JP5455481B2 - Photoelectric conversion device - Google Patents

Description

The present invention relates to a photoelectric conversion device in which substrates are bonded to each other through a bonding material.

  The solar cell as a photoelectric conversion device has various forms such as a bulk crystal silicon solar cell and a thin film amorphous silicon solar cell using an amorphous silicon thin film. In addition, for the purpose of reducing silicon raw materials, a dye-sensitized solar cell using an organic material has been proposed as a next-generation solar cell that does not use silicon.

  The solar cell is mainly used outdoors, and in that case, the surface temperature is exposed to a high temperature exceeding 80 ° C. Moreover, it will also be exposed to wind and rain for a long time. Under such conditions of use, the solar cell is made up of a low-reactivity member due to heat, and the inside of the solar cell is protected from substances that react with the member, such as moisture and oxygen, to deteriorate the characteristics. It was necessary to hermetically seal the inside of the solar cell. Thus, a method has been proposed in which a pair of substrates is bonded with a bonding material, and a photoelectric conversion element is sealed between the substrates (see Patent Document 1).

JP 2001-185244 A

  When sealing a photoelectric conversion element with a glass substrate, when a stress is received at the glass substrate central portion, the glass substrate is deformed to generate stress.

  As the size of the photoelectric conversion device increases, the area for sealing the photoelectric conversion elements, that is, the area surrounded by the bonding material for bonding the glass substrates increases, and the deformation of the glass substrate also increases.

  The photoelectric conversion device repeatedly receives stress from the outside due to, for example, falling objects from the sky, and there is a problem that the glass substrate is easily broken.

  Such stress from the outside of the glass substrate not only destroys the glass substrate itself, but also causes problems such as destruction of the photoelectric conversion element inside the photoelectric conversion device and peeling of the solder of the photoelectric conversion element. There has been a problem of reducing the reliability of the conversion device.

  The present invention has been completed in view of the above-described conventional problems, and an object of the present invention is to provide a bonded structure having high resistance to destruction by increasing the strength of the bonded structure after bonding the substrates. That is.

One embodiment of the photoelectric conversion device of the present invention includes a pair of opposing substrates, a photoelectric conversion element provided between the pair of substrates, and a pressure-bonded to the photoelectric conversion element provided on the pair of substrates. A resin that holds the photoelectric conversion element and a bonding material that bonds the pair of substrates to each other, the resin and the bonding material are separated from each other and orthogonal to the facing surfaces of the pair of substrates. In the cross-section of the substrate and the bonding material crossing the side surface on the photoelectric conversion element side of the bonding material and the side surface on the opposite side, the central portion of the bonding material is thin and the substrate follows the bonding material. It is characterized by being curved.

  With such a configuration, the substrate is deformed so as to protrude toward the bonding material in accordance with the shape of the bonding material at the bonding portion of the substrate with the bonding material. As a result of this deformation, a stress is generated outward from the photoelectric conversion element side at a portion of the substrate corresponding to the photoelectric conversion element. As a result, resistance to stress applied from the outside toward the photoelectric conversion element is increased, and the reliability of the operation of the photoelectric conversion device can be increased.

  In the photoelectric conversion device of the present invention, preferably, the bonding material is glass.

  In the photoelectric conversion device of the present invention, preferably, the photoelectric conversion element contains crystalline silicon.

  In the photoelectric conversion device of the present invention, preferably, the bonding material is located at an end portion of the substrate.

  With such a configuration, in the central portion of the substrate corresponding to the photoelectric conversion element, it is possible to satisfactorily generate stress directed outward from the photoelectric conversion element side, and resistance to stress applied from the outside toward the photoelectric conversion element. Can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the intensity | strength of the joining structure body after joining of board | substrates can be raised, and the joining structure body with high tolerance with respect to destruction can be provided.

It is sectional drawing which shows 1st Embodiment of the photoelectric conversion apparatus which concerns on this invention. It is sectional drawing which shows 2nd Embodiment of the photoelectric conversion apparatus as a reference . It is sectional drawing which shows 3rd Embodiment of the photoelectric conversion apparatus as a reference .

  Hereinafter, embodiments of a photoelectric conversion device as a connection structure of the present invention will be described in detail with reference to the drawings schematically shown.

