KR101526752B1 - Organic-Inorganic Hybrid Solar Cells Containing Boron Derivatives as a Surface Modifier and Fabricating Method therof - Google Patents

Abstract

The present invention provides organic-inorganic hybrid solar cells containing a boron-based surface treatment agent, comprising: upper and lower substrates; first and second electrodes formed to face each other on the upper substrate and the lower substrate, respectively; a counter electrode; and an electrolyte between a semiconductor layer (a compound semiconductor layer) formed on the first electrode and the counter electrode, wherein a dye and a boron-based surface treatment agent are introduced to a surface of the semiconductor layer in order to improve a photoelectric conversion efficiency. In addition, the present invention provides a producing method of the organic-inorganic hybrid solar cells, comprising the steps of: generating a first electrode on a first substrate; forming a semiconductor layer including titanium dioxide on the first electrode and forming a lower substrate; forming a second electrode and a counter electrode which face the first electrode on a second substrate and forming an upper substrate; introducing an electrolyte between the upper substrate and the lower substrate; and depositing the lower substrate in a deposition solution in which a boron-based surface treatment agent and a dye are dissolved, and introducing the dye and the boron-based surface treatment agent having an insulation property to a surface of the semiconductor layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic-inorganic hybrid solar cell including a boron-based surface treatment agent and a method of manufacturing the same. 2. Description of the Related Art Organic-Inorganic Hybrid Solar Cells Containing Boron Derivatives as a Surface Modifier and Fabricating Method

The present invention relates to an organic-inorganic hybrid solar cell and a method of manufacturing the same. More particularly, the present invention relates to an organic-inorganic hybrid solar cell, and more particularly, An inorganic hybrid solar cell and a manufacturing method thereof.

Climate uncertainties such as the crisis of depletion of fossil fuels such as petroleum, coal and natural gas, the enactment of the Kyoto Protocol's Climate Change Convention, and the explosive energy demand of emerging economies (BRICs) And technological development of new and renewable energy is proceeding at national level. Among renewable energy, solar cells (solar cells or photovoltaic cells) are the core elements of solar power generation that convert sunlight directly into electricity, and are now widely used for power supply from space to homes. In the early days when the solar cell was first made, it was mainly used for space use. However, since the 1970s, when it was undergoing two oil fluctuations, it became possible to use it as a ground power source. It began to be used as a dragon. Recently, air, meteorological and communication fields have been used, and photovoltaic vehicles and photovoltaic air conditioners are attracting attention. Although these solar cells mainly use silicon, they are manufactured in a semiconductor device fabrication process, so that they are expensive to manufacture and have difficulty in receiving and supplying silicon raw materials. In this situation, organic-inorganic hybrid solar cells (Dye-sensitized solar cells) that do not use silicon materials at all have been studied in earnest. And it is possible to manufacture a flexible solar cell regardless of the shape, and it is getting much attention now.

   Unlike silicon solar cells, organic-inorganic hybrid solar cells use photosensitive dye molecules capable of absorbing visible light to generate electron-hole pairs, and transition metal oxides that transfer generated electrons as main constituent materials Is a photoelectrochemical solar cell. A typical example of the known y-inorganic hybrid solar cell is disclosed in 1991 by Gracelet et al. Of Switzerland. The solar cell by Gratel et al. Consists of a transparent electrode, a semiconductor layer made of nano-sized titanium dioxide coated with dye molecules, a counter electrode (platinum electrode), and an electrolyte filled therebetween. This battery has attracted attention because it has a lower manufacturing cost per electric power than a conventional silicon battery, and thus it is possible to replace the existing solar cell.

The structure of a conventional organic-inorganic hybrid solar cell includes a first substrate, a first electrode (transparent electrode), a recombination barrier layer, a semiconductor layer, a light scattering layer, an iodine (I) electrolyte, a counter electrode, 2 substrate and a barrier rib, and the semiconductor layer is made of a nano-sized semiconductor compound (mainly TiO ₂ : TiO ₂ ) on which dye molecules are adsorbed, and glass is most utilized for the first substrate and the second substrate As the first electrode and the second electrode, FTO (Fluorine-doped Tin Oxide) having excellent heat resistance is the most widely used. Here, the dye molecule absorbs sunlight to generate electron-hole pairs, and the semiconductor compound (mainly titanium dioxide) serves to transfer generated electrons.

