CN102544126B

CN102544126B - Thin-film solar cells back electrode strap and thin-film solar cells manufacture method

Info

Publication number: CN102544126B
Application number: CN201110416932.0A
Authority: CN
Inventors: 米泽岳洋; 马渡芙弓; 山崎和彦
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2010-12-14
Filing date: 2011-12-14
Publication date: 2016-03-23
Anticipated expiration: 2031-12-14
Also published as: CN102544126A

Abstract

The present invention relates to a kind of thin-film solar cells back electrode strap and use the manufacture method of thin-film solar cells of this back electrode strap.Problem of the present invention is simplification and the efficient activity of the operation can seeking the backplate manufacturing thin-film solar cells, and then be omitted in a part for the laser scribing process used in the manufacture of general thin-film solar cells, and the high speed of the manufacturing process of thin-film solar cells can be realized.Thin-film solar cells back electrode strap of the present invention, is characterized in that, laminating transparent electrode film and reflecting electrode film, and transparent electrode thin film has caking property.Be preferably the thin-film solar cells back electrode strap at the further lamination barrier layer film of reflecting electrode film side.

Description

Thin-film solar cells back electrode strap and thin-film solar cells manufacture method

Technical field

The present invention relates to a kind of thin-film solar cells back electrode strap and use the manufacture method of thin-film solar cells of this back electrode strap.More specifically, relate to and a kind ofly can manufacture thin-film solar cells by easy manufacture method, and can effectively utilize incident sunlight to improve the thin-film solar cells back electrode strap of the generating efficiency of thin-film solar cells.

Background technology

At present, from the position of environmental protection, advancing the research and development of green energy resource and practical, from inexhaustible as the sunlight of the energy and be the aspect such as nuisanceless, solar cell gets most of the attention.In the past, solar cell utilized the block solar cell of monocrystalline silicon or polysilicon always, but because the manufacturing cost of block solar cell is higher and productivity ratio is also lower, was therefore badly in need of exploitation and practices every conceivable frugality the solar cell of silicon amount.

Therefore, endeavour to develop the thin-film solar cells that thickness is such as the semiconductor of the amorphous silicon of 0.3 ~ 2 μm etc.The structure of this thin-film solar cells owing to being the semiconductor layer forming the amount needed for opto-electronic conversion on glass substrate or heat-resistant plastic substrate, therefore has slim and light weight, low cost and the easy advantage such as large area.

Thin-film solar cells has cladding plate (ス mono-パ mono-ストレ mono-ト) type structure and substrate (サ Block ストレ mono-ト) type structure, cover plate profile structure due to sunlight incident from light-transmitting substrate side, therefore usually take the structure formed with the order of substrate-transparency electrode-photoelectric conversion layer-backplate.

One example of the sectional view of thin-film solar cells shown in Fig. 1.In addition, Fig. 1 is the example of cladding plate type.In Fig. 1, be formed with nesa coating 50, the amorphous Si layer 61 forming photoelectric conversion layer and crystallite Si layer 62, nesa coating 10, conductive reflecting film 20 and strengthening membrane 30 on the substrate 40.The position of laser scribing when P1, P2 and P3 of Fig. 1 represent manufacture.In Fig. 1, more forming 1 thin-film solar cells in the portion of keeping left than P3, be electrically connected in series by nesa coating 50 and the thin-film solar cells across the right side that P3 adjoins.At this, in thin-film solar cells, because nesa coating 10 and conductive reflecting film 20 are formed at the opposing face of the input side of sunlight when observing from photoelectric conversion layer, be therefore called backplate in the lump.

Then, the manufacture method of general thin-film solar cells in the past shown in Fig. 2.In addition, Fig. 2 is the example of cladding plate type.In Fig. 2, (A) first prepares base material 40.(B) nesa coating 50 is formed on the substrate 40 with vacuum film formation such as sputterings.(C) carry out laser scribing P1 processing (dotted line represents laser irradiating position) from above, pattern formation is carried out to nesa coating 50.(D) nesa coating 50 formed at pattern with vacuum film formation such as sputterings is formed photoelectric conversion layer 60 (corresponding with the amorphous Si layer 61 of Fig. 1 and crystallite Si layer 62).(E) carry out laser scribing P2 processing (dotted line represents laser irradiating position) from below, pattern formation is carried out to photoelectric conversion layer 60.(F) photoelectric conversion layer 60 formed at pattern with vacuum film formation such as sputterings forms nesa coating 10, conductive reflecting film 20 and strengthening membrane 30.(G) carry out laser scribing P3 processing (dotted line represents laser irradiating position) from below, pattern formation is carried out to nesa coating 10, conductive reflecting film 20 and strengthening membrane 30.As more than, the worker ordinal number of the manufacture method of general thin-film solar cells is more, thus requires the shortening of worker ordinal number.

As above-mentioned, in the manufacture method of general thin-film solar cells, wait vacuum film formation to form nesa coating 10,50 or conductive reflecting film 20 etc. with sputtering in the past, but general importing, maintain, need significant cost when running large-scale vacuum film formation apparatus.In order to improve this point, disclosing and using transparent conductive film composition and conductive reflecting film composition and using the technology (patent documentation 1) forming nesa coating and conductive reflecting film as the wet type coating of more cheap manufacture method.But, even if according to above-mentioned wet type coating, also can directly be coated with transparent conductive film composition and conductive reflecting film composition respectively on photoelectric conversion layer or solidification etc., therefore cause the worker ordinal number of thin-film solar cells to become many, thus wish to make worker ordinal number shortening, simplification, efficient activity.In above-mentioned wet type coating, be in layer coated with base material, back electrode strap of the present invention can be manufactured continuously by RoletoRole on the other hand, therefore, it is possible to operation is simplified further, high speed.Further, in above-mentioned wet type coating, heat treatment step is more, likely damages photoelectric conversion layer, but the backplate of the application of the invention brings reduction heat treatment number of times, can make the further low temperature of heat putting on photoelectric conversion layer.

Patent documentation 1: Japanese Patent Publication 2009-88489 publication

Summary of the invention

Problem of the present invention is simplification and the efficient activity of the manufacturing process of the backplate can seeking thin-film solar cells, and then be omitted in a part (the laser scribing P3 of (G) of Fig. 2 processes) for the laser scribing process used in the manufacture of general thin-film solar cells, and the high speed of the manufacturing process of thin-film solar cells can be realized.

The present invention relates to and a kind ofly solve the thin-film solar cells back electrode strap of above-mentioned problem, the manufacture method of thin-film solar cells and thin-film solar cells by scheme shown below.

[1] a thin-film solar cells back electrode strap, wherein, be laminated with transparent electrode thin film and reflecting electrode film, transparent electrode thin film has caking property.

[2] the thin-film solar cells back electrode strap as described in above-mentioned [1], wherein, is laminated with barrier film further in reflecting electrode film side.

[3] the thin-film solar cells back electrode strap as described in above-mentioned [1] or [2], wherein, is laminated with carrier band further at the opposing face of transparent electrode thin film.

[4] the thin-film solar cells back electrode strap as described in above-mentioned [3], it is the thin-film solar cells back electrode strap comprising base material, transparent electrode layer, photoelectric conversion layer, transparent electrode thin film and reflecting electrode film, forms transparent electrode thin film and reflecting electrode film in its region opposed with described photoelectric conversion layer.

[5] manufacture method for thin-film solar cells, wherein, comprises successively: (A) prepares the operation being formed with the material to be bonded of base material, transparent electrode layer and photoelectric conversion layer; (B) operation of the transparent electrode thin film of the thin-film solar cells back electrode strap according to any one of photoelectric conversion layer laminating above-mentioned [1] ~ [4] of described material to be bonded.

The manufacture method of the thin-film solar cells [6] as described in above-mentioned [5], wherein, makes transparent electrode thin film and reflecting electrode film hardening again after (B) operation.

[7] thin-film solar cells, it comprises the thin-film solar cells back electrode strap according to any one of above-mentioned [1] ~ [4].

In the present invention [1], transparent electrode thin film and reflecting electrode film can be bonded on the photoelectric conversion layer of thin-film solar cells, can seek simplification and the efficient activity of the manufacturing process of backplate, the Post RDBMS of bonding and become backplate.And, thin-film solar cells back electrode strap can be formed at smooth carrier band etc. with wet type coating, with be directly coated into opto-electronic conversion stratiform phase ratio with wet type coating, thin-film solar cells back electrode strap can be formed at a high speed, and the high speed of the manufacturing process of thin-film solar cells can be sought.

According to the present invention [4], reliably can be omitted in a part (the laser scribing P3 of (G) of Fig. 2 processes) for the laser scribing process used in the manufacture of thin-film solar cells, and further simplification and the efficient activity of the manufacturing process of thin-film solar cells can be sought.

According to the present invention [5], due to the backplate of thin-film solar cells can be manufactured easily, therefore, it is possible to make the manufacturing process of thin-film solar cells simplify and efficient activity.

Accompanying drawing explanation

Fig. 1 is an example of the sectional view of thin-film solar cells.

Fig. 2 is the figure of the manufacture method representing in the past general thin-film solar cells.

Fig. 3 is the figure of the example representing the method forming transparent electrode thin film etc. on the carrier band in the region opposed with photoelectric conversion layer.

Fig. 4 is the figure of an example of the manufacture method representing thin-film solar cells.

Fig. 5 is the figure of other examples of the manufacture method representing thin-film solar cells.

