POWER-GENERATING BUILDING MATERIALS AND PREPARATION PROCESS THEREFOF

Abstract

A power-generating building material, comprising a substrate (1), a power-generating layer (2) and a protective layer (4), wherein the power-generating layer (2) is disposed on the substrate (1), and the protective layer (4) covers the power-generating layer (2). The substrate (1) is glass, metal plate, cement-based board, flexible plastic film, ceramic or tile, and the protective layer (4) has a weighted average transmittance of 0% to 79% in a wavelength range of 300 nm to 1300 nm. A process for preparing the power-generating building material, comprises: 1) cleaning the surface of the substrate; 2) attaching the power-generating layer to the substrate and extracting a positive electrode and a negative electrode; and 3) coating a protective layer on the solar cells.

Claims

1.-22. (canceled)

23. A power-generating building material, comprising a substrate, a power-generating layer and a protective layer, wherein the power-generating layer is disposed on the substrate, the protective layer covers the power-generating layer; the protective layer has a weighted average transmittance of 10% to 85% in a wavelength range of 300 nm to 1300 nm; and an adhesion between the protective layer and the power-generating layer is 1 MPa.

24. The power-generating building material of claim 23, wherein the substrate layer has a thickness of 0.01 mm to 5 cm.

25. The power-generating building material of claim 23, wherein the power-generating layer has a structure of copper indium gallium selenide thin-film solar cell, gallium arsenide solar cell, crystalline silicon solar cell, silicon based thin-film solar cell, cadmium telluride thin-film solar cell, organic solar cell, copper zinc tin sulfur thin-film solar cell or perovskite thin-film solar cell.

26. The power-generating building material of claim 23, wherein the protective layer is made with an inorganic silicate material or an inorganic-organic composite material.

27. The power-generating building material of claim 23, wherein the protective layer has a thickness of 0.01 mm to 5 mm.

28. The power-generating building material of claim 23, wherein the solar cell further comprises an encapsulation layer located between the power-generating layer and the protective layer, the encapsulation layer comprises an ethylene-octene copolymer or an ethylene-vinyl acetate copolymer.

29. The power-generating building material of claim 28 wherein the encapsulation layer has a thickness of 0.05 mm to 3 mm.

30. The power-generating building material claim 23, wherein the surface layer has a haze of 10% to 99%.

31. The power-generating building material of claim 23, wherein the protective layer comprises one or more selected from the group consisting of ceramic film, ethylene-vinyl acetate copolymer, polyvinyl butyral, polyethylene-butene copolymer, silica gel, polyethylene, polyethylene-tetrafluoroethylene copolymer, perfluoroethylene propylene copolymer, polyvinylidene fluoride, polyethylene terephthalate, inorganic glass, organic glass and polycarbonate; the protective layer only has ceramic film; or when the protective layer comprises one or more selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl butyral, polyethylene oxide and silica gel, the protective layer further comprises a front film; the front film comprises inorganic glass and/or polymer material.

32. The power-generating building material of claim 31, wherein the polymer material comprises one or more selected from the group consisting of organic glass, polycarbonate, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride film, perfluoroethylene propylene copolymer, polyethylene terephthalate and polyethylene terephthalate/polyethylene.

33. A process for preparing the power-generating building material of claim 23, comprising: (1) attaching the power-generating layer to the substrate and extracting a positive electrode and a negative electrode, or directly preparing the power-generating layer on the substrate, and extracting a positive electrode and a negative electrode; and (2) coating a protective layer material at liquid state at room temperature and curing at room temperature to form a solid enamel protective layer.

34. The process of claim 33, wherein the substrate is treated with polishing and cleaning before preparing the power-generating layer, and the treated substrate has a surface roughness of less than 100 nm and a contact angle of 5 to 15.

35. The process of claim 33, wherein the step (1) further comprises forming an encapsulation layer after extracting the positive electrode and negative electrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0111] FIG. 1 shows a cross-sectional view of the structure of a novel power-generating building material, in which 1 is a material of the substrate layer (ceramic, cement substrate, metal plate, plastic film, tile, and the like), 2 is a power-generating layer, 3 is an encapsulation layer, and 4 is a protective layer (enamel).

[0112] FIG. 2 shows a transmittance curve of different enamel protective layers in the wavelength range of 300 nm to 1300 nm.

