Glass laminate and solar cell

Abstract

The disclosed glass laminate includes: a glass film having a first main surface and a second main surface; two resin layers respectively disposed on the first main surface and the second main surface; and an inorganic oxide layer disposed on a resin layer. In the energy spectrum of the strain distribution of the glass laminate, the value of the energy of the strain distribution at a spatial frequency of 1.4 mm-1 is 0 to 1000. The energy spectrum of the strain distribution is obtained by measuring the strain distribution of a 10 mm x 10 mm sample when the sample is held in a 150°C environment for 2 hours and then held in a 23°C environment for 30 minutes.

Description

Glass laminates and solar cells

[0001] This disclosure relates to glass laminates and solar cells.

[0002] Flexible glass laminates including a thin glass film have been proposed conventionally. Claim 1 of Patent Document 1 (Japanese Patent Application Publication No. 2022-83323) discloses "an optical laminate comprising a glass plate, an adhesive layer, and a film in order toward one side in the thickness direction, wherein the glass plate has a thickness of less than 40 μm, the average tanδ of the film at -100°C to -50°C, determined by a dynamic viscoelasticity test in tensile mode at a frequency of 10 Hz and a heating rate of 2°C / min, is 0.04 or more, and the average tensile storage modulus E' of the film at -100°C to -50°C, determined by the dynamic viscoelasticity test, is 3 GPa or more and 6 GPa or less." Patent Documents 2 to 4 also propose laminates including a glass plate.

[0003] Japanese Patent Publication No. 2022-83323, Japanese Patent Publication No. 2022-83324, Japanese Patent Publication No. 2022-83325, Japanese Patent Publication No. 2022-83326

[0004] Flexible glass laminates are used in a variety of applications, such as electronic devices (e.g., solar cells). However, when glass laminates are strained, the performance of the devices may deteriorate. One of the objectives of this disclosure is to provide a glass laminate with low strain.

[0005] One aspect of this disclosure is a glass laminate comprising a glass film having a first principal surface and a second principal surface, two resin layers disposed on the first principal surface and the second principal surface, and an inorganic oxide layer disposed on one of the resin layers, wherein the energy spectrum of the strain distribution is 1.4 mm －１ The present invention relates to a glass laminate in which the energy value of the strain distribution at spatial frequency is between 0 and 1000, and the energy spectrum of the strain distribution is obtained by measuring the strain distribution of a 10 mm × 10 mm sample after it has been held in an environment of 150°C for 2 hours and then held in an environment of 23°C for 30 minutes.

[0006] Another aspect of this disclosure relates to a solar cell comprising a glass laminate according to this disclosure and a perovskite layer laminated on the inorganic oxide layer side of the glass laminate, wherein the inorganic oxide layer is a conductive layer.

[0007] According to this disclosure, glass laminates with low strain can be obtained. Novel features of the present invention are described in the appended claims, but the present invention, both in terms of structure and content, and in conjunction with other objects and features of the present invention, will be better understood by the following detailed description in conjunction with the drawings.

[0008] Figure 1 is a schematic cross-sectional view showing a part of the glass laminate of Embodiment 1. Figure 2 is a schematic cross-sectional view showing a part of the solar cell of Embodiment 2.

[0009] The embodiments relating to this disclosure will be described below with examples, but this disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be given as examples, but other numerical values ​​and other materials may be applied as long as the effects of this disclosure are obtained. In this specification, the description "numerical value A to numerical value B" includes numerical value A and numerical value B, and can be read as "greater than or equal to numerical value A and less than or equal to numerical value B". In the following description, when lower and upper limits of numerical values ​​relating to specific physical properties or conditions are given as examples, either the given lower limit and either the given upper limit may be arbitrarily combined, as long as the lower limit does not exceed the upper limit. In the following description, when examples of components or methods are listed, unless otherwise specified, only one of the listed examples may be used, or multiple of the listed examples may be used in combination.

[0010] (Glass Laminate) The glass laminate according to this embodiment may be referred to as "glass laminate (G)" or "laminated (G)" below. The laminate (G) includes a glass film having a first main surface and a second main surface, two resin layers disposed on the first main surface and the second main surface respectively, and an inorganic oxide layer disposed on one of the resin layers. The laminate (G) satisfies the following condition (1). (1) In the energy spectrum of the strain distribution of the laminate (G), 1.4 mm －１The energy value of the strain distribution at the spatial frequency is between 0 and 1000. Below, in the energy spectrum of the strain distribution, the spatial frequency is 1.4 mm. －１ The energy value of the strain distribution at this time is sometimes referred to as "value V". The energy spectrum of this strain distribution is obtained by measuring the strain distribution of a 10 mm × 10 mm (length × width) sample (laminated material (G)) that was held in an environment of 150°C for 2 hours and then held in an environment of 23°C for 30 minutes.