Symbol description

1, 1a-transparent electrode thin film, 2, 2a-reflecting electrode film, 3, 3a-barrier film, 4-base material, 5-transparent electrode layer, 6-photoelectric conversion layer, 7-material to be bonded, 8, 8a-carrier band, 9, 9a-back electrode strap, 10-nesa coating, 20-conductive reflecting film, 30-strengthening membrane, 40-base material, 50-nesa coating, 60-photoelectric conversion layer, 61-amorphous Si layer, 62-crystallite Si layer, 70-material to be bonded, P1, P2-laser scribing position, P3-laser scribing position or groove portion, 100-transparent electrode thin film etc., 101, 102, 103-transparent electrode thin film etc., 110, 111-carrier thin film, 120-groove portion.

Embodiment

Below, according to execution mode, the present invention is specifically described.In addition, as long as no illustrating especially, and except the intrinsic situation of numerical value, % is quality %.

The feature of thin-film solar cells back electrode strap of the present invention is, be laminated with transparent electrode thin film and reflecting electrode film, transparent electrode thin film has caking property.Thin-film solar cells back electrode strap of the present invention can be used in various thin-film solar cells, but is particularly suited for cladding plate type thin-film solar cells.

[transparent electrode thin film]

Transparent electrode thin film has caking property, have (1) transparent electrode thin film itself to have close-burning situation and (2) are formed with tack coat situation on the surface of transparent electrode thin film.

For transparent electrode thin film itself or the binding agent forming tack coat, the state (hereinafter referred to as initial condition) when forming transparent electrode thin film or tack coat is required to be liquid or approximate with it flow-like, and its pattern mainly can enumerate following 4.

<1> response class

Initial condition is composition before there is chemical reaction, and to be main body liquid, is divided into mixing or chemical reaction type that the external factor such as moisture in heat or air starts react also polymerization reaction take place, moisture absorption, condensation reaction etc. and the thermohardening type that solidifying by heating, boning by monomer and effect promoter.Crylic acid resin, polyurethanes, cellulose family, olefines, epoxy resin, cyanoacrylate, silicone, polyimide, polybenzimidazoles class and polyvinyl butyral resin class can be enumerated.

<2> solution class

Initial condition is liquid in water or the solvent such as alcohol or organic solvent of the polymeric solid such as synthetic resin or rubber component dissolves, and solute solidification residual after gasifying by making solvent bonds.Solvent based or water class etc. is divided into according to the kind of solvent.Polyesters, polystyrene type, cellulose family, olefines, polyvinyl chloride-base, rubber-like and plexiglass class can be enumerated.

<3> aqueous dispersion class

Initial condition is the aqueous suspension of polymerization macromolecule solid constituent in water.Macromolecule in colloidal state is emulsified and can state soluble in water, and is bondd by water and solute solidification.Crylic acid resin, polyurethanes, polyvinyl alcohol, polyvinyl acetate, epoxy resin and rubber-like can be enumerated.

<4> solid

Initial condition is powder or pellet or film or the solid such as netted, by heating the state that is thawing to the solid binder of thermoplastic resin elements and the basis of giving mobility (heat is melted) being coated with and carrying out cooling to be cured, bond.Polyurethanes, polyamide-based, polyvinyl acetate and olefines can be enumerated.

At this, have close-burning transparent electrode thin film and have following situation, namely (A) is bonded in situation (above-mentioned <1>, <2>, the <3> on substrate by the adherence of transparent electrode thin film itself.Hereinafter referred to as (A) type) and the non-adhesiveness of (B) transparent electrode thin film own, but manifest close-burning situation (above-mentioned <4> by heat etc. after fitting with non-adherent thing.Hereinafter referred to as (B) type).

" (1) transparent electrode thin film itself has close-burning situation "

Transparent electrode thin film can be formed from transparent electrode thin film composition, the composition comprising electroconductive oxide particle and adhesive can be enumerated as transparent electrode thin film composition.

ITO (IndiumTinOxide: indium tin oxide) is preferably as electroconductive oxide particle, the stannic oxide powder of ATO (AntimonydopedTinOxide: antimony-doped tin oxide) or comprise B containing being selected from, Al, Co, Fe, In, the Zinc oxide powder etc. of at least one metal in the group of Ga and Ti, wherein, be more preferably ITO, ATO, AZO (AluminumdopedZincOxide: aluminium-doped zinc oxide), IZO (IndiumdopedZincOxide: indium doping zinc oxide), GZO (GariumdopedZincOxide: Ga-doped zinc oxide).Further, the average grain diameter of electroconductive oxide particulate in order to keep stability in decentralized medium, preferably in the scope of 10 ~ 100nm, wherein more preferably in the scope of 20 ~ 60nm.At this, average grain diameter utilizes the dynamic light scattering method based on the BET method of the specific area measuring according to QUANTACHROMEAUTOSORB-1 or the LB-550 manufactured by the making of hole field to measure.When not special record, the BET method based on the specific area measuring according to QUANTACHROMEAUTOSORB-1 is utilized to measure.

Preferred adhesive is comprise the composition of either one or both in polymer type adhesive by being heating and curing or non-polymeric adhesive.Be more preferably the adhesive not comprising and photoelectric conversion layer is brought to the moisture of bad influence or acid, the alkali metal that the characteristic of above-mentioned electroconductive oxide particle is declined or alkaline-earth metal and ion thereof.

As polymer type adhesive, crylic acid resin, polymethyl methacrylate (PMMA) class, polycarbonate-based, polyesters, alkyd resins class, polyurethanes, acroleic acid polyurethane class, polystyrene type, polyacetals, polyamide-based, polyvinyl alcohol (PVA), polyvinyl acetate, cellulose family, olefines, ethylene-vinyl acetate copolymer (EVA) class and siloxane type polymers etc. can be enumerated.Wherein, even if due to the polyurethanes of the typical example as solid binder, polyamide-based, polyvinyl acetate, olefines or as also boning by heating after the disposable complete settable cementitious layer such as polyvinyl alcohol, polystyrene, ethylene-vinyl acetate copolymer, polymethyl methacrylate of the shaping thermoplastic resin of relatively low temperature hemostasis, therefore preferred from operating aspect.

And comprise the hydrolysis body of the metallic soap of aluminium, silicon, titanium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum or tin, metal complex or metal alkoxide in preferred polymers type adhesive.As non-polymeric adhesive, metallic soap, metal complex, metal alkoxide, silicon halide alkanes, 2-alkoxyethanol, beta-diketon and alkyl acetates etc. can be enumerated.And, the metal comprised in metallic soap, metal complex or metal alkoxide is preferably aluminium, silicon, titanium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, tin, indium or antimony, be more preferably the alkoxide (such as, tetraethoxysilane, tetramethoxy-silicane, aluminium ethylate, aluminium isopropoxide) of silicon, aluminium.These polymer type adhesives, non-polymeric adhesive solidify by heating, and can form the transparency electrode of lower mist degree and specific insulation under low temperature thus.In addition, metal alkoxide can be hydrolysate or its dehydrate.

Transparent electrode thin film composition comprises the electroconductive oxide particle of 98 ~ 50 mass parts relative to solid constituent (electroconductive oxide particle and adhesive etc.) 100 mass parts in transparent electrode thin film composition, preferably comprises 90 ~ 70 mass parts.This is because if exceed higher limit, then adhesiveness declines, if be less than lower limit, then conductivity declines.

Preferably these adhesives containing proportional be 2 ~ 50 mass parts relative to solid constituent (electroconductive oxide particle and adhesive etc.) 100 mass parts in transparent electrode thin film composition, more preferably 10 ~ 30 mass parts.Further, when using metal alkoxide as adhesive and using nitric acid as catalyst, from the viewpoint of the remaining quantity of the curing rate of adhesive, nitric acid, be preferably the nitric acid of 0.03 ~ 3 mass parts relative to the metal alkoxide of 100 mass parts.In addition, if less as the amount of the nitric acid of catalyst, then the polymerization speed as the hydrolysis body of the metal alkoxide of adhesive is slack-off, during water shortage needed for hydrolysis, likely cannot obtain firm nesa coating.And, if consider the hydrating solution of the eyed structure that the degree of polymerization is higher when taking by burning till solidification, then in the form of the stress additional conductive particle contact each other applied when shrinking, therefore can become photoelectric conversion layer worsening reason from the viewpoint of due to excessive adding, be preferably the water of 0.1 ~ 1.0 mass parts relative to the metal alkoxide of 100 mass parts.

Transparent electrode thin film composition preferably adds coupling agent according to other used compositions.This is the adhesiveness in order to improve and between the associativity of electrically conductive microparticle and adhesive and the transparent electrode thin film formed by this transparent electrode thin film composition and the photoelectric conversion layer be laminated on base material or reflecting electrode film.Silane coupler, aluminum coupling agent and titanium coupling agent etc. can be enumerated as coupling agent.The content of preferred coupling agent is 0.2 ~ 5 mass parts relative to solid constituent (electroconductive oxide particle, adhesive and silane coupler etc.) 100 mass parts shared in transparent electrode thin film composition, more preferably 0.5 ~ 2 mass parts.

