JP2013115233A - Photoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable photoelectric conversion module which reduces the occurrence of cracks in a substrate.SOLUTION: A photoelectric conversion module includes: a first substrate; a photoelectric conversion part 1 disposed on the first substrate; a covering member 9 covering the photoelectric conversion part 1; and a second substrate disposed on the covering member 9. Further, according to one embodiment, the photoelectric conversion module includes: a sealing member 12 which is disposed in a frame like manner so as to enclose the photoelectric conversion part 1 between the first substrate and the second substrate and fill an internal space with the covering member 9; and a reinforcement member 13 disposed on the first substrate in an inner peripheral edge part at the photoelectric conversion part 1 side of the sealing member 12.

Description

  The present invention relates to a photoelectric conversion module.

  There are various types of photoelectric conversion modules used for photovoltaic power generation and the like. Among these, chalcopyrite materials such as CIS (copper indium selenide) and CIGS (copper indium gallium selenide) are easy to manufacture large-area photoelectric conversion modules at a relatively low cost. Research and development is ongoing.

  In such a photoelectric conversion module, when moisture enters from the outside, the photovoltaic element made of the above-described material may be deteriorated, and the photoelectric conversion efficiency may be lowered. Therefore, a covering member made of a polymer material is provided around the photovoltaic element. Further, in such a photoelectric conversion module, a sealing member is provided on the outer peripheral portion of the substrate serving as a support to enhance the waterproof effect (for example, see Patent Document 1).

Special table 2010-541265

  However, in a conventional photoelectric conversion module, when used in a high temperature environment, the covering member expands, and stress tends to concentrate on the substrate in the vicinity of the boundary between the covering member and the sealing member. As a result, cracks may occur in the substrate at the boundary.

  One object of the present invention is to provide a highly reliable photoelectric conversion module that reduces the occurrence of cracks in a substrate.

  A photoelectric conversion module according to an embodiment of the present invention is disposed on a first substrate, a photoelectric conversion unit disposed on the first substrate, a covering member that covers the photoelectric conversion unit, and the covering member. And a second substrate. Further, in the present embodiment, a sealing member disposed in a frame shape so as to surround the photoelectric conversion portion between the first substrate and the second substrate and fill an internal space with the covering member, and the sealing member And a reinforcing member disposed on the first substrate at the inner peripheral edge of the stop member on the photoelectric conversion portion side.

  In the photoelectric conversion module according to one embodiment of the present invention, since the reinforcing member is provided on the first substrate in the vicinity of the boundary portion between the covering member and the sealing member, even if stress is concentrated in the vicinity of the boundary portion. The occurrence of cracks in the first substrate can be reduced.

It is a perspective view which shows an example of the photoelectric conversion part of the photoelectric conversion module which concerns on one Embodiment. It is sectional drawing which shows an example of the photoelectric conversion part of the photoelectric conversion module which concerns on one Embodiment. It is a schematic diagram of the photoelectric conversion module which concerns on one Embodiment. It is the schematic diagram which abbreviate | omitted the 2nd board | substrate of FIG. It is sectional drawing in the AA part of FIG. It is a schematic diagram of the photoelectric conversion module which concerns on other embodiment.

  An example of an embodiment of the photoelectric conversion module of the present invention will be described with reference to the drawings.

  First, a photoelectric conversion unit that is a part of the photoelectric conversion module will be described. Each figure may have a right-handed XYZ coordinate with the X-axis being the alignment direction of photoelectric conversion cells described later.

<Photoelectric conversion unit>
The photoelectric conversion unit 1 is provided on one main surface of a first substrate (hereinafter referred to as a substrate 2). And this photoelectric conversion part 1 was equipped with the lower electrode 3 as a 1st electrode, the photoelectric converting layer provided with the light absorption layer 4 and the buffer layer 5, the translucent conductive layer 6, and the current collection electrode 7. And an upper electrode as a second electrode. In the photoelectric conversion unit 1, photoelectric conversion is performed by the light absorption layer 4 and the buffer layer 5 sandwiched between the lower electrode 3 and the upper electrode.

  As shown in FIG. 1, the photoelectric conversion unit 1 is configured such that a plurality of photoelectric conversion cells 1 a and 1 b are electrically connected. Specifically, as shown in FIG. 1, an upper electrode (collecting electrode 7) of one photoelectric conversion cell 1a and a lower electrode 3 of the other photoelectric conversion cell 1b adjacent to one photoelectric conversion cell 1a are provided. Electrically connected. Thereby, the adjacent photoelectric conversion cells 1 a and 1 b are connected in series along the X direction in FIG. 1 and are integrated on the substrate 2.