[0011] A laminate of a thin glass film and a resin layer (e.g., a resin film) (a glass laminate) possesses a certain degree of flexibility. Therefore, glass laminates are sometimes used in applications that require folding or bending. However, when a glass laminate contains an inorganic oxide layer, the performance of products using the glass laminate (hereinafter sometimes referred to as "product (P)") can easily deteriorate.

[0012] As a result of their investigation, the inventors of this application have newly discovered that by setting the value V within a predetermined range, a glass laminate capable of producing a high-performance product (P) can be obtained. This disclosure is based on this new finding.

[0013] The reason why setting the value V within the above range makes it possible to manufacture a product (P) with high performance is not currently clear. However, setting the value V within the above range suppresses strain in the glass laminate (especially strain at high temperatures). In the case of a glass laminate containing an inorganic oxide layer, the glass laminate is prone to strain due to temperature changes. Therefore, suppressing strain is particularly important in glass laminates containing an inorganic oxide layer. By suppressing strain in the glass laminate, it may be possible to manufacture a product (P) with high performance.

[0014] (Energy spectrum of strain distribution) The method for obtaining and analyzing the energy spectrum of the strain distribution of a glass laminate is described below. First, the glass laminate is cut into 10 mm x 10 mm (area: 100 mm) sections. ２A sample of ) is prepared. Next, the surface of the sample in the initial state at 23°C is measured. Next, after the sample is heated to 150°C and held for 2 hours, the surface of the sample when it is held for 30 minutes in an environment at 23°C and 50% relative humidity is measured. From the two measured results, the strain distribution (displacement distribution) is obtained. The measurement of the strain distribution is performed by analysis using the digital image correlation method (DIC method). The DIC method is a technique that compares images of random patterns before and after deformation of the object surface and measures the amount of movement (displacement) of the object surface.

[0015] In the measurement of the strain distribution using the DIC method, first, a random pattern is applied to the sample. Next, after the surface of the sample is measured with a camera in an environment at 23°C and 50% RH (relative humidity), the sample is heated to 150°C and held for 2 hours. Next, after changing the environment where the sample is placed to 23°C and 50% RH (relative humidity) and holding for 30 minutes, the surface of the sample is measured with a camera. By using a plurality of cameras, the strain distribution (displacement distribution) of the three-dimensional surface can be measured.

[0016] When the orthogonal coordinates of the sample surface are represented by (x, y), the strain (displacement) at the coordinates (x, y) can be expressed as a two-dimensional function h(x, y) of the coordinates (x, y). From the two-dimensional function h(x, y), the two-dimensional function H(f ｘ , f ｙ ) is obtained by the two-dimensional Fourier transform defined by the following formula.

[0017]

[0018] In the above formula, f ｘ and f ｙ are the frequencies in the x-direction and y-direction, respectively, and have the dimension of the reciprocal of length. In the above formula, π is the ratio of the circumference of a circle to its diameter, and i is the imaginary unit. By squaring the obtained two-dimensional function H(f ｘ , f ｙ ), the energy spectrum H ２ (f ｘ , f ｙ ) can be obtained. This energy spectrum H ２ (f ｘ , f ｙ) represents the spatial frequency distribution of strain in a glass laminate due to heating. Three-dimensional information of strain measured by methods such as the DIC method is generally obtained as discrete values, i.e., displacements at a number of measurement points. As mentioned above, 1.4 mm －１ The energy value V (energy spectrum H) of the strain distribution of a glass laminate (G) at the spatial frequency. ２ (f ｘ , f ｙ The value of (V) is between 0 and 1000. A small value V is preferable. A smaller value V indicates less strain. The value V may be 900 or less, 500 or less, 300 or less, 100 or less, or 50 or less.

[0019] The required horizontal resolution for the measuring instrument used to measure strain distribution is 60 μm, and the required vertical resolution is also 60 μm.

[0020] For measuring strain distribution, for example, StrainMaster from LaVision can be used. Measurement and analysis are performed with 60 μm per pixel, 45 pixels as subsets, and 5 pixels as steps. A subset is one of the micro-regions obtained when a subject is divided into multiple micro-regions in digital image correlation. Each subset becomes a measurement point. Displacement (strain) is calculated by measuring the displacement of the subset. When detecting displacement (strain), a mesh is created by setting the step (interval between subsets). By detecting the amount and direction of movement of each subset, the displacement distribution (strain distribution) of the measured object is obtained.

[0021] The glass laminate (G) is a laminate comprising a glass film (glass layer) and a resin layer. The resin layer may contain a resin film, or it may be a resin film. That is, each of the two resin layers may contain a resin film, or it may be a resin film. The resin film may be bonded to the glass film by an adhesive layer (resin composition). In that case, the resin layer comprises the resin film and the adhesive layer. Typically, the glass film and the resin layer are in contact. The glass laminate (G) may be composed of a laminated structure of resin layer / glass film / resin layer / inorganic oxide layer. The glass laminate (G) may include a laminated structure of resin layer / glass film / resin layer / inorganic oxide layer.