  FIG. 1 is a cross-sectional view showing a first embodiment of the photoelectric conversion device of the present invention. The photoelectric conversion device X includes a first resin 3 and a second resin on a pair of substrates (hereinafter, referred to as a first substrate 1 and a second substrate 2) arranged so that one principal surface faces each other. The resin 4 is formed. Further, the first resin 3 and the second resin 4 are pressure-bonded to the photoelectric conversion element 5. From the photoelectric conversion element 5, the first electrode 6 and the second electrode 7 are connected to extract electric charges, and electric charges are extracted outside the photoelectric conversion device X by the third electrode 8 and the fourth electrode 9, respectively. .

  And in the photoelectric conversion apparatus X which concerns on embodiment of this invention, the inside of the photoelectric conversion apparatus X is sealed with the bonding material 10 provided so that the photoelectric conversion element 5 may be surrounded, and a pair of board | substrates 1 and 2 In the cross section of the bonding material that is orthogonal to the opposite surface and crosses the side surface on the photoelectric conversion element side of the bonding material 10 and the side surface on the opposite side, the central portion of the bonding material is thin. That is, the bonding material 10 is formed in a frame shape so as to surround the photoelectric conversion element 5, and the central portion is formed thinner than the thickness of the inner peripheral side and the outer peripheral side of the frame-shaped bonding material 10. ing. Therefore, stress is applied to the substrate 1 depending on the shape of the bonding material 10 while ensuring hermetic sealing with the bonding material 10, and the bonding portion of the first substrate 1 with the bonding material 10 is opposed to the second substrate 2 side. It is deformed to be convex. By doing in this way, the site | part corresponding to the photoelectric conversion element 5 of the 1st board | substrate 1, ie, the site | part inside the bonding | jointing material 10 of the 1st board | substrate 1, is outside the photoelectric conversion apparatus X (photoelectric conversion element 5). It can be deformed so as to be convex toward the opposite side), and can have a shape resistant to stress from the outside of the photoelectric conversion device X.

  Below, the detail of the member which comprises the photoelectric conversion apparatus which concerns on embodiment of this invention mentioned above is shown.

<First and second substrates>
The first substrate 1 supports the first resin 3 and the photoelectric conversion element 5 arranged on the first resin 3 on one main surface, and a bonding material 10 and a second substrate 2 described later. Thus, the photoelectric conversion device X is sealed. Moreover, when the 1st board | substrate 1 is provided in the light incident side, it needs to have translucency.

  Examples of the material of the first substrate 1 include glass materials such as blue plate glass, white plate glass, and non-alkali glass, which are transparent to visible light.

  The second substrate 2 supports the second resin 4 and the photoelectric conversion element 5 disposed on the second resin 4 on one main surface, and the bonding material 10 and the first substrate 2 provide photoelectric The conversion device X is sealed. Moreover, when the 2nd board | substrate 2 is provided in the light incident side, it needs to have translucency.

  Examples of the material of the second substrate 2 include glass materials such as blue plate glass, white plate glass, and non-alkali glass that are transparent to visible light.

<First and second resins>
The first resin 3 holds the photoelectric conversion element 5 and protects it from damage due to impact or the like. At the same time, when light is incident from the first substrate 1, a transparent resin is used. Alternatively, when light is incident from the second substrate 2, it may be transparent or colored in a color that reflects and scatters light. Moreover, the function which supplements adhesion | attachment with the 1st electrode 6 and the photoelectric conversion element 5 which are mentioned later, or the 1st electrode 6 and the 3rd electrode 8 mentioned later can also be provided. Similarly, it is possible to provide a function of compensating adhesion between the second electrode 7 and the photoelectric conversion element 5 described later, or between the second electrode 7 and the fourth electrode 9 described later.

  The second resin 4 holds the photoelectric conversion element 5 and protects it from damage due to impact or the like. At the same time, when light is incident from the second substrate 2, a transparent resin is used. Alternatively, when light is incident from the first substrate 1, it may be transparent or colored in a color that reflects and scatters light. Moreover, the function which supplements adhesion | attachment with the 1st electrode 6 and the photoelectric conversion element 5 which are mentioned later, or the 1st electrode 6 and the 3rd electrode 8 mentioned later can also be provided. Similarly, it is possible to provide a function of compensating adhesion between the second electrode 7 and the photoelectric conversion element 5 described later, or between the second electrode 7 and the fourth electrode 9 described later.

