. And a display unit for displaying.

  The first power source 101 is composed of a photoelectric conversion element that converts light L into electricity, and the second power source 102 is composed of an electrochemical element. The electrochemical element is constituted by a primary battery in the present embodiment.

  The power supply switching switch 120 can switch the power supply 100 to the first power supply 101 or the second power supply 102 in accordance with the illuminance of light emitted to the first power supply 101. Specifically, when the illuminance of light irradiated to the first power source 101 is high (for example, 200 to 100,000 lux), the power source 100 for supplying power to the power consuming unit 110 is used as the first power source 101. When the illuminance of light irradiated to the first power source 101 is low (for example, less than 200 lux), the power source 100 supplying power to the power consuming unit 110 can be switched to the second power source 102 It has become.

  FIG. 2 is a cross-sectional view showing the first power source 101 of FIG. As shown in FIG. 2, the first power source 101 is constituted by a photoelectric conversion element using a dye, and the photoelectric conversion element has a photoelectric conversion cell 50. The photoelectric conversion cell 50 includes an electrode substrate 10, an opposing substrate 20 facing the electrode substrate 10, an annular sealing portion 30 connecting the electrode substrate 10 and the opposing substrate 20, an electrode substrate 10, an opposing substrate 20, and sealing. An electrolyte 40 surrounded by the portion 30 and an oxide semiconductor layer 13 provided on the counter substrate 20 side of the electrode substrate 10 are provided. A dye is supported on the oxide semiconductor layer 13.

  The electrode substrate 10 has a transparent substrate 11 and a conductive layer 12 provided on the opposite substrate 20 side of the transparent substrate 11.

  The opposite substrate 20 is formed of a counter electrode, and has a conductive substrate 21 which doubles as a substrate and an electrode, and a catalyst layer 22 provided on the conductive substrate 21.

  The electrolyte 40 contains platinum ions, and the concentration of platinum ions in the electrolyte 40 is 1 to 9 mM.

  According to the electronic device 200, when the illuminance of the light L irradiated to the first power supply 101 is high, the power supply switch 120 switches the power supply for supplying power to the power consumption unit 110 to the first power supply 101. At this time, according to the first power supply 101, the resistance of the interface between the electrolyte 40 and the conductive layer 12 of the electrode substrate 10 is sufficiently reduced because the electrolyte 40 contains platinum ions in the range of 1 to 9 mM. . It is considered that this is because platinum ions dissolved in the electrolyte 40 are deposited as platinum on the surface of the conductive layer 12 while the first power source 101 is placed under high illuminance. In this state, the first power source 101 moves from high illuminance to low illuminance, and the power switch 100 switches the power source 100 from the first power source 101 to the second power source 102, and the first power source 101 from high illuminance Even if a high voltage from the second power supply 102 is applied to the first power supply 101 immediately after the light intensity is shifted to low illumination, and a large reverse current flows in the first power supply 101, the current flows through the conductive layer 12 and the oxide semiconductor layer In addition to the above, it is possible to sufficiently pass between the conductive layer 12 and the electrolyte 40 as well. That is, even when a large reverse current flows in the first power supply 101 immediately after the first power supply 101 moves from high illuminance to low illuminance, the current flows only between the conductive layer 12 and the oxide semiconductor layer 13. It is also possible to disperse between the conductive layer 12 and the electrolyte 40. Therefore, the flow of a large current to the dye supported on the oxide semiconductor layer 13 is sufficiently suppressed. Therefore, in the first power supply 101, it is possible to sufficiently suppress the decrease in the power generation performance due to the deterioration of the dye. Therefore, according to the electronic device 200, even when the power source 100 is switched to the first power source 101 by the power source switching switch 120, a reduction in the power supplied to the power consumption unit 110 can be sufficiently suppressed.

Next, the first power supply 101 will be described in detail.
As described above, the first power source 101 includes the electrode substrate 10, the oxide semiconductor layer 13, the counter substrate 20, the dye, the sealing portion 30, and the electrolyte 40. These will be described in detail below.