[0022] The thickness of the glass laminate (G) may be 20 μm or more, or 50 μm or more, and may be 450 μm or less, 350 μm or less, 200 μm or less, or 150 μm or less.

[0023] (Glass film) Glass film is sometimes also referred to as thin glass. It is preferable that the glass film has a uniform thickness.

[0024] The thickness of the glass film may be 10 μm or more, 30 μm or more, 50 μm or more, 80 μm or more, or 100 μm or more. The thickness of the glass film may be 200 μm or less, 100 μm or less, 80 μm or less, 50 μm or less, or 30 μm or less. By setting the thickness of the glass film to 200 μm or less (for example, 100 μm or less or 50 μm or less), a laminate (G) with high flexibility can be obtained. On the other hand, if the glass film is too thin, the laminate (G) will be prone to deformation. By setting the thickness of the glass film to 50 μm or less (for example, in the range of 10 to 50 μm) and the thickness of the resin film to 50 μm or more (for example, in the range of 50 to 100 μm), it is possible to achieve both high flexibility and suppression of deformation.

[0025] The thickness of the glass film may be in the range of 10-200 μm, 30-200 μm, 50-200 μm, 80-200 μm, or 100-200 μm. Within any of these ranges, the upper limit may be 100 μm or less, 80 μm or less, 50 μm or less, or 30 μm, as long as the lower limit does not exceed the upper limit.

[0026] The composition of the glass constituting the glass film is not particularly limited. Examples of glass include soda-lime glass, borate glass, aluminosilicate glass, and quartz glass. The glass may be alkali-free glass or low-alkali glass. The alkali metal component of the glass (e.g., Na ２ O, K ２ O, Li ２ The total content of O) may be 15% by mass or less, or 10% by mass or less.

[0027] In this specification, unless otherwise specified, the thickness of each component of the glass laminate is an average value. Specifically, the thickness of each component of the glass laminate is the arithmetic mean of five thickness measurements arbitrarily selected in the cross-sectional image.

[0028] Glass films are manufactured by any suitable method. In one example of a glass film manufacturing method, first, a mixture containing the main raw material, ceramics (silica, alumina, etc.), an antifoaming agent (sodium sulfate, antimony oxide, etc.), and a reducing agent (carbon, etc.) is prepared. Next, the mixture is melted at a temperature of 1400°C to 1600°C, then formed into a film and cooled. In this way, a glass film is manufactured. The method of forming the molten material into a film is not limited, and methods such as the slot-down draw method, fusion method, and float method may be used. Glass films obtained by these methods may be chemically polished with a solvent (hydrofluoric acid, etc.). Chemical polishing can make the glass film even thinner. In addition, glass polishing may improve the smoothness of the surface and edges of the glass film.

[0029] In order to enhance the adhesion between the glass film and the adhesive layer, the surface of the glass film may be surface-treated. The surface treatment is not particularly limited, and corona treatment, plasma treatment, coupling treatment, etc. may be used.

[0030] (Resin layer) Resin layers (the first resin layer, the second resin layer) are formed on both surfaces (the first major surface and the second major surface) of the glass film of the glass laminate (G). That is, the first resin layer is formed on the first major surface of the glass film, and the second resin layer is formed on the second major surface of the glass film. As described above, the resin layer may be a resin film, or may include a resin film and an adhesive layer. The composition and material of the first resin layer and the composition and material of the second resin layer may be the same or different. The thickness of the first resin layer and the thickness of the second resin layer may be the same or different. However, from the viewpoint of suppressing the strain of the glass laminate (G), the composition, material, and thickness of the first resin layer are preferably the same as or substantially the same as the composition, material, and thickness of the second resin layer. For example, the first resin layer and the second resin layer may satisfy the following conditions (2) to (4). In the following conditions (2) to (4), "the first resin layer" and "the second resin layer" may be replaced with "the resin film contained in the first resin layer (the first resin film)" and "the resin film contained in the second resin layer (the second resin film)", respectively. In condition (2), the content rate of the main component may be 80% by mass or more. (2) The main component (content rate: 50% by mass or more) of the material of the first resin layer is the same as the main component (content rate: 50% by mass or more) of the material of the second resin layer. The first resin layer and the second resin layer may be formed of the same material. (3) The thickness T1 of the first resin layer is in the range of 0.7 to 1.4 times (for example, in the range of 0.8 to 1.3 times, or in the range of 0.9 to 1.1 times) the thickness T2 of the second resin layer. (4) The dimensional change rate Rt (described later) of the first resin layer and the dimensional change rate Rt of the second resin layer are each 0.20% or less (in the range of 0 to 0.20%). Those dimensional change rates Rt may each be 0.10% or less, or 0.04% or less.

[0031] When two resin layers having the same thickness and the same physical properties are disposed on both surfaces of a glass film, the same stress is generated in the two resin layers. As a result, the strain of the glass laminate (G) can be particularly suppressed, and the characteristics of the product (P) using the glass laminate (G) can be particularly enhanced. In that regard, it is preferable that the first resin layer and the second resin layer satisfy the above conditions (2) to (4).