[0113] FIG. 3 shows an I-V curve of a power-generating building material.

[0114] FIG. 4 shows a structural diagram of a photovoltaic building material (comprising a ceramic film), in which 1 is a surface layer, 2 is a power-generating layer and 3 is a substrate layer.

[0115] FIG. 5 shows a side view of the structure of the photovoltaic building material shown in FIG. 4, in which 1 is a surface layer, 2-1 is a ceramic film, 2-2 is a solar cell layer, 2*2 is a negative electrode surface, 2*3 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0116] FIG. 6 shows a structural diagram of a photovoltaic building material (comprising a front film and a gel film), in which 1 is a surface layer, 2 is a power-generating layer and 3 is a substrate layer.

[0117] FIG. 7 shows a side view of the structure of the photovoltaic building material shown in FIG. 6, in which 2-1 is a front film, 2-2 is a gel film, 2-3 is a solar cell layer, 2*2 is a negative electrode surface, 2*3 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0118] FIG. 8 shows a structural diagram of a photovoltaic building material (comprising a ceramic film and a gel film), in which 1 is a surface layer, 2 is a power-generating layer and 3 is a substrate layer.

[0119] FIG. 9 shows a side view of the structure of the photovoltaic building material shown in FIG. 8, in which 1 is a surface layer, 2-1 is a ceramic film, 2-2 is a solar cell layer, 3-1 is a gel film, 3-2 is a substrate, 2*2 is a negative electrode surface, 2*3 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0120] FIG. 10 shows a structural diagram of a photovoltaic building material (comprising a front film and two gel films), in which 1 is a surface layer, 2 is a power-generating layer and 3 is a substrate layer.

[0121] FIG. 11 shows a side view of the structure of the photovoltaic building material shown in FIG. 10, which 1 is a surface layer, 2-1 is a front film, 2-2 is a gel film, 2-3 is a solar cell layer, 3-1 is a gel film, 3-2 is a substrate, 2*3 is a negative electrode surface, 2*4 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0122] FIG. 12 shows a structural diagram of a photovoltaic building material (comprising a ceramic film and two gel films), in which 1 is a surface layer, 2 is a power-generating layer, 3 is a first substrate layer and 4 is a second substrate layer.

[0123] FIG. 13 shows a side view of the structure of the photovoltaic building material shown in FIG. 12, in which 1 is a surface layer, 2-1 is a ceramic film, 2-2 is a solar cell layer, 3-1 is a gel film, 3-2 is a first substrate, 4-1 is a gel film, 4-2 is a second substrate, 2*2 is a negative electrode surface, 2*3 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0124] FIG. 14 shows a structural diagram of a photovoltaic building material (comprising a front film and three gel films), in which 1 is a surface layer, 2 is a power-generating layer, 3 is a first substrate layer, 4 is a second substrate layer, 2-1 is a front film, 2-2 is a gel film, 2-3 is a solar cell layer, 3-1 is a gel film, 3-2 is a first substrate, 4-1 is a gel film, 4-2 is a second substrate, 2*3 is a negative electrode surface, 2*4 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0125] FIG. 15 shows a side view of the structure of the photovoltaic building material shown in FIG. 14, in which 1 is a surface layer, 2-1 is a front film, 2-2 is a gel film, 2-3 is a solar cell layer, 3-1 is a gel film, 3-2 is a first substrate, 4-1 is a gel film, 4-2 is a second substrate, 2*3 is a negative electrode surface, 2*4 is a positive electrode surface, e1 is an extracted negative electrode and e2 is an extracted positive electrode.

[0126] FIG. 16 shows a transmittance curve of the surface layer of Example 6 of the present disclosure in the wavelength range of 300 nm to 1300 nm. The weighted average transmittance is 85%.

[0127] FIG. 17 shows a transmittance curve of the surface layer of Example 7 of the present disclosure in the wavelength range of 300 nm to 1300 nm. The weighted average transmittance is 35%.

[0128] FIG. 18 shows a transmittance curve of the surface layer of Example 8 of the present disclosure in the wavelength range of 300 nm to 1300 nm. The weighted average transmittance is 52%.

[0129] FIG. 19 shows a transmittance curve of the surface layer of Example 9 of the present disclosure in the wavelength range of 300 nm to 1300 nm. The weighted average transmittance is 10%.