<Electrode substrate>
As described above, the electrode substrate 10 is configured of the transparent substrate 11 and the conductive layer 12 provided on the transparent substrate 11.

  The material constituting the transparent substrate 11 may be, for example, a transparent material, and as such a transparent material, for example, glass such as borosilicate glass, soda lime glass, white sheet glass, quartz glass, polyethylene terephthalate (PET) And polyethylene naphthalate (PEN), polycarbonate (PC), and polyether sulfone (PES). Although the thickness of the transparent substrate 11 is suitably determined according to the size of the 1st power supply 101, and it does not specifically limit, For example, what is necessary is just to set it as the range of 50 micrometers-40 mm.

Examples of the material constituting the conductive layer 12 include conductive metal oxides such as tin-doped indium oxide (ITO), tin oxide (SnO ₂ ), and fluorine-doped tin oxide (FTO). The conductive layer 12 may be a single layer or a laminate of a plurality of layers composed of different conductive metal oxides. When the conductive layer 12 is formed of a single layer, the conductive layer 12 is preferably formed of FTO because it has high heat resistance and chemical resistance. The thickness of the conductive layer 12 may be, for example, in the range of 0.01 to 2 μm.

<Oxide semiconductor layer>
The oxide semiconductor layer 13 is composed of oxide semiconductor particles. The oxide semiconductor particles are, for example, titanium oxide (TiO ₂ ), zinc oxide (ZnO), tungsten oxide (WO ₃ ), niobium oxide (Nb ₂ O ₅ ), strontium titanate (SrTiO ₃ ), tin oxide (SnO ₂ ) , Indium oxide (In ₃ O ₃ ), zirconium oxide (ZrO ₂ ), thallium oxide (Ta ₂ O ₅ ), lanthanum oxide (La ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), holmium oxide (Ho ₂ O ₃ ) ₃ ) Bismuth oxide (Bi ₂ O ₃ ), cerium oxide (CeO ₂ ), aluminum oxide (Al ₂ O ₃ ) or two or more of these. The thickness of the oxide semiconductor layer 13 may be, for example, 0.1 to 100 μm.

<Opposite substrate>
As described above, the counter substrate 20 includes the conductive substrate 21 and the conductive catalyst layer 22 provided on the electrode substrate 10 side of the conductive substrate 21 and contributing to the reduction of the electrolyte 40.

  The conductive substrate 21 is made of, for example, a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, tungsten, aluminum, stainless steel or the like. However, the conductive substrate 21 may be configured by separating the substrate and the electrode, and forming a film made of a conductive oxide such as ITO or FTO on the above-described transparent substrate 11. The thickness of the conductive substrate 21 is appropriately determined in accordance with the size of the first power source 101 and is not particularly limited, but may be, for example, 5 μm to 4 mm.

  The catalyst layer 22 is made of platinum, a carbon-based material, a conductive polymer, or the like. Here, carbon nanotubes are suitably used as the carbon-based material.

<Pigment>
As the dye, for example, a ruthenium complex having a ligand containing a bipyridine structure, a terpyridine structure or the like, a photosensitizing dye such as an organic dye such as porphyrin, eosin, rhodamine or merocyanine, or an organic matter such as a lead halide perovskite crystal -Inorganic composite dyes and the like can be mentioned. For example, CH ₃ NH ₃ PbX ₃ (X = Cl, Br, I) is used as the lead halide-based perovskite. Among the above dyes, a ruthenium complex having a ligand containing a bipyridine structure or a terpyridine structure is preferable. In this case, the photoelectric conversion characteristics of the first power source 101 can be further improved.

<Sealing part>
Examples of the sealing portion 30 include thermoplastic resins such as modified polyolefin resin and vinyl alcohol polymer, and resins such as ultraviolet curing resin. Examples of the modified polyolefin resin include ionomers, ethylene-vinyl acetate anhydride copolymers, ethylene-methacrylic acid copolymers and ethylene-vinyl alcohol copolymers. These resins can be used alone or in combination of two or more.