[0032] The resin constituting the resin film may be a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include polyether sulfone resins, polycarbonate resins, acrylic resins, polyester resins, polyolefin resins, cycloolefin resins, polyimide resins, polyamide resins, polyimide amide resins, polyarylate resins, polysulfone resins, and polyetherimide resins. Examples of polyester resins include aromatic polyester resins (such as polyalkylene arylate resins). Examples of polyalkylene arylate resins include polyethylene terephthalate (PET) resins, polybutylene terephthalate resins, and polyethylene naphthalate resins. Examples of cycloolefin resins include norbornene resins. Examples of thermosetting resins include epoxy resins, urethane resins, and silicone resins. The resin film may be formed of one type of resin or two or more types of resins. The resin film may be single-layer or multi-layer. A film made of PET resin is preferable from the viewpoints of the handling property and strength of the glass laminate (G).

[0033] The resin layer (the first resin layer and the second resin layer) may include a resin film. The thickness of the resin film (one resin film) may be 10 μm or more, 20 μm or more, 30 μm or more, or 50 μm or more, and may be 100 μm or less, 80 μm or less, or 75 μm or less. The thickness of the resin film may be 20 μm or more and 100 μm or less. By setting the thickness of the resin film within this range, both conveyance property and scattering prevention property can be achieved.

[0034] The resin film contained in the glass laminate (G) preferably has a small rate of dimensional change due to heat. Specifically, the rate of dimensional change Rt of the resin film may be 0.20% or less (in the range of 0 to 0.20%). The rate of dimensional change Rt of the resin film is the rate of dimensional change of the resin film when only the resin film (a sample of the resin film) is suspended vertically in an air-circulating constant temperature bath at 140°C for 90 minutes, and then the resin film is removed from the constant temperature bath and held in an environment of 23°C and 50% relative humidity for 30 minutes.

[0035] The dimensional change rate Rt may be 0.10% or less, or 0.04% or less. By setting the dimensional change rate of the resin film to 0.20% or less, strain in the glass laminate (G) under high-temperature conditions can be particularly suppressed. The dimensional change rate Rt of the resin film can be changed by the material, manufacturing method, and heat treatment. For example, the dimensional change rate Rt of the resin film can be reduced by the method described later.

[0036] The dimensional change rate of a resin film alone can be measured by the following procedure. The resin film to be measured is either a resin film before adhesion to a glass film, or a resin film peeled off from a glass laminate. First, a sample is prepared by cutting the resin film to be measured into a rectangle with a long side of 120 mm and a short side of 90 mm. At this time, the resin film is cut so that the MD direction of the resin film is parallel to the long side and the TD direction of the resin film is parallel to the short side. Next, the sample is heated at 140°C for 90 minutes. At this time, the length of the long side L0 (mm) before heating and the length of the long side L1 (mm) after heating are measured. Details of the method for measuring the dimensional change rate will be explained in the examples. The dimensional change rate Rt is calculated by the following formula. Note that |L0 - L1| is the absolute value of the difference between L0 and L1. Dimensional change rate (%) = 100 × |L0 - L1| / L0

[0037] The thermal shrinkage rate and thermal expansion rate when the above resin film sample is heated under the above conditions may be within the range exemplified for the dimensional change rate Rt. The thermal shrinkage rate and thermal expansion rate are expressed by the following formulas, respectively: Thermal shrinkage rate (%) = 100 × (L0 - L1) / L0 Thermal expansion rate (%) = 100 × (L1 - L0) / L0

[0038] An example of a method for reducing the dimensional change rate Rt of a resin film by heat treatment is described below. In this method, the dimensional change rate Rt is reduced by annealing the precursor film (resin film). The precursor film may be a film made of the resin material exemplified for resin films. The precursor film may be manufactured by known methods. Alternatively, a commercially available film may be used as the precursor film. The size of the precursor film may be determined considering thermal shrinkage or thermal expansion due to the annealing treatment.

[0039] In the annealing treatment of the precursor film, the precursor film is heated. The annealing temperature may be 90°C or higher, or 100°C or higher, or 200°C or lower, or 160°C or lower. The annealing time may be 1 minute or more, or 5 minutes or more, or 60 minutes or lower, or 40 minutes or lower. The annealing treatment may be carried out in an atmospheric environment or in an inert gas atmosphere (such as nitrogen gas, helium gas, or argon gas). The conditions for the annealing treatment may be selected so that the dimensional change rate Rt of the resin film alone is within the above range.

[0040] A preferred example of annealing is carried out at a temperature between 90°C and 200°C. This example of annealing may be carried out in an atmosphere with a relative humidity in the range of 50% RH to 60% RH.