In order to film forming well, preferably clear electrode film composition comprises decentralized medium.As decentralized medium, can enumerate: water; The alcohols such as methyl alcohol, ethanol, isopropyl alcohol, butanols; The ketones such as acetone, methyl ethyl ketone, cyclohexanone, isophorone; The hydro carbons such as toluene, dimethylbenzene, hexane, cyclohexane; The amide-type such as DMF, DMA; The glycols such as sulfoxide type or ethylene glycol such as dimethyl sulfoxide (DMSO); And the gylcol ether etc. such as ethyl cellosolve.In order to obtain good film forming, the content of preferred decentralized medium is 80 ~ 99 mass parts relative to the transparent electrode thin film composition of 100 mass parts.

In addition, according to used composition, preferably add low resist (low opposing drug) or water-soluble cellulose derivative etc.As low resist, be preferably selected from that to comprise in the inorganic acid salt of cobalt, iron, indium, nickel, lead, tin, titanium and zinc and the group of acylate one kind or two or more.Such as, the mixture etc. of the mixture of the mixture of the mixture of nickel acetate and iron chloride, zinc naphthenate, tin octoate and antimony chloride, indium nitrate and lead acetate, acetyl group acetic acid titanium and cobalt octoate can be enumerated.Preferably the content of these low resists is 0.2 ~ 15 mass parts relative to the electroconductive oxide powder of 100 mass parts.Water-soluble cellulose derivative is non-ionic surfactant, even if but add the amount being less than other surfactants, the ability of dispersed electro-conductive oxide powder is also high, in addition, by adding water-soluble cellulose derivative, also improve the transparency of the nesa coating formed.As water-soluble cellulose derivative, hydroxypropyl cellulose, hydroxypropyl methylcellulose etc. can be enumerated.The addition of preferred water soluble cellulose derivative is 0.2 ~ 5 mass parts relative to the electroconductive oxide particle of 100 mass parts.

Transparent electrode thin film composition is in the scope not damaging object of the present invention and can coordinate filler, stress moderator and other additives etc. as required.

Transparent electrode thin film composition can by the composition according to common method and desired by the mixing such as paint mixer, ball mill, puddle mixer, centrifugal mill, triple-roller mill, and dispersed electro-conductive oxide particle, spherical colloid silica dioxide granule etc. manufacture.Certainly, also can be manufactured by common stirring operation.In addition, transparent conductivity adhesive can also be used as transparent electrode thin film composition.

Then, on substrate, be coated with transparent electrode thin film composition with wet type coating, and make its drying, solidifications etc., thus can manufacture there is close-burning transparent electrode thin film.

Above-mentioned base material can use any one or the duplexer of more than two kinds that is selected from these groups in glass, pottery, the substrate that is made up of metal or macromolecular material.Although impact can not be brought on the characteristic of thin-film solar cells by these base materials, be more preferably and according to the workability etc. when boning to material to be bonded, there is flexibility and the higher raw material such as weatherability, moisture-proof, thermal endurance.

In addition, above-mentioned wet type coating is preferably any one in spraying process, point gum machine rubbing method (デイスペ Application サ mono-コ mono-テイ Application グ method), spin-coating method, knife coating, slot coated method, ink-jet application method, screen painting method, flexographic printing process or mold rubbing method, but be not limited to this, all methods can be utilized.

Spraying process makes transparent electrode thin film composition be vaporific by compressed air and coats on substrate or pressurize with the vaporific method coated on substrate to dispersion itself, point gum machine rubbing method such as transparent electrode thin film composition is injected syringe and presses the piston of this syringe, makes dispersion spue from the minute nozzle of syringe front end and coat the method substrate thus.Spin-coating method is the transparent electrode thin film composition expanded the method for the transparent electrode thin film composition that this drips by its centrifugal force to substrate periphery of dripping on the substrate rotated, knife coating can arrange to horizontal direction the substrate separating predetermined gap with the front end of scraper movably, supply transparent electrode thin film composition to than this scraper closer on the substrate of upstream side, move horizontally the method for substrate towards downstream.Slot coated method makes transparent electrode thin film composition flow out from narrow slit and coat the method substrate, and ink-jet application method is filled in by transparent electrode thin film composition in the print cartridge of commercially available ink-jet printer and on substrate, carries out the method for ink jet printing.Screen painting method utilizes yarn as pattern instruction material and by the domain picture that the is made method to substrate transfer transparent electrode thin film composition thereon.Flexographic printing process does not make the transparent electrode thin film composition invested in version directly be attached on substrate, but be transferred to film from version is disposable, and again transfer to the printing process utilizing the water proofing property of transparent electrode thin film composition substrate from film.Mold rubbing method distributes by manifold the transparent electrode thin film composition that is supplied in mould and is extruded on film by slit, to the method for the surface coating of the substrate of advancing.Mold rubbing method has slotted coating method or slidingtype coating method, curtain coating mode.

Finally, in an atmosphere or in the inactive gas such as nitrogen or argon gas atmosphere the substrate of the film with transparent electrode thin film composition is carried out drying or burnt till.When (A) type, this drying or burn till and make transparent electrode thin film be exercisable intensity, and carry out under the condition that adherence residues in transparent electrode thin film composition, such as, for making the degree of the solvent drying in transparent electrode thin film composition.Further, when (B) type, also can be fully dry.At this, the thickness of drying or the transparent electrode thin film composition after burning till is preferably the scope of 0.03 ~ 0.5 μm, is more preferably 0.05 ~ 0.1 μm.This is because when the thickness of drying or the transparent electrode thin film composition after burning till is less than 0.03 μm, the uniformity of film declines, and adhesiveness declines, if more than 0.5 μm, then the transparency and conductivity decline.At this, if above-mentioned drying or the transparent electrode thin film after solidifying have flexibility, then preferable operability during back electrode strap used for solar batteries to photoelectric conversion layer adhered film, therefore preferably.

" (2) form the situation of tack coat on the surface of transparent electrode thin film "

Transparent electrode thin film, except the film that can use drying or solidify above-mentioned transparent electrode thin film composition, can also use the film of ITO, AZO, GZO, the ATO etc. formed by the vacuum film formation such as sputtering, MBE, PLD, evaporation or spray heating decomposition.The thickness of transparent electrode thin film is at this moment preferably 0.001 ~ 10 μm, is more preferably 0.01 ~ 0.1 μm from the viewpoint of the transparency, saving resource, operation.

As tack coat, can enumerate epoxy resin, acrylic resin, silicone resin, silica sol-gel etc., their type of latex is also preferred.The thickness of tack coat is preferably 0.005 ~ 1 μm, is more preferably 0.01 ~ 0.1 μm.This is to not only have caking property but also maintain the contact with photoelectric conversion layer.

[reflecting electrode film]

Because reflection electrode layer requires higher diffuse reflectance, therefore when reflecting electrode film is metal forming, alloy or the alloy such as nichrome or stainless steel of the higher metal of reflectivity metals such as () silver, iron, chromium, tantalum, molybdenum, nickel, aluminium, cobalt or titaniums or these metals can be enumerated, especially preferably silver, aluminium.When the film etc. formed for the vacuum film formation such as use sputtering, evaporation, ion plating, MBE or plating, alloy or the alloy such as nichrome or stainless steel of the higher metal of reflectivity metals such as () silver, iron, chromium, tantalum, molybdenum, nickel, aluminium, cobalt or titaniums or these metals can be enumerated, especially preferably silver, aluminium.Reflecting electrode film, can also by carrying out wet type coating to manufacture to the thin film composition of reflecting electrode except using these metal formings or the film etc. by vacuum film formation or plating film forming.

The thin film composition of reflecting electrode for being manufactured by wet type coating preferably comprises metal nanoparticle, as metal nanoparticle, the one kind or two or more mixing composition in the group being selected from and comprising silver, gold, platinum, palladium, ruthenium, nickel, copper, tin, indium, zinc, iron, chromium and manganese or alloy composition can be enumerated, be preferably silver-colored and golden from the viewpoint of reflectivity, conductivity.The average grain diameter of metal nanoparticle is preferably 10 ~ 50nm.At this, average grain diameter utilizes the BET method based on the specific area measuring according to QUANTACHROMEAUTOSORB-1 to measure.Consider from dispersed, reflexive viewpoint, the shape of preferable alloy nano particle is spherical, tabular.In addition, in order to prevent cohesion, the protective agent coating metal nano granule such as polyvinylpyrrolidone (PVP) or polyvinyl alcohol (PVA), citric acid is preferably used.

Consider from adhesiveness, reflexive viewpoint, the thin film composition of reflecting electrode preferably comprises additive.As additive, from least a kind that reflectivity, adhering viewpoint are considered more preferably to comprise the group being selected from and comprising organic polymer, metal oxide, metal hydroxides, organo-metallic compound and silicone oil.

As the organic polymer being used as additive, consider from reflexive viewpoint, be preferably selected from least a kind that comprises in polyvinylpyrrolidone, the copolymer of polyvinylpyrrolidone and the group of water-soluble cellulose.As the copolymer of polyvinylpyrrolidone, PVP-methylmethacrylate copolymer, PVP-styrol copolymer, PVP-vinyl acetate co-polymer etc. can be enumerated.And as water-soluble cellulose, the cellulose ethers such as hydroxypropyl methylcellulose, methylcellulose, HEMC can be enumerated.

As being used as the metal oxide of additive, be preferably containing be selected from comprise aluminium, silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, tin, indium and antimony group in the oxide of at least a kind or composite oxides.As composite oxides, specifically above-mentioned ITO, ATO, IZO, AZO etc. can be enumerated.

As being used as the metal hydroxides of additive, be preferably containing be selected from comprise aluminium, silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, tin, indium and antimony group in the hydroxide of at least a kind.