<Photoelectric conversion element>
Examples of the photoelectric conversion element 5 include a surface treatment, a pn junction, a finger electrode, a bus bar electrode, and a back electrode, and a polycrystalline solar cell element produced so that an electromotive force can be generated by sunlight. .

  Other examples include a single crystal silicon solar cell element and a back contact cell in which electrodes are collected on the back surface. When using a back contact cell, although not shown, the first electrode 6 and the second electrode 7 are connected to the same main surface of the photoelectric conversion element 5.

  In addition, the photoelectric conversion element 5 may convert light into electricity, or may convert electricity into light. Examples of the photoelectric conversion element 5 include photovoltaic elements such as solar battery elements, light emitting elements, photodiodes, and the like.

<First, second, third and fourth electrodes>
The first electrode 6 is an electrode that draws one charge from the photoelectric conversion element 5, and is connected to the third electrode 8 to supply the charge to the outside of the photoelectric conversion device X.

  Similarly, the second electrode 7 is an electrode that extracts the other charge from the photoelectric conversion element 5, and is connected to the fourth electrode 9 to supply the charge to the outside of the photoelectric conversion device X.

  Although not shown, a plurality of photoelectric conversion elements 5 can be connected in series inside the photoelectric conversion device X and connected in series. By doing in this way, it becomes possible to take out the charge of a plurality of cells with high voltage, and the Joule loss is reduced, so that the conversion efficiency of the photoelectric conversion device X is improved.

  The third electrode 8 is an electrode existing between the bonding material 10 and the second substrate 2, is connected to the first electrode 6, and takes out one charge of the photoelectric conversion element 5 to the outside of the photoelectric conversion device X. Here, the third electrode 8 is made of a metal such as aluminum, titanium, or molybdenum, a tin-doped indium oxide film, a fluorine-doped tin oxide film, or the like. Is required. The shape of the third electrode 8 may be any shape as long as it does not contact the fourth electrode 9 described later. The third electrode 8 is partially exposed in the portion located between the bonding material 10 and the second substrate 2 in order to ensure contact between the bonding material 10 and the second substrate 2. As such, it may have a non-formed part.

  Further, the third electrode 8 may be made of the same material as the first electrode 6 as long as the above-described heat resistance is not a problem. In this case, it is not necessary to separate the first electrode 3 and the third electrode 8, and it is possible to connect the photoelectric conversion element 5 with a single member and take out the charge outside the photoelectric conversion device X.

  The fourth electrode 9 is an electrode existing between the bonding material 10 and the second substrate 2, is connected to the second electrode 7, and takes out the other charge of the photoelectric conversion element 5 to the outside of the photoelectric conversion device X. Here, the fourth electrode 9 is made of a metal such as aluminum, titanium, or molybdenum, a tin-doped indium oxide film, a fluorine-doped tin oxide film, or the like, and has heat resistance sufficient to seal the bonding material 10 on the fourth electrode 9 by heating. Is required. The shape of the fourth electrode 9 may be any shape as long as it does not contact the third electrode 8. The fourth electrode 9 is partially exposed in order to ensure contact between the bonding material 10 and the second substrate 2 at a portion located between the bonding material 10 and the second substrate 2. As such, it may have a non-formed part.

  Further, the fourth electrode 9 may be made of the same material as the second electrode 7 as long as the above-described heat resistance is not a problem. In this case, it is not necessary to separate the second electrode 7 and the fourth electrode 9, and it is possible to connect the photoelectric conversion element 5 with a single member and take out the charge outside the photoelectric conversion device X.

<Bonding material>
The bonding material 10 is a member that seals the photoelectric conversion device X with the first substrate 1, the second substrate 2, the third electrode 8, and the fourth electrode 9.

