TWI469381B - Method of preparing the dye-sensitized solar cell - Google Patents

Description

Method for preparing dye-sensitized solar cell Field of invention

The present invention relates to a method for preparing a dye-sensitized solar cell, and more particularly to a method for preparing a dye-sensitized solar cell using a low melting glass frit composition and a light Curing the resin composition, thus making low temperature laser sintering possible to reduce damage to a thermally unstable component, and the method is pre-sealed with a photocurable resin, thereby increasing the efficiency and process efficiency of the frit seal In order to avoid the volatilization of the electrolyte from the sealing portion of one of the solar cells (which is exposed to a harsh external environment), thereby extending the durability life, and thereby providing protection against external impact or damage and high strength. The sealability thus extends the life of a dye-sensitized solar cell and increases the durability of the cell.

Background of the invention

Since Michael Gratzel et al. of the Swiss Federal Institute of Technology Lausanne (EPFL) invented a dye-sensitized nanoparticle titanium dioxide solar cell in 1991, many studies related to this aspect have continued to develop. Because dye-sensitized solar cells have very low manufacturing costs compared to existing tantalum solar cells, they can replace existing amorphous tantalum solar cells. Moreover, the dye-sensitized solar cell is a photoelectrochemical solar cell mainly composed of a dye molecule (which can absorb visible light to generate an electron-hole pair) and a transition metal oxide (used to transport the generated electron). .

In general, a unit cell of a dye-sensitized solar cell is formed of an upper and lower transparent substrate, a conductive transparent electrode respectively formed on the transparent substrate, and a porous layer of a transition metal oxide adsorbing the dye (formed on The conductive thin electrode corresponding to a first electrode, a catalytic thin film electrode formed on the conductive transparent electrode corresponding to a second electrode, and a porous filled with a transition metal oxide (for example, TiO ₂ ) The electrolyte is composed of an electrolyte between the electrode and the catalytic film electrode.

Therefore, in order to stably maintain the electrolyte filled between the first and second electrodes, a thermoplastic polymer film is placed between the first and second electrodes and is hot pressed to the first and second electrodes. In combination, thereby forming an empty chamber, an electrolyte solution can be injected into the empty chamber and stored between the first and second electrodes.

However, since the thermoplastic polymer film does not have a delicate structure, it is liable to be deteriorated by high temperature, excessive sunlight, heat cycle, etc., and the electrolyte is volatilized by thermal cycles such as night/day or winter/summer, and solar energy is lowered. The efficiency of the battery ultimately ends the life of the battery. Moreover, the thermoplastic polymer film is liable to be damaged by external impact (caused by its limited mechanical strength), and shortens the life of a solar cell, thereby causing a problem of durability.

Summary of invention

In order to overcome the aforementioned problems, it is an object of the present invention to provide a method for preparing a dye-sensitized solar cell using a low melting glass frit composition and a photocurable resin composition. Therefore, low temperature lightning sintering is made possible to reduce damage to a thermally unstable component, and the method is pre-sealed with a photocurable resin, thereby increasing the efficiency and process efficiency of the frit sealing, thereby avoiding a solar energy A battery (which is operated under exposure to a harsh external environment), one of which evaporates from the sealed portion, thereby extending the durability and providing a seal against external impact or damage and high strength, thereby extending a dye Sensitize the life of solar cells and increase the durability of the battery.

In order to achieve the foregoing objects, the present invention provides a method for preparing a dye-sensitized solar cell comprising bonding an upper substrate and a bonding substrate, the bonding substrate being bonded to the upper substrate, comprising the steps of: a sealing line of the dye-sensitized solar cell, applying a glass frit on the bonding surface of one of the upper substrate or the bonding substrate; at an edge of the bonding surface of the upper substrate or the bonding substrate, and away from the sealing line, Applying a photocurable resin composition; bonding the upper substrate and the bonding substrate to form an assembly; irradiating light to cure the photocurable resin composition on the assembly to cure the assembly; and along the total The resulting frit is irradiated with a laser to be sintered.

The present invention also provides a dye-sensitized solar cell prepared by the aforementioned method.