The operation principle of a conventional organic-inorganic hybrid solar cell is as follows. Dyes excited by sunlight inject electrons into the conduction band of semiconductor compounds (mainly titanium dioxide). The injected electrons pass through the semiconductor layer to reach the first electrode and are transferred to an external circuit. However, not all electrons reaching the first electrode are transmitted to the external circuit. That is, the upper surface of the first electrode is mostly in contact with the semiconductor compound, but some of the electrons reach the first electrode. Therefore, some of the electrons reaching the first electrode are not transferred to the external circuit and disappear into the electrolyte again. This phenomenon is referred to as recombination, which causes a decrease in photoelectric conversion efficiency. In order to minimize the recombination phenomenon, a recombination barrier layer may be formed on the top of the first electrode.

The external sunlight reaches the semiconductor layer via the first substrate, the first electrode, and the recombination barrier layer, and the sunlight is absorbed by the dye present in the semiconductor layer. However, solar light reaching from the outside is not completely absorbed by the semiconductor layer, and there is light that passes through the semiconductor layer, which causes a decrease in photoelectric conversion efficiency.

In order to solve such a problem, Korean Patent Laid-Open Publication No. 2003-0032538 discloses that a light scattering layer is formed to shield light passing through a semiconductor layer to induce light scattering, and the scattered light is absorbed again into the semiconductor layer, Of the population.

As mentioned above, the dye absorbing solar light forms an electron-hole pair, and electrons are transferred to the first electrode through a semiconductor compound (mainly titanium dioxide). On the other hand, the holes are transferred to the counter electrode through the redox reaction of the electrolyte, and then transferred to the external circuit through the second electrode.

At present, various methods are being tried for commercialization of the organic-inorganic hybrid solar cell as an item for which improvement of the photoelectric conversion efficiency is the most prior art. Among them, a method of improving photoactivity (photoelectric conversion efficiency) by coating a metal hydrate or a metal oxide based material on the surface of a semiconductor compound (mainly titanium dioxide) constituting a semiconductor layer is widely known.

Korean Patent Registration No. 10-0643054 discloses that a semiconductor compound (mainly titanium dioxide) particles are dispersed in an aqueous solution containing a metal salt, ball milled and baked at a high temperature (350-500) to form a metal oxide Thereby providing a method for producing coated particles. Particularly, in order to improve the photoelectric conversion efficiency, the metal oxide fine particles coated on the surface of the semiconductor compound (mainly titanium dioxide) increase the adsorption amount of the dye and the electrons injected into the semiconductor compound in the dye are discharged to the electrolyte, ), Thereby improving the photoelectric conversion efficiency.

More specifically, a metal salt solution is prepared in order to coat a metal oxide on the surface of a semiconductor compound (for example, TiO ₂ ) and form a thin film on the transparent electrode. TiO ₂ powder is added to the metal salt solution, milling and, by hydration of the metal salt and coating the hydrate to the TiO ₂ surface, the TiO ₂ forming the oxide from the coated hydrate in powder form (high-temperature calcination), and a mixture of TiO ₂ is a metal oxide coated with such a polymeric binder A paste is produced, printed several times on a transparent electrode by a printing method, and subjected to a high-temperature firing step for removing the organic polymer from the printed thin film.

In this method, the semiconductor compound fine particles are coated on the surface of the semiconductor compound to disperse the semiconductor compound fine particles into the metal salt solution and the ball milling and high temperature baking process for several hours to several tens of hours are required, Which is problematic in terms of economy. In addition, since the metal oxide has mostly a semiconducting property, there is a problem that electrons escaping from the semiconductor compound to the electrolyte can not be completely blocked.

Conventionally, a conventional organic-inorganic hybrid solar cell has been fabricated by forming a lower plate (consisting of a first substrate, a first electrode, a recombination barrier layer, a semiconductor layer, and a scattering layer), dye adsorption, Electrode), the upper and lower plates are cemented and the electrolyte is produced / injected / sealed.

(1) FTO substrate cleaning, (2) immersion in an aqueous solution of TiCl _{4 for the} recombination barrier layer, (3) printing of semiconductor compound for semiconductor layer (mainly titanium dioxide), (4) printing of inorganic particles for scattering layer , (5) high-temperature firing, (6) dipping in a dye solution to adsorb the dye to semiconductor compound and inorganic particles to complete the lower plate, (7) cleaning the second substrate / second electrode, (8) (9) bonding the upper and lower plates, and (10) preparing / injecting / sealing the electrolyte.