As the bonding material 10, an inorganic material, an organic material, an organic-inorganic composite material, or the like is used. From the viewpoint of enhancing the sealing performance, it is preferably made of an inorganic material such as glass. When the bonding material 10 is made of glass, the bonding material 10 includes magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), and potassium oxide. (K ₂ O), diboron trioxide (B ₂ O ₃ ), vanadium pentoxide (V ₂ O 5), zinc oxide (ZnO), tellurium dioxide (TeO ₂ ), aluminum trioxide (Al 2 O 3), silicon dioxide (SiO ₂ ) Lead oxide (PbO), tin oxide (SnO), phosphorus pentoxide (P ₂ O ₅ ), ruthenium oxide (Ru ₂ O), rubidium oxide (Rb ₂ O), rhodium oxide (Rh ₂ O), iron trioxide (Fe) ₂ O ₃ ), copper oxide (CuO), titanium dioxide (TiO ₂ ), tungsten trioxide (WO ₃ ), bismuth trioxide (Bi ₂ O ₃ ), triacid One substance selected from the group consisting of antimony phosphide (Sb ₂ O ₃ ), lead-borate glass, tin-phosphate glass, and boron silicate, or It is desirable that the glass is a combination of these. Thereby, the softening point of the bonding material 10 can be made lower than the softening points of the first substrate 1 and the second substrate 2 made of a glass material such as blue plate glass, white plate glass, and non-alkali glass, and the photoelectric conversion device X It is possible to suppress the occurrence of thermal stress on the first substrate 1 and the second substrate 2 when sealing the substrate.

  The bonding material 10 is orthogonal to the opposing surfaces of the pair of substrates 1 and 2 and is on the center side of the photoelectric conversion device X in the cross section of the bonding material 10 across the side surface of the bonding material 10 on the photoelectric conversion element 5 side and the opposite side surface. Compared with the part 10a (photoelectric conversion element 5 side) and the part 10c outside the photoelectric conversion device X, the central portion 10b is formed thinner. By doing so, stress can be applied to at least one of the first substrate 1 and the second substrate 2. At this time, the direction in which the stress is applied is the direction in which the joint between the first substrate 1 and the joint material 10 or the joint between the second substrate 2 and the joint material 10 receives tensile stress toward the joint material 10. . As a result, a stress is generated that pushes the portion corresponding to the photoelectric conversion element 5 of the first substrate 1 or the second substrate 2 (the portion on the inner side of the bonding material 10) to the side opposite to the photoelectric conversion element 5. Therefore, when a stress is applied to the photoelectric conversion device X from the outside, the stress is applied in the opposite direction, and the deformation of the first substrate 1 or the second substrate 2 due to the stress from the outside is suppressed. Can do.

  For example, when the first substrate 1 and the second substrate 2 are bonded to each other, the bonding material 10 having a thin central portion 10b is formed on the side surface (photoelectric conversion element 5 side). And after melting so as to be higher than the portions 10a and 10c on the opposite side), the bonding material 10 is cooled, and the central portion 10b of the bonding material 10 is contracted to a greater extent than the side portions 10a and 10c. Thus, the central portion 10b of the bonding material 10 can be thinned. That is, when the bonding material 10 is cooled from a higher temperature, the shrinkage rate is larger, so that the portion of the bonding material 10 after being cooled becomes thinner.

  The method of setting the central portion 10b of the bonding material 10 to a high temperature is, for example, generating a temperature difference between the side portions 10a and 10c and the central portion 10b by irradiating the central portion 10b of the bonding material 10 with a laser. Can do.

  In addition, the bonding material 10 having a thin central portion 10b generates bubbles in the central portion 10b of the bonding material 10 when the bonding material 10 is melted to bond the first substrate 1 and the second substrate 2. Or after enlarging the bubble of the center part 10b, the joining material 10 can be cooled, said bubble can be shrunk | reduced, and the center part 10b of the joining material 10 can be made thin. That is, since the gas constituting the bubbles has a large shrinkage rate at the time of cooling, if the volume occupied by the bubbles in the central portion 10b is larger than the side portions 10a and 10c when the bonding material 10 is melted, the bonding material When 10 is cooled, the part occupied by the bubbles is greatly contracted.

  As described above, as a method for generating bubbles in the central portion 10b of the bonding material 10 or enlarging the bubbles in the central portion 10b, the bonding material 10 includes gas and moisture, When the substrate 1 and the second substrate 2 are bonded through the bonding material 10, the central portion 10 b of the bonding material 10 is locally heated by laser irradiation or the like, whereby the contained gas or moisture is bubbled. Can be grown as. Further, the bonding material 10 may contain a substance that generates a gas by heating.