  In addition, the photoelectric conversion unit 1 is provided with output electrodes 8 (output electrodes 8a and 8b) for leading the electrical output obtained by the photoelectric conversion unit 1 to the outside.

  Next, each member of the photoelectric conversion unit 1 will be described.

  A plurality of lower electrodes 3 are arranged on one main surface of the substrate 2 at intervals in one direction (X direction in FIG. 1). In the present embodiment, as shown in FIG. 2, three lower electrodes 3 are provided that are separated from each other by a separation groove P <b> 1 corresponding to the interval. The number of lower electrodes 3 is not limited to that shown in FIG. Such a lower electrode 3 may be a thin film containing a metal such as molybdenum (Mo), aluminum (Al), titanium (Ti), tantalum (Ta) or gold (Au) or an alloy thereof. Moreover, the structure formed by laminating | stacking these metals may be sufficient. The lower electrode 3 may be formed to a thickness of about 0.2 to 1 μm on the substrate 2 by using a sputtering method or a vapor deposition method, for example.

The light absorption layer 4 is disposed on the lower electrode 3. The light absorption layer 4 includes, for example, a compound semiconductor. An example of such a compound semiconductor is a chalcogen compound semiconductor. A chalcogen compound semiconductor contains sulfur (S), selenium (Se) or tellurium (Te) which are chalcogen elements. An example of the chalcogen compound semiconductor is an I-III-VI compound semiconductor. An I-III-VI compound semiconductor is a compound of a group IB element (also referred to as a group 11 element), a group III-B element (also referred to as a group 13 element) and a group VI-B element (also referred to as a group 16 element). It is a semiconductor. Such an I-III-VI compound semiconductor has a chalcopyrite structure and is also called a chalcopyrite compound semiconductor (also referred to as a CIS compound semiconductor). Examples of the I-III-VI compound semiconductor include copper indium diselenide (CuInSe ₂ ), copper indium diselenide / gallium (Cu (In, Ga) Se ₂ ), diselen selenide / copper indium / gallium (gallium ( Cu (In, Ga) (Se, S) ₂ ), copper indium gallium disulfide (Cu (In, Ga) S ₂ ), or a thin film of selenium disulfide / copper indium / gallium as a surface layer There are multi-element compound semiconductor thin films such as copper indium selenide and gallium. The compound semiconductor included in the light absorption layer 4 is not only the above-described I-III-VI compound semiconductor, but also, for example, CZTS including copper (Cu), zinc (Zn), tin (Sn), and sulfur (S). It may be of the type. An example of such a CZTS compound semiconductor is Cu ₂ ZnSnS ₄ . Since the CZTS compound semiconductor does not use rare metal unlike the I-III-VI compound semiconductor, it is easy to secure the material. The light absorption layer 4 has, for example, a p-type conductivity and has a thickness of about 1 to 3 μm.

  The light absorption layer 4 is formed by a vacuum process such as sputtering or vapor deposition. The light absorption layer 4 is also formed by a process such as a coating method or a printing method. In the coating method or the printing method, for example, a complex solution of elements mainly contained in the light absorption layer 4 is applied on the lower electrode 3 and then dried and heat-treated.

  The buffer layer 5 is provided on the main surface on the + Z side of the light absorption layer 4 and has a second conductivity type (here, n-type conductivity type) different from the first conductivity type of the light absorption layer 4. Mainly includes semiconductors. Note that semiconductors having different conductivity types are semiconductors having different conductive carriers. Moreover, the conductivity type of the light absorption layer 4 may be n-type, and the conductivity type of the buffer layer 5 may be p-type. Here, a heterojunction region is formed between the buffer layer 5 and the light absorption layer 4. For this reason, in each photoelectric conversion cell, photoelectric conversion can occur in the light absorption layer 4 and the buffer layer 5 that form the heterojunction region.

The buffer layer 5 mainly contains a compound semiconductor. Examples of such compound semiconductors include cadmium sulfide (CdS), indium sulfide (In ₂ S ₃ ), zinc sulfide (ZnS), zinc oxide (ZnO), indium selenide (In ₂ Se ₃ ), In (OH, S), (Zn, In) (Se, OH) and (Zn, Mg) O. Further, if the buffer layer 5 has a resistivity of 1 Ω · cm or more, generation of leak current can be reduced. The buffer layer 5 can be formed by, for example, a chemical bath deposition (CBD) method or the like.

