JP5898895B2 - Solution concentration adjusting method, solution concentration adjusting device, and method for producing dye-sensitized solar cell - Google Patents

Description

The present invention relates to a solution concentration adjusting method, a solution concentration adjusting device, and a method for producing a dye-sensitized solar cell.

The dye-sensitized solar cell can photoelectrically convert a wide wavelength region by adsorbing a sensitizing dye having a sensitizing action on the surface of the porous semiconductor layer.
As a method for adsorbing a sensitizing dye to a porous semiconductor layer, a method of immersing the porous semiconductor layer in a dye solution containing a sensitizing dye is generally used. In this method, the amount of the sensitizing dye adsorbed on the porous semiconductor layer varies depending on the time during which the porous semiconductor layer is immersed in the dye solution. The amount of the sensitizing dye adsorbed on the porous semiconductor layer greatly affects the power generation efficiency. Therefore, in order to produce a dye-sensitized solar cell with good reproducibility and little performance variation in the same process, It is necessary to keep the concentration of the solution constant.

Conventionally, as a method of keeping the concentration of the dye solution constant, a method of measuring the concentration of the dye solution with a dye concentration detecting device and adjusting the concentration of the dye solution with the dye concentration adjusting device based on the information is known. (For example, refer to Patent Documents 1 and 2).
However, the above-described method requires a plurality of devices such as a dye concentration control device in addition to the dye concentration detection device and the dye concentration adjustment device, and thus the device becomes complicated and the running cost increases. was there.

JP-A-6-204623 JP-A-8-71494

 The present invention has been made in view of the above circumstances, and uses a solution concentration adjusting method, a solution concentration adjusting device, and a solution concentration adjusting device capable of adjusting the solution concentration at low cost with simple equipment. It is an object of the present invention to provide a dye-sensitized solar cell or an optical device manufactured in the above manner.

 The solution concentration adjusting method of the present invention is a method of accommodating a saturated solution and a low concentration solution in a container through a semipermeable membrane and adjusting the concentration of the low concentration solution, wherein the saturated solution and the low concentration solution The concentration of the low concentration solution is adjusted by adjusting the pressure difference and the temperature of the saturated solution and the low concentration solution.

 In the solution concentration adjusting method of the present invention, the saturated solution and the low concentration solution preferably contain a sensitizing dye used in a dye-sensitized solar cell.

 The solution concentration adjusting device of the present invention is a solution concentration adjusting device including a container for storing a saturated solution and a low concentration solution through a semipermeable membrane, and adjusts a pressure difference between the saturated solution and the low concentration solution. And means for adjusting the temperature of the saturated solution and the low concentration solution.

 In the solution concentration adjusting apparatus of the present invention, it is preferable that the saturated solution and the low concentration solution contain a sensitizing dye used in a dye-sensitized solar cell.

The method for producing a dye-sensitized solar cell according to the present invention includes a pair of opposing substrates, a pair of electrode films disposed to face each other, and a photoelectric conversion layer formed between these electrode films. and an electrolyte layer, a manufacturing method of the dye-sensitized solar cell equipped with, the photoelectric conversion layer, the solution concentration control system of the present invention was immersed in a dye solution, which is the concentration adjusted, in the photoelectric conversion layer characterized Rukoto to have a step of Ru is supported the sensitizing dye.

 According to the present invention, it is possible to adjust the solution concentration with only simple equipment as compared with the conventional method of adjusting the concentration of the dye solution.

It is a schematic sectional drawing which shows one Embodiment of the solution concentration adjustment apparatus of this invention. It is a schematic sectional drawing which shows a part of board | substrate formation process of the manufacturing method of the solar cell using the solution concentration adjustment apparatus and solution concentration adjustment method of this invention. It is a schematic sectional drawing which shows a part of board | substrate formation process of the manufacturing method of the solar cell using the solution concentration adjustment apparatus and solution concentration adjustment method of this invention. It is a schematic sectional drawing which shows a part of board | substrate bonding process of the manufacturing method of the solar cell using the solution concentration adjustment apparatus and solution concentration adjustment method of this invention. It is a schematic sectional drawing which shows a solar cell as one Embodiment of this invention.