According to the method for producing a dye-sensitized solar cell of the present invention, a low-melting glass frit composition and a photocurable resin composition are used to make low-temperature laser sintering possible to reduce the Thermally unstable components are pre-sealed with a photocurable resin to increase the efficiency and process efficiency of the frit seal, thereby avoiding the operation of a solar cell that is exposed to harsh external environments. An electrolyte evaporates from the sealing portion, thereby prolonging the durability life, and providing a sealing property against external impact or damage and high strength, thereby prolonging the life of a dye-sensitized solar cell and increasing the durability of the battery.

Simple illustration

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram showing a method for preparing a dye-sensitized solar cell in accordance with an embodiment of the present invention.

Mode for carrying out the invention

The invention will be explained in detail with reference to the drawings.

The present invention relates to a method for preparing a dye-sensitized solar cell comprising bonding an upper substrate and a bonded substrate bonded to the upper substrate, the method comprising the steps of: one along the dye-sensitized solar cell a sealing line, applying a frit on the bonding surface of the upper substrate or the bonding substrate; applying a photocurable resin to the edge of the bonding surface of the upper substrate or the bonding substrate and away from the sealing line Bonding the upper substrate and the bonding substrate to form an assembly; irradiating light to cure the photocurable resin composition on the assembly to cure the assembly; and irradiating the laser along the frit of the assembly Sintered.

In general, a dye-sensitized solar cell consists of a first electrode (corresponding to the substrate below the first drawing - a bonding substrate composed of a substrate having a porous film containing a dye), The two electrodes (corresponding to the upper electrode of Fig. 1 arranged in relation to the first electrode (lower electrode)) and an electrolyte filled between the electrodes. In the present invention, in order to stably store the electrolyte between the first and second electrodes for a long period of time, the first and second electrode systems are spaced apart from each other, and the empty space therebetween is sealed by sintering the glass frit, and the sealing is empty. The chamber is filled with an electrolyte. As for the porous film, various known dye-adsorbable porous films can be used. For example, a transition metal oxide (for example, TiO ₂ having a size of 10 to 15 nm) can be applied and sintered to obtain a porous film. Film. The transparent substrate on which the porous film is formed is not necessarily limited to a flat substrate and may include a curved substrate, and various types of solar cells (which may be used for visible light or specific wavelength light waves) may be used. A transparent substrate that penetrates a substrate (made of glass). A conductive substrate is preferably used for an electrode. Specific examples of the transparent substrate include known transparent glass, transparent resin, PET, ITO, or FTO, and the like. Meanwhile, in order to obtain conductivity, in addition to the foregoing materials, a conductive film or a coating (ITO, FTO, or conductive polymer) may be further included between the porous film and the substrate. As for the second electrode (upper substrate) disposed with respect to the first electrode, any substrate which is often used as the second electrode of a solar cell can be used, and it is not necessarily limited to a flat substrate, but may include a curved substrate. The substrate is preferably made of a material that can transmit light of visible light or a specific wavelength, such as glass, and for this reason, it can be made of known transparent glass, PET glass, ITO glass, FTO glass, and the like. . In order to obtain conductivity, it is preferred to further comprise a conductive film or coating (ITO, FTO, or conductive polymer). Moreover, in order to increase the absorption effect of sunlight and activate the reaction, a catalytic metal layer may be further included at the outermost side of the first electrode.

The upper substrate of the dye-sensitized solar cell may be made of glass, and if necessary, the lower substrate or the bonding substrate may be made of glass (as shown in Fig. 1), or it may be made of other materials (if a dye The sensitized solar cell has only upper and lower substrates, and the lower substrate corresponds to a bonding substrate; and if it has a multilayer structure of more than two layers, a bonding substrate is bonded to the bottom of the upper substrate, and other substrates may be Bonded to the underlying bonding substrate).