DETAILED DESCRIPTION

[0130] The present disclosure will be further explained and illustrated in the following description with reference to the accompanying drawings, which are used only to explain but not to limit the present invention.

[0131] Referring to FIG. 1, a novel power-generating building material is shown.

[0132] From bottom to the top, the power-generating building material comprises a substrate layer 1, a thin-film solar cell, a drainage strip 2 and a protective layer 3 (an enamel film).

[0133] The substrate material can be glass, ceramic, cement, metal plate, plastic film, tile, and the like.

[0134] The thin-film solar cell can be the core structure of a plurality of solar cells. The specific structure can be a structure having a CIGS thin-film solar cell, GaAs thin-film solar cell, amorphous silicon thin-film solar cell, CdTe thin-film solar cell, OPV thin-film solar cell, CZTS thin-film solar cell or perovskite thin-film solar cell.

[0135] The protective layer film has an optimum thickness of 0.01 mm to 5 mm. The thicker film will provide better protection, but obviously the transmittance of the protective layer will reduce.

[0136] The film can be an enamel film. A film with a gloss glaze, a semi-gloss glaze, a matt glaze or an embossed glaze can used for the power-generating building material. Different colors can be selected for an enamel film as desired. According to the usual practice in the field, the protective layer should be as transparent as possible so that sunlight can pass through at the maximum. While in the present disclosure, by introducing an enamel layer and selectively coloring the enamel layer, the power-generating building material can be integrated into the surrounding environment. This broadens the application of solar cells.

[0137] The enamel film as used is preferably an inorganic silicate material or an inorganic-organic composite material. The composition thereof comprises a plurality of elements selected from the group consisting of O, Na, Ga, Mg, S, Si, Al, Ca, Co, K, Zr, Ba, P and B. A glaze can be formed by reacting a raw material comprising these elements (such as an oxide or a corresponding salt, for example sodium silicate, magnesium hydroxide and potassium carbonate) at a low temperature.

[0138] Taking the preparation of glaze 0.05MgSO.sub.4.0.05CaO.0.15ZrO.0.70N a.sub.2SiO.sub.3.0.05Al.sub.2(SO.sub.4).sub.3 as an example, the raw materials are accurately weighed according to the raw material component ratio of the above glaze. 30-35% by weight of water is added. The resultant mixture is ball milled over 36 h to 40 h to achieve the glaze fineness of 250 mesh and sieve residue of less than 0.015%. As a result, a qualified glaze abrasive is obtained.

[0139] The raw material can also be selected from sodium titanate, quartz sand, feldspar powder, sodium carbonate, sodium nitrate, cryolite, zirconium dioxide, aluminum phosphate, cobalt nitrate, nickel nitrate, zinc oxide, barium carbonate, and the like as a source of different oxides.

[0140] The abrasive is sintered at a high temperature (such as 800 to 850 C.), quenched and pulverized to obtain an enamel glaze. The glaze can be ball milled to obtain fine particles in order to be applied to inkjet printing or sprayed directly.

[0141] Other components of the glaze that can be used may also be 0.06MgSO.sub.4.0.10CaO.0.12ZrO.0.64Na.sub.2SiO.sub.3.0.05Al.sub.2(SO.sub.4).sub.3.0.03Co.sub.2O.sub.3, 0.06BaSO.sub.4.0.11CaO.0.13TiO.sub.2.0.65Na.sub.2SiO.sub.3.0.04Al.sub.2(SO.sub.4).sub.3.0.01Co.sub.2O.sub.3, 0.10BaSO.sub.4.0.10TiO.sub.2.0.75K.sub.2SiO.sub.3.0.04Al.sub.2(SO.sub.4).sub.3.0.01Co.sub.2O.sub.3, 0.06MgSO.sub.4.0.10TiO.sub.2.0.12ZrO.0.605K.sub.2SiO.sub.3.0.085Al.sub.2(SO.sub.4).sub.3.0.03CoCl.sub.2, 0.08BaO.0.10Ga.sub.2O.sub.3.0.12ZrO.0.565K.sub.2SiO.sub.3.0.085Al.sub.2(SO.sub.4).sub.3.0.03CoCl.sub.2.0.02B.sub.2O.sub.3, and the like.

[0142] In the following examples, the aqueous glaze may be any one of the above materials.