More specifically, the FTO formed on the glass substrate is washed with acetone, ethanol, distilled water or the like, and immersed in a 70% TiCl ₄ aqueous solution for 30 minutes to form a recombination barrier layer. Next, a paste composed of a nano-sized semiconductor compound (mainly titanium dioxide), a binder polymer, and an additive is printed (about 20 m) on the top of the FTO by a screen printing method to form a semiconductor compound film (mainly titanium dioxide film) The scattering layer having a thickness of about m / m is also formed by a screen printing method. The substrate having undergone the above steps is fired at about 500 ° C. to remove the polymer binder, and the TiCl ₄ component is converted to titanium dioxide. After the high-temperature heat treatment is completed, the substrate is immersed in a dye solution (N719 dye + acetronitrile + t-butylalcohol) to adsorb the dye on the semiconductor compound surface to produce a lower plate. Next, the second substrate / second electrode is cleaned, platinum paste is coated, and heat treatment is performed to complete the counter electrode, thereby manufacturing the top plate. Using the manufactured upper and lower plates, the barrier ribs are arranged between the plates, and then they are cemented. Next, an electrolyte solution (0.6M butylmethyl imidazolium iodide + 0.03MI ₂ + 0.05M 4-tert-butylpyridine + 0.1M guanidinium thiocyanate) was prepared and the electrolyte was injected through the holes formed in the upper plate and sealed, The solar cell is completed.

The present invention is conceived to improve the photoelectric conversion efficiency of a solar cell. The present invention relates to a semiconductor device in which an insulating boron-based surface treatment agent is introduced by immersing a lower plate containing a titanium dioxide thin film in a deposition solution in which a completely insulating boron- Layer and a method of manufacturing the same.

The organic-inorganic hybrid solar cell according to the present invention comprises a first substrate, a first electrode formed on the first substrate, a semiconductor layer formed on the first electrode and having a dye and a boron- An upper plate including a second substrate, a second electrode formed on the second substrate so as to face the first electrode, and a counter electrode, and a lower electrode including a lower electrode and a lower electrode, And a boron-based surface treatment agent comprising a sealing member (partition wall) for sealing the upper plate and an electrolyte layer injected between the upper plate and the lower plate sealed by the sealing member (partition wall).

It is still another object of the present invention to provide a method for manufacturing a semiconductor device, which comprises forming a first electrode on a first substrate, forming a semiconductor layer (semiconductor compound layer) on the first electrode, introducing a dye and a boron- Forming a second electrode and a counter electrode opposite to the first electrode on a second substrate, and introducing an electrolyte between the semiconductor layer and the counter electrode; Inorganic hybrid solar cell into which a surface treatment agent is introduced.

The present invention can prevent electrons lost (recombined) with an electrolyte by introducing a boron-based surface treatment agent on the surface of the titanium dioxide semiconductor layer. That is, the boron-based surface treatment agent according to the present invention has at least two Or more) of oxygen atoms, which is effective in protecting the surface of the semiconductor layer from the electrolyte effectively.

In addition, the insulating boron-based surface treatment agent according to the present invention is advantageous in that it has a high electron blocking effect because it is a completely insulating substance unlike a metal oxide having a semiconductor characteristic.

Further, although the conventional metal oxide requires a high-temperature firing process, the boron-based surface treatment agent according to the present invention can be introduced into the surface of the semiconductor layer by a simple deposition process, and thus has an excellent process and economical advantage.

FIG. 1 is a cross-sectional view illustrating the structure of an organic-inorganic hybrid solar cell including a semiconductor layer to which a boron-based surface treatment agent is introduced according to an embodiment of the present invention,
FIG. 2 is an enlarged view of a semiconductor layer and a light scattering layer of an organic-inorganic hybrid solar cell including a semiconductor layer to which a boron-containing surface treatment agent is introduced according to an embodiment of the present invention.
FIG. 3 is a conceptual view illustrating a boron-based surface treating agent introduced into the surface of a semiconductor layer according to an embodiment of the present invention to prevent electron transfer to the electrolyte,
4 is a graph showing current-voltage characteristics of a solar cell according to Comparative Example 1,
5 is a graph showing current-voltage characteristics of a solar cell according to Example 1 of the present invention,
FIG. 6 is a graph showing an open-circuit voltage decrease with time of the solar cell according to Comparative Example 1 (black square) and Example 3 (red circle)
7 is a graph showing current-voltage characteristics of a solar cell according to Example 4 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating the structure of an organic-inorganic hybrid solar cell including a semiconductor layer to which a boron-based surface treatment agent is introduced according to an embodiment of the present invention.