As being used as the organo-metallic compound of additive, be preferably containing be selected from comprise silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum and tin group at least a kind metallic soap, metal complex, metal alkoxide or metal alkoxide hydrolysate.Such as, metallic soap can enumerate chromic acetate, formic acid manganese, ironic citrate, cobaltous formate, nickel acetate, silver citrate, Schweinfurt green, copper citrate, tin acetate, zinc acetate, zinc oxalate, acetic acid molybdenum etc.And metal complex can enumerate acetylacetone,2,4-pentanedione zinc complex, acetylacetone,2,4-pentanedione chromium complex, acetylacetone,2,4-pentanedione nickel complex etc.And metal alkoxide can enumerate titanium isopropoxide, methyl silicate, NCO propyl trimethoxy silicane, TSL 8330 etc.

As the silicone oil being used as additive, straight chain type silicone oil and modified silicone oil both sides can be used.The part that modified silicone oil can also be used in the side chain of polysiloxanes import organic group structure (side chain type), import the structure (single tip type) of organic group in either party importing in the structure (two tip type) of organic groups, two ends at polysiloxanes of two ends of polysiloxanes and import the structure (side chain two tip type) of organic group in the part of the side chain of polysiloxanes and two ends.Modified silicone oil responding property silicone oil and non-reacted silicone oil, but its two kinds all can use as additive of the present invention.In addition, reactive silicone oil meter shows amino modified, epoxide modified, carboxy-modified, carbinol-modified, sulfhydryl modified and xenogenesis functional group modification (epoxy radicals, amino, polyether-based), and non-reacted silicone oil represents polyether-modified, the modification of methyl styrene base, alkyl-modified, higher fatty acids is ester modified, fluorine richness and the special modification of hydrophily.

The thin film composition of reflecting electrode containing the proportional removal decentralized medium relative to 100 mass parts of additive, is preferably 0.1 ~ 25 mass parts, is more preferably 0.2 ~ 10 mass parts.If more than 0.1 mass parts, then good with the cohesive force of nesa coating, if below 25 mass parts, then film when not easily producing film forming is uneven.

Metal nanoparticle, relative to the thin film composition of the reflecting electrode of 100 mass parts, is preferably more than 75 mass parts from the viewpoint of reflectivity, conductivity, is more preferably more than 80 mass parts.Further, consider from the adhering viewpoint of the thin film composition of reflecting electrode, be preferably below 95 mass parts, be more preferably more than 80 mass parts.

Further, in order to film forming well, the thin film composition of reflecting electrode preferably comprises decentralized medium.Identical with the situation of transparent electrode thin film composition about the decentralized medium in the thin film composition of reflecting electrode.

The thin film composition of reflecting electrode within the scope without prejudice to the object of the present invention and can coordinate filler, stress moderator and other additives etc. as required.

Then, according to dry after wet type coating coating reflecting electrode thin film composition or burn till, thus reflecting electrode film can be manufactured.Reflecting electrode film coating layer is formed through wet type coating be coated with and heat, burn till after thickness be 0.05 ~ 2.0 μm, preferably become the thickness of 0.1 ~ 1.5 μm.This is because when being less than 0.05 μm, the sheet resistance value of the electrode needed for solar cell is not very abundant.According to the coating of wet type coating, dry or to burn till the method for the thin film composition of reflecting electrode identical with the situation of transparent electrode thin film composition, but because reflecting electrode film is without the need to caking property, therefore about dry or burn till, in an atmosphere or in the inactive gas such as nitrogen or argon gas atmosphere with the temperature of 130 ~ 400 DEG C, preferably 150 ~ 350 DEG C keep 5 minutes ~ 1 hour, preferably 15 ~ 40 minute are burnt till.The scope that the heating-up temperature of reflecting electrode film coating layer is set to 130 ~ 400 DEG C be because; when being less than 130 DEG C, metal nanoparticle sintering is not each other very abundant, and the protective agent of metal nanoparticle is difficult to be departed from by heating or decompose (being separated or burning).If above-mentioned drying or the reflecting electrode film after solidifying have flexibility, then preferable operability during back electrode strap used for solar batteries to photoelectric conversion layer adhered film, therefore preferably.In addition, carry out drying identically with the situation of transparent electrode thin film composition or burn till, making reflecting electrode film keep caking property.

[thin-film solar cells back electrode strap]

The method of laminating transparent electrode film and reflecting electrode film can use the method for well known to a person skilled in the art, the method etc. of carrying out drying or solidification after either party in transparent electrode thin film composition or the thin film composition of reflecting electrode being coated on the reflecting electrode film of the opposing party or transparent electrode thin film according to wet type coating can be enumerated, carry out stacked under transparent electrode thin film has close-burning state.

Thin-film solar cells back electrode strap is preferably at the further lamination barrier layer film of reflecting electrode film side.Further, preferably at the further stacked carrier band of the opposing face of transparent electrode thin film.Below, successively barrier film and carrier band are described.

[barrier film]

For barrier film, if with wet type coating thin film composition of barrier-coating on reflecting electrode film, then the operating cost of manufacturing equipment can be reduced with easy operation, therefore preferably.

Barrier film composition comprises either one or both by the mineral-type basic material of the organic or mineral-type basic material or non-polymeric adhesive carrying out heating the polymer type adhesive solidified after Ultraviolet radiation or heating or Ultraviolet radiation.Solidify these polymer type adhesives, non-polymeric adhesive by carrying out heating after Ultraviolet radiation or heating or Ultraviolet radiation, thus the barrier film of the densification of display weatherability, resistance to water, moisture-proof, thermal endurance etc. can be formed.

It is one kind or two or more that the organic basic material of polymer type adhesive preferably includes in the group being selected from the polymer comprising acrylic compounds, epoxies, polyurethanes, acroleic acid polyurethane class, propylene oxide acids, cellulose family and type siloxane.Be used in acrylic monomer as acrylic adhesives and add Photoepolymerizationinitiater initiater, and to the acrylic polymer that this mixture irradiation ultraviolet radiation (UV) makes its photopolymerization to obtain.Can enumerate to be selected from as acrylic monomer and comprise 1, one kind or two or more single monomer in the group of 6-hexanediyl ester, trimethylolpropane triacrylate, neopentylglycol diacrylate, tetramethylol methane tetraacrylate, two trimethylolpropane tetra-acrylate, 1,9-nonanediol diacrylate, tripropylene glycol diacrylate, peroxidating cyanuric acid triacrylate and tetramethylol methane tetraacrylate or mix monomer.In these monomers, preferably add MIBK (methyl iso-butyl ketone (MIBK)), PGME (propylene glycol monomethyl ether: 1-methoxy-2-propanol), PGMEA (propylene glycol monomethyl ether acetate: 1-methoxy-2-propanol acetate) equal solvent.But, if the common organic solvents of above-mentioned monomer can be dissolved, then can use ethanol, methyl alcohol, benzene,toluene,xylene, NMP (1-METHYLPYRROLIDONE), acrylonitrile, acetonitrile, THF (oxolane), ethyl acetate, MEK (methyl ethyl ketone), butyl carbitol, butyl carbitol acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, IPA (isopropyl alcohol), acetone, DMF (dimethyl formamide), DMSO (dimethyl sulfoxide (DMSO)), piperidines, phenol etc.And 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-ketone, 2-hydroxyl-1-{4-[4-(2-hydroxy-2-methyl-propiono)-benzyl]-phenyl can be enumerated as Photoepolymerizationinitiater initiater }-2-methyl-propan-1-ketone, 1-[4-(2-hydroxyl-oxethyl)-phenyl]-2-hydroxy-2-methyl-1-propane-1-ketone etc.Acrylic monomer can relative to above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.Photoepolymerizationinitiater initiater adds 0.1 ~ 30 mass parts relative to the acrylic monomer of 100 mass parts.This is because solidify insufficient when the addition of Photoepolymerizationinitiater initiater is less than 0.1 mass parts relative to the acrylic monomer of 100 mass parts, if more than 30 mass parts, then cured film (backplate strengthening membrane) variable color or residual stress and causing adheres to bad.So will add solvent and Photoepolymerizationinitiater initiater in acrylic monomer and the mixed liquor stirring and obtain as barrier film composition basal liquid.In addition, when in acrylic monomer, add solvent and Photoepolymerizationinitiater initiater and the mixed liquor stirring and obtain is uneven, can heat to about 40 DEG C.

As epoxy adhesive, can use adding solvent and stir in epoxylite, and in this mixed liquor, add thermal curing agents and stir, thus obtained mixed liquor be carried out heating and the epoxide polymer obtained.Biphenyl type epoxy resin, cresol-novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol f type epoxy resin, naphthalene type epoxy resin etc. can be enumerated as epoxylite.And BCA (butyl carbitol acetate), ECA (ethyl carbitol acetate), BC (butyl carbitol) etc. can be enumerated as solvent.As long as but can dissolve above-mentioned epoxylite common organic solvents, just ethanol can be used, methyl alcohol, benzene, toluene, dimethylbenzene, PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monomethyl ether acetate), NMP (1-METHYLPYRROLIDONE), MIBK (hexone), acrylonitrile, acetonitrile, THF (oxolane), ethyl acetate, MEK (methyl ethyl ketone), butyl carbitol, butyl carbitol acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, IPA (isopropyl alcohol), acetone, DMF (dimethyl formamide), DMSO (dimethyl sulfoxide (DMSO)), piperidines, phenol etc.2-ethyl-4-methylimidazole, boron fluoride monoethanolamine, DICY (dicyanodiamine), diethylaminopropylamine, IPD, diaminodiphenyl-methane, piperidines, 2 can be enumerated as thermal curing agents, 4,6-tri--(dimethylaminomethyl) phenol, glyoxal ethyline, HHPA, 7,11-18 carbon dialkylene-1,18-bis-carbohydrazide etc.Epoxylite can by above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.Thermal curing agents adds 0.5 ~ 20 mass parts relative to the epoxylite of 100 mass parts.This is because solidify insufficient when the addition of thermal curing agents is less than 0.5 mass parts relative to the epoxylite of 100 mass parts, if more than 20 mass parts, then produce during solidification and cause adhesiveness bad compared with large inner stress.So will add solvent and thermal curing agents in epoxylite and the mixed liquor stirring and obtain as the basal liquid of barrier film composition.In addition, can heat to about 40 DEG C the mixed liquor obtained when adding solvent also to stir in epoxylite is uneven.