  The bonding material 10 is preferably formed on the first substrate 1 or the second substrate 2 by a screen printing method or a dispensing method. When the bonding material 10 is applied by a screen printing method or a dispensing method, air is likely to be mixed into the bonding material 10. As a result, the bubble 10 can be generated easily and easily by expanding the bonding material and the mixed air.

  When the bonding material 10 is heated with a laser, the bonding material 10 is, for example, a glass containing a light absorbing agent such as a pigment, or a layer of laminated glass containing a light absorbing material such as a pigment. That's fine. When bonding the first substrate 1 and the second substrate 2 by heating the bonding material 10 with a laser, the bonding material 10 is sufficiently softened while suppressing the amount of heat given to the other members of the photoelectric conversion device X as much as possible. This is preferable. Further, the bonding material 10 may not contain a pigment as long as it can be laser heated. Further, in order to protect the third electrode 8 and the fourth electrode 9 from the heat at the time of laser heating, a pigment and a dye that absorb laser light are arranged on the first substrate 1 side, and the third electrode 8 It is preferable to have a multi-stage structure with as few pigments and dyes as possible on the electrode 9 side.

  In addition, the bonding material 10 is preferably located at at least one end of the first substrate 1 and the second substrate 2. With such a configuration, in the central portion of the substrate corresponding to the photoelectric conversion element 5, it is possible to satisfactorily generate stress outward from the photoelectric conversion element 5 side, and stress applied from the outside toward the photoelectric conversion element 5. It is possible to further increase the resistance to.

FIG. 2 is a cross-sectional view showing a second embodiment of a photoelectric conversion device as a reference . In the photoelectric conversion device X ′ of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. The photoelectric conversion device X ′ of the second embodiment is the same as that of the first embodiment in that the thin film photoelectric conversion body 12 including the semiconductor layer formed on the surface of the second substrate 2 is used as the photoelectric conversion element. It differs from the photoelectric conversion device X.

  Also in the photoelectric conversion device X ′ using such a thin film photoelectric conversion body 12, by using the bonding material 10 with a thin central portion 10 b, resistance to stress from the outside of the photoelectric conversion device X ′ can be increased.

<Thin film photoelectric converter>
The thin film photoelectric conversion body 12 is, for example, an amorphous silicon photoelectric conversion body, an amorphous silicon / microcrystalline silicon tandem photoelectric conversion body, a CdTe photoelectric conversion body, a CIGS photoelectric conversion body, or an organic thin film photoelectric conversion body. At least one pn junction or pin junction is formed so that an electromotive force can be generated by sunlight.

  The thin film photoelectric converter 12 illustrated in FIG. 2 is formed on the fifth electrode 20 by a thin film forming method or the like, and has a sixth electrode 21 thereon. The fifth electrode 20 of the thin film photoelectric converter 12 is connected to the sixth electrode 21 of the adjacent thin film photoelectric converter 12, and a plurality of thin film photoelectric converters 12 are connected in series on the main surface of the second substrate 2. Is forming. By doing in this way, it becomes possible to take out the charge of a plurality of cells with high voltage, and the Joule loss is reduced, so that the conversion efficiency of the photoelectric conversion device X is improved.

<Fifth electrode and sixth electrode>
The first electrode 6 is an electrode that draws one charge from the thin film photoelectric converter 12 and is connected to the third electrode 8 to supply the charge to the outside of the photoelectric conversion device X.

  The fifth electrode 20 is formed on the second substrate 2 and is divided into a plurality of parts by laser scribing or the like, and has the thin film photoelectric converter 12 on each main surface. The fifth electrode 20 is connected to the function of extracting one charge from the thin film photoelectric converter 12 and extracting the other charge to the outside of the photoelectric conversion device X ′, and the sixth electrode 21 of the adjacent photoelectric converter 12. Thus, the charge can be divided into a function of combining one charge and the other charge and a function of taking out the other charge extracted by the sixth electrode 21 to the outside of the thin film photoelectric conversion device X ′.