1, a solar cell 100 according to the present invention includes a first substrate 111, a first electrode 112 formed on the first substrate 111, and a second electrode 112 formed on the first electrode 112 A lower substrate 110 including a semiconductor layer 114 on which a dye and a boron-based surface treatment agent are introduced at the same time and a second electrode 121 formed on the second substrate 121 and the first electrode 112 And a sealing member (partition wall) 140 for sealing the lower plate 110 and the upper plate 120. The upper plate 120 includes a first electrode 122 and a counter electrode 123, And an electrolyte layer 130 injected between the upper plate 120 and the lower plate 110 sealed by the sealing member (partition wall) 140.

In order to improve the photoelectric conversion efficiency, the lower plate 110 may further include a light-scattering layer 115 on the recombination blocking layer 113 and the semiconductor layer 114 above the first electrode 111, can do.

The semiconductor layer includes a nano-sized semiconductor compound adsorbed by a dye molecule. The dye molecules in the semiconductor layer absorb visible light to generate electron-hole pairs. The semiconductor compound (titanium dioxide) .

Specifically, the dyes excited by the sunlight inject electrons into the conduction band of the semiconductor compound. The injected electrons pass through the semiconductor layer to reach the first electrode and are transferred to an external circuit. At this time, electrons which can not be transferred to an external circuit due to the contact state between the nano-sized semiconductor layer constituting the semiconductor layer and the first electrode are generated. Some of the electrons transferred from the semiconductor layer to the vicinity of the first electrode are not brought into contact with the first electrode and the semiconductor layer but disappear into the electrolyte through the portion exposed to the electrolyte solution. This phenomenon is referred to as recombination, which causes a decrease in photoelectric conversion efficiency. In order to minimize the recombination phenomenon, a recombination barrier layer 113 may be formed on the lower substrate 110 as shown in FIG. Also, external sunlight reaches the semiconductor layer through the first substrate, the first electrode, and the recombination barrier layer, and the sunlight is absorbed by the dye present in the semiconductor layer. Light which is not completely absorbed by the semiconductor layer and passes through the semiconductor layer is present in the solar light reached from the outside, which also causes a decrease in the photoelectric conversion efficiency. In order to block the light passing through the semiconductor layer, the light scattering layer 115 is formed to induce light scattering, and the scattered light is absorbed into the semiconductor layer again. The dye absorbing solar light forms an electron-hole pair, and the electrons are transferred to the first electrode 112 through the semiconductor layer. On the other hand, the holes are transferred to the second electrode 122 through the redox reaction of the electrolyte and then transferred to the external circuit through the second electrode 122.

In the present invention, in order to prevent the deterioration of the photoelectric conversion efficiency, the recombination blocking layer 113 and the light scattering layer 115 are formed, and the lower plate 110 including the semiconductor layer 114 containing titanium dioxide, Can be immersed in a boron-based surface treatment agent immersion solution to prevent electrons lost by the electrolyte, thereby improving the photoelectric conversion efficiency.

FIG. 2 is an enlarged view of a semiconductor layer 114 and a light-scattering layer 115 in which an insulating boron-based surface treatment agent is immersed in a boron-based surface treatment agent immersion solution according to the present invention.

≪ First Substrate / First Electrode and Cleaning >

The first electrode formed on the first substrate is immersed in acetone, ethanol, distilled water or a mixed solution thereof, followed by ultrasonic cleaning. As the first substrate, glass, plastic, metal foil or the like may be used. In addition to the FTO, the first electrode may be formed of a transparent material such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO-Ga ₂ O ₃ , ZnO- Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ , An electrode can be used.

≪ Formation of titanium dioxide thin film &

The cleaned first substrate is immersed in a precursor solution (TiCl ₄ ) at a concentration of 40 mM, left to stand at 70 for 30 minutes, and washed with distilled water and ethanol to form a recombination barrier layer. A paste containing titanium dioxide (TiO ₂ ) having an average particle diameter of 20 nm is coated on the recombination barrier layer to form a thin film. Next, a paste containing titanium dioxide (TiO ₂ ) having an average particle diameter of 300 to 400 nm is coated on the above-mentioned 20 nm thick titanium dioxide (TiO ₂ ) thin film, and heat treatment (450 to 450 nm) 550) is performed so that the recombination barrier layer, the semiconductor layer, and the light scattering layer are formed to complete the manufacture of the lower plate. In some cases, the prepared lower plate may be immersed in a TiCl ₄ solution and then heat-treated at 450 to 550 to induce additional efficiency improvement. As the method for forming the titanium dioxide thin film, a doctor blade coating, a screen printing, a flexography method, a gravure printing method, or the like can be used.

1, the bottom plate of the organic-inorganic hybrid solar cell is composed of the first substrate / the first electrode / the recombination barrier layer / the semiconductor layer / the light scattering layer, but the recombination blocking layer and the light scattering layer are formed of the organic- Inorganic hybrid solar cell without any layer or two layers of the anti-recombination layer and the light-scattering layer, because it is formed for the purpose of improving the photoelectric conversion efficiency of the battery.