As an embodiment of the present invention, a solution concentration adjusting method, a solution concentration adjusting device, a dye-sensitized solar cell, and an optical device will be described.
Note that this embodiment is specifically described in order to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

"Solution concentration adjuster"
FIG. 1 is a schematic cross-sectional view showing an embodiment of the solution concentration adjusting device of the present invention.
The solution concentration adjusting apparatus 10 according to the present embodiment includes a semipermeable membrane 11, a container 12 that contains a saturated solution 21 and a low concentration solution 22 through the semipermeable membrane 11, and a pressure difference between the saturated solution 21 and the low concentration solution 22. The pressure adjusting device 13 for adjusting the temperature and the temperature adjusting device 14 for adjusting the temperature of the saturated solution 21 and the low concentration solution 22 are roughly configured.

 The semipermeable membrane 11 is not particularly limited as long as it transmits the solvent constituting the saturated solution 21 and the low concentration solution 22 and does not pass the solute constituting the saturated solution 21 and the low concentration solution 22. For example, a porous film made of regenerated cellulose (cellophane), acetylcellulose, polyacrylonitrile, polytetrafluoroethylene, polyester polymer alloy, polysulfone, or the like is used.

Here, the saturated solution 21 and the low concentration solution 22 are solutions composed of the same solvent and solute. The saturated solution 21 and the low concentration solution 22 differ in the amount (concentration) of the solute.
In the present embodiment, the saturated solution 21 means a solution in a saturated or supersaturated state, and the low concentration solution 22 means a solution having a concentration lower than that of the saturated solution 21 and adjusted to a predetermined concentration. ing.

The solvent which comprises the saturated solution 21 and the low concentration solution 22 is not specifically limited, Various organic solvents and water are mentioned.
Solutes constituting the saturated solution 21 and the low concentration solution 22 are not particularly limited, and examples thereof include substances that can be dissolved in various organic solvents and water.

When the solution concentration adjusting device 10 is used for adsorbing the sensitizing dye to the porous semiconductor layer of the dye-sensitized solar cell, the saturated solution 21 and the low-concentration solution 22 are dye solutions containing the sensitizing dye. is there.
As a solvent constituting the dye solution, water, methanol, ethanol, acetonitrile, propanol, t-butanol, acetone, ethyl acetate, hexane, cyclohexane, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), benzene, Examples include toluene, tetrahydrofuran (THF), methyl ethyl ketone, dichloromethane, chloroform and the like.
A sensitizing dye that is a solute constituting the dye solution is composed of an organic dye or a metal complex dye.
Examples of organic dyes include various organic dyes such as coumarin, polyene, cyanine, hemicyanine, and thiophene.
Examples of the metal complex dye include a ruthenium complex.

The container 12 includes a saturated solution storage unit 12A that stores a saturated solution 21 and a low concentration solution storage unit 12B that stores a low concentration solution 22.
The shape and size of the container 12 are not particularly limited. For example, when the solution concentration adjusting device 10 is used to adsorb the sensitizing dye to the porous semiconductor layer of the dye-sensitized solar cell, The low-concentration solution storage unit 12B has a shape and size that can store the porous semiconductor layer.

 The material of the container 12 is not particularly limited as long as it is a stable material that is not corroded by the saturated solution 21 and the low concentration solution 22. For example, glass, quartz, stainless steel, polypropylene, polycarbonate, acrylic, polytetrafluoro Examples include ethylene and silicone.

As the pressure adjusting device 13, for example, a pressing unit 15 that presses the liquid surface 21a of the saturated solution 21, a pressurizing unit (not shown) that pressurizes the pressing unit 15, and a control unit that controls the force applied to the pressing unit. (Not shown) is used.
The pressing unit 15 is not particularly limited as long as it can uniformly press the liquid surface 21 a of the saturated solution 21, and is a plate-like material made of a material that is not corroded by the saturated solution 21 and the low concentration solution 22. Things are used.
As the pressurizing unit, a spring, a piston using air pressure, a piston using hydraulic pressure, or the like is used.
As a control part, what connects a piping to 12A of saturated solution storage parts, and controls the pressure to a pressurization part with a pressure control valve, monitoring a pressure gauge is used. Further, the pressure control by the control unit can be automatically controlled using a mass flow controller.