[0041] (Adhesive layer) The glass film and the resin film may be bonded together via an adhesive layer. The adhesive that forms the adhesive layer is applied to the surface of the glass film and / or the surface of the resin film. After applying the adhesive layer, the glass film and the resin film are bonded together via the adhesive layer. Then, the adhesive layer is cured while applying pressure to the laminate of the glass film and the resin film. In this way, the glass film and the resin film are bonded together. If the resin layer includes an adhesive layer and a resin film, the glass laminate (G) includes a laminated structure of resin film / adhesive layer / glass film / adhesive layer / resin film.

[0042] The adhesive forming the bonding layer is not particularly limited, and any suitable adhesive (resin composition) can be used. Examples of adhesives include adhesives containing resins having cyclic ether groups (epoxy groups, glycidyl groups, oxetanyl groups, etc.), adhesives containing acrylic resins, and adhesives containing silicone resins. The adhesive may be thermosetting or photocuring (e.g., UV curing).

[0043] The thickness of the adhesive layer may be 0.5 μm or more, 1 μm or more, or 5 μm or more, and may be 20 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less. By making the thickness of the adhesive layer 8 μm or less, the waviness of the surface of the laminate (G) can be particularly suppressed. In terms of improving the performance of the product (P) using the laminate (G), it is particularly preferable that the thickness of the adhesive layer be 8 μm or less.

[0044] (Inorganic Oxide Layer) The inorganic oxide layer may be a layer having functions required for the product (P) in which the glass laminate (G) is used. For example, if the product (P) is a solar cell or a display device, the inorganic oxide layer may be a conductive layer (e.g., a transparent conductive layer). Examples of transparent conductive layers include an indium tin oxide layer and a zinc oxide layer. That is, the inorganic oxide layer may be an indium tin oxide layer or a zinc oxide layer. The conductive layer (e.g., a transparent conductive layer) may function as a carrier transport layer (hole transport layer or electron transport layer).

[0045] The inorganic oxide layer may have a crystalline structure. If the inorganic oxide layer is an indium tin oxide layer, the crystallinity of the indium tin oxide layer can be increased by heat treatment. The inorganic oxide layer may also contain polycrystalline (including microcrystalline) inorganic oxides.

[0046] The thickness of the inorganic oxide layer may be selected according to the function required of the inorganic oxide layer in the product (P). The thickness of the inorganic oxide layer may be 20 nm or more, or 200 nm or more, or 2 μm or less, or 2 μm or less.

[0047] The inorganic oxide layer may be placed on only one resin layer (the first resin layer). In this case, the glass laminate (G) includes a laminated structure of inorganic oxide layer / first resin layer / glass film / second resin layer. The inorganic oxide layer may be placed on two resin layers (the first and second resin layers). In this case, the glass laminate (G) includes a laminated structure of inorganic oxide layer / first resin layer / glass film / second resin layer / inorganic oxide layer.

[0048] The method for forming the inorganic oxide layer is not particularly limited, and known methods may be applied. The inorganic oxide layer may be formed by gas-phase deposition or liquid-phase deposition. Examples of gas-phase deposition methods include sputtering.

[0049] (Other layers) The glass laminate (G) may further include films and / or layers other than those described above. For example, the glass laminate (G) may further include a surface coating layer disposed on the surface. Examples of surface coating layers include a fingerprint-resistant coating layer, a hard coating layer, an anti-reflective layer, an anti-glare layer, an anti-fouling layer, an anti-sticking layer, a hue-adjusting layer, an anti-static layer, an easy-adhesion layer, a deposition prevention layer, an impact-absorbing layer, and a shatterproof layer.

[0050] The glass laminate (G) may further include an antifouling layer and / or an anti-reflective layer. These layers may be disposed on top of an inorganic oxide layer (e.g., a transparent conductive layer). The antifouling layer and anti-reflective layer are not particularly limited, and known antifouling and anti-reflective layers may be used.

[0051] The glass laminate (G) may include an optical film or a multilayer film containing an optical film. The multilayer film may also include an optical film and a substrate film (such as the resin film mentioned above).

[0052] Optical films are films that have optical functions. Examples of optical films include polarizing films, phase difference films, and isotropic films. Examples of materials that make up optical films include polyvinyl alcohol resins, polyolefin resins, cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, (meth)acrylic resins, (meth)acrylic urethane resins, polysulfone resins, acetate resins, epoxy resins, and silicone resins.

[0053] The method for manufacturing the glass laminate (G) is not particularly limited. In one example of a method for manufacturing a glass film (G), a resin film is attached to both sides of the glass film via an adhesive layer. Next, an inorganic oxide layer is formed on the resin film (resin layer). In this way, the glass laminate (G) can be manufactured. If the glass laminate (G) includes other layers (or films), the other layers (or films) may be attached to the resin layer or inorganic oxide layer by known methods. Alternatively, the other layers may be formed on the resin layer or inorganic oxide layer by known methods.

[0054] The method for bonding the glass film and the resin film is not particularly limited. In one example, the glass film and the resin film may be bonded together by sandwiching them between a roll that presses the glass film and a roll that presses the resin film. In this method, a roll-to-roll method may be used.