<Introduction (adsorption) of an insulating boron-based surface treatment agent>

 In order to introduce an insulating boron-based surface treatment agent onto the surface of the titanium dioxide, in the present invention, a boron-based surface treatment agent having at least two (two or more) oxygen atoms represented by the following structural formula 1 or a mixture thereof is added to a solvent, And a lower plate having the titanium dioxide thin film formed thereon is immersed therein to introduce a boron-based surface treatment agent onto the titanium dioxide surface. The functional groups of the hydroxyl group and the boron-based surface treatment agent present on the surface of the titanium dioxide thin film can adsorb the boron-based surface treatment agent to the titanium dioxide surface by chemical reaction or interaction. In this case, the immersion time is preferably about 0.1 minute to 24 hours, and after the immersion, cleaning is performed using distilled water and alcohol solvents, and the resultant is dried at a temperature of about 60 to 70 for about 10 to 20 minutes, A semiconductor layer thin film having an insulating boron-based surface treatment agent introduced (adsorbed) on its surface is produced.

In the present invention, various boron-based surface treatment agents containing at least two oxygen atoms are shown as Structural Formula 1, but the present invention is not construed as being limited thereto.

[Structural formula 1]

         B1 B2 B3 B4

        B5 B6 B7 B8

                 B9 B10 B11

                 B12 B13 B14

               B15 B16 B17

                    B18 B19

                  B20 B21

                   B22 B23

B24

As the solvent, water, ethanol, acetone, isopropyl alcohol, methyl ethyl ketone, acetonitrile, butyl alcohol, tetrahydrofuran, benzene, toluene, chloroform, ether and the like can be used alone or in combination. In order to increase the solubility of the boron-based surface treatment agent, a small amount of an acid or an alkaline compound may be added.

FIG. 3 is a conceptual view illustrating the role of the insulating boron-based surface treatment agent according to the present invention. The insulating boron-based surface treatment agent is effectively adsorbed on the surface of the semiconductor layer, and the surface of the semiconductor layer is not in direct contact with the electrolyte, To prevent electrons from escaping into the electrolyte. As a result, the efficiency of the entire solar cell can be improved by reducing the loss of electrons. Since the boron-based surface treatment agent of the present invention has at least two bonding groups, the surface area of the semiconductor layer per unit molecule is large, thereby effectively protecting the surface from the electrolyte.

In addition, since the insulating boron-based surface treatment agent of the present invention is an insulating substance unlike a metal oxide having a conventional semiconductor property, the electron blocking effect is much larger, and it is advantageous that the surface treatment agent can be introduced to the surface of the semiconductor layer by a simple deposition process .

&Lt; Dye introduction >

In order to complete the solar cell, the dye should be introduced onto the surface of the titanium dioxide into which the boron-based surface treatment agent is introduced. Such a dye absorbs light, thereby causing electrons to transfer from the ground state to the excited state to form an electron-hole pair. The electrons in the excited state are injected into the conduction band of the titanium dioxide and then transferred to the electrode to generate electromotive force. When such a dye is dissolved in an organic solvent in an appropriate concentration to prepare a dye solution and the titanium dioxide thin film into which the boron-based surface treatment agent is introduced is immersed in the solution for a predetermined time, the dye is adsorbed on the surface of the titanium dioxide thin film, Thereby forming a titanium dioxide semiconductor layer on which the surface treatment agent is adsorbed. The dyes used herein are not limited as long as they are generally used in the field of solar cells, but ruthenium complexes [N719 dye; bis (tetrabutylammonium) -cis- (dithiocyanato) -N, N'-bis (4-carboxylato-4'-carboxylic acid-2,2'-bipyridine) ruthenium (II), N3 dye; cis-bis (4,4-dicarboxy-2,2-bipyridine) dithiocyanato ruthenium (II), Black dye; triisothiocyanato- (2,2 ': 6', 6-terpyridyl-4,4 ', 4-tricarboxylato) ruthenium (II) tris (tetra-butylammonium). However, it is not particularly limited as long as it has a charge-separating function and exhibits a sensitizing action. In addition to the ruthenium complex, a cyanine dye such as rhodamine B, rose bengal, eosine, erythrosine, etc., a cyanine dye such as quinoxine and cryptoxine, Basic dyes such as naphtha pranine, carbo blue, thiosine and methylene blue, porphyrin compounds such as chlorophyll, zinc porphyrin and magnesium porphyrin, other azo dyes, phthalocyanine compounds and complex compounds such as Ru trispyridyl, Dyes, quinacridone dyes, organic dyes and the like. These dyes can be used singly or in combination of two or more.