As the temperature control device 14, a device including a heating device (heater) for heating the saturated solution 21 and the low concentration solution 22 and a cooling device for cooling the saturated solution 21 and the low concentration solution 22 is used. .
Examples of the cooling method of the low concentration solution 22 by the cooling device include a method of circulating cooling water around the container and a cooling method by air cooling such as an air conditioner.
Further, the temperature adjusting device 14 may be capable of adjusting the temperature of the saturated solution 21 and the low concentration solution 22 in a lump, or may be capable of adjusting the temperature of the saturated solution 21 and the low concentration solution 22 individually.

"Solution concentration adjustment method"
Next, the method for adjusting the solution concentration of the present embodiment will be described by explaining the method of using the solution concentration adjusting device 10.
Here, the case where the solution concentration adjusting device 10 is used for adsorbing a sensitizing dye to the porous semiconductor layer of the dye-sensitized solar cell will be described as an example.

First, the low concentration solution 22 adjusted to a predetermined concentration is injected into the low concentration solution storage portion 12B of the container 12.
Here, when the low concentration solution 22 is a dye solution, the low concentration solution 22 having a predetermined concentration is used because the concentration of the dye solution is supported on the porous oxide semiconductor layer of the dye-sensitized solar cell. A solution containing the necessary amount of sensitizing dye.

On the other hand, the saturated solution 21 is injected into the saturated solution storage portion 12 </ b> A of the container 12.
The saturated solution 21 is a sensitizing dye solution in a saturated or supersaturated state, and when it is in a supersaturated state, it is a solution containing a solid sensitizing dye that is not dissolved in a solvent.
The solid sensitizing dye is a sensitizing dye that is not dissolved in the saturated solution 21 but is precipitated or dispersed as a powder, or a sensitizing dye that is precipitated as a lump.

 In the solution concentration adjusting device 10, the concentration of the low concentration solution 22 is adjusted by adjusting the pressure difference between the saturated solution 21 and the low concentration solution 22 and the temperature of the saturated solution 21 and the low concentration solution 22. Keep the concentration of 22 constant. That is, the concentration of the low-concentration solution 22 prepared so as to be the amount of sensitizing dye necessary for supporting the porous oxide semiconductor layer in advance is kept constant.

In the present invention, the pressure difference generated from the contact between “solute (sensitizing dye) + saturated solution 21 (saturated state)” and “solute (sensitizing dye) + low concentration solution 22 (unsaturated state)” is adjusted. doing.
Here, the osmotic pressure π [atm] of the solution is expressed by the following Phantohof equation (1).
π = MRT (1)
In the above formula (1), M represents a molar concentration [mol / dm ³ ], R represents a gas constant [atm · dm ³ / K · mol], and T represents a temperature [K].

 From the above equation (1), it can be seen that when the temperature T is constant, the molar concentration of the saturated solution 21 and the molar concentration of the low-concentration solution 22 are proportional to the osmotic pressures. Therefore, by keeping the temperature of the saturated solution 21 and the low concentration solution 22 constant and keeping the pressure difference between the saturated solution 21 and the low concentration solution 22 constant, the molar concentration of the saturated solution 21 and the molar concentration of the low concentration solution 22 are maintained. As a result, the concentration of the low concentration solution 22 can be kept constant.

 In order to keep the temperature of the saturated solution 21 and the low concentration solution 22 constant, the temperature adjusting device 14 heats and / or cools the saturated solution 21 and the low concentration solution 22.

In order to keep the pressure difference between the saturated solution 21 and the low-concentration solution 22 constant, the liquid surface 21 a of the saturated solution 21 is pressed by the pressing unit 15 of the pressure adjusting device 13.
The pressure of the low concentration solution 22 is calculated based on the concentration adjusted in advance as described above and the temperature of the low concentration solution 22. The force (pressure) for pressing the liquid surface 21a of the saturated solution 21 is adjusted by the pressing unit 15 of the pressure adjusting device 13 so that the pressure difference between the low concentration solution 22 and the saturated solution 21 is always constant.
Alternatively, the force of pressing the liquid surface 21a of the saturated solution 21 by the pressing unit 15 of the pressure adjusting device 13 so that the concentration of the saturated solution 21 becomes constant while measuring the concentration of the saturated solution 21 by ultraviolet visible absorption analysis. Adjust (pressure).