Cellulose family adhesive can to adding solvent and stir and add gelatin and the mixed liquor stirring and obtain heats and obtains in this mixed liquor in cellulosic polymer.The hydroxypropyl cellulose, hydroxypropyl methylcellulose, methylcellulose, HEMC etc. as water-soluble cellulose derivative can be enumerated as cellulosic polymer.And IPA (isopropyl alcohol), ethanol, methyl alcohol, PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monomethyl ether acetate), MIBK (hexone), acetone etc. can be enumerated as solvent.Cellulosic polymer can by above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.Gelatin adds 0.1 ~ 20 mass parts relative to the cellulosic polymer of 100 mass parts.If this is because the addition of gelatin is less than 0.1 mass parts relative to the cellulosic polymer of 100 mass parts or more than 20 mass parts, then cannot obtain the viscosity being suitable for being coated with.So will add solvent and gelatin in cellulosic resin and the mixed liquor stirring and obtain as the basal liquid strengthening film composition.In addition, undertaken stirring by adding solvent and gelatin and be heated into about 30 DEG C in cellulosic polymer and make mixed liquor even.

Following preparation uses the polyurethane binding of Thermocurable polyurethane resin.First, making with toluene di-isocyanate(TDI) (TDI), diphenylmethane isocyanate (MDI) etc. is that polyalcohols composition reacts to obtain the urethane prepolymer containing end active NCO with being representative with the polyol compound such as trimethylolpropane or neopentyl glycol for the excessive polyisocyanate compounds of representative.Then, the phenols as taken sylvan as representative is made, as the lactams that is representative with β-butyrolactam or the block agents such as ketoxime class are reacted with the urethane prepolymer containing this end active NCO if methyl ethyl ketone oxime is representative.Ketone, alkyl benzene, cellosolve class, ester class, alcohols etc. can be used as solvent.Object lesson as ketone can enumerate acetone, methyl ethyl ketone etc., and the object lesson as alkyl benzene can enumerate benzene, toluene etc.And can enumerate methyl cellosolve, butyl cellosolve etc. as the object lesson of cellosolve class, the object lesson as ester class can enumerate butyl cellosolve acetate, butyl acetate etc., and the object lesson as alcohols can enumerate isopropyl alcohol, butanols etc.On the other hand, polyamine can be used as thermal curing agents (reactant).Object lesson as polyamine can enumerate N-octyl group-N-aminopropyl-N '-aminopropyl propane diamine, N-lauroyl-N-aminopropyl-N '-aminopropyl propane diamine, N-myristyl-N-aminopropyl-N '-aminopropyl propane diamine, N-octyl group-N-aminopropyl-N ', N '-two (aminopropyl) propane diamine etc.The urethane prepolymer containing end active NCO obtained making above-mentioned polyol component and isocyanate compound reaction implements blocked according to block agent, makes block polyisocyanate.The equivalent proportion of the NCO that the amino that polyamine has has relative to this block polyisocyanate is preferably about 1 (scope of 0.7 ~ 1.1).If this is because the equivalent proportion of NCO that the amino that polyamine has has relative to block polyisocyanate is less than 0.7 or more than 1.1, then either party in block polyisocyanate and polyamine can become many and react insufficient, so solidify insufficient.Polyether polyols with reduced unsaturation can by above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.

As acroleic acid polyurethane class adhesive, can enumerate and comprise urethane acrylate quasi-oligomer, the ultraviolet light UV-3310B solidified by irradiation ultraviolet radiation (UV) or ultraviolet light UV-6100B (Japanese Synesis Company manufactures) or the acroleic acid polyurethane base polymer such as EBECRYL4820 or EBECRYL284 (manufacture of Daicel-Cytec company), U-4HA or UA-32P (manufacture of chemical industrial company of Xin Zhong village).And curability can be improved by being added on the Photoepolymerizationinitiater initiater (such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-ketone etc.) used in esters of acrylic acid as required.Further, ketone, alkyl benzene, cellosolve class, ester class, alcohols etc. can be used as solvent.Object lesson as ketone can enumerate acetone, methyl ethyl ketone etc., and the object lesson as alkyl benzene can enumerate benzene, toluene etc.And can enumerate methyl cellosolve, butyl cellosolve etc. as the object lesson of cellosolve class, the object lesson as ester class can enumerate butyl cellosolve acetate, butyl acetate etc., and the object lesson as alcohols can enumerate isopropyl alcohol, butanols etc.Photoepolymerizationinitiater initiater can be added in the scope of 0.1 ~ 30 mass parts as required relative to the acroleic acid polyurethane base polymer of 100 mass parts.This is because solidify insufficient when the addition of Photoepolymerizationinitiater initiater is less than 0.1 mass parts, if more than 30 mass parts, internal stress becomes large and adhesiveness is bad.And acroleic acid polyurethane base polymer (containing oligomer) can with above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.

Propylene oxide base polymer can be used as propylene oxide class adhesive.Bisphenol-a epoxy acrylate can be enumerated (such as propylene oxide base polymer, the NKOligoEA-1020 that chemical industrial company of Xin Zhong village manufactures) or 1,6-hexanediol diglycidyl ether diacrylate (NKOligoEA-5521 that such as chemical industrial company of Xin Zhong village manufactures) etc.And Neopor8318 or Neopor8355 etc. that Japanese U-PICA company manufactures can be used.Ketone, alkyl benzene, cellosolve class, ester class, alcohols etc. can be used as solvent.Object lesson as ketone can enumerate acetone, methyl ethyl ketone etc., and the object lesson as alkyl benzene can enumerate benzene, toluene etc.And can methyl cellosolve, butyl cellosolve etc. be enumerated as the object lesson of cellosolve class.Object lesson as ester class can enumerate butyl cellosolve acetate, butyl acetate etc.Object lesson as alcohols can enumerate isopropyl alcohol, butanols etc.Thermal curing agents or Photoepolymerizationinitiater initiater can be added as required in propylene oxide base polymer.And undertaken being heating and curing by thermal curing agents or Photoepolymerizationinitiater initiater or be heating and curing after UV solidification or UV solidification.And propylene oxide base polymer can with above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.

Siloxane type polymers can be used as Silicone Adhesives.Dimethyl silicone polymer, polymethyl hydrogen siloxane, PSI etc. can be enumerated as siloxane type polymers.And straight chain type silicone oil and modified silicone oil both sides can be used as the siloxane type polymers represented at this.The part that can also be used in the side chain of polysiloxanes as modified silicone oil import organic group structure (side chain type), import the structure (single tip type) of organic group in either party importing in the structure (two tip type) of organic groups, two ends at polysiloxanes of two ends of polysiloxanes and import the structure (side chain two tip type) etc. of organic group in the part of the side chain of polysiloxanes and two ends.Modified silicone oil responding property silicone oil and non-reacted silicone oil, but its both sides can be used.In addition, reactive silicone oil meter shows amino modified, epoxide modified, carboxy-modified, carbinol-modified, sulfhydryl modified or xenogenesis functional group modification (epoxy radicals, amino, polyether-based), and non-reacted silicone oil represents polyether-modified, the modification of methyl styrene base, alkyl-modified, higher fatty acids is ester modified, fluorine richness or the special modification of hydrophily.Further, ketone, alkyl benzene, cellosolve class, ester class, alcohols etc. can be used as solvent.Object lesson as ketone can enumerate acetone, methyl ethyl ketone etc.Object lesson as alkyl benzene can enumerate benzene, toluene etc.And can methyl cellosolve, butyl cellosolve etc. be enumerated as the object lesson of cellosolve class.Object lesson as ester class can enumerate butyl cellosolve acetate, butyl acetate etc.Object lesson as alcohols can enumerate isopropyl alcohol, butanols etc.Thermal curing agents or Photoepolymerizationinitiater initiater can be added in siloxane type polymers as required, but even if do not add thermal curing agents, also without the need to thermal curing agents during cured film.And siloxane type polymers can with above-mentioned any solvent dilution and the viscosity being adjusted to easy coating use.