In the sealing portion 30, the oxygen transmission rate ratio r represented by the following formula (1) is not particularly limited, but it is 0.0004 to 0.0015 cm ³ (STP) / (day · mL) Is preferred.
Oxygen transmission rate ratio r = v / m (1)
(In said formula (1), v represents the oxygen transmission rate (cm ³ (STP) / day) of the sealing part 30, and m represents the quantity (mL) of the electrolyte 40.)

In this case, when the oxygen permeation rate ratio r is that is ^{0.0015cm 3 (STP) / (day} · mL) below, the oxygen transmission rate ratio r is greater than the ^{0.0015cm 3 (STP) / (day} · mL) In comparison with the above, the permeation of oxygen in the sealing portion 30 is more sufficiently suppressed, and the oxidation of the deposited platinum is more sufficiently suppressed. As a result, the deposited platinum is less likely to be dissolved in the electrolyte 40, and the resistance at the interface between the electrolyte 40 and the conductive layer 12 is more sufficiently reduced. In addition, when the oxygen transmission rate ratio r is 0.0004 cm ³ (STP) / (day · mL) or more, the oxygen transmission rate ratio r is less than 0.0004 cm ³ (STP) / (day · mL) The amount of oxygen transmission when standing in a dark place is much higher than that in the dark, and the platinum that is deposited is more sufficiently dissolved by the permeated oxygen, so precipitation of platinum under high illuminance The temporarily increasing leakage current can be more fully dissipated in the dark.

In addition, the oxygen transmission rate v of the sealing part 30 is the following formula (A)
v = d x p x a / w (A)
(In the above formula (A), d represents the oxygen permeability coefficient (cm ³ (STP) · mm / (m ² · day · atm) of the sealing portion 30), and a is the oxygen transmission area of the sealing portion 30 (M ² ) is expressed, p is the absolute value (atm) of the difference between the oxygen partial pressure inside the cell space and the oxygen partial pressure outside the cell space, w is the width (mm) of the sealing portion 30 Represent)

  Here, “the permeation area of oxygen in the sealing portion 30” refers to the product of the circumferential length of the outer periphery of the annular sealing portion 30 and the height h of the sealing portion 30. Here, “peripheral length of the outer periphery of the sealing portion 30” means “peripheral length of the outer periphery of the sealing portion 30 at the interface between the sealing portion 30 and the electrode substrate 10 (hereinafter referred to as“ first interface ”). And “peripheral length of the outer periphery of the sealing portion 30 at the interface between the sealing portion 30 and the counter substrate 20 (hereinafter referred to as“ second interface ”)”, the shorter one of the circumferential lengths When the circumferential length of the outer periphery of the sealing portion 30 at one interface and the “peripheral length of the outer periphery of the sealing portion 30 at the second interface” are the same length, the circumferential length is said. The “height h of the sealing portion 30” refers to the distance from the first interface to the second interface.

  Also, “the width w of the sealing portion 30” is the shorter of “the width of the annular sealing portion 30 at the first interface” and the “width of the annular sealing portion 30 at the second interface”. The width refers to the width when “the width of the annular sealing portion 30 at the first interface” and the “width of the annular sealing portion 30 at the second interface” are the same width.

The oxygen transmission rate ratio r is more preferably ^{0.00040~0.00100cm 3 (STP) / (day} · mL), is ^{0.00042~0.00060cm 3 (STP) / (day} · mL) Is particularly preferred.

<Electrolyte>
The electrolyte 40 contains a redox couple, an organic solvent, and platinum ions.