In order to adsorb the sensitizing dye to the porous semiconductor layer of the dye-sensitized solar cell using the solution concentration adjusting device 10, the porous semiconductor layer is predetermined in the low-concentration solution 22 adjusted to a predetermined concentration. Soak for the time.
When the porous semiconductor layer is immersed in the low concentration solution 22 in this manner, the sensitizing dye is adsorbed on the porous semiconductor layer, and the amount of the sensitizing dye contained in the low concentration solution 22 decreases. Then, the temperature of the saturated solution 21 and the low concentration solution 22 is kept constant, and the pressure difference between the saturated solution 21 and the low concentration solution 22 is kept constant. The solvent moves (penetrates) into the accommodating portion 12A, and the concentration of the low concentration solution 22 is kept constant.
At this time, although the amount of the solvent in the saturated solution storage portion 12A increases, the saturated solution 21 contains a solid sensitizing dye that is not dissolved in the solvent in advance, and therefore the solid solvent increases in the increased solvent. The dye is dissolved and the concentration of the saturated solution 21 is kept constant.

On the other hand, when the amount of the solvent constituting the low concentration solution 22 decreases, the temperature of the saturated solution 21 and the low concentration solution 22 is kept constant, and the pressure difference between the saturated solution 21 and the low concentration solution 22 is constant. Since it is maintained, the solvent moves (penetrates) from the saturated solution container 12A to the low concentration solution container 12B, and the concentration of the low concentration solution 22 is kept constant.
At this time, the solvent in the saturated solution 21 decreases, but since the saturated solution 21 is originally a saturated solution, it becomes supersaturated and the sensitizing dye is solidified and only precipitates or disperses. Is also kept constant.

 According to the solution concentration adjusting apparatus and the solution concentration adjusting method of the present embodiment, the solution concentration can be adjusted with only simple equipment as compared with the conventional method of adjusting the dye solution concentration.

The solution concentration adjusting device and the solution concentration adjusting method of the present embodiment can also be applied to a method for manufacturing a dye-sensitized solar cell other than the above-described immersion method. For example, in the dyeing method of the dye using the spray method, it is desirable that the concentration of the dye solution to be used is kept constant. Therefore, the concentration of the dye solution is adjusted by the solution concentration adjusting device and the solution concentration adjusting method of the present embodiment. Is kept constant, a dye solution having a constant concentration can be supplied.
Furthermore, the solution concentration adjusting device and the solution concentration adjusting method of the present embodiment can be applied in addition to a method for manufacturing a dye-sensitized solar cell. For example, a solution having a constant concentration can be supplied to a dye laser device or a spin coater.

"Solar cell and manufacturing method thereof"
With reference to FIGS. 2-5, the manufacturing method of the solar cell using the solution concentration adjustment apparatus and solution concentration adjustment method of this embodiment is demonstrated.
The manufacturing method of the solar cell of this embodiment includes (I) a substrate forming step for forming a photoelectrode substrate and a counter electrode substrate, and (II) a substrate for bonding the photoelectrode substrate and the counter electrode substrate formed by the substrate forming step. And a bonding step.

(I) Substrate Formation Step The photoelectrode substrate 31 is produced.
First, a transparent electrode film 33 made of tin-doped indium oxide, fluorine-doped tin oxide, zinc oxide or the like is formed on one surface 32a of the first substrate 32 by sputtering or printing (see FIG. 2).

Next, a paste containing a metal oxide such as titanium oxide that can be baked is applied to one surface 33a of the transparent electrode film 33 by a photolithography method or a printing method, and sintered as necessary. A photoelectric conversion layer 34 made of a porous semiconductor is formed (see FIG. 2).
Further, the photoelectric conversion layer 34 may be formed by an aerosol deposition method (AD method).