[0143] Various dopants can be added in the above-mentioned film so that light can transmit in a specific wavelength range. For example, benzotriazoles are added as ultraviolet absorbers. The absorption of ultraviolet light can be achieved by adding one or more selected from the group consisting of 2-(2-hydr oxy-5-methyl)-benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methyl)-5-chloro-benzo triazole, 2-(2-hydroxy-35-di-tert-butyl)-5-chloro-benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole and 2-(2-hydroxy-5-tert-octyl)-benzotriazole. The regulation of near-infrared light can be achieved by adding one or more selected from the group consisting of indium tin oxide, antimony tin oxide, tungsten trioxide, molybdenum trioxide, tungsten bronze and copper sulfides with oxygen deficiency. The regulation of visible light absorption can be achieved by adding fullerene derivative PC61BM or PC71BM (see CN 1060 25080 A) or other colored materials.

[0144] The film can also be a fluorine-containing polymer. The typical fluorine-containing polymer is polytetrafluoroethylene. When a fluorine-containing polymer with a thickness of 0.01 to 1 mm is used as a protective layer, it not only can ensure light transmission, but can change the appearance of a solar cell.

[0145] The film of a protective layer has a transmittance of 0% to 79% in a wavelength range of 300 nm to 1300 nm. One skilled in the art can further improve this as desired. For example, specific components can be added or doped in the film, so that light at specific wavelength range can be absorbed or high transmittance can be maintained. Referring to the absorption spectrum of the enamel layer material as shown in FIG. 2, there is the transmittance of 0% to 79% in at least one of the following wavelength ranges: 300 to 400 nm, 400 to 500 nm, 500 to 600 nm, 600 to 700 nm, 700 to 760 nm, 760 to 860 nm and 860 to 1300 nm. In addition, the transmittance of visible light and light of 760 to 1300 nm decreases from top to bottom in turn in accordance with the different types of the films.

[0146] FIG. 3 shows an I-V curve of a power-generating building material with the structure shown in FIG. 1. As shown in FIG. 3, the conversion efficiency of a small-area power-generating building material is greater than 14%.

Example 1

[0147] A power-generating building material comprised a substrate, which was a flexible stainless steel foil and had a thickness of 0.2 mm. A power-generating electrode layer was disposed on the substrate and had wires to extract electrodes. A protective layer was disposed on a cell layer. The protective layer was made with an aqueous glaze. The aqueous glaze comprised a soluble silicon inorganic metal salt. The protective layer had a thickness of 0.1 mm and marble patterns.

[0148] The preparation process was as follows:

[0149] The flexible stainless steel foil substrate was washed and placed in a magnetron sputtering machine. In order to prevent the elements in the stainless steel from diffusing into the solar cell, firstly, a 0.5 m WTi barrier layer was sputtered. The working gas was Ar gas. The sputtering gas pressure was 0.7 Pa. The background vacuum was 2.010.sup.3 Pa. The substrate was not heated during sputtering. The Mo film was prepared by a three-sublayer process. The sputtering pressure of the first layer was 1.5 Pa. The sputtering pressure of the second layer was 0.6 Pa. The sputtering pressure of the third layer was 1.5 Pa. A 2 m CIGS film was deposited by sputtering on the Mo film at a sputtering gas pressure of 0.7 Pa and a background vacuum of 1.510.sup.3 Pa, followed by selenization annealing treatment. The selenized film was placed in a mixed solution of cadmium sulfate, thiourea, and ammonia, 50 nm CdS was deposited at 70 C. Then, the film was placed in the sputtering chamber again. The working gas was 02 and Ar. The sputtering pressure was 0.7 Pa. The background vacuum was 2.010.sup.3 Pa. The substrate temperature was kept at 200 C. during sputtering. Intrinsic ZnO film and AZO film were deposited, separately. Finally, a NiAl gate was deposited by evaporation to prepare a flexible thin-film solar cell panel.

[0150] The protective layer was prepared by inkjet printing. The raw materials of the enamel layer comprised cobalt acetate, ferrous chloride, potassium chromate and zirconium hypochlorite. The glaze solution was prepared by a conventional process (dissolving with water or an alcohol solvent and adding OP and aqueous acrylic emulsion). The glaze solutions were loaded into different printer equipment according to different colors of the glazes and printed directly according to the patterns of the marble to obtain the power-generating building material.