[0055] (Solar Cell) The solar cell according to this embodiment includes a glass laminate (G) and a semiconductor layer that functions as a power generation layer. The semiconductor layer may be laminated on the inorganic oxide layer side of the glass laminate (G). The solar cell may also include a glass laminate (G) and a perovskite layer laminated on the inorganic oxide layer side of the glass laminate (G). That is, the solar cell may be a perovskite solar cell. The inorganic oxide layer is a conductive layer. The solar cell may further include other layers as needed. Examples of other layers include carrier transport layers (electron transport layers, hole transport layers) and current collector layers. The solar cell may include a carrier transport layer (electron transport layer or hole transport layer) disposed between the inorganic oxide layer and the perovskite layer (power generation layer).

[0056] A solar cell may include a laminated structure of resin layer / glass film / resin layer / inorganic oxide layer / first carrier transport layer / perovskite layer (power generation layer) / second carrier transport layer. The solar cell may also include layers other than those listed above. One of the first and second carrier transport layers is an electron transport layer, and the other is a hole transport layer. For example, a solar cell may include a laminated structure of resin layer / glass film / resin layer / inorganic oxide layer / electron transport layer / perovskite layer (power generation layer) / hole transport layer. Alternatively, a solar cell may include a laminated structure of resin layer / glass film / resin layer / inorganic oxide layer / hole transport layer / perovskite layer (power generation layer) / electron transport layer. A current collector layer is usually formed on the second carrier transport layer. When a solar cell generates electricity from light incident from the glass laminate (G) side, each layer constituting the glass laminate (G) is a light-transmitting layer. The inorganic oxide layer may be a transparent conductive layer.

[0057] The layers other than the glass laminate (G) are not particularly limited, and layers used in known perovskite solar cells may be used. The perovskite layer is formed using a perovskite semiconductor. The perovskite layer may be a lead halonide perovskite layer. If the inorganic oxide layer is a transparent conductive layer, the inorganic oxide layer may be an indium tin oxide layer. The method for forming the layers other than the glass laminate (G) is not particularly limited, and known formation methods may be used.

[0058] The glass laminate (G) is thin and flexible. Therefore, it is possible to manufacture solar cells using the roll-to-roll method by using the glass laminate (G). Furthermore, solar cells using the glass laminate (G) can be installed on curved surfaces. The glass laminate (G) may also be used as a substrate for solar cells other than perovskite solar cells (amorphous silicon solar cells, chalcogenide solar cells, organic thin-film solar cells, etc.). In addition, if the inorganic oxide layer and / or current collector layer functions as a carrier transport layer, at least one of the carrier transport layers may be omitted.

[0059] The glass laminate (G) can be used as a component of products (P) other than solar cells. For example, the glass laminate (G) can be used in a variety of electronic devices. Products (P) are not particularly limited. Examples of products (P) include display devices, dimming devices (such as electrochromic devices and polymer-dispersed liquid crystal devices), and light-emitting devices (such as laser devices).

[0060] Hereinafter, examples of embodiments relating to this disclosure will be specifically described with reference to the drawings. The components of the examples described below can be the components described above. Furthermore, the components of the examples described below can be modified based on the above description. In addition, the matters described below may be applied to the embodiments described above. Furthermore, in the examples described below, components that are not essential to the glass laminate and solar cell of this disclosure may be omitted.

[0061] (Embodiment 1) Embodiment 1 describes an example of a glass laminate (G). Figure 1 shows a cross-sectional view of a part of the glass laminate 10 of Embodiment 1. The glass laminate 10 includes a glass film 11, a first resin layer 21, a second resin layer 22, and an inorganic oxide layer 31. The glass film 11 has a first main surface 11a and a second main surface 11b. The first resin layer 21 is arranged on the first main surface 11a. The second resin layer 22 is arranged on the second main surface 11b. The first resin layer 21 includes an adhesive layer 21a and a resin film 21b. The resin film 21b is attached to the glass film 11 by the adhesive layer 21a. The second resin layer 22 includes an adhesive layer 22a and a resin film 22b. The resin film 22b is attached to the glass film 11 by the adhesive layer 22a.

[0062] The inorganic oxide layer 31 is formed on the first resin layer 21. As described above, an inorganic oxide layer may also be formed on the second resin layer 22.

[0063] (Embodiment 2) Embodiment 2 describes an example of a solar cell. Figure 2 shows a cross-sectional view of a part of the solar cell 100 of Embodiment 2. The solar cell 100 includes a glass laminate 10, a carrier transport layer 111, a perovskite layer 112, a carrier transport layer 113, and a current collector layer 114. One of the carrier transport layers 111 and 113 is an electron transport layer, and the other is a hole transport layer. For example, the carrier transport layer 111 may be an electron transport layer and the carrier transport layer 113 may be a hole transport layer. Note that other semiconductor layers may be used instead of the perovskite layer.