As shown in Fig. 1, a unit cell of a plurality of dye-sensitized solar cells (in a 2 x 2 array in Fig. 1) can be fabricated on a substrate, or only one unit cell can be fabricated on a substrate. Since each unit cell must maintain a seal on its joint surface, as shown in Fig. 1, the frit composition is applied along a seal line which has a circular curve to seal the outside of the unit cell. The seal line can take various shapes depending on the shape of the element. As shown in Fig. 1, the frit is applied along a seal line on the joint surface. The bonding surface may be the top of the bottom substrate or the lower substrate (or the bonding substrate bonded to the upper substrate) of the upper substrate, which maintains the sealing property of the bonding portion. The frit can be applied by a variety of conventionally known methods, and by way of example, the frit can be prepared as a glass paste and printed and dried by screen printing.

As for the glass frit, any conventional glass frit can be used, and it is preferably used with 0 to 30 mol% of P ₂ O ₅ , 0 to 50 mol% of V ₂ O ₅ , 0 to 20 mol% of ZnO, 0 to 15 mol% of BaO, and 0. ~20mol% As ₂ O ₃ , 0~20mol% Sb ₂ O ₃ , 0~5mol% In ₂ O ₃ , 0~10mol% Fe ₂ O ₃ , 0~5mol% Al ₂ O ₃ , 0~20mol% B ₂ A glass frit of O ₃ , 0-10 mol% Bi ₂ O ₃ , and 0-10 mol% TiO ₂ .

A frit containing glass frit is applied along the edges, and the frit composition may comprise a) the frit, b) an organic binder, and c) an organic solvent. The frit composition preferably comprises a) from 60 to 90 parts by weight of the glass frit, b) from 0.1 to 5 parts by weight of the organic binder, and c) from 5 to 35 parts by weight of the organic solvent.

The glass frit preferably comprises 10 to 25 mol% of P ₂ O ₅ , 40 to 50 mol% of V ₂ O ₅ , 10 to 20 mol% of ZnO, 1 to 15 mol% of BaO, 1 to 10 mol% of Sb ₂ O ₃ , and 1 to 10 mol%. Fe ₂ O ₃ , 0.1 to 5 mol% Al ₂ O ₃ , 0.1 to 5 mol% B ₂ O ₃ , 1 to 10 mol% Bi ₂ O ₃ , and 0.1 to 5 mol% TiO ₂ , more preferably 15 to 20 mol% P ₂ O ₅ , 40 to 50 mol% V ₂ O ₅ , 10 to 20 mol% ZnO, 5 to 10 mol% BaO, 3 to 7 mol% Sb ₂ O ₃ , 5 to 10 mol% Fe ₂ O ₃ , 0.1 to 5 mol% Al ₂ O ₃ 0.1 to 5 mol% B ₂ O ₃ , 1 to 5 mol% Bi ₂ O ₃ , 0.1 to 5 mol% TiO ₂ .

If the content of the glass frit component exceeds the above range, vitrification may not be achieved, the waterproof property may be significantly deteriorated, or electro-sinter sintering may not be achieved.

The glass frit preferably has a glass transition temperature (T _g ) from 300 to 400 ° C and a softening point (T _dsp ) from 300 to 400 ° C. In these ranges, the sintering stability at low temperatures is optimal.

Moreover, the glass frit preferably has a particle size of from 0.1 to 20 μm. In this range, a low temperature process is made feasible and thus suitable for sealing a pair of thermally unstable components, and a laser process system becomes feasible, thereby increasing the sealing effect of the electrical components.

In the frit paste composition, a) the frit is as described above, and as the b) organic binder, a commercially available organic binder can be used. Specific examples of the organic binder include a copolymer of an ethyl group or a copolymer of an acrylic group. Further, as for the organic solvent, any organic solvent compatible with the organic binder used in the frit paste composition of the present invention may be used, and specific examples include an organic binder suitable for the ethyl group. A mixture of butylcarbitolacetate (BCA), terpineol (TPN), dibutyl phthalate (DBP), or the like. 30 to 70 parts by weight of the organic solvent in 100 parts by weight of the organic solvent to be used is mixed with an organic binder to prepare a carrier, and then the remaining organic solvent is mixed with the glass frit and the obtained carrier to prepare a carrier. The glass frit composition can further improve the dispersibility of the frit paste composition. In the preparation of the carrier, 30 to 70 parts by weight of the organic solvent is more preferably composed of 20 to 55 parts by weight of BCA, 3 to 10 parts by weight of TPN, and 1 to 5 parts by weight of DBP, and in the glass frit. When mixed, BCA is used as a solvent.