   As the solvent of such a dye, tertiary butyl alcohol, acetonitrile, tetrahydrofuran, ethanol, isopropyl alcohol or a mixture thereof may be used, and a lower plate having a titanium dioxide thin film on which the boron surface treating agent is adsorbed, It is sufficient to immerse the dye in the dye solution for 72 hours to introduce the dye onto the titanium dioxide surface. At this time, the dye can also be introduced onto the surface of titanium dioxide for the scattering layer, and the penetration of the dye into the semiconductor compound for the recombination blocking layer is difficult, so that only a trace amount of dye is introduced or almost no introduction occurs. When the introduction of the dye is completed, the dye on the surface of the semiconductor compound is washed with a solvent such as an alcohol and dried.

This method is a method in which a boron-based surface treatment agent is introduced first and a dye is introduced, but there is no problem in operation of a solar cell even if the order is changed. That is, it is also possible to adsorb the boron-based surface treating agent after first adsorbing the dye by the above-described method. Also, a solution in which a dye and a boron-based surface treatment agent are simultaneously dissolved is prepared, and a titanium dioxide thin film is immersed therein and left for a predetermined time to obtain a titanium dioxide semiconductor layer in which a dye and a boron-based surface treatment agent are simultaneously adsorbed. Examples of the method of introducing the boron-based surface treatment agent and dye into the titanium dioxide thin film in this manner include (1) a method of introducing a boron-based surface treatment agent first and then a dye, (2) a method of simultaneously introducing a boron- And (3) a dye is first introduced and then a boron-based surface treatment agent is introduced.

<Formation of Opposite Electrode>

In the method for manufacturing a solar cell of the present invention, any of the opposite electrodes can be used without limitation as long as it is a conductive material. Specifically, it is preferable to use platinum, gold, carbon, or the like. The counter electrode may be formed by vacuum deposition using a sputter or the like, or may be used by coating or baking a paste or a conductive material precursor in a solution state on the second electrode / second substrate. In addition to FTO, the second electrode may be formed of ITO (indium tin oxide), IZO (indium zinc oxide), ZnO-Ga ₂ O ₃ , and the like _{ZnO-Al 2 O 3, SnO} 2 -Sb 2 O 3 may be used.

&Lt; Injection and encapsulation process of upper and lower coagulating electrolyte >

In the solar cell manufacturing method of the present invention, the electrolyte was prepared by mixing 0.8 M of 1,2-dimethyl-3-octyl-imimidazolium iodide and 40 mM of I ₂ ( iodine), a 3-methoxy-propionitrile (3-methoxypropionitile) that I ³ / I dissolved in ^- be mentioned as an example, but not limited to this, any such organic semiconductor materials (conductive polymers), which hole conduction function would Can be used without restrictions.

A hole having a diameter of about 1 mm is formed for injecting the electrolyte into a specific portion of the second substrate / the second electrode / the counter electrode. A partition wall (about 40 m in thickness) is disposed between the upper plate (second substrate / second electrode / counter electrode) and the lower plate (first substrate / first electrode / titanium dioxide) To about 140 at a pressure of about 1 to about 3 atmospheric pressure to complete the laminating process. Next, the organic-inorganic hybrid solar cell according to the present invention is completed by filling the space between the two plates through the fine holes formed on the surface of the counter electrode and sealing the holes. As the sealing material (partition wall material), a polymer material called a sealing material of Solaronix, Surlyn, an epoxy resin or an ultraviolet (UV) curing agent of Dupont can be used.

Example

Hereinafter, an organic-inorganic hybrid solar cell including a semiconductor layer to which the boron-containing surface treatment agent of the present invention is introduced and a method for producing the same will be described in more detail with reference to examples. However, the present invention is not to be construed as being limited by the following examples.