[0151] The power-generating building material had a marble pattern. The transmittance in visible light at 500 nm to 700 nm was 71% and the photovoltaic conversion efficiency was 14.6%.

Example 2

[0152] A power-generating building material comprised a substrate, which was ceramic with a thickness of 8.0 mm. A cell layer was disposed on the substrate and had wires to extract electrodes. The solar cell layer had a CdTe solar cell structure.

[0153] The specific preparation process was as follows.

[0154] Firstly, a washed substrate was placed in a sputtering apparatus. The working gas was Ar gas. The sputtering gas pressure was 0.7 Pa. The background vacuum was 1.510.sup.3 Pa. A transparent conductive indium tin oxide thin-film was sputtered and deposited on the substrate. Subsequently, a CdS slurry was coated to form a film by screen-printing method. The film was dried at 120 C. for 3 h and sintered in a nitrogen atmosphere for 2 h at a sintering temperature of 650 C. A slurry containing CdTe powder was printed on the CdS film and sintered for 1 h. Finally, a carbon electrode and Ag slurry were printed on CdTe as extraction electrodes. A protective layer was disposed on the cell layer. The protective layer was made with an aqueous glaze. The aqueous glaze comprised a soluble inorganic metal salt. The protective layer had a thickness of 0.1 mm and marble patterns.

[0155] The glaze solution can be coated on the surface of the cell layer by spray coating, screen printing or flow impeller. The transmittance of light at 450 nm to 760 nm was 52%. The obtained cell has a photoelectric conversion efficiency of not less than 14.1% and can be used on the exterior walls of buildings.

Example 3

[0156] A power-generating building material comprised a substrate, which was an aluminum nitride ceramic with a thickness of 1.0 cm. A cell layer was disposed on the substrate, and had wires to extract electrodes. An encapsulation layer and a protective layer were disposed on the cell layer. The protective layer was made with a polytetrafluoroethylene and had a thickness of 0.05 mm. The surface of the protective layer was dark gray. The surface of a power-generating layer had 4 or less layers of graphene.

[0157] For the preparation of the cell, refer to Example 1. The graphene layer can be prepared at low temperature. In order to avoid adverse effects on the power-generating layer, the graphene layer must be prepared at a temperature of not higher than 400 C.

[0158] The cell obtained in the present Example had a light transmittance of 21% at 450 nm to 760 nm and a photoelectric conversion efficiency of not less than 14.0%. The power-generating building material can be used on the exterior walls of buildings.

Example 4

[0159] A power-generating building material comprised a substrate, which was a polyimide film. A cell layer was disposed on the substrate and had wires to extract electrodes. An encapsulation layer and a protective layer were disposed on the cell layer. The protective layer was made with polytetrafluoroethylene and had a thickness of 0.05 mm. The surface of the protective layer was beige. See embodiment 1 for the preparation of the solar cell.

[0160] The cell obtained in the present Example had a light transmittance of 50% at 500 nm to 760 nm and a photoelectric conversion efficiency of not less than 14.2%.

Example 5

[0161] A power-generating building material comprised a substrate, which was enamel. A cell layer was disposed on the substrate and had wires to extract electrodes. A protective layer was disposed on the cell layer. The protective layer was made with polytetrafluoroethylene and had a thickness of 0.6 mm. The surface of the protective layer was white. Refer to Example 1 for the preparation of the cell. The surface of the cell was covered with graphene. The number of graphene layer was not more than 15. The graphene layers can be prepared by low temperature method. In order to avoid interference with the power-generating layer, the graphene layers must be prepared at a temperature of not higher than 400 C.

[0162] The cell obtained in the present Example had a light transmittance of 76% at 450 nm to 760 nm and a photoelectric conversion efficiency of not less than 14.2%.

Example 6

[0163] FIGS. 4 and 5 show a photovoltaic building material.

[0164] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer.

[0165] The substrate was a flexible stainless steel foil and had a thickness of 0.2 mm. The power-generating layer was disposed on the substrate and had wires to extract electrodes. The surface layer was disposed on the power-generating layer.

[0166] The process for preparing the power-generating layer was as follows.