  The buffer layer 5 has a thickness in the normal direction (+ Z direction) of one main surface of the light absorption layer 4. This thickness is set to, for example, 10 to 200 nm. When the thickness of the buffer layer 5 is 100 to 200 nm, damage is unlikely to occur in the buffer layer 5 when the translucent conductive layer 6 is formed on the buffer layer 5 by a sputtering method or the like.

  The translucent conductive layer 6 is provided on the main surface on the + Z side of the buffer layer 5 and is, for example, a transparent conductive layer (also referred to as a transparent conductive layer) having an n-type conductivity type. The translucent conductive layer 6 functions as an electrode for extracting charges generated in the light absorption layer 4 (also referred to as an extraction electrode). The translucent conductive layer 6 mainly includes a material having a lower resistivity than the buffer layer 5. The translucent conductive layer 6 may include what is called a window layer, and may include a window layer and a transparent conductive layer.

The translucent conductive layer 6 mainly includes a material having a wide forbidden band, transparent, and low resistance. Examples of such a material include zinc oxide (ZnO), a compound of zinc oxide, and metal oxide semiconductors such as indium oxide (ITO) containing tin and tin oxide (SnO ₂ ). The zinc oxide compound contains any one element of aluminum, boron, gallium, indium, and fluorine.

  The translucent conductive layer 6 can be formed by sputtering, vapor deposition, chemical vapor deposition (CVD), or the like. The thickness of the translucent conductive layer 6 is, for example, 0.05 to 3.0 μm. Here, if the translucent conductive layer 6 has a resistivity of less than 1 Ω · cm and a sheet resistance of 50 Ω / □ or less, the charge is transferred from the light absorption layer 4 via the translucent conductive layer 6. Can be taken out well.

  The buffer layer 5 and the translucent conductive layer 6 may have a property (also referred to as light transmissivity) that allows light to easily pass through the wavelength band of light that can be absorbed by the light absorption layer 4. Thereby, the fall of the light absorption efficiency in the light absorption layer 4 can be reduced. Moreover, if the thickness of the translucent conductive layer 6 is 0.05 to 0.5 μm, the light transmissivity in the translucent conductive layer 6 is enhanced, and at the same time, the current generated by the photoelectric conversion is satisfactorily transmitted. obtain. Furthermore, if the absolute refractive index of the translucent conductive layer 6 and the absolute refractive index of the buffer layer 5 are substantially the same, the incidence caused by the reflection of light at the interface between the translucent conductive layer 6 and the buffer layer 5 Light loss can be reduced.

  The current collecting electrode 7 has a linear portion 7 a provided on the + Z side main surface (also referred to as one main surface) of the translucent conductive layer 6 and a connection portion 7 b. Then, for example, the charges collected by the translucent conductive layer 6 of the photoelectric conversion cell 1a can be further collected by the linear portion 7a and transmitted to the adjacent photoelectric conversion cell 1b through the connection portion 7b.

  By providing the linear portion 7a, the conductivity of the translucent conductive layer 6 is supplemented, so that the translucent conductive layer 6 can be thinned. Thereby, securing of charge extraction efficiency and improvement of light transmittance in the translucent conductive layer 6 can both be achieved. In addition, if the linear part 7a mainly contains the metal which was excellent in electroconductivity, such as silver, the conversion efficiency in the photoelectric conversion part 1 can improve. In addition, as a metal contained in the linear part 7a, copper, aluminum, nickel, etc. are mentioned, for example.

  Moreover, if the width | variety of the linear part 7a is 50-400 micrometers, the fall of the incident amount of the light to the light absorption layer 4 is ensured, ensuring favorable electroconductivity between the adjacent photoelectric conversion cell 1a and the photoelectric conversion cell 1b. Can be reduced. When a plurality of linear portions 7a are provided in one photoelectric conversion cell, the interval between the plurality of linear portions 7a may be about 2.5 mm, for example.