As the organic solvent, acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, valeronitrile, pivalonitrile or the like can be used. As the redox pair, for example, a redox complex containing a halogen atom such as iodide ion / polyiodide ion (eg, I ⁻ / I ₃ ⁻ ), bromide ion / polybromide ion, etc., a zinc complex, iron complex, cobalt complex And redox couples such as The iodide ion / polyiodide ion can be formed of iodine (I ₂ ) and a salt (ionic liquid or solid salt) containing iodide (I ⁻ ) as an anion. When using an ionic liquid having an iodide as an anion, only iodine may be added, and when using an organic solvent, or using an ionic liquid other than an iodide as an anion, as an anion such as LiI or tetrabutylammonium iodide. iodide (I ^-) may be added salt containing. Further, as the electrolyte 40, an ionic liquid may be used instead of the organic solvent. As the ionic liquid, for example, known iodides such as pyridinium salts, imidazolium salts and triazolium salts are used. As such an iodide salt, for example, 1-hexyl-3-methylimidazolium iodide, 1-ethyl-3-propylimidazolium iodide, 1-ethyl-3-methylimidazolium iodide, 1,2 -Dimethyl-3-propylimidazolium iodide, 1-butyl-3-methylimidazolium iodide, or 1-methyl-3-propylimidazolium iodide is preferably used.

  In addition, as the electrolyte 40, a mixture of the ionic liquid and the organic solvent may be used instead of the organic solvent.

  Also, additives can be added to the electrolyte 40. Additives include benzoimidazole such as 1-methylbenzimidazole (NMB), 1-butylbenzimidazole (NBB), LiI, tetrabutylammonium iodide, 4-t-butylpyridine, guanidinium thiocyanate, etc. . Among them, benzimidazole is preferred as the additive.

Furthermore, as the electrolyte 40, a nanocomposite gel electrolyte which is a quasi-solid electrolyte formed by kneading nanoparticles such as SiO ₂ , TiO ₂ and carbon nanotubes into the above-mentioned electrolyte may be used, and polyvinylidene fluoride may be used. An electrolyte gelled with an organic gelling agent such as polyethylene oxide derivative or amino acid derivative may be used.

  The concentration of platinum ions in the electrolyte 40 is 1 to 9 mM. In this case, the decrease in the power generation performance can be sufficiently suppressed as compared with the case where the concentration of platinum ions in the electrolyte 40 is out of the above range.

  The concentration of platinum ions in the electrolyte 40 is more preferably 1.2 to 5 mM. In this case, the decrease in the power generation performance can be sufficiently suppressed as compared with the case where the concentration of platinum ions in the electrolyte 40 is out of the above range.

In the first power supply 101, the resistance R1 (Ω · cm ² ) of the interface between the conductive layer 12 and the electrolyte 40 immediately after being placed under irradiation of artificial sun of 1 sun for 12 hours corresponds to 1 sun of the first power supply 101. Of the interface between the conductive layer 12 and the electrolyte 40 after standing for 12 hours under the irradiation of pseudo-sunlight for 12 hours and then standing for 100 hours in the dark, even if the resistance is smaller than R 2 (Ω · cm ² ) It may be R2 or more, but is preferably smaller than the resistance R2.

  In this case, a large reverse current flows when a high voltage is applied to the photoelectric conversion element 100 immediately after the photoelectric conversion element 100 is transferred from the high illuminance state to the low illuminance state as compared to the case where R1 is R2 or more. The dispersion of the power generation performance due to the deterioration of the dye can be sufficiently suppressed by being dispersed not only between the conductive layer 12 and the oxide semiconductor layer 13 but also between the conductive layer 12 and the electrolyte 40. it can.

  Here, R1 / R2 is not particularly limited as long as it is smaller than 1, but is preferably 0.050 or less. However, it is preferable that R1 / R2 is 0.011 or more. in this case. Compared to the case where R1 / R2 is less than 0.011, the leakage current is smaller and the power generation performance is higher.

In the first power supply 101, it is preferable that R1 satisfy the following formula (2) and R2 satisfy the following formula (3).
R1 <1.5 × 10 ⁵ (2)
R2 ≧ 1.5 × 10 ⁵ (3)

In this case, compared with the case where R2 is less than 1.5 × 10 ⁵ Ω · cm ² , the leakage current after being left in the dark after the photoelectric conversion element 100 is placed under high illuminance is It becomes smaller and power generation performance becomes higher.