Comparative Example 1

The washed FTO substrate was immersed in a 40 mM aqueous solution of TiCl ₄ (70) for 30 minutes to form an anti-recombination layer. Then, commercial (manufacturer: Solaronix, TiO ₂ particle size: 20 nm) TiO ₂ paste was coated by doctor blade method and then fired at 450 for 30 minutes to form 15 semiconductor layers. Subsequently, a thin film was formed on the semiconductor layer using a paste containing TiO ₂ having an average particle diameter of 400 nm, followed by baking at 500 to 60 minutes to form a scattering layer. The fired substrate was immersed in a dye solution (N719 of Solaronix Inc. in acetronitrile + tert-butylalcohol at a concentration of 0.5 mM) for 24 hours to allow the dye to sufficiently penetrate into the TiO ₂ porous film, and then the dye was adsorbed on the acetonitrile solvent Washed and dried to complete the lower plate. The Pt paste was coated on the cleaned FTO substrate and fired at 400 to 30 minutes to form the counter electrode, thereby preparing the top plate. Two holes were pre-drilled for electrolyte injection before coating the Pt paste. Sealing material (manufactured by Solaronix, thickness: about 60 m), which is a sealing material (partition wall), was disposed between the upper plate and the lower plate into which the dye was introduced so as to face each other. While this was placed on a 120 hot plate, pressure was applied from the upper side to adhere the upper plate and the lower plate. By the heat and pressure, the partition wall material is strongly adhered (adhered) to the two upper and lower plate surfaces. Subsequently, the electrolyte is filled between the upper plate and the lower plate through holes previously formed in the upper plate. The electrolyte used was I ^- / I ₃ ^- redox couple from Solaronix. After the electrolyte solution is filled, the holes formed in the upper plate are sealed to complete the solar cell element fabrication. The photoelectric conversion efficiency of the completed device was measured using a solar simulator and IV measurement equipment. The IV curves were obtained after irradiating the device with light of AM 1.5 (100 mW / cm ² ) to the fabricated solar cell device. The measurement results are shown in FIG. 4, and V _OC (open circuit voltage) was 0.681 V , J _SC (short circuit current density) was 16.21 mA / cm ^2, and FF (fill factor) was 63.76%, indicating a photoelectric conversion efficiency of 7.04%.

Example 1

The bottom plate obtained by the solar cell manufacturing process shown in Comparative Example 1 was immersed in a dipping solution consisting of 0.1 mM B3 (see Structural Formula 1) and water (solvent) for 3 minutes before being immersed in the dye, A hybrid solar cell was fabricated in the same manner as in Comparative Example 1 except for the additional step of washing and drying. The photovoltaic conversion efficiency was measured by the same equipment and method. The V _OC was 0.771 V, the J _SC was 18.92 mA / cm ^2, and the fill factor was 68.98%, showing a photoelectric conversion efficiency of 10.06%, which is shown in FIG.

Example 2

The organic-inorganic hybrid solar cell was manufactured in the same manner as in Example 1, except that 0.7 mM of B9 was used in the manufacturing process of the solar cell. At this time, the measurement results showed 0.767 V in V _OC , 18.85 mA / cm ^{2 in} J _SC , and 70.03% in Fill Factor, and the photoelectric conversion efficiency was 10.12%.

Example 3

A 0.2 mM B5 immersion solution was prepared in place of the 0.1 mM B3 solution in the solar cell manufacturing process described in Example 1. [ In addition, unlike Example 1, except that the dye was adsorbed first and the lower plate was immersed in the solution for 30 minutes for 5 minutes to adsorb the boron-based surface treatment agent, the organic-inorganic hybrid solar cell was manufactured Respectively. At this time, the V _OC was 0.78 V , the J _SC was 18.98 mA / cm ^2, and the fill factor was 70.12%, indicating that the photoelectric conversion efficiency was 10.38%.

FIG. 6 is an OCVD (Open Circuit Voltage Decay) curve of a solar cell manufactured under the conditions of Comparative Example 1 and Example 3, and is the OCVD curve of the solar cell according to Example 3 (Y-axis) is small. It can be seen that the electron lifetime of the solar cell into which the insulating boron-based surface treatment agent is introduced is longer. That is, it can be confirmed that the insulating boron-based surface treatment agent effectively blocks the electrons that escape from the surface of the semiconductor layer into the electrolyte, thereby prolonging the lifetime of the electron. It can be seen that such an increase in electron lifetime leads to an increase in efficiency.

Example 4

The formation of the recombination barrier layer, the titanium dioxide semiconductor layer and the titanium dioxide scattering layer in the solar cell manufacturing process was the same as that of Example 1. In order to simultaneously adsorb boron-based surface treatment agents and dyes, 0.5mM B14 solution and 0.5mM N719 dye solution were added to a mixed solvent of acetonitrile, trisarybutyl alcohol and chloroform in a volume ratio of 1: 1: 1 The mixture was mixed at a ratio of 1: 1 to prepare a dipping solution. The lower plate prepared above was immersed in this solution for 24 hours at room temperature to form an insulating boron-based surface treatment agent and a dye simultaneously on the surface of the semiconductor layer. The other counter electrodes were formed, the upper and lower plate encapsulation processes, and the electrolyte injection process were carried out in the same manner as in Example 1, to fabricate an organic-inorganic hybrid solar cell. At this time, the V _OC was 0.76 V , the J _SC was 18.34 mA / cm ^2, and the fill factor was 70.89%. As a result, the photoelectric conversion efficiency was 9.88%, and the current-voltage characteristic graph was shown in FIG.