[0167] The flexible stainless steel foil substrate was washed and placed in a magnetron sputtering machine. In order to prevent the elements in the stainless steel from diffusing into the solar cell, firstly, a 1.0 m WTi barrier layer was sputtered. The working gas was Ar gas. The sputtering gas pressure was 0.7 Pa. The background vacuum was 2.010.sup.3 Pa. The substrate was not heated during sputtering. A Mo film was prepared by a three-sublayer process. The sputtering pressure of the first layer was 1.5 Pa. The sputtering pressure of the second layer was 0.6 Pa. The sputtering pressure of the third layer was 1.5 Pa. A 1.2 m CIGS film was deposited by sputtering on the Mo film at a sputtering gas pressure of 0.7 Pa and a background vacuum of 1.510.sup.3 Pa, followed by selenization annealing treatment. The selenized film was placed in a mixed solution of cadmium sulfate, thiourea, and ammonia. 30 nm CdS was deposited at 70 C. Then, the film was placed in the sputtering chamber again. The working gas was 02 and Ar. The sputtering pressure was 0.7 Pa. The background vacuum was 2.010.sup.3 Pa. The substrate temperature was kept at 200 C. during sputtering. Intrinsic ZnO film and AZO film were deposited, separately. Finally, a NiAl gate was deposited by evaporation to prepare a flexible thin-film solar cell panel. A layer of aluminum nitride with a thickness of 15 m was deposited by RF sputtering to finally prepare the power-generating layer.

[0168] The surface layer was prepared by printing method. The surface layer mainly comprised a mother liquid and supplemented with an inorganic pigment. Based on parts by weight, the mother solution accounted for 155 parts, the pigment accounted for 7 parts. The pigment was titanium dioxide and iron oxide red powder with the same weights. The mother solution comprised 764 parts of deionized water, 0.4 parts of A1522 cross-linking agent, 3 parts of 250HBR cellulose, 1.5 parts of 5040 dispersing agent, 1.5 parts of AMP-95 multifunctional auxiliary agent, 2.5 parts of M30 bactericide, 21 parts of R103 forming agent, 4 parts of ethylene glycol, 9.5 parts of C-12 film-forming auxiliary agent, 0.1 part of silicone light diffusing agent, 0.02 parts of semiconductor ceria quantum dot, 0.001 parts of graphene, 21 parts of soap-free polymerized silicone-acrylic emulsion, 90 parts of core-shell copolymerized self-crosslinking silicone-acrylic emulsion and 70 parts of silicone grafted acrylate emulsion. The thickness of the prepared surface layer was 0.01 mm. The curing temperature was 90 C. The curing time was 1 h.

[0169] In accordance with the transmittance curve of visible light at 300 nm to 1300 nm as shown in FIG. 16, the surface layer of the photovoltaic building material had a weighted average transmittance of 85%.

Example 7

[0170] FIGS. 6 and 7 show a photovoltaic building material.

[0171] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer.

[0172] A photovoltaic building material comprised the substrate, which was glass and had a thickness of 2.0 mm. A cell layer was disposed on the substrate and had wires to extract electrodes. The process for preparing the cell was similar to that of Example 1, except that the CIGS film was replaced with Cu.sub.2(ZnSn)(SSe).sub.4 and the post-treatment process of the film was replaced with selenization or vulcanization. A protective layer was disposed on the cell layer. The protective layer was EVA and glass. The surface layer was prepared by manual spraying method.

[0173] Based on parts by weight, 186 parts of mother solution and 5 parts of pigment were used. The mother solution as used comprised 45 parts of potassium water glass, 130 parts of filler, which was a mixture of talc powder, calcium carbonate and kaolin with the weight ratio of 2:1:1, 0.2 part of silicone resin, 3 parts of silicone gel, 1 part of lauryl alcohol ester, 6 parts of vinyltriamine, 20 parts of water, and 0.2 part of barium sulfate light diffusing agent. The pigment was a mixture of stone green and realgar with the weight ratio of 1:3. The thickness of the obtained surface layer was 2 mm. The curing temperature was 20 C. The curing time was 2 h.

[0174] In accordance with the transmittance curve of visible light at 300 nm to 1300 nm as shown in FIG. 17, the surface layer of the photovoltaic building material had a weighted average transmittance of 35%.

Example 8

[0175] FIGS. 6 and 7 show a photovoltaic building material.

[0176] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer.