  The fifth electrode 20 is selected from one kind of metal such as aluminum, titanium, molybdenum, tin-doped indium oxide film, fluorine-doped tin oxide film, antimony-doped tin oxide film, or a laminate thereof. The fifth electrode 20 is formed between the second substrate 2 and the bonding material 10 so that one charge can be taken out of the photoelectric conversion device X ′. Thus, it has heat resistance sufficient to seal the bonding material 10 by heating. The fifth electrode 20 may have a non-forming portion that exposes the second substrate 2 in part in order to ensure contact between the bonding material 10 and the second substrate 2.

  The sixth electrode 21 is formed on the thin film photoelectric converter 12 and has a function of extracting the other charge from the thin film photoelectric converter 12. The sixth electrode 21 is selected from one kind of metal such as aluminum, titanium, and molybdenum, a tin-doped indium oxide film, a fluorine-doped tin oxide film, and an antimony-doped tin oxide film, or a laminate thereof. Furthermore, a finger electrode made of a metal such as silver is formed on the sixth electrode 21 by a printing method, dispensing, or the like, and is fired to further reduce the resistance and improve the conversion efficiency.

FIG. 3 is a cross-sectional view showing a third embodiment of a photoelectric conversion device as a reference . In the photoelectric conversion device X ″ according to the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals. The photoelectric conversion device X ″ of the third embodiment uses a photoelectric conversion body 16 (a dye-sensitized photoelectric conversion body) including the charge transport layer 14 and the porous light absorption layer 13 as a photoelectric conversion element. Thus, the photoelectric conversion devices X and X ′ of the first and second embodiments are different.

  In the photoelectric conversion device X ″, a pair of electrodes 22, a porous light absorption layer 13, a charge transport layer 14, a catalyst layer 15, and a spacer 17 are formed. One electrode 22 is connected to one side of the porous light absorption layer 13 in order to extract one charge. Further, the charge transport layer 14 and the other electrode 22 are connected to the other side of the porous light absorption layer 13 in order to take out the other electrode.

  Even in the photoelectric conversion device X ″ using the photoelectric conversion body 16 including the charge transport layer 14 and the porous light absorption layer 13, the photoelectric conversion device X ′ is obtained by using the bonding material 10 having a thin central portion 10 b. The resistance to external stress can be increased.

<A pair of electrodes>
The pair of electrodes 22 has a function of taking out charges generated in the porous light absorption layer 13 described later, and is provided on one main surface of the first substrate 1 and one main surface of the second substrate 2. When the electrode 22 is on the light incident side, the electrode 22 needs to have translucency with respect to visible light.

  As a material of the electrode 22, for example, an ITO (tin-doped indium oxide: indium tin oxide) layer, an FTO (fluorine-doped tin oxide) layer, or a tin oxide layer is formed. In addition, the thickness of the electrode 22 is preferably about 0.3 to 2 μm from the viewpoint of ease of manufacture and appropriate sheet resistance. Such an electrode 22 is formed in layers by, for example, a CVD method, a sputtering method, a spray method, or the like.

<Catalyst layer>
The catalyst layer 15 is made of Pt, Pd, Ru, Os, Rh, Ir, etc., carbon, PEDOT: TsO (polyethylenedioxythiophene-toluenesulfonate), etc. on the contact surface with the charge transport layer 14. In this way, charge transfer from the charge transport layer 14 to the electrode 22 can be performed efficiently.

<Charge transport layer>
The charge transport layer 14 has a function of transferring the charge received from the catalyst layer 15 to a dye in the porous light absorption layer 13 described later. For example, the charge transport layer 14 may be liquid (electrolytic solution), gel, or solid (polymer), and may be solid after injection.

  When the charge transport layer 14 is an electrolytic solution, examples thereof include iodine / iodide salts, bromine / bromide salts, cobalt complexes, and potassium ferrocyanide. The notation “iodine / iodide salt” means that the content of iodine and iodide salt changes due to the chemical reaction of the electrolyte. In addition, when the charge transport layer 14 is liquid or gel at the time of injection and becomes a solid after injection, the charge transport layer 14 is a solid electrolyte such as a gel electrolyte or a polymer electrolyte, a conductive polymer such as polythiophene / polypyrrole or polyphenylene vinylene, or a fullerene derivative. And organic molecular electron transport agents such as pentacene derivatives, perylene derivatives, and triphenyldiamine derivatives. The distance between the charge transport layer 14, that is, the one principal surface of the first substrate 1 and the one principal surface of the second substrate is preferably about 1 to 500 μm.