It is one kind or two or more that the mineral-type basic material of polymer type adhesive preferably comprises in the group being selected from the hydrolysis body comprising metallic soap, metal complex and metal alkoxide.The mineral-type basic material of these polymer type adhesives is the material being become mineral-type basic material by heating from organic.Namely can by burning till the film being formed and there is the character of mineral-type basic material.And it is one kind or two or more that metal contained in the hydrolysis body of above-mentioned metallic soap, metal complex or metal alkoxide is preferably selected from the group comprising aluminium, silicon, titanium, zirconium and tin.Chromic acetate, formic acid manganese, ironic citrate, cobaltous formate, nickel acetate, silver citrate, Schweinfurt green, copper citrate, tin acetate, zinc acetate, zinc oxalate, acetic acid molybdenum etc. can be enumerated as above-mentioned metallic soap.And acetylacetone,2,4-pentanedione zinc complex, acetylacetone,2,4-pentanedione chromium complex, acetylacetone,2,4-pentanedione nickel complex etc. can be enumerated as metal complex.Titanium isopropoxide, methyl silicate, NCO propyl trimethoxy silicane, aminopropyltriethoxywerene werene etc. can be enumerated in addition as metal alkoxide.

On the other hand, the mineral-type basic material as non-polymeric adhesive can enumerate SiO ₂bonding agent.This SiO ₂a bonding agent example as shown below makes.First, make HCl be dissolved in pure water while stirring, the preparation HCl aqueous solution.Then, mixing tetraethoxysilane and alcohol, heat after adding the above-mentioned HCl aqueous solution and react in this mixed liquor.Make SiO thus ₂bonding agent.And it is one kind or two or more that non-polymeric adhesive preferably comprises in the group being selected from and comprising metallic soap, metal complex, the hydrolysis body of metal alkoxide, halogenated silanes class, 2-alkoxyethanol, beta-diketon and alkyl acetates.The hydrolysis body of this metal alkoxide comprises sol-gel.And it is one kind or two or more that metal contained in the hydrolysis body of above-mentioned metallic soap, metal complex or metal alkoxide is preferably selected from the group comprising aluminium, silicon, titanium, zirconium and tin.Chromic acetate, formic acid manganese, ironic citrate, cobaltous formate, nickel acetate, silver citrate, Schweinfurt green, copper citrate, tin acetate, zinc acetate, zinc oxalate, acetic acid molybdenum etc. can be enumerated as above-mentioned metallic soap, acetylacetone,2,4-pentanedione zinc complex, acetylacetone,2,4-pentanedione chromium complex, acetylacetone,2,4-pentanedione nickel complex etc. can be enumerated as metal complex, titanium isopropoxide, methyl silicate, NCO propyl trimethoxy silicane, aminopropyltriethoxywerene werene etc. can be enumerated as metal alkoxide.And chlorosilane, bromo-silicane, silicon fluoride etc. can be enumerated as halogenated silanes class.2-methyl cellosolve, cellosolvo, butoxy ethanol etc. can be enumerated as 2-alkoxyethanol.2,4-pentane diketone, 1,3-hexichol-1,3-pentanedione etc. can be enumerated as beta-diketon.Ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate etc. can be enumerated in addition as alkyl acetates.

Preferably in barrier film composition, add coupling agent according to other compositions used.This is to improve the adhesiveness with the reflecting electrode film as lower floor.Silane coupler, aluminum coupling agent and titanium coupling agent etc. can be enumerated as coupling agent.

And barrier film composition preferably includes and is selected from one kind or two or more metal oxide microparticle in the group comprising cataloid, aerosil particle, silica dioxide granule, mica particles and montmorillonite particle or flat particle.These metal oxide microparticles or flat particle being added in barrier film composition, the steric effect preventing moisture from immersing can be obtained thus, therefore when using the adhesive of organic basic material, especially effectively improving resistance to water, water proofing property.

Cataloid is SiO ₂or the colloid of its hydrate, average grain diameter is 1 ~ 100nm, is preferably 5 ~ 50nm and does not have fixing structure.Aerosil particle is by making silicon chloride gasify and generating with gas phase state oxidation in thermal-flame, and average grain diameter is 1 ~ 50nm, is preferably 5 ~ 30nm.Silica dioxide granule is average grain diameter is 1 ~ 100nm, the particle being preferably 5 ~ 50nm.Mica particles is be the particle of 10 ~ 50000nm by the average grain diameter of synthetic method manufacture, is preferably average diameter and is 1 ~ 20 μm and average thickness is the flat particle of 10 ~ 100nm.Montmorillonite particle is that be made up of ionic bond etc., surperficial mutually with the one of the ion exchangeable laminar silicate compounds of the crystal structure of the parallel overlap of more weak bonding force, and for average grain diameter be the particle of 10 ~ 100000nm, be preferably average diameter and be 1 ~ 20 μm and average thickness is the flat particle of 10 ~ 100nm.Barrier film composition comprises cataloid and aerosil particle etc., thus can increase the hardness of barrier film further.At this, average grain diameter refers to by laser diffraction/diffuse transmission type particle size distribution device (hole field makes manufactured LA-950) mensuration and size grade scale is set to the 50% average grain diameter (D that number carries out computing ₅₀).The value of the number standard average grain diameter measured by this laser diffraction/diffuse transmission type particle size distribution device with to pass through its average grain diameter when carrying out practical measurement particle diameter to any 50 particles in the image that scanning electron microscope (S-4300SE and S-900 that Hitachi tip science and technology (HitachiHigh-Technologies) manufactures) observes roughly consistent.And the average diameter of the average diameter of above-mentioned flat particle and average thickness or each flat particulate described later and the average thickness value also for measuring in the same manner as described above.

In addition, the average grain diameter of above-mentioned cataloid being limited to 1 ~ 100nm scope is that if more than 100nm, particle diameter is comparatively large and can not become dispersion liquid because colloid is unstable and easily condense when being less than 1nm.And the size of above-mentioned aerosil particle, silica dioxide granule, mica particles, montmorillonite particle being limited to above-mentioned scope is because it is obtainable particle size or can not becomes large size range compared with the film thickness of lower floor.

Further, barrier film composition preferably include containing be selected from comprise gold, platinum, palladium, ruthenium, nickel, copper, tin, indium, zinc, iron, chromium, manganese and aluminium group in one kind or two or more metal or the particulate of their metal oxide or flat particulate.By adding these particulates or flat particulate, the steric effect that prevent moisture from immersing identical with metal oxide microparticle or flat particle can be obtained.The size of these particulates and addition can be identical with the size of the particulate recorded in aforesaid reinforcement film composition and addition.

In addition, in the basal liquid of barrier film composition, add the additives such as above-mentioned required particle, particulate, flat particulate and enable these additives method be scattered in basal liquid use the method identical with the method for the composition mixed in above-mentioned transparent electrode thin film composition.

The preferred alternately stacked use of barrier film contains the mineral-type barrier layer of more than 1 layer or 2 layers of the barrier film composition of the mineral-type basic material of polymer type adhesive or the mineral-type basic material of non-polymeric adhesive and uses the organic barrier layer of more than 1 layer or 2 layers of the barrier film composition of the organic basic material containing polymer type adhesive to be formed.More preferably alternately stacked mineral-type barrier layer and organic barrier layer form 3 ~ 5 layers multiple stacked in addition.Multiplely stackedly barrier film can be formed thus by of different nature.Moisture-proof and the thermal endurance on the mineral-type barrier layer formed by the barrier film composition containing mineral-type basic material are higher, and the effect of the aspect excellence obtaining hard films and so on can be expected, but easily cause the unfavorable condition producing in film and become the hole of defect.On the other hand, the resistance to water on the organic barrier layer formed with composition by the barrier film containing organic basic material and excellent impact resistance, but poor in moisture-proof because water vapour permeability is higher.Therefore by making up mutual shortcoming by multiple stacked barrier film that formed of different nature, and the effect that plays a role as barrier film that is tight and the various excellents such as resistance to water, moisture-proof, weatherability, resistance to impact, thermal endurance can be obtained.If more than 6 layers, although the unfavorable condition then not having in characteristic, can material be wasted and increase process number and manufacturing cost increases, therefore not preferred.

Then, by the thin film composition of wet type coating barrier-coating.Wet type coating can use the method identical with the method recorded in above-mentioned transparent electrode thin film composition.

Single one layer or more irradiation ultraviolet radiation that the thin film composition of barrier-coating is obtained or be preferably heated to 120 ~ 400 DEG C, be more preferably heated to 120 ~ 200 DEG C or irradiation ultraviolet radiation after be preferably heated to 120 ~ 400 DEG C, be more preferably heated to 120 ~ 200 DEG C to form barrier film.At this, if above-mentioned drying or the barrier film after solidifying have flexibility, then preferable operability during back electrode strap used for solar batteries to photoelectric conversion layer adhered film, therefore preferably.When heating-up temperature is less than 120 DEG C, the nubbin of solvent etc. hinders the solidification in backplate strengthening membrane and solidifies insufficient, if more than 400 DEG C, cannot produce the advantage in the production of low temperature process and so on.Namely manufacturing cost is caused to increase and productivity ratio decline.Especially, when fitting in the Post RDBMS of photoelectric conversion layer, likely impact is brought on the wavelength region of amorphous silicon, microcrystal silicon or the opto-electronic conversion in utilizing these mixed type (many maqting type) silicon solar cell module.And the thickness of the barrier film formed preferably is set to 0.2 ~ 20 μm.When the thickness of barrier film is less than 0.2 μm, be difficult to keep sufficient weatherability, resistance to water, moisture-proof etc. when producing the situation etc. of defect, if more than 20 μm, although there is no special unfavorable condition waste material.Wherein more preferably the thickness of barrier film is set to 0.2 μm ~ 10 μm.