[0064] The carrier transport layer 111 is formed on the inorganic oxide layer 31 of the glass laminate 10. In this case, the inorganic oxide layer 31 is made of an inorganic oxide that has conductivity. When power is generated by light incident from the glass laminate 10 side, a transparent conductive layer is used for the inorganic oxide layer 31.

[0065] Each layer from the carrier transport layer 111 to the current collector layer 114 is formed sequentially on the inorganic oxide layer 31. Each of these layers can be formed by known methods.

[0066] The following examples are disclosed based on the above description. (Example 1) A glass laminate comprising a glass film having a first main surface and a second main surface, two resin layers disposed on the first main surface and the second main surface respectively, and an inorganic oxide layer disposed on one of the resin layers, wherein the energy spectrum of the strain distribution is 1.4 mm －１ (Example 2) The glass laminate according to Example 1, wherein the energy value of the strain distribution at the spatial frequency is 0 or greater and 1000 or less, and the energy spectrum of the strain distribution is the spectrum obtained by measuring the strain distribution of a 10 mm × 10 mm sample after holding it in an environment of 150°C for 2 hours and then holding it in an environment of 23°C for 30 minutes. (Example 3) The glass laminate according to Example 1 or 2, wherein the inorganic oxide layer has a crystalline structure. (Example 4) The glass laminate according to any one of Examples 1 to 3, wherein the resin layer includes a resin film, and the thickness of the resin film is 20 μm or more and 100 μm or less. (Example 5) The glass laminate according to any one of Examples 1 to 4, wherein the resin layer includes a resin film, and after the resin film alone is suspended vertically in an air-circulating constant temperature bath at 140°C and held for 90 minutes, and then the resin film is removed from the constant temperature bath and held for 30 minutes in an environment of 23°C and 50% relative humidity, the dimensional change rate of the resin film is 0.20% or less. (Example 6) The glass laminate according to any one of Examples 1 to 5, wherein the inorganic oxide layer is an indium tin oxide layer. (Example 7) A solar cell comprising a glass laminate according to any one of Examples 1 to 6 and a perovskite layer laminated on the inorganic oxide layer side of the glass laminate, wherein the inorganic oxide layer is a conductive layer.

[0067] The present disclosure will be specifically described below with reference to examples.

[0068] The glass laminate and solar cell were manufactured using the following procedure: (1) Preparation of resin film A PET film (polyethylene terephthalate film) was cut to obtain a rectangular precursor film with a long side of 200 mm and a short side of 100 mm. At this time, the PET film was cut so that the direction parallel to the MD direction became the long side and the direction parallel to the TD direction became the short side. A biaxially oriented PET film with a thickness of 100 μm (Lumirror®, manufactured by Toray Industries, Inc.) was used as the PET film.

[0069] Next, the precursor film was heated (annealed) at 150°C for 30 minutes in an atmospheric environment. In this way, a resin film FA1 for use in the glass laminate was obtained.

[0070] (2) Lamination of glass film and resin film An adhesive (resin composition) was applied to one side (first main surface) of the glass film (thickness: 100 μm) and one side of the resin film FA1. OA-10G manufactured by Nippon Electric Glass Co., Ltd. was used for the glass film. An ultraviolet-curable epoxy resin was used for the adhesive. The adhesive was applied so that the thickness of the adhesive layer was 1.5 μm. Next, the glass film and the resin film FA1 were bonded together via the adhesive to obtain a laminate. The adhesive was cured by irradiating the laminate with UV light while applying pressure in the thickness direction to form an adhesive layer. Next, the resin film FA1 was attached to the other side (second main surface) of the glass film in the same manner as described above.

[0071] (3) Formation of the inorganic oxide layer An inorganic oxide layer (thickness: 70 nm) was formed on the resin film FA1 placed on the first main surface of the glass film. Specifically, an indium tin oxide layer (ITO layer) was formed as the inorganic oxide layer by sputtering. In this way, a laminate (glass laminate) A1 was obtained.

[0072] (4) A hole transport layer, a perovskite layer, an electron transport layer, and a current collector layer were formed on the ITO layer of the solar cell manufacturing laminate A1 (size: 50 mm x 50 mm). The electron transport layer material was [6,6]-phenyl C ６１Methyl butyrate (PCBM) was used. Methylammonium lead iodide (MAPbI) was used as the material for the perovskite layer. ３ ) was used. PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid) was used as the material for the hole transport layer. Silver was used as the material for the current collector layer. In this way, solar cell SA1 was formed. Solar cell SA1 was formed so as to be located in the center of the laminate A1. The size of solar cell SA1 was 25 mm x 25 mm.

[0073] The manufactured resin film FA1, laminate A1, and solar cell SA1 were evaluated using the following procedure.