  In addition, if the surface of the linear part 7a has the property to reflect the light of the wavelength region which the light absorption layer 4 can absorb, when the photoelectric conversion part 1 is modularized, the linear part The light reflected on the surface of 7a can be reflected again in the module and incident on the light absorption layer 4. Thereby, the conversion efficiency in the photoelectric conversion part 1 can improve. Such a linear portion 7a may be formed using, for example, a paste in which metal particles such as silver having a high light reflectance are added to a translucent resin. It can also be realized by depositing a metal having a high light reflectance such as aluminum on the surface of the linear portion 7a.

  As shown in FIG. 2, the connection portion 7 b is disposed in a separation groove P <b> 2 that separates the light absorption layer 4 and the buffer layer 5. The connection portion 7b is electrically connected to the linear portion 7a. For example, the connection portion 7b located in the photoelectric conversion cell 1a has a hanging portion that connects to the lower electrode 3 extending from the adjacent photoelectric conversion cell 1b through the separation groove P2. Thereby, the connection part 7b can electrically connect the upper electrode (the translucent conductive layer 6 and the linear part 7a) of the photoelectric conversion cell 1a and the lower electrode 3 of the photoelectric conversion cell 1b in FIG. In FIG. 1, the linear portion 7a of the photoelectric conversion cell 1a electrically connected to the translucent conductive layer 6 and the lower electrode 3 of the photoelectric conversion cell 1b are directly connected. Not limited. For example, the connecting portion 7b electrically connects the upper electrode of the photoelectric conversion cell 1a and the lower electrode 3 of the photoelectric conversion cell 1b via at least one of the buffer layer 5 and the translucent conductive layer 6 disposed in the separation groove P2. It may be a form of connection to. That is, the upper electrode may be composed of only the translucent conductive layer 6. At this time, the connection part 7b becomes an aspect in which the translucent conductive layer 6 is disposed in the separation groove P2.

  The connecting portion 7b may be made of the same material and method as the linear portion 7a. Therefore, the connecting portion 7b may be performed simultaneously with the formation of the linear portion 7a. Moreover, the connection part 7b may be a part of the linear part 7a.

  The output electrodes 8a and 8b output the current converted from light in each photoelectric conversion cell to the outside. One of the output electrode 8a and the output electrode 8b is a positive electrode, and the other is a negative electrode. In the present embodiment, an output electrode 8a is provided on one end side of the photoelectric conversion unit 1, and an output electrode 8b is provided on the other end side. That is, it can be said that the output electrode 8 a and the output electrode 8 b are electrically connected to the photoelectric conversion unit 1. Specifically, in the present embodiment, the output electrode 8a corresponds to a portion where a part of the lower electrode 3 located on one end side (−X direction) of the photoelectric conversion cell 1a is extended. On the other hand, the output electrode 8b corresponds to a portion where a part of the lower electrode 3 located on the other end side (+ X direction) of the photoelectric conversion cell 1b is extended. In the present embodiment, the output electrode 8a and the output electrode 8b are formed by extending a part of the lower electrode 3, but the present invention is not limited to this. For example, the output electrode 8a and the output electrode 8b may be formed by extending a part of the upper electrode of the photoelectric conversion cell. When three or more photoelectric conversion cells are arranged, the output electrode 8 a is provided in the photoelectric conversion cell located at one end of the photoelectric conversion unit 1, and the photoelectric conversion cell located at the other end of the photoelectric conversion unit 1. Is provided with an output electrode 8b.

  Next, an example of a method for manufacturing the photoelectric conversion unit 1 will be described.

  First, a metal such as molybdenum is formed on the substantially entire surface of the substrate 2 by sputtering to form a metal layer. Next, YAG (yttrium, aluminum, garnet) laser or the like is irradiated to a desired position of the metal layer to form the division grooves P1, and a plurality of lower electrodes 3 are obtained. Next, the light absorption layer 4 is formed on the patterned lower electrode 3 by using a sputtering method, a vapor deposition method, a printing method, or the like. Next, the buffer layer 5 is formed on the light absorption layer 4 by a chemical bath deposition method (CBD method) or the like.

  Next, the translucent conductive layer 6 is formed on the buffer layer 5 by sputtering or metal organic chemical vapor deposition (MOCVD). Next, the dividing groove P2 is formed by mechanical scribing or the like, and the light absorption layer 4, the buffer layer 5, and the translucent conductive layer 6 are patterned. Next, after applying a metal paste on the translucent conductive layer 6 by screen printing or the like, the current collector electrode 7 is formed by baking. Next, the photoelectric conversion unit 1 is formed by forming a plurality of photoelectric conversion cells arranged in the X direction by forming the dividing grooves P3 along the Y direction by mechanical scribing or the like and performing patterning.