Example 5

Inorganic hybrid solar cells were prepared in the same manner as in Example 4, except that 0.5 mM of B7 solution was used instead of 0.5 mM of B14 solution. At this time, the V _OC was 0.77 V , the J _SC was 18.54 mA / cm ^2, and the fill factor was 70.87%, indicating that the photoelectric conversion efficiency was 10.12%.

Example 6

Inorganic hybrid solar cells were prepared in the same manner as in Example 1, except that 0.2 mM of B19 solution was used instead of 0.1 mM of B3 solution. At this time, the V _OC was 0.76 V , the J _SC was 18.33 mA / cm ^2, and the fill factor was 70.83%, indicating that the photoelectric conversion efficiency was 9.87%.

Example 7

An organic-inorganic hybrid solar cell was prepared in the same manner as in Example 4, except that a mixture of 0.2 mM of B20 solution and 0.2 mM of B21 solution was used instead of 0.5 mM of B14 in the solar cell manufacturing process of Example 4 . At this time, the V _OC was 0.79 V , the J _SC was 19.08 mA / cm ^2, and the fill factor was 71.73%, indicating that the photoelectric conversion efficiency was 10.81%.

Example 8

An organic-inorganic hybrid solar cell was prepared in the same manner as in Example 1 except that 0.1 mM of B23 solution was used instead of 0.1 mM of B3 solution. At this time, the V _OC was 0.79 V , the J _SC was 19.41 mA / cm ^2, and the fill factor was 70.01%, indicating that the photoelectric conversion efficiency was 10.74%.

111: first substrate
112: first electrode
113: recombination barrier layer
114: semiconductor (semiconductor compound) layer
115: Light scattering layer
110: lower plate
121: second substrate
122: second electrode
123: opposed electrode
120: top plate
130: electrolyte layer
140: sealing member (partition wall)
100: Solar cell

Claims (11)

A lower substrate comprising a first substrate, a first electrode formed on the first substrate, and a semiconductor layer (semiconductor compound layer) formed on the first electrode;
A second electrode formed on the second substrate so as to face the first electrode,
An upper plate including a large (opposing) electrode;
A solar cell including an electrolyte between the lower plate and the upper plate,
Wherein the semiconductor layer comprises a boron-based surface treatment agent, wherein a dye and a boron-based surface treatment agent are simultaneously introduced onto the surface of the semiconductor layer.
The method according to claim 1,
Wherein the boron-based surface treatment agent is a boron compound containing at least two oxygen atoms per molecule.
The method according to claim 1,
Wherein the first electrode and the semiconductor layer further include a recombination preventing layer between the first electrode and the semiconductor layer.
The method according to claim 1,
Wherein the light-scattering layer further comprises a light scattering layer on the semiconductor layer.
Forming a first electrode on a first substrate;
Forming a semiconductor layer (semiconductor compound layer) containing titanium dioxide on the first electrode;
Forming a lower plate by introducing a dye and a boron-based surface treatment agent onto the surface of the semiconductor layer;
Forming a top plate by forming a second electrode and a counter electrode opposite to the first electrode on a second substrate;
Tightly attaching the lower plate and the upper plate to each other; And
And introducing and sealing an electrolyte between the upper plate and the lower plate. The method of manufacturing a hybrid organic / inorganic hybrid solar cell according to claim 1,
6. The method of claim 5,
Wherein the boron-based surface treatment agent is a boron compound containing at least two oxygen atoms per molecule.
6. The method of claim 5,
Further comprising the step of forming a further anti-recombination layer between the first electrode and the semiconductor layer.
6. The method of claim 5,
Forming a light-scattering layer on the semiconductor layer; and forming a light-scattering layer on the semiconductor layer. A method for fabricating an organic-inorganic hybrid solar cell,
6. The method of claim 5,
Wherein the boron-based surface treatment agent is introduced into the surface of the semiconductor layer, and then the boron-based surface treatment agent is introduced.
6. The method of claim 5,
Wherein the boron-based surface treatment agent is first introduced into the surface of the semiconductor layer, and then the dye is introduced into the surface of the semiconductor layer.
6. The method of claim 5,
Wherein the boron-based surface treatment agent and the dye are simultaneously introduced onto the surface of the semiconductor layer.

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