[0074] (1) Evaluation of resin film FA1 A sample was obtained by cutting the manufactured resin film FA1 using the method described in the measurement method of dimensional change rate above. The sample (resin film) was suspended vertically in an air-circulating constant temperature bath at 140°C for 90 minutes, and then the sample was removed from the constant temperature bath and held in an environment of 23°C and 50% relative humidity for 30 minutes. The thermal shrinkage rate of the sample was calculated by measuring the sample before and after these treatments.

[0075] (2) Evaluation of laminate A1 The energy spectrum of the strain distribution of laminate A1 was obtained using the method described above.

[0076] (3) Evaluation of solar cell SA1 The power generation efficiency of solar cell SA1 was measured by irradiating it with light.

[0077] (Manufacturing of other resin films, glass laminates, and solar cells) Resin films FA2-FA3, FC1-FC4, and FC4' were prepared in the same manner and under the same conditions as resin film FA1, except that the thickness of the precursor film and / or the presence or absence of annealing treatment (150°C, 30 minutes) of the precursor film were varied as shown in Table 1. Resin films FC1-FC4 are precursor films that were not annealed.

[0078] Laminates (glass laminates) A2-A3, C1, C2, and C4, and laminate C3 were manufactured under the same conditions and methods as for laminate A1, except that the thickness of the resin film and glass film were changed as shown in Table 1. Laminate C3 was formed by bonding two resin films together. That is, laminate C3 does not contain a glass film. Of the two resin films used to form laminate C4, the resin film FC4 that was not annealed was placed on the power generation element side. The annealed resin film FC4' was placed on the outside (opposite side from the power generation element). Solar cells SA2-SA3 and SC1-SC4 were manufactured under the same conditions and methods as for solar cell SA1, except that laminates A2-A3 and C1-C4 were used instead of laminate A1.

[0079] The manufactured resin film, glass laminate, and solar cell were evaluated using the same method as the evaluation of the resin film FA1, laminate A1, and solar cell SA1. Some of the manufacturing conditions for the resin film and glass laminate, along with the evaluation results, are shown in Table 1. Note that H in Table 1 refers to... ２ (f ｘ , f ｙ ) has a spatial frequency of 1.4 mm －１ This is the value when [condition].

[0080]

[0081] Laminates A1 to A3, C1, C2, and C4 are glass laminates. Laminates A1 to A3 are glass laminates (G) according to the present disclosure. Laminates C1 to C4 are comparative examples. Solar cells SA1 to SA3 are solar cells according to the present disclosure. Solar cells SC1 to SC4 are comparative examples.

[0082] As shown in Table 1, the thermal shrinkage rate (dimensional change rate) of the resin films FA1 to FA3 was small. By using glass laminates A1 to A3 that satisfy the above-mentioned condition (1), it was possible to manufacture solar cells with high power generation efficiency.

[0083] This disclosure is applicable to glass laminates and solar cells. Although the present invention has been described in relation to preferred embodiments at present, such disclosure should not be constrained. Various modifications and alterations will undoubtedly become apparent to those skilled in the art in the field to which the invention pertains by reading the above disclosure. Accordingly, the appended claims should be construed as encompassing all modifications and alterations without departing from the true spirit and scope of the invention.

[0084] 10: Glass laminate 11: Glass film 11a: First main surface 11b: Second main surface 21: First resin layer 21a, 22a: Adhesive layer 21b, 22b: Resin film 22: Second resin layer 31: Inorganic oxide layer 100: Solar cell 112: Perovskite layer

Claims

1. A glass laminate comprising a glass film having a first main surface and a second main surface, two resin layers disposed on the first main surface and the second main surface respectively, and an inorganic oxide layer disposed on one of the resin layers, wherein the energy spectrum of the strain distribution is 1.4 mm －１ A glass laminate in which the energy value of the strain distribution at spatial frequency is between 0 and 1000, and the energy spectrum of the strain distribution is obtained by measuring the strain distribution of a 10 mm × 10 mm sample after it has been held in an environment of 150°C for 2 hours and then held in an environment of 23°C for 30 minutes.

2. The glass laminate according to claim 1, wherein the thickness of the glass film is 200 μm or less.

3. The glass laminate according to claim 1 or 2, wherein the inorganic oxide layer has a crystalline structure.

4. The glass laminate according to claim 1 or 2, wherein the resin layer includes a resin film, and the thickness of the resin film is 20 μm or more and 100 μm or less.

5. The glass laminate according to claim 1 or 2, wherein the resin layer includes a resin film, and when only the resin film is suspended vertically in an air-circulating constant temperature bath at 140°C for 90 minutes, and then the resin film is removed from the constant temperature bath and held in an environment at 23°C and 50% relative humidity for 30 minutes, the dimensional change rate of the resin film is 0.20% or less.

6. The glass laminate according to claim 1, wherein the inorganic oxide layer is an indium tin oxide layer.

7. A solar cell comprising a glass laminate according to claim 1 or 2, and a perovskite layer laminated on the inorganic oxide layer side of the glass laminate, wherein the inorganic oxide layer is a conductive layer.

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