In order to control the coefficient of thermal expansion, the frit composition may further comprise a filler. Specific examples of the filler include 0.1 to 20 μm cordierite, preferably 0.1 to 30 parts by weight.

Further, the frit paste composition preferably has a viscosity of from 500 to 50,000 cps, more preferably from 2,000 to 35,000 cps. Within this range, the application of the screen printing method becomes feasible, thereby further improving the usability.

Then, on the bonding surface of the upper substrate or the bonding substrate (which is bonded to the upper substrate), a photocurable resin composition is applied around the surface from the sealing line space, which further increases the sealing effect of the glass frit. The photocurable resin composition can be applied to the substrate on which the frit is applied, as shown in Figure 1, or it can be applied to the top of the lower substrate. In terms of configuration, the photocurable resin composition is preferably applied to the same substrate to which the glass frit is applied. In detail, the substrate (or the bonding substrate) corresponding to the first electrode is provided with an electrode and a porous film containing a dye, as shown in FIG. 1 (if necessary, it may further comprise a connecting line, The glass frit and the photocurable resin composition are applied as shown, on the upper substrate (corresponding to the second electrode). Preferably, at the time of application, the frit and the resin composition do not achieve a sealing effect on the complete sealing line, and one part of the sealing line is opened as an electrolyte inlet, so that an electrolyte can be filled later Into the empty space between the joint surfaces of the assembly.

The photocurable resin composition can be applied by various known methods, and, for example, a screen printing method or a gravia printing or the like can be used.

As the photocurable resin composition, a general photocurable resin composition can be used, and the photocurable resin composition preferably contains (a) 100 parts by weight of an epoxy resin, and (b) 0.01 to 20 parts by weight. The photopolymerization initiator, (c) 0.01 to 10 parts by weight of the coupling agent, (d) 0.01 to 100 parts by weight of the inorganic filler, and (e) 0.05 to 10 parts by weight of the photoacid generator.

The photocurable resin composition has a viscosity of 5,000 to 150,000 cps, preferably 10,000 to 100,000 cps (at 25 ° C), thereby making the screen printing process feasible, thereby shortening the processing time and reducing the cost.

The preferred composition of the photocurable resin composition is as follows.

For a) epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD epoxy resin, naphthalene epoxy resin, biphenyl epoxy resin, glycidol can be used. Amine type epoxy resin, naphthol novolac type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, ring fat ring An oxyresin, a prepolymer of the foregoing epoxy resin, a polyether modified epoxy resin, a polyfluorene modified epoxy resin, a copolymer of an epoxy resin and other polymers, or a mixture thereof.

For the b) photopolymerization initiator, a diazonium salt, an aromatic sulfonium salt, an aromatic cerium aluminum salt, an aromatic cerium aluminum salt, a metal aromatic compound, a steel arene compound, and the like can be used. a mixture.

In particular, in terms of photocurability, an aromatic sulfonium salt is preferred, and in terms of curability and adhesion, an aromatic hexafluorophosphate, an aromatic hydrazine, a hexafluoroantimonite or the like The mixture is preferred.

The photopolymerization initiator is preferably used in an amount of from 0.01 to 20 parts by weight, more preferably from 0.1 to 10 parts by weight, most preferably from 1 to 6 parts by weight, based on 100 parts by weight of the epoxy resin. If it exceeds 20 parts by weight, it cannot participate in the reaction, and the remaining components may deteriorate the properties of the photocurable resin composition.

c) a coupling agent is used to increase the adhesion (adhesion), and a decane coupling agent (such as trimethoxy benzoic acid or γ-glycidoxypropyl trimethoxy decane), a titanium coupling agent, a polyoxygen compound, or a mixture thereof.

The coupling agent is preferably used in an amount of from 0.01 to 10 parts by weight, more preferably from 0.1 to 5 parts by weight, most preferably from 0.1 to 2 parts by weight, based on 100 parts by weight of the epoxy resin. If it exceeds 10 parts by weight, it cannot participate in the reaction, and the remaining components may deteriorate the properties of the photocurable resin composition.