  Next, a method of manufacturing the above-described first power supply 101 will be described.

  First, an electrode substrate 10 in which the conductive layer 12 is formed on one transparent substrate 11 is prepared.

  As a method of forming the conductive layer 12, a sputtering method, a vapor deposition method, a spray thermal decomposition method, a CVD method, or the like is used.

  Next, the oxide semiconductor layer 13 is formed over the conductive layer 12. The oxide semiconductor layer 13 is formed by printing a paste for forming an oxide semiconductor layer containing oxide semiconductor particles and baking the paste.

  The oxide semiconductor layer-forming paste contains, in addition to the above-described oxide semiconductor particles, a resin such as polyethylene glycol and a solvent such as terpineol.

  As a printing method of the oxide semiconductor layer forming paste, for example, a screen printing method, a doctor blade method, or a bar coating method can be used.

  The firing temperature varies depending on the material of the oxide semiconductor particles, but is usually 350 to 600 ° C. The firing time also varies depending on the material of the oxide semiconductor particles, but is usually 1 to 5 hours.

  Thus, the electrode substrate 10 is obtained.

  Next, a dye is supported on the surface of the oxide semiconductor layer 13 of the electrode substrate 10. For this purpose, the electrode substrate 10 is immersed in a solution containing a dye, and after the dye is adsorbed to the oxide semiconductor layer 13, excess dye is washed away with the solvent component of the solution and dried. Good.

  Next, the electrolyte 40 is prepared. The electrolyte 40 may be prepared such that the concentration of platinum ions in the electrolyte 40 is 1 to 9 mM. Such an electrolyte 40 can be obtained, for example, by adding a halogen and a platinum-containing compound containing a platinum atom to a solution containing a halide salt.

  Next, the electrolyte 40 is disposed on the oxide semiconductor layer 13. The electrolyte 40 can be disposed by a printing method such as screen printing, for example.

  Next, an annular sealing portion forming body is prepared. The sealing portion forming body can be obtained, for example, by preparing a sealing resin film and forming one rectangular opening in the sealing resin film.

  Then, the sealing portion forming body is adhered on the electrode substrate 10. At this time, adhesion of the sealing portion forming body to the electrode substrate 10 can be performed, for example, by heating and melting the sealing portion forming body.

  Next, the opposing substrate 20 is prepared, and disposed so as to close the opening of the sealing portion forming body, and is then bonded to the sealing portion forming body. At this time, the sealing portion forming body may be adhered to the opposite substrate 20 in advance, and the sealing portion forming body may be bonded to the sealing portion forming body on the electrode substrate 10 side. Bonding of the opposing substrate 20 to the sealing portion forming body may be performed under atmospheric pressure or under reduced pressure, but is preferably performed under reduced pressure.

  The first power source 101 is obtained as described above.

  The present invention is not limited to the above embodiment. For example, although the photoelectric conversion element which comprises the 1st power supply 101 is comprised by one photoelectric conversion cell 50 in the said embodiment, the photoelectric conversion element may be equipped with two or more photoelectric conversion cells 50. FIG.

  Furthermore, in the above-mentioned embodiment, although the electrochemical element which constitutes the 2nd power supply 102 is constituted by the primary battery, the electrochemical element may be constituted by a secondary battery or a capacitor or the like.

  Further, in the above embodiment, the counter substrate 20 of the first power source 101 is configured as a counter electrode, but the counter substrate 20 may be an insulating substrate. However, in this case, it is necessary to provide a counter electrode between the counter substrate 20 and the electrode substrate 10.

  The electronic device of the present invention is also applicable to environmental sensors, communication devices, etc. in addition to calculators.

  Hereinafter, the contents of the present invention will be more specifically described by way of examples, but the present invention is not limited to the following examples.