  Next, for the photoelectric conversion cells (photoelectric conversion cell 1a and photoelectric conversion cell 1b in this embodiment) located at both ends in the X direction, for example, using a blade, a wheel brush, or the like, the light absorption layer 4, the buffer layer 5, the transparent layer The photoconductive layer 6, the collecting electrode 7 and the like are scraped off with a width of about 2 to 7 mm, and a part of the lower electrode 3 is extended. Thereby, the output electrode 8a is formed at one end of the photoelectric conversion cell 1a, and the output electrode 8b is formed at the other end of the photoelectric conversion cell 1b.

<Photoelectric conversion module>
Next, a photoelectric conversion module M according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 3 to 5, the photoelectric conversion module M includes a photoelectric conversion unit 1, a substrate 2, a covering member 9, a protective substrate 10 as a second substrate, a wiring conductor 11, and a sealing member 12. And a reinforcing member 13. In FIG. 3, each member disposed between the substrate 2 and the protective substrate 10 is indicated by a solid line instead of a dotted line for convenience. 4 and 6 are diagrams in which the protective substrate 10 is omitted, and each member covered with the covering member 9 and the sealing member 12 is indicated by a dotted line.

The substrate 2 as the first substrate has a function of supporting the photoelectric conversion unit 1. Examples of the material of the substrate 2 include blue plate glass (soda lime glass) having a thickness of about 1 to 3 mm and heat resistant plastics such as polyimide resin. Further, as the substrate 2, a metal foil such as stainless steel or titanium having a thickness of about 100 to 200 μm whose surface is covered with an insulating film such as an oxide film may be used. Moreover, the shape of the board | substrate 2 should just be flat form, such as rectangular shape and circular shape, for example.

  As shown in FIG. 5, the covering member 9 is filled between one main surface of the substrate 2 and the protective substrate 10 facing each other. The covering member 9 mainly has a function of protecting the photoelectric conversion unit 1 and is disposed so as to cover the photoelectric conversion unit 1. Examples of such a covering member 9 include a resin mainly composed of copolymerized ethylene vinyl acetate (EVA). Note that EVA may contain a crosslinking agent such as triallyl isocyanurate in order to promote crosslinking of the resin. Moreover, the board | substrate 2 and the protective substrate 10 may be adhere | attached by EVA, and these may be integrated.

  The protective substrate 10 as the second substrate is provided so as to be in contact with the covering member 9 and has a function of protecting the photoelectric conversion unit 1 and the like from the outside. The size and shape of the protective substrate 10 are substantially the same as those of the substrate 2. As the protective substrate 10, for example, white plate glass that has been tempered with air cooling can be used in terms of light transmittance and required strength.

  The wiring conductor 11 is electrically connected to the output electrode 8 and has a function of guiding the output obtained by the photoelectric conversion unit 1 to the outside through the output electrode 8. In the present embodiment, the wiring conductor 11a is electrically connected to the output electrode 8a. That is, the wiring conductor 11a is electrically connected to the lower electrode 3 as the first electrode. On the other hand, the wiring conductor 11b is electrically connected to the output electrode 8b. As shown in FIG. 2, the output electrode 8b is electrically connected to the upper electrode (collecting electrode 7). That is, the wiring conductor 11b is electrically connected to the upper electrode as the second electrode. Accordingly, the pair of wiring conductors 11a and 11b are electrically connected to the first electrode (lower electrode 3) and the second electrode (upper electrode), respectively.

  As such a wiring conductor 11, for example, a metal foil containing copper, silver, aluminum and the like having a thickness of about 0.3 to 2.0 mm can be used. The wiring conductor 11 may be an alloy containing the above-described metal or a laminate of these metals. The width of the wiring conductor 11 may be about 50% to 90% of the width of the output electrodes 8a and 8b, for example. The wiring conductor 11 is connected to the output electrode 8 via solder. Solder may be coated on the wiring conductor 11 in advance.

  The wiring conductor 11 is led out to the back side of the substrate 2 through a through hole 2a provided in the substrate 2 and extends to a terminal box (not shown). The through hole 2a is formed from one main surface of the substrate 2 toward the other main surface. That is, the through hole 2a penetrates the substrate 2 up and down. The through hole 2a may be provided in advance before the photoelectric conversion unit 1 is formed on the substrate 2, or may be provided after the photoelectric conversion unit 1 is formed. When the substrate 2 is a metal such as stainless steel, glass or plastic, the through hole 2a can be formed by a machining method using a drill or the like, a laser processing method using a YAG (yttrium, aluminum, garnet) laser, or the like.