In the case of d) inorganic fillers, plate-shaped or spherical inorganic fillers such as cerium oxide, talc, MgO, mica, montmorillonite, alumina, graphite, cerium oxide, aluminum nitride, cerium carbide, and rich may be used. Aluminite, enamel, etc.

In the case of inorganic fillers, talc is particularly preferred because of its excellent barrier properties and light penetration, and avoids shrinkage after photocuring.

Moreover, in order to increase the adhesion in the photocurable resin composition and the dispersibility of the epoxy resin, the inorganic filler may be replaced by a substitute.

The inorganic filler is preferably used in an amount of from 0.01 to 100 parts by weight, more preferably from 0.1 to 80 parts by weight, based on 100 parts by weight of the epoxy resin. If it exceeds 100 parts by weight, it may interfere with the reaction of the resin composition, thereby deteriorating the properties of the composition. The inorganic filler preferably has an average particle size of from 0.1 to 30 μm.

In the case of e) photoacid generators, any compound which can be lighted to produce Lewis acid or Brucella (and thus acid by light) can be used without limitation. For example, a sulfonic acid compound such as an organic sulfonic acid, a monoterpenoid such as a phosphonium salt, or a mixture thereof may be used. Specific examples of the photoacid generator include phthalimide trifluoromethanesulfonate, dinitrobenzyltoluenesulfonate, n-fluorenyldihydrazide, naphthalimine trifluoromethanesulfonate, Diphenyliodo hexafluoroarcenate, diphenyliodo hexafluoroantimonate, diphenyl-p-methoxyphenylphosphonium trifluoride Methanesulfonate, diphenyl-p-isobutoxyphenyl fluorene trifluoromethanesulfonate, triphenyl sulfonium hexafluoroarcenate, triphenyl sulfonium triphenyl sulfonium Hexafluoroantimonate), triphenylsulfonium trifluoromethanesulfonate, dibutylnaphthoquinone trifluoromethanesulfonate, and the like.

The photoacid generator is preferably used in an amount of from 0.05 to 10 parts by weight based on 100 parts by weight of the epoxy resin. If it exceeds 10 parts by weight, the photoacid generator absorbs too much deep ultraviolet light and generates a lot of acid, thereby deteriorating the properties of the photocurable resin composition.

The photocurable resin composition may further comprise a spacer. As the spacer, any spacer which can stably maintain the thickness of one panel can be used without limitation, and it is preferable to use a spacer which can maintain a thickness of 5 to 50 μm, more preferably 5 to 25 μm. The shape of the spacer may be spherical, round, or the like, and the shape is not particularly limited thereto if the thickness of the panel can be stably maintained. The spacer is preferably used in an amount of from 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

The aforementioned photocurable resin composition preferably has an epoxy resin change rate of 85% or more of the cured resin.

Then, the resultant upper substrate is bonded to the bonded substrate (which is bonded to the upper substrate) to produce an assembly. In the first drawing, the lower substrate corresponds to the bonded substrate. Since the internal access is limited after the lower and the bonded substrate are joined to form an assembly, the bonding to the bonded substrate must be completed in all necessary steps for forming a unit cell (including as shown in FIG. 1 The electrode formation, dye absorption, etc.) are performed.

Moreover, when the frit and the photocurable resin composition are applied along the seal line, they or the like may be completely applied to maintain a complete seal, or, if necessary, leave a connecting line to The internal empty room is in contact. In the dye-sensitized solar cell of the present invention, since an electrolyte must be filled, an electrolyte inlet can be left.

In the joined assembly, the frit and the photocurable resin composition are not cured. Therefore, the next step is to illuminate the light to cure the photocurable resin composition on the assembly to cure the assembly. As shown in Fig. 1, if a photocurable resin composition is UV-curable, UV is irradiated to cure. The glass frit of the assembly must then be cured. In order to cure the glass frit of the assembly, a laser is irradiated along the applied frit to be sintered. As noted above, a low melting frit can be used so that a low output laser can be used, thereby minimizing thermal damage to the component. Wherein the resin composition layer that has been cured and surrounds the frit avoids gas generation and contact with oxygen and supports the assembly during sintering of the frit. Therefore, the efficiency and process efficiency of the frit seal can be increased by pre-sealing.