[carrier band]

Carrier band keeps transparent electrode thin film and reflecting electrode film, according to circumstances keeps barrier film.Especially a kind of back electrode strap used for solar batteries comprising base material, transparent electrode layer, photoelectric conversion layer, transparent electrode thin film and reflecting electrode film, transparent electrode thin film and reflecting electrode film is formed in the region opposed with described photoelectric conversion layer, when according to circumstances forming barrier film, transparent electrode thin film is prevented to be separated with reflecting electrode film etc.

The substrate etc. formed by organic polymers such as polyimides or PET (polyethylene terephthalate) can be enumerated as carrier band.When on photoelectric conversion layer during the transparent electrode thin film of attaching film back electrode strap used for solar batteries, if carrier band has flexibility, operability is good, therefore preferably.

If be coated with the thin film composition of reflecting electrode, transparent electrode thin film composition successively by wet type coating on this carrier band or the thin film composition of barrier-coating, the thin film composition of reflecting electrode, transparent electrode thin film composition form thin-film solar cells back electrode strap successively, then manufacturing process can be simplified, therefore preferably.

By forming transparent electrode thin film and reflecting electrode film on the carrier band in the region opposed with above-mentioned photoelectric conversion layer, the example of method that according to circumstances forms barrier film (hereinafter referred to as transparent electrode thin film etc.) is shown in Fig. 3.At this, the region opposed with photoelectric conversion layer refers to that the left part as the P3 of Fig. 1 forms the part of each thin-film solar cells, also comprise the part (part that laser scribing P2 processes) not forming photoelectric conversion layer in Fig. 1, but do not comprise the groove portion P3 of the nesa coating only formed for being electrically connected in series multiple battery block on matrix.In addition, the dotted line of Fig. 3 is corresponding with the position of the P3 of Fig. 1.First, the method back electrode strap that pattern is formed being bonded to material to be bonded is enumerated.As the method that pattern is formed, first can enumerate as Fig. 3 (A) be shown in and carrier thin film 110 be coated with 1 row transparent electrode thin film etc. 100 with the width of photoelectric conversion layer and repeat this coating to form the method for multiple row transparent electrode thin film etc. 100.And, can enumerate as Fig. 3 (B) be shown in transparent electrode thin film carrier thin film 111 being formed multiple row amount (Complex ordered series of numbers divides) etc. 101 after, form the method for multiple row transparent electrode thin film etc. 102 in the part segmentation represented by single dotted broken line.At this, the method for segmentation transparent electrode thin film etc. 101 can enumerate the method removing groove portion 120 with the punching presses such as mould or mechanically rule etc.; Carrier thin film 111 is formed in uncured mode the transparent electrode thin film etc. of multiple row amount, and waits by etching the method removing groove portion 120 after only solidifying the local of multiple row transparent electrode thin film etc. 102; By the method that the print process patterns such as flexographic printing, hectographic printing, screen painting are formed; The method etc. of the width in the region opposed with photoelectric conversion layer is cut into by each carrier band.And laser scribing or mechanically ream after back electrode strap can being bonded to material to be bonded, but become miscellaneous due to operation, therefore preferred pattern formation is carried out to back electrode strap itself.

The example of the structure of thin-film solar cells back electrode strap is shown in following (1) ~ (8), but the structure of thin-film solar cells back electrode strap of the present invention is not limited to following.In addition, following example does not comprise barrier film, but each self-structure certainly can be made to comprise barrier film.

(1) the transparent electrode thin film film of tack coat is possessed, based on the reflecting electrode film of the metallic film of vapor phase method, the combination of carrier band;

(2) what formed with wet type coating has close-burning transparent electrode thin film, based on the reflecting electrode film of the metallic film of vapor phase method, the combination of carrier band;

(3) combination of the transparent electrode thin film film of tack coat, the reflecting electrode film of metal forming is possessed;

(4) with the combination of reflecting electrode film with close-burning transparent electrode thin film, metal forming that wet type coating is formed;

(5) what formed with wet type coating has close-burning transparent electrode thin film, the reflecting electrode film of metallic film with the formation of wet type coating, the combination of carrier band;

(6) the transparent electrode thin film film of tack coat, the reflecting electrode film of metallic film with the formation of wet type coating, the combination of carrier band is possessed;

(7) the transparent electrode thin film film of tack coat is possessed, based on the reflecting electrode film of the metallic film of plating, the combination of carrier band; And

(8) what formed with wet type coating has close-burning transparent electrode thin film, based on the reflecting electrode film of the metallic film of plating, the combination of carrier band.

[manufacture method of thin-film solar cells]

The feature of the manufacture method of thin-film solar cells of the present invention is, comprises (A) successively and prepares to be formed with the operation of the material to be bonded of base material, transparent electrode layer and photoelectric conversion layer and (B) and to fit on the photoelectric conversion layer of described material to be bonded the operation of transparent electrode thin film of above-mentioned thin-film solar cells back electrode strap.Preferably after (B) operation, make transparent electrode thin film and reflecting electrode film hardening again.Below, an example of the manufacture method of thin-film solar cells is shown, but the present invention is not limited to following manufacture method.

One example of the manufacture method of thin-film solar cells shown in Fig. 4.In addition, the symbol 9 in (B) of Fig. 4 is thin-film solar cells back electrode strap (hereinafter referred to as back electrode strap) from the example of carrier band sequentially laminated with barrier film, reflecting electrode film, transparent electrode thin film.As shown in (A) of Fig. 4, first prepare the material to be bonded 7 being formed with base material 4, transparent electrode layer 5 and photoelectric conversion layer 6 successively.Base material 4 is formed (A) of method as Fig. 2 ~ (E) of transparent electrode layer 5 and photoelectric conversion layer 6 successively.

As shown in (B) of Fig. 4, then, the transparent electrode thin film 1 of back electrode strap 9 is fitted into as shown in (C) of Fig. 4 by the photoelectric conversion layer 6 of material to be bonded 7.This back electrode strap 9 is sequentially laminated with transparent electrode thin film 1, reflecting electrode film 2, barrier film 3 and carrier band 8.

As shown in (D) of Fig. 4, after peeling off carrier band 9, form the groove portion P3 as shown in (E) of Fig. 4.The method forming this groove portion P3 can enumerate the method removing groove portion P3 with punching presses such as moulds; After uncured back electrode strap 9 is fitted in photoelectric conversion layer 6, only the back electrode strap 9 of the part that solidification is corresponding with photoelectric conversion layer 6 is afterwards with etching the method waiting and remove groove portion P3; Mechanically ream the method etc. of method and the laser scribing removed.

Other examples of the manufacture method of thin-film solar cells shown in Fig. 5.In addition, Fig. 5 is also back electrode strap from the example of carrier band sequentially laminated with barrier film, reflecting electrode film, transparent electrode thin film.This example is formed in the region (removing the region of groove portion P3) corresponding with photoelectric conversion layer 6 carrying out transparent electrode thin film 1a, reflecting electrode film 2a and the barrier film 3a of pattern formation with P3 insulation tank corresponding to trace of ruling in structure in the past.As shown in (A) of Fig. 5, first prepare the material to be bonded 7 being formed with base material 4, transparent electrode layer 5 and photoelectric conversion layer 6 successively.

As shown in (B) of Fig. 5, the laminating as shown in (C) of Fig. 5 is carried out in the contraposition then making the transparent electrode thin film 1 of back electrode strap 9 and the photoelectric conversion layer 6 of material to be bonded 7 carry out groove portion P3.In (D) of Fig. 5, remove carrier band, but this carrier band itself using the raw material that weatherability, thermal endurance, moisture-proof, resistance to water etc. are higher, therefore without the need to removing this carrier band, and then increasing reliability, therefore more preferably.

When the manufacture method of Fig. 4, arbitrary thin-film solar cells illustrated in fig. 5, all preferably include attaching and comprise transparent electrode thin film and reflecting electrode film, the operation making it solidify after according to circumstances comprising the back electrode strap of barrier film.

By the structure that the thin-film solar cells of the manufacture method manufacture of these thin-film solar cells is identical with representing Fig. 1 of thin-film solar cells in the past.But the advantage of thin-film solar cells of the present invention is, owing to using back electrode strap, therefore, it is possible to seek simplification and the efficient activity of the manufacturing process of backplate, and a part for the laser scribing process used in the manufacture of general thin-film solar cells can be omitted.And be also advantageous in that by shortening heat processing procedure and the fire damage that alleviates due to low temperature photoelectric conversion layer, improve conversion efficiency thus.

[embodiment]

Below, according to embodiment, the present invention is described in detail, but the present invention is not limited to these.And in evaluation of the present invention, use many bonding films silicon solar cell, but can apply solar cell of the present invention is not limited to this.As following mensuration conversion efficiency.To the many maqting type thin film silicon solar cell of the evaluation after electrode fabrication, wire leads on the substrate after on-line machining solar cell block, uses solar simulator and digital sourcemeter, obtains and irradiates AM:1.5,100mW/cm ²i-V (current-voltage) curve of light time.In addition, by the current value (I) in I-V (current-voltage) curve obtained is obtained J-V curve (Current density-voltage) divided by the surface area of solar cell block.Be 2 limits with voltage axis and current density axis in this J-V curve, the output in the area when rectangular area depicted by the point linked on initial point and J-V curve is maximum is set to the highest output density (mW/cm ²), will [the highest output density (mW/cm ²)]/[100 (mW/cm ²)] × 100 be set to conversion efficiency (%).These results shown in table 1,2.