<Spacer>
The spacer 17 confines the charge transport layer 14 between the first substrate 1 and the second substrate 2 and suppresses energy loss due to charge recombination between adjacent porous light absorption layers 13. Arranged around the layer 15. The spacer 17 is made of, for example, a glass material such as a glass frit, polyethylene, modified polyethylene, maleic acid-modified polyethylene, polypropylene, modified polypropylene, maleic acid-modified polypropylene, ionomer resin, fluorine resin, epoxy resin, or acrylate resin. Materials. Further, when the spacer 17 is made of a resin material, the organic material described above is arranged at a portion that contacts the charge transport layer 14, and the outer periphery of the organic material is further covered with a glass material. Airtightness and mechanical strength can be increased.

<Porous light absorption layer>
The porous light absorption layer 13 is composed of a porous body having a function of supporting a dye in the pores and a dye adsorbed on the porous body. Since the porous light absorption layer 13 has a large surface area of the porous body and can carry (adsorb) more dye, it absorbs light efficiently and contributes to improvement in photoelectric conversion efficiency.

  Examples of such a porous material include titanium (Ti), zinc (Zn), tin (Sn), niobium (Nb), indium (In), yttrium (Y), lanthanum (La), zirconium ( Zr), tantalum (Ta), hafnium (Hf), strontium (Sr), barium (Ba), calcium (Ca), vanadium (V), at least one metal oxide semiconductor such as tungsten (W) Moreover, it may contain one or more of non-metallic elements such as nitrogen (N), carbon (C), fluorine (F), sulfur (S), chlorine (Cl), phosphorus (P) and the like. In particular, titanium oxide is preferable because it has a band gap of 3.7 eV that does not absorb sunlight with visible light or less. The porous body is preferably an n-type semiconductor whose conduction band is lower than the conduction band of the dye at the electron energy level.

  Moreover, since the porous light absorption layer 13 is a porous body, it has many fine pores (having a pore diameter of preferably about 10 to 40 nm) inside. Moreover, the thickness of the porous light absorption layer 13 is 1-50 micrometers from a viewpoint of optimizing a photoelectric conversion effect | action, More preferably, 10-30 micrometers is good. Further, an ultrathin (thickness: about 200 nm) dense layer of an n-type oxide semiconductor may be inserted between the porous light absorption layer 13 and the electrode 22 to suppress the reverse current from the electrode 22 to the charge transport layer 14. There is an effect to.

  Examples of the dye include ruthenium-tris, ruthenium-bis, osmium-tris, osmium-bis type transition metal complexes, polynuclear complexes, or ruthenium-cis-diaqua-bipyridyl complexes, or phthalocyanines, porphyrins, polycyclic aromatic compounds, It is preferable to use a xanthene group such as rhodamine B.

  In order to adsorb the dye to the porous light absorption layer 13, it is effective that the dye has at least one carboxyl group, sulfonyl group, hydroxamic acid group, alkoxy group, aryl group, phosphoryl group or the like as a substituent. is there. Here, the substituent is not particularly limited as long as it can strongly adsorb the dye itself to the porous body of the porous light absorption layer 13 and can easily transfer the charge from the excited sensitizing dye to the porous body. .

Examples of the method for adsorbing the dye on the porous light absorption layer 13 include a method of immersing the porous light absorption layer 13 formed on the first substrate 1 in a solution in which the dye is dissolved. When the dye is adsorbed on the porous light absorption layer 13, examples of the solvent of the solution for dissolving the dye include alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether, nitrogen compounds such as acetonitrile, and the like. May be one or a mixture of two or more. The concentration of the dye in the solution is preferably about 5 × 10 ⁻⁵ to 2 × 10 ⁻³ mol / l (l (liter): 1000 cm ³ ).

<Injection hole and sealing member>
Although not shown in FIG. 3, by forming an injection hole in the first substrate 1 or the second substrate 2, dye adsorption to the porous light absorption layer 13 and injection of the charge transport layer 14 are performed. It can also be performed after the bonding material 10 is formed.