Therefore, the double-layer sealing of the dye-sensitized solar cell is maintained by the glass frit and a resin composition. Then, as shown in Fig. 1, an empty space between the sealing line and the application site of the photocurable resin composition can be cut to separate the cured portion of the photocurable resin composition. In Fig. 1, a plurality of unit cell systems are fabricated on one substrate, and therefore, a dicing step is performed for preparing a plurality of unit cells. Further, after the frit is sintered or cut, an electrolyte may be injected into the aforementioned electrolyte inlet, and then a glass frit is used for final sealing to complete the sealing.

The present invention is not limited to the foregoing embodiments and the accompanying drawings, and various modifications and changes can be made by those skilled in the art without departing from the scope and scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram showing a method for preparing a dye-sensitized solar cell in accordance with an embodiment of the present invention.

Claims (6)

A method for preparing a dye-sensitized solar cell, comprising: bonding an upper substrate and a bonding substrate bonded to the upper substrate, the method comprising the steps of: sealing a solar cell along the dye-sensitized a glass frit composition comprising a) 60 to 90 parts by weight of a glass frit, b) 0.1 to 5 parts by weight of an organic binder, and c on a bonding surface of one of the upper substrate or the bonding substrate 5 to 35 parts by weight of an organic solvent; at the edge of the upper substrate or the bonding surface of the bonding substrate and away from the sealing line, a photocurable resin composition comprising a) 100 parts by weight of a ring is applied Oxygen resin, b) 0.01 to 20 parts by weight of one photopolymerization initiator, c) 0.01 to 10 parts by weight of one coupling agent, d) 0.01 to 100 parts by weight of one inorganic filler selected from cerium oxide, a group consisting of talc, MgO, mica, montmorillonite, alumina, graphite, cerium oxide, aluminum nitride, tantalum carbide, mullite, lanthanum, and the like, and e) 0.05 to 10 parts by weight a photoacid generator; bonding the upper substrate to the bonding a substrate to form an assembly; irradiating light of the photocurable resin composition on the assembly to cure the assembly; irradiating a laser along the frit of the assembly to sinter; and cutting a seal An empty space between the wire and the application site of the photocurable resin composition is applied to separate the cured portion of the photocurable resin composition. The method of claim 1, wherein the glass frit comprises 0 to 30 mol% of P ₂ O ₅ , 0 to 50 mol% of V ₂ O ₅ , 0 to 20 mol% of ZnO, 0 to 15 mol% of BaO, and 0 to 20 mol%. As ₂ O ₃ , 0-20 mol% Sb ₂ O ₃ , 0-5 mol% In ₂ O ₃ , 0-10 mol% Fe ₂ O ₃ , 0-5 mol% Al ₂ O ₃ , 0-20 mol% B ₂ O ₃ , 0~10mol% Bi ₂ O ₃ , and 0~10mol% TiO ₂ . The method of claim 1, wherein the a) epoxy resin is selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin. Resin, biphenyl type epoxy resin, glycidylamine type epoxy resin, naphthol novolac type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin (phenol novolac type epoxy resin), cycloaliphatic epoxy resin, prepolymer of the epoxy resin, polyether modified epoxy resin, polyoxymethylene modified epoxy resin, the epoxy resin and other polymers a group consisting of a copolymer, a mixture thereof, and the like. The method of claim 1, wherein the b) photopolymerization initiator is selected from the group consisting of a diazonium salt, an aromatic cerium salt, an aromatic cerium aluminum salt, an aromatic cerium aluminum salt, a metal aromatic compound, and a fragrance. A group of hydrocarbon arene compounds and mixtures thereof. The method of claim 1, wherein the c) coupling agent is selected from the group consisting of a decane coupling agent, a titanium coupling agent, a polyoxymethylene compound, and a mixture thereof. The method of claim 1, wherein the e) photoacid generator is selected from the group consisting of a monosulfonic acid compound, a monoterpenoid, and the like.