  The sealing member 12 is disposed between the substrate 2 and the protective substrate 10 so as to surround the photoelectric conversion unit 1 and the covering member 9 in plan view of the substrate 2 and the protective substrate 10. That is, the sealing member 12 is arranged in a frame shape when the substrate 2 and the protective substrate 10 are viewed in plan. Therefore, the covering member 9 fills the internal space surrounded by the substrate 2, the protective substrate 10 and the sealing member 12. The sealing member 12 has a function of reducing intrusion of foreign matter that enters the photoelectric conversion unit 1 side from between the substrate 2 and the protective substrate 10. Such foreign matter includes moisture that enters from the outside. Further, the sealing member 12 is arranged so as to contact the covering member 9. Thereby, the clearance gap between the sealing member 12 and the coating | coated member 9 is reduced. Therefore, substantially uniform rigidity can be maintained against external stress.

  Further, the width of the sealing member 12 in the X direction in FIG. 5 may be about 5 to 20 mm, for example. Moreover, the height (thickness) in the Z direction of FIG. 5 should just be 0.1-3 micrometers, for example.

The sealing member 12 may be a polymer material such as an elastic body made of a resin such as polyethylene or rubber such as butyl rubber or ethylene propylene rubber, or a mixture of the above-described resin and rubber. The above-mentioned butyl rubber has a water vapor permeability as low as about 0.1 g / m ² / day and has excellent waterproof performance. Further, the sealing member 12 may include an adsorbent that adsorbs moisture. Examples of the adsorbent include calcium oxide (CaO), sodium oxide (Na ₂ O), magnesium oxide (MgO), calcium chloride (CaCl ₂ ), anhydrous sodium sulfate (Na ₂ SO ₄ ), and anhydrous copper sulfate. and the like salts (CuSO ₄₎ or calcium sulfate (CaSO _4). The above-mentioned calcium oxide has a large moisture absorption capacity at low humidity and has a property of being difficult to deliquesce, so that it is easy to maintain the adsorption power even in a low humidity environment. The particle size of such an adsorbent is, for example, about 0.5 to 10 μm. Further, the butyl rubber may contain calcium oxide as an adsorbent, and the sealing member 12 may contain about 10 to 50 parts by weight of calcium oxide with respect to 100 parts by weight of butyl rubber. Thereby, the sealing member 12 becomes easy to acquire the moisture adsorption effect, maintaining the adhesive strength of the board | substrate 2, the protective substrate 10, and butyl rubber. Therefore, in this embodiment, the amount of moisture reaching the photoelectric conversion unit 1 can be reduced.

  The reinforcing member 13 mainly has a function of increasing the strength of the substrate 2. When the photoelectric conversion module M is used in a high-temperature environment, the covering member 9 expands and stress tends to concentrate on the substrate 2 in the vicinity of the boundary E between the covering member 9 and the sealing member 12. As shown in FIG. 4, the boundary E between the covering member 9 and the sealing member 12 corresponds to the inner peripheral edge of the sealing member 12 arranged in a frame shape on the photoelectric conversion portion 1 side. And in this embodiment, the reinforcement member 13 is arrange | positioned on the board | substrate 2 in the said inner peripheral part (boundary part E). Thereby, even if stress concentrates in the vicinity of the boundary part E, generation | occurrence | production of the crack etc. of the board | substrate 2 can be reduced.

  On the other hand, it can be said that the reinforcing member 13 is covered with the covering member 9 and the sealing member 12 as shown in FIG. Thereby, the adhesive force between the covering member 9 and the sealing member 12 and the substrate 2 is increased by the anchor effect of the reinforcing member 13.

  The shape of the reinforcing member 13 is not particularly limited as long as the reinforcing member 13 is disposed on the substrate 2 in the boundary portion E. Therefore, the shape of the reinforcing member 13 may be, for example, a rectangular shape such as a rectangular shape, a parallelogram, or a circular shape. For example, as shown in FIG. 4, when the sealing member 12 has a quadrangular shape when seen in a plan view, the reinforcing member 13 may be disposed at the corner of the sealing member 12. Usually, the stress in the vicinity of the boundary E described above tends to concentrate on the portion of the substrate 2 located immediately below the corner. Therefore, if the reinforcing member 13 is disposed at this portion, the generation of cracks in the substrate 2 due to stress concentration can be reduced more efficiently. In addition, a plurality of reinforcing members 13 may be arranged along the inner peripheral edge of the sealing member 12 at intervals.