[0177] A photovoltaic building material comprised the substrate, which was ceramic and had a thickness of 8.0 mm. A cell layer was disposed on the substrate and had wires to extract electrodes. The cell layer had a CdTe solar cell structure.

[0178] The specific preparation process was as follows.

[0179] Firstly, the washed substrate was placed in a sputtering apparatus. The working gas was Ar gas. The sputtering gas pressure was 0.7 Pa. The background vacuum was 1.810.sup.3 Pa. A transparent conductive indium tin oxide thin-film was sputtered and deposited on the substrate. Subsequently, a CdS slurry was coated to form a film by screen printing method. The film was dried at 100 C. for 2 h and sintered in a nitrogen atmosphere for 2 h at 680 C. A slurry comprising CdTe powder was printed on the CdS film and sintered for 1 h. Finally, a carbon electrode and an Ag slurry were printed on CdTe as extraction electrodes. A protective layer was disposed on the cell layer. The protective layer was PVB and ETFE. The surface layer was prepared on the protective layer. The thickness of the surface layer was 0.1 mm. The raw materials of the surface layer were as follows.

[0180] Based on parts by weight, 100 parts of mother solution and 5 parts of pigment were used. The raw materials of the mother solution comprised base material, filler and auxiliary agent. The base material accounted for 60 parts. The filler accounted for 15 parts. The auxiliary agent accounted for 3.8 parts. The base material comprised a fluorocarbon resin. The pigment used natural mineral pigments. The natural mineral pigments comprised mica and coral. The filler comprised wollastonite powder, quartz powder and bentonite with the weight ratio of 1:1.5:0.8. The auxiliary agent comprised 0.2 parts of sulfoxide, 1.1 parts of sodium carboxylate, 0.3 parts of emulsified silicone oil, 1.5 parts of dodecyl alcohol, 0.2 parts of o-phenylphenol and 0.5 parts of methyl cellulose.

[0181] The liquid raw materials constituting the surface layer were coated on the surface of the cell layer by flow impeller method. The curing temperature was 100 C. The curing time was 0.2 s.

[0182] In accordance with the transmittance curve of visible light at 300 nm to 1300 nm as shown in FIG. 18, the surface layer had a weighted average transmittance of 52%.

Example 9

[0183] FIGS. 4 and 5 show a photovoltaic building material.

[0184] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer.

[0185] A photovoltaic building material comprised a substrate, which was aluminum nitride ceramic and had a thickness of 20.0 mm. A cell layer, which was amorphous silicon cell, was disposed on the substrate and had wires to extract electrodes. A protective layer was disposed on the cell layer. The protective layer was made with a silica ceramic film and had a thickness of 5 m. The silica was prepared by reactive sputtering. The reactive sputtering was carried out after the vacuum chamber was pumped to pressure of 2.010.sup.3 Pa. The sputtering was carried out under the constant power sputtering of 600 W, the sputtering gas pressure of 0.6 Pa, the sputtering atmosphere of Ar and O.sub.2, wherein Ar:O.sub.2 was 3:1. The target was monocrystalline silicon with 6 N purity. The target base distance was 60 mm.

[0186] The surface layer was prepared by printing method. Based on parts by weight, a mother solution accounted for 240 parts, and pigment accounted for 10 parts. The mother solution as used comprised 75 parts of sodium water glass, 112 parts of filler, which was a mixture of talc powder, aluminum silicate and kaolin with the weight ratio of 3:2:5, 0.1 parts of silicone resin, 5 parts of methylcellulose, 5 parts of dodecyl alcohol ester, 6 parts of m-phenylenediamine, 14 parts of water, and 0.05 parts of a silicone light diffusing agent. The pigment was phthalocyanine pigment. The thickness of the obtained surface layer was 0.5 mm. The curing temperature was 10 C. The curing time was 48 h.

[0187] In accordance with the transmittance curve of visible light at 300 nm to 1300 nm as shown in FIG. 19, the surface layer of the photovoltaic building material had a weighted average transmittance of 45%.

Example 10

[0188] FIGS. 8 and 9 shows a photovoltaic building material.

[0189] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer.

[0190] A photovoltaic building material used polycrystalline silicon components. The substrate was ceramic and had a water absorption rate of less than 1% and a thickness of 5 mm. The power-generating layer had wires to extract electrodes. A protective layer was disposed on the cell layer. The protective layer was a silica ceramic film.