  In this case, the shape and the like of the injection hole are not particularly limited as long as the charge transport layer 14 can be injected between the first and second substrates. For example, the cross-sectional shape is circular, It may be an ellipse or a polygon such as a quadrangle. As the size of the injection hole, for example, if the cross-sectional shape is circular, the diameter is preferably about 0.1 to 3 mm. Further, the number of injection holes is not limited to one, and a plurality of injection holes may be provided. Further, the injection hole may be provided only in the first substrate 1 or may be provided in each of the first and second substrates. The injection hole can be used not only for injecting the charge transport layer 14 but also for discharging the charge transport layer 14, injecting and discharging the dye solution, and the like.

  Further, when an injection hole is formed in the first substrate 1 or the second substrate 2, the charge transport layer 14 is prevented from leaking to the outside by the sealing member, and oxygen and moisture are externally supplied from the photoelectric conversion device X ′. 'Prevent from entering. This sealing member is bonded to the other main surface of the first substrate 1 or the second substrate 2 so as to close the injection hole.

  The sealing member includes a resin material having high corrosion resistance to the charge transport layer 14. Examples of such resin materials include film-shaped polyethylene, modified polyethylene, maleic acid-modified polyethylene, polypropylene, modified polypropylene, maleic acid-modified polypropylene, ionomer resins, and fluororesins or liquid butyl resins, epoxy resins, and acrylates. Examples thereof include resins. Moreover, these resin materials may contain a filler etc. as needed from a viewpoint of improving mechanical strength.

Moreover, it is preferable to use a glass frit containing a laser absorption component and a glass component for adhesion of the sealing member. The laser absorbing component plays a role of selectively melting and sintering the glass frit by selectively absorbing laser light and converting the energy into heat. The laser absorbing component is preferably melted as part of the matrix forming the glass frit, but may be segregated in the matrix. Further, if the thermal expansion coefficient of the glass frit is close to the thermal expansion coefficient of the second substrate 2, the occurrence of defects such as cracks can be reduced. Examples of the glass component forming the glass frit include SiO ₂ —Bi ₂ O ₃ —MO _X , B ₂ O ₃ —Bi ₂ O ₃ —MO _X , and SiO ₂ —CaO—Na (K) ₂ O—MO. _X- type, P ₂ O ₅ —MgO—MO _X- type (M is one or more metal elements, and X is an integer). Examples of the laser absorbing component include chromium, iron, nickel, cobalt, manganese, copper, or a simple substance or oxide of carbon, or two or more kinds of these compounds.

  The connection structure and the manufacturing method thereof according to the present invention include the above-described photoelectric conversion device and the manufacturing method thereof, but are not limited thereto. The present invention can be applied not only to the photoelectric conversion device but also to other fields. For example, in a package for storing electronic components, the present invention can also be applied to a bonding structure in which a container for storing electronic components and a lid are bonded via a bonding material.

X, X ′, X ″: photoelectric conversion device (connection structure)
1: first substrate 2: second substrate 3: first resin 4: second resin 5: photoelectric conversion element 6: first electrode 7: second electrode 8: third electrode 9: first 4 electrode 10: bonding material 10a: photoelectric conversion element side portion 10b of bonding material: bonding material central portion 10c: bonding material outer side portion 12: thin film photoelectric conversion body (photoelectric conversion element)
13: porous light absorption layer 14: charge transport layer 15: catalyst layer 16: photoelectric conversion element 20: fifth electrode 21: sixth electrode 22: electrode

Claims (4)

A substrate made of a pair of opposing glasses;
A photoelectric conversion element provided between the pair of substrates;
A resin that is provided on the pair of substrates and that holds the photoelectric conversion element by pressure bonding to the photoelectric conversion element;
A bonding material for bonding the pair of substrates,
The resin and the bonding material are separated from each other,
In the cross section of the substrate and the bonding material that is orthogonal to the opposing surfaces of the pair of substrates and crosses the side surface of the bonding material on the photoelectric conversion element side and the side surface on the opposite side, the central portion of the bonding material is thinned. And the substrate is curved following the bonding material.   The photoelectric conversion device according to claim 1, wherein the bonding material is glass.   The photoelectric conversion device according to claim 1, wherein the photoelectric conversion element includes crystalline silicon. The photoelectric conversion device according to any one of claims 1 to 3 wherein the bonding material is characterized in that located at the end portion of the substrate.

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