Next, the photoelectric conversion layer 34 is immersed in the low-concentration solution 22 in the low-concentration solution storage unit 12B using the solution concentration adjusting device 10 described above, and the sensitizing dye is supported on the photoelectric conversion layer 34, and the photoelectrode substrate 31. Get.
Further, after the sensitizing dye is supported on the photoelectric conversion layer 34, the surface of the photoelectric conversion layer 34 may be washed with anhydrous alcohol or the like.

Next, a sealing resin 35 is formed on one surface 33 a of the transparent electrode film 33 by an inkjet method or the like so as to leave a predetermined distance from the photoelectric conversion layer 34 and to surround the photoelectric conversion layer 34.
Here, when the photoelectrode substrate 31 and a counter electrode substrate 36, which will be described later, are bonded together, the photoelectric conversion layer 34 and the counter electrode film 38 of the counter electrode substrate 36 are spaced apart from each other by a predetermined distance, and an electrolyte, which will be described later. The thickness of the sealing resin 35 is adjusted so that the layer 39 has a required thickness.

A counter electrode substrate 36 is produced.
A counter electrode film 36 made of platinum, polyaniline, polyethylenedioxythiophene (PEDOT), carbon, or the like is formed on one surface 37a of the second substrate 37 by a sputtering method or a printing method to obtain a counter electrode substrate 36 ( (See FIG. 3).

(II) Substrate bonding step The photoelectrode substrate 31 and the counter electrode substrate 36 are bonded to each other through the sealing resin 35 formed on the photoelectrode substrate 31, and the photoelectrode substrate 31 and the counter electrode substrate 36 are bonded by the sealing resin 35. Are bonded and fixed (see FIG. 4).
By this substrate bonding step, a gap is formed between the photoelectrode substrate 31 and the counter electrode substrate 36.

Next, an electrolyte is injected into a gap between the photoelectrode substrate 31 and the counter electrode substrate 36 from an injection port (not shown) formed in the photoelectrode substrate 31 or the counter electrode substrate 36 in advance, and the photoelectrode substrate 31 and the counter electrode 36 are counteracted. An electrolyte layer 39 is formed between the substrates 36.
Next, the inlet is sealed to obtain a solar cell 30 as shown in FIG.

"Optical device"
The optical device in the present embodiment is manufactured using a solution adjusted to a certain concentration by the solution concentration adjusting apparatus and the solution concentration adjusting method of the present embodiment. Examples of such an optical device include a dye laser, a magnetic recording body, and an organic thin film solar cell.

DESCRIPTION OF SYMBOLS 10 Solution concentration adjustment apparatus 11 Semipermeable membrane 12 Container 12A Saturated solution storage part 12B Low concentration solution storage part 13 Pressure adjustment apparatus 14 Temperature adjustment apparatus 15 Press part 21 Saturated solution 22 Low concentration solution

Claims (5)

A method of accommodating a saturated solution and a low concentration solution in a container through a semipermeable membrane and adjusting the concentration of the low concentration solution,
A solution concentration adjusting method, wherein the concentration of the low concentration solution is adjusted by adjusting a pressure difference between the saturated solution and the low concentration solution, and a temperature of the saturated solution and the low concentration solution.   2. The solution concentration adjusting method according to claim 1, wherein the saturated solution and the low-concentration solution contain a sensitizing dye used in a dye-sensitized solar cell. A solution concentration adjusting device comprising a container for containing a saturated solution and a low concentration solution through a semipermeable membrane,
A solution concentration adjusting apparatus comprising: means for adjusting a pressure difference between the saturated solution and the low concentration solution; and means for adjusting temperatures of the saturated solution and the low concentration solution.   The solution concentration adjusting apparatus according to claim 3, wherein the saturated solution and the low concentration solution contain a sensitizing dye used in a dye-sensitized solar cell. A dye-sensitized solar cell comprising a pair of opposing substrates, a pair of electrode films disposed between these substrates, and a photoelectric conversion layer and an electrolyte layer formed between these electrode films A manufacturing method of
Said photoelectric conversion layer, and wherein Rukoto billing immersed in a dye solution, which is the concentration adjusted by the solution concentration control system according to claim 3 or 4, having a step of Ru is supported a sensitizing dye in the photoelectric conversion layer To produce a dye-sensitized solar cell.

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