Moreover, the aspect arrange | positioned over the inner peripheral part of the sealing member 12, ie, the perimeter of the boundary part E, may be sufficient as the reinforcement member 13 as shown in FIG. In FIG. 6, the reinforcing member 13 is indicated by a portion surrounded by an alternate long and short dash line. At this time, the reinforcing member 13 has a frame shape like the sealing member 12. Thereby, even if stress concentration occurs near any boundary portion E, it is easy to reduce the generation of cracks due to the stress concentration. In the photoelectric conversion module M, moisture may enter from the interface between the substrate 2 and the sealing member 12 depending on the environment in which it is used. On the other hand, in the photoelectric conversion module M, since the reinforcing member 13 is disposed so as to surround the photoelectric conversion unit 1, up to the photoelectric conversion unit 1 of moisture entering from the interface between the substrate 2 and the sealing member 12. The time to reach can be delayed. This is because moisture easily moves along the surface of the reinforcing member 13. At this time, moisture may move so as to bypass the reinforcing member 13. This makes it difficult for moisture to reach the photoelectric conversion unit 1. Therefore, long-term reliability for moisture is improved.

  The thickness and width of the reinforcing member 13a are not particularly limited. In the case of a shape surrounding the photoelectric conversion unit 1 as shown in FIG. 6, for example, the width is 2 to 5 μm and the thickness is 2 to 3 μm. Further, the reinforcing member 13 may be disposed so as to be separated from the photoelectric conversion unit 1. Thereby, since the insulation with the photoelectric conversion part 1 can be ensured, the fall of an output can be reduced. At this time, the distance between the reinforcing member 13 and the photoelectric conversion unit 1 may be, for example, 5 mm or more. On the other hand, the reinforcing member 13 is preferably arranged so as not to be exposed to the outside from the sealing member 12, as shown in FIG. Thereby, generation | occurrence | production of the water | moisture content permeating from the interface of the board | substrate 2 and the reinforcement member 13 can be reduced. At this time, the distance S between the outer side of the substrate 2 and the outer side of the reinforcing member 13 in the X direction of FIG. 5 may be at least half the length of the sealing member 12 in the X direction.

For the reinforcing member 13, for example, a metal such as molybdenum, gold, silver, or titanium can be used. Further, the reinforcing member 13 may be SiO ₂ or the like. At this time, if the reinforcing member 13 is made of molybdenum, it may be formed by, for example, a sputtering method or a vacuum deposition method. The reinforcing member 13 be composed by SiO _2, for example, a sputtering method, may be formed by CVD method or a printing method, or the like. The reinforcing member 13 may be made of a material having a Young's modulus larger than that of the substrate 2. This makes it easier to reinforce the substrate 2. For example, if blue glass (Young's modulus: 60 to 80 GPa) is used for the substrate 2, a metal layer made of molybdenum (Young's modulus: 324 GPa), titanium (Young's modulus: 116 GPa), or the like is used for the reinforcing member 13. Good. Thus, if the board | substrate 2 is comprised with glass and the reinforcement member 13 is comprised with a metal layer, compared with the reinforcement member 13 which consists of resin, adhesiveness with the board | substrate 2 will improve. The above Young's modulus can be measured by, for example, a nanoindentation method. In this method, first, the micro load is continuously changed, the indenter is pushed into the substrate 2 or the reinforcing member 13, the displacement at that time is measured, and the obtained unloading curve is analyzed. From this analysis result, the Young's modulus can be calculated by obtaining the projected area at the contact depth. In addition, since the reinforcing member 13 is measured in a state of being disposed on the substrate 2, the reinforcing member 13 is more accurately reinforced by subtracting the analysis result obtained by measuring only the substrate 2 from the analysis result of the reinforcing member 13. The Young's modulus of the member 13 can be calculated.