[0191] The surface layer was prepared by automatic spraying method. The raw materials comprised a mother solution and a pigment. Based on parts by weight, the mother solution accounted for 75 parts, and the pigment accounted for 1 part. The raw materials of the mother solution comprised base material, filler and auxiliary agent. The base material accounted for 70 parts. The filler accounted for 10 parts. The auxiliary agent accounted for 6 parts. The base material was fluorocarbon resin. The pigment was artificial pigment. The artificial pigment was iron blue. The filler comprised quartz powder and precipitated barium sulfate. The auxiliary agent comprised 0.4 parts of glycerin, 1.0 part of sodium polycarboxylate, 0.4 parts of Polyoxyethylene polyoxyepropanolamine ether, 2 parts of lauryl alcohol, 0.1 part of ammonium persulfate and 0.6 parts of hydroxypropyl methylcellulose.

[0192] The liquid raw materials constituting the surface layer were coated on the surface of the cell layer by printing. The thickness of the surface layer was 0.3 mm. The curing temperature was 50 C. The curing time was 1 s. The surface layer had a weighted average transmittance of visible light at 300 nm to 1300 nm of 45%.

Example 11

[0193] FIGS. 10 and 11 show a photovoltaic building material.

[0194] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer and a substrate layer in turn.

[0195] A photovoltaic building material used a commercially available monocrystalline silicon solar cell module. The substrate was a glass and had a thickness of 2 mm. The power-generating layer had wires to extract electrodes and a protective layer. The protective layer comprised a silica gel and a front film. The front film was ETFE.

[0196] The surface layer was prepared by spin coating method. The raw materials comprised a mother solution and a pigment. Based on parts by weight, the mother solution accounted for 140 parts, and the pigment accounted for 5 parts.

[0197] The mother solution comprised 800 parts of deionized water, 0.3 part of A151 cross-linking agent, 2 parts of 250HBR cellulose, 0.5 part of 5040 dispersing agent, 3 parts of AMP-95 multifunctional auxiliary agent, 1 part of M30 bactericide, 15 parts of R103 forming agent, 6 parts of ethylene glycol, 8 parts of C-12 film-forming auxiliary agent, 0.1 part of nano-silica light diffusing agent, 28 parts of soap-free polymerized silicone-acrylic emulsion, 70 parts of the self-crosslinking silicon-acrylic emulsion copolymerized by core-shell structure, and 110 parts of silicone grafted acrylate emulsion. Pigment was azo pigment and accounted for 1 part. The thickness of the prepared surface layer was 0.05 mm. The curing temperature was 10 C. the curing time was 30 h.

[0198] The product prepared in the present Example had a weighted average light transmittance of 55% at 300 nm to 1300 nm.

Example 12

[0199] FIGS. 12 and 13 show a photovoltaic building material.

[0200] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer, a first substrate layer and a second substrate layer in turn.

[0201] For a photovoltaic building material, a power-generating layer was a monocrystalline silicon solar cell module. The module was adhered to a tile. The module had wires to extract electrodes. A surface layer was disposed on the power-generating layer.

[0202] Example 7 was referred to for the process for preparing the surface layer.

Example 13

[0203] FIGS. 14 and 15 show a photovoltaic building material.

[0204] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer, a first substrate layer and a second substrate layer in turn.

[0205] For a photovoltaic building material, a power-generating layer was a monocrystalline silicon solar cell module. The module was adhered to a ceramic. The module had wires to extract electrodes. A surface layer was disposed on the power-generating layer.

[0206] Example 9 was referred to for the process for preparing the surface layer.

Example 14

[0207] From top to bottom, a photovoltaic building material comprised a surface layer, a power-generating layer, a first substrate layer and a second substrate layer in turn.

[0208] The power-generating layer was an amorphous silicon thin-film solar cell module. The module was adhered to a cement substrate. The module had wires to extract electrodes. A surface layer was disposed on the power-generating layer.

[0209] Example 8 was referred to for the process for preparing the surface layer.

[0210] It should be noted that the above embodiments are merely illustrating rather than limiting the technical solutions of the present disclosure. Although the disclosure has been described in detail herein with reference to the embodiments, one skilled in the art should understand that modifications and equivalent replacements of the technical solution of the present disclosure without departing from the spirit and scope of the technical solutions of the present disclosure will fall within the scope of the claims.