(Examples 1 to 4 and Comparative Examples 1 to 4)
<Preparation of Electrolyte>
Table 1 shows the concentration of dissolved platinum ions by adding iodine and potassium hexaiodoplatinate (IV) to a 3-methoxypropionitrile solution containing 0.6 M of 1,2-dimethyl-3-propylimidazolium iodide. The electrolyte was prepared to have the value shown in 1. At this time, when 1 equivalent of potassium hexaiodoplatinate (IV) was dissolved in the above solution, the same change in absorbance as in the case of adding 1 equivalent of iodine was observed, so 1 equivalent to 1 equivalent of potassium hexaiodoplatinum (IV) It was considered that iodine was added, and the addition amount of iodine was adjusted so that the iodine concentration was 0.01M.

<Fabrication of photoelectric conversion element>
First, an electrode substrate was prepared by forming a transparent conductive layer of FTO having a thickness of 0.6 μm on a transparent substrate of a thickness of 2.2 mm made of glass.

  Next, on the transparent conductive layer of the electrode substrate, a paste for forming an oxide semiconductor layer containing titania was applied, dried, and fired at 500 ° C. for 0.5 hours. Thus, an oxide semiconductor layer having a thickness of 10 μm × 5 cm × 5 cm was formed over the electrode substrate.

  Next, the electrode substrate is made of cis-di (thiocyanato)-(2,2′-bipyridyl-4,4′-dicarboxylic acid) (4,4′-dinonyl-2,2′-bipyridyl) -ruthenium (II) After soaking overnight in a dye solution using a mixed solvent of acetonitrile and t-butanol containing 0.2 mM of a photosensitizing dye consisting of (Z907) and mixed at a volume ratio of 1: 1 as a solvent, take out and dry The oxide semiconductor layer was made to carry a photosensitizing dye. Thus, the working electrode was obtained.

  Next, a sealing resin film having a size of 5.4 cm × 5.4 cm was prepared, and one opening of 5 cm × 5 cm was formed in the sealing resin film to prepare a sealed portion forming body. . At this time, a film made of maleic anhydride-modified polyethylene (trade name "BAYEL 4164", manufactured by DuPont) was used as the sealing resin film. Further, the width w (cm) of the sealing portion forming body was as shown in Table 1.

  Then, the sealing portion forming body was placed on the electrode substrate of the working electrode, and then the sealing portion forming body was heated and melted to adhere to the electrode substrate.

  Next, the electrolyte prepared as described above was placed inside the sealing portion. At this time, the amount m (mL) of the electrolyte was 0.15 mL as shown in Table 1.

  Next, a counter electrode as an opposing substrate was prepared. The counter electrode was prepared by sputtering on a 40 μm thick titanium foil to form a 5 nm thick platinum catalyst layer.

Then, after arranging the counter electrode so as to close the opening of the sealing portion forming body, it was attached to the sealing portion forming body. And it heated at 190 degreeC, pressurizing a sealing part formation body by 0.1 Mpa in this state, and heating-melting the sealing part formation body was carried out. Thus, a sealing portion was formed between the electrode substrate of the working electrode and the counter electrode. The oxygen permeation coefficient d (cm ³ (STP) · mm · m ² · day / atm), height h (cm), oxygen permeation area a (m ³ ), oxygen partial pressure p in the atmosphere The values of the oxygen transmission rate ratio r represented by atm), oxygen transmission rate v (cm ³ (STP) / day), and the following formula (1) were as shown in Table 1.
r = v / m (1)
(In the above formula (1), v represents the oxygen transmission rate (cm ³ (STP) / day) and m represents the amount of electrolyte (mL).)

  Thus, a photoelectric conversion element composed of one photoelectric conversion cell was obtained.

  Then, using a SI 1260 Impedance / gain phase analyzer (manufactured by Schlumberger) and SI 1286 electrochemical interface (manufactured by Schlumberger) in a dark place while applying a forward voltage of 0.05 V to the photoelectric conversion element immediately after fabrication. The resistance value corresponding to the resistance of the transparent conductive layer / electrolyte interface was obtained by measuring the electrochemical impedance.

  Moreover, it measured similarly similarly about resistance value R1 immediately after putting the said photoelectric conversion element under pseudo | simulation sunlight irradiation of 1 sun for 12 hours.