  The reinforcing member 13 may be the same material as the lower electrode 3. For example, after the metal layer constituting the lower electrode 3 and the reinforcing member 13 is disposed on the substrate 2, the lower electrode 3 and the reinforcing member 13 may be formed at the same time by patterning the metal layer with a laser or sandblast. . This simplifies the manufacturing process. Further, if the reinforcing member 13 is a metal containing molybdenum, it becomes easy to understand that moisture has reached the reinforcing member 13. This is because when molybdenum is oxidized with oxygen in moisture to produce molybdenum oxide, the color changes compared to molybdenum. Therefore, by observing the color of the reinforcing member 13, it is possible to confirm the degree of moisture penetration. Then, repair such as replacement of the covering member 9 and the sealing member 12 may be performed in accordance with the degree of moisture penetration. The color change of the reinforcing member 13 can be visually confirmed from the back surface of the substrate 2, for example, if the substrate 2 is formed of a translucent member.

  Next, an example of a method for manufacturing the photoelectric conversion module M will be described.

  The photoelectric conversion unit 1 is formed on the substrate 2 by the manufacturing method described above. Next, the lower electrode 3 and the reinforcing member 13 are formed by patterning a metal layer located in an area of about 3 to 20 mm from the outer periphery of the substrate 2 with a laser or sand blasting.

  Next, two through holes 2a having a diameter of about 3 to 5 mm are formed on the substrate 2 using a laser. Next, the wiring conductor 11a and the wiring conductor 11b are respectively connected to the output electrode 8a and the output electrode 8b with solder. Next, one end sides of the wiring conductor 11a and the wiring conductor 11b that are not connected by solder are led out to the back side of the substrate 2 through the through hole 2a.

  Next, the precursor of the sealing member 12 is applied to the outer peripheral side portion of the substrate 2 so as to surround the photoelectric conversion unit 1 and to cover a part of the reinforcing member 13. For this application, the precursor of the sealing member 12 is filled in a discharge device such as a dispenser, and a predetermined amount of precursor is discharged from the discharge port and applied to a predetermined region. At this time, the precursor of the sealing member 12 may be provided on the outer peripheral side of the substrate 2 with a width of about 2 to 8 mm.

  Next, the covering member 9 such as EVA and the protective substrate 10 are placed on the photoelectric conversion unit 1 in this order. Next, the laminated body in which each member is laminated is set in a laminating apparatus, and is pressed and integrated at a temperature of about 100 to 200 ° C. under a reduced pressure of about 50 to 150 Pa for about 15 to 60 minutes. Next, the photoelectric conversion module M can be manufactured by fixing the terminal box 12 to the back surface of the substrate 2 and electrically connecting the wiring conductor 11a and the wiring conductor 11b to a terminal in the terminal box (not shown).

  In addition, this invention is not limited to the said embodiment, Many corrections and changes can be added within the scope of the present invention. For example, the photoelectric conversion module is not limited to the above-described CIS-based chalcopyrite photoelectric conversion module, such as a thin film solar cell using amorphous silicon or microcrystalline silicon, a crystalline silicon solar cell using a silicon substrate, or the like. It can also be applied to a photoelectric conversion module.

M: photoelectric conversion module 1: photoelectric conversion unit 2: substrate 2a: through-hole 3: lower electrode 4: light absorption layer 5: buffer layer 6: translucent conductive layer 7: current collecting electrode 7a: linear portion 7b : Connection portion 8, 8a, 8b: Output electrode 9: Cover member 10: Protection substrate 11, 11a, 11b: Wiring conductor 12: Sealing member 13: Reinforcing member

Claims (5)

A first substrate;
A photoelectric conversion unit disposed on the first substrate;
A covering member covering the photoelectric conversion part;
A second substrate disposed on the covering member;
A sealing member disposed in a frame shape so as to surround the photoelectric conversion portion between the first substrate and the second substrate and fill an internal space with the covering member;
The photoelectric conversion module provided with the reinforcement member arrange | positioned on the said 1st board | substrate in the inner peripheral part of the said photoelectric conversion part side of this sealing member.   The photoelectric conversion module according to claim 1, wherein the reinforcing member has a Young's modulus larger than that of the first substrate.   The photoelectric conversion module according to claim 1, wherein the sealing member has a quadrangular shape, and the reinforcing member is disposed at a corner of the sealing member.   The photoelectric conversion module according to any one of claims 1 to 3, wherein the reinforcing member is disposed over the entire circumference of the inner peripheral edge of the sealing member. The first substrate is made of glass,
The photoelectric conversion module according to claim 1, wherein the reinforcing member is a metal layer.

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