Furthermore, the resistance R2 (Ω · cm ²⁾ of the interface between the conductive layer 12 and the electrolyte 40 after leaving the photoelectric conversion element placed under pseudo-sunlight irradiation for 1 sun for 12 hours in the dark for an additional 100 hours ) Was similarly measured.

  The results of R1 and R2 are shown in Table 1.

<Evaluation of power generation performance>
The photoelectric conversion elements of Examples 1 to 4 and Comparative Examples 1 to 4 obtained as described above were subjected to IV measurement under a fluorescent lamp of 600 lux to obtain an initial output P0.

Next, the photoelectric conversion element was placed for 12 hours under pseudo sun light irradiation for 1 sun, then moved to the dark and a forward voltage of 8 V was applied for 30 seconds between the working electrode and the counter electrode. Then, after the photoelectric conversion element was allowed to stand in a dark place for 100 hours, I-V measurement was performed under a fluorescent lamp of 600 lux to obtain an output P1. Then, based on the outputs P0 and P1, the output maintenance ratio (P1 / P0) was calculated. The results are shown in Table 1.

  From the results shown in Table 1, it was found that the photoelectric conversion elements of Examples 1 to 4 can more sufficiently suppress the reduction in the power generation performance as compared with the photoelectric conversion elements of Comparative Examples 1 to 4.

  As mentioned above, according to the photoelectric conversion element of this invention, it was confirmed that the fall of electric power generation performance can fully be suppressed.

12 conductive layer 13 oxide semiconductor layer 15 electrode substrate 20 counter substrate 30 sealing portion 40 electrolyte 50 photoelectric conversion cell 100 power supply 101 first power supply 102 second power supply 110 power consumption unit 120 ... Power supply changeover switch 200 ... Electronic equipment

Claims (5)

A photoelectric conversion element comprising a photoelectric conversion cell,
The photoelectric conversion cell is
An electrode substrate,
An opposing substrate facing the electrode substrate;
An oxide semiconductor layer provided on the electrode substrate;
An electrolyte provided between the electrode substrate and the counter substrate;
A sealing portion which connects the electrode substrate and the opposite substrate and which surrounds the electrolyte together with the electrode substrate and the opposite substrate;
And a dye supported on the oxide semiconductor layer,
The electrode substrate has a conductive layer in contact with the electrolyte;
The electrolyte comprises platinum ions,
The photoelectric conversion element whose platinum ion concentration in the said electrolyte is 1-9 mM. The photoelectric conversion element according to claim 1, wherein the oxygen transmission rate ratio r represented by the following formula (1) is 0.0004 to 0.0015 cm ³ (STP) / (day · mL) in the sealing portion. .
Oxygen transmission rate ratio r = v / m (1)
(In said formula (1), v represents the oxygen transmission rate (cm < ³ > (STP) / day) of the said sealing part, m represents the quantity (mL) of the said electrolyte.)   The resistance R1 of the interface between the conductive layer and the electrolyte immediately after being placed under 1 sun simulated sunlight irradiation for 12 hours, is placed in the dark after being placed under 1 sun simulated sunlight irradiation for 12 hours The photoelectric conversion element according to claim 1, wherein the resistance R 2 of the interface between the conductive layer and the electrolyte after standing for 100 hours is smaller than the resistance R 2 of the interface. The photoelectric conversion element according to any one of claims 1 to 3, wherein the R1 satisfies the following formula (2), and the R2 satisfies the following formula (3).
R1 <1.5 × 10 ⁵ (2)
R2 ≧ 1.5 × 10 ⁵ (3) A power supply comprising a first power supply and a second power supply connected in parallel to the first power supply;
A power consumption unit that consumes power supplied from the power supply;
An electronic device comprising: a power supply changeover switch capable of switching the power supply to the first power supply or the second power supply,
The said 1st power supply is comprised with the photoelectric conversion element as described in any one of Claims 1-4,
The electronic device, wherein the second power source is composed of an electrochemical element.

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