< embodiment 1>

Utilize (A) of Fig. 2 ~ (E) to be described the method manufacturing material to be bonded, operation afterwards utilizes Fig. 5 to be described.First, as shown in (B) of Fig. 2, transparency carrier 40 prepares that length and width 10cm is square, thickness is the glass plate of 4mm, uses SnO as nesa coating 50 ₂.At this moment the thickness of nesa coating 50 is 800nm, and sheet resistance is 10 Ω/, and mist degree is 15 ~ 20%.

Then, as shown in (C) of Fig. 2, utilize plasma CVD method from the nesa coating 50 proceeding to laser scribing P1 processing with 300nm thickness film forming amorphous silicon layer 61, then utilize plasma CVD method with 1.7 μm of thickness film forming microcrystal silicon layers 62 on amorphous silicon layer 61, form the silicon class photoelectric conversion layer 60 as shown in (D) of Fig. 2 thus.As shown in (E) of Fig. 2, laser scribing P2 is implemented to this photoelectric conversion layer 60 and processes, using this as material to be bonded 70.Material to be bonded is represented by symbol 7 in (A) of Fig. 5.

On the other hand, in order to make back electrode strap 9a as shown in Figure 5, with the thickness of mold apparatus for coating on polyethylene terephthalate (PET) carrier band 8a processed after coating heat treatment be the methylcellulose of 1 μm as barrier film 3a, and heat treatment 10 minutes at 120 DEG C.Pass through the Ag film of spatter film forming 100nm on this basis as reflecting electrode film 2a.

Then, using with atomic ratio measuring is the ITO target of Sn/ (Sn+In)=0.05, by the transparent electrode thin film 1a of spatter film forming 10nm thickness.On this basis acrylic resin is adjusted to the thickness after the heat treatment of 10nm, carries out coating with mold apparatus for coating, form tack coat.The laser scribing P3 that this tack coat is implemented as shown in (B) of Fig. 5 is processed, makes back electrode strap 9a.

Then, as shown in (C) of Fig. 5, utilize contact panel bonding process device accurate contraposition back electrode strap 9a and material to be bonded 7, after laminating back electrode strap 9a and material to be bonded 7, at 120 DEG C, solidify process 10 minutes.

< embodiment 2 ~ 23>

Except being set as the condition shown in table 1, test by the method identical with embodiment 1.At this, the SB-10A that the silica sol-gel used in embodiment 2 grade uses MATERIAL company of Mitsubishi to manufacture.Further, the following thin film composition of the reflecting electrode used in wet type coating making embodiment 12 grade.

First, silver nitrate is dissolved in deionized water, prepares aqueous metallic ions.Further, be dissolved in by natrium citricum in deionized water, preparation concentration is the sodium citrate aqueous solution of 26 quality %.In the nitrogen air-flow of maintenance 35 DEG C, directly add granular ferrous sulfate to this sodium citrate aqueous solution and make it dissolve, preparing the reducing agent aqueous solution containing citrate ions and ferrous ion with the mol ratio of 3: 2.Then, under the state that above-mentioned nitrogen air-flow is kept 35 DEG C, the stirrer of magnetic stirring apparatus is put into the reducing agent aqueous solution, with the rotating speed Stirring of 100rpm, while stirring the above-mentioned reducing agent aqueous solution, to drip above-mentioned aqueous metal salt synthesizing to this reducing agent aqueous solution.At this, add the amount of aqueous metal salt about to the reducing agent aqueous solution, the concentration of each solution be adjusted to less than 1/10 of the water-soluble liquid measure of reducing agent, even if thus the aqueous metal salt of room temperature of dripping, reaction temperature also keeps 40 DEG C.Further, the mixing ratio of the above-mentioned reducing agent aqueous solution and aqueous metal salt is adjusted to, and the equivalent of the ferrous ion added as reducing agent becomes 3 times of metal ion equivalent.Terminate to after the reducing agent aqueous solution drips aqueous metal salt, then continue stirring 15 minutes mixed liquors, produce metallic particles in mixed liquor inside thus and obtain the metallic particles dispersion liquid being dispersed with metallic particles.The pH of metallic particles dispersion liquid is 5.5, and the stoichiometry growing amount of the metallic particles in dispersion liquid is 5g/dm ³.The dispersion liquid obtained is placed on room temperature, precipitates the metallic particles in dispersion liquid thus, by the condensation product of the metallic particles of decantation precipitation and separation.Add deionized water as dispersion to the metal agglomerates thing be separated, after carrying out desalting processing by ultrafiltration, then carry out displacement cleaning with methyl alcohol, thus metal (silver) content is set to 50 quality %.Afterwards, utilize centrifugal force adjust of centrifugal separator to this centrifugal separator to be separated the Argent grain of the greater particle size more than 100nm, thus to be adjusted in number be all silver nano-grain within the scope of 10 ~ 50nm containing the primary particle size of 71%.That is, be adjusted to primary particle size account for the silver nano-grain within the scope of 10 ~ 50nm relative to all silver nano-grains 100% ratio in number all become 71%.Be the protective agent chemical modification of the organic backbone of carbon number 3 by carbon skeleton to the silver nano-grain obtained.

Then, by add be mixed in 90 mass parts comprise in the mixed solution of water, ethanol and methyl alcohol the metal nanoparticle obtained disperseing 10 mass parts.In addition, in this dispersion liquid, add the polyvinylpyrrolidone of 4 mass parts and the silver citrate of 1 mass parts as additive, so that the ratio of metal nanoparticle becomes 95 mass parts, thus obtain the thin film composition of reflecting electrode.After being coated with the thin film composition of obtained reflecting electrode by the mode that wet type coating becomes the thickness shown in table 1 with the thickness after burning till on being identically formed on polyethylene terephthalate (PET) carrier band processed barrier film with embodiment 1, under 180 DEG C (heat resisting temperature deriving from PET carrier band is the temperature of 200 DEG C), the condition of less than 60 minutes, burn snearing film, thus form reflecting electrode film.

In embodiment 13, by sputtering at the transparent electrode thin film of film forming 1nm thickness on formed reflecting electrode film.On this basis acrylic resin is adjusted to the thickness after the heat treatment of 100nm, carries out coating with mold apparatus for coating, form tack coat.The laser scribing P3 that this tack coat is mechanically implemented as shown in (B) of Fig. 5 is processed, makes back electrode strap.

< embodiment 24>

Fig. 5 is utilized to be described.Material to be bonded 7 shown in (a) of Fig. 5 uses the material to be bonded made in embodiment 1.Then, on polyethylene terephthalate (PET) carrier band 8a processed, become the mode coating silica sol-gel of 1 μm as barrier film 3a using the thickness after heat treatment with mold apparatus for coating, and heat treatment 10 minutes at 120 DEG C.Pass through the Ag film of spatter film forming 800nm on this basis as reflecting electrode film 2a.

Then, the transparent electrode thin film composition used when following preparation forms transparent electrode thin film 1a.As electrically conductive microparticle, the AZO powder that add 50 mass parts take atomic ratio measuring as Al/ (Al+Zn)=0.02, particle diameter is 0.03 μm, adds IPA as decentralized medium, thus entirety is set to 100 mass parts.Use the zirconium oxide bead of 0.3mm diameter to operate 2 hours horizontal mills (Horizontal sand mill) to this mixture, make the microparticulate in mixture.In this dispersion liquid, count AZO as adhesive mixed silica sol-gel to make becoming mass ratio: silica sol-gel=7: 3, then be diluted to ethanol and be scaled 2 mass parts with AZO, obtain transparent electrode thin film composition.It is 50nm that this transparent electrode thin film composition is adjusted to the thickness after heat treatment, carries out coating with mold apparatus for coating.The laser scribing P3 shown in (B) this mechanically being implemented to Fig. 5 processes, and makes back electrode strap 9a.

In addition, the method about the average grain diameter measuring above-mentioned electrically conductive microparticle is as following, and all calculates according to number.With the dynamic light scattering determination based on the LB-550 manufactured by the making of hole field, also confirm particle diameter from electron micrograph.About used electron microscope, the kind according to particle size, powder suitably separately uses SEM or TEM.

< embodiment 25 ~ 45>

Except being set as the condition shown in table 2, test by the method identical with embodiment 24.

< comparative example 1>

Fig. 2 is utilized to be described.The material to be bonded 70 of carrying out laser scribing P2 processing shown in (E) of Fig. 2 uses the material to be bonded made in embodiment 1.The transparent conductive film composition that following preparation uses when forming the nesa coating 10 of side, the inside.As electrically conductive microparticle, the ito powder that add 1.0 mass parts take atomic ratio measuring as Sn/ (Sn+In)=0.1, particle diameter is 0.03 μm, the silica sol-gel of 0.05 mass parts is added as adhesive, add the ethanol of 98.95 mass parts as decentralized medium further, thus entirety is set to 100 mass parts.In addition, about measuring the method for average grain diameter of above-mentioned electrically conductive microparticle for such as described in embodiment 24.

Use the zirconium oxide bead of 0.3mm diameter, this mixture is operated 2 hours horizontal mills (Horizontal sand mill), makes the microparticulate in mixture, thus obtain transparent conductive film composition.

Then, by spin-coating method on photoelectric conversion layer 60 by the transparent conductive film composition coating of above-mentioned preparation be burn till after thickness become 80nm, at 200 DEG C, burn snearing film 30 minutes, thus formed nesa coating 10.Thickness after burning till is measured by the photo being taken cross section by SEM.Burn till and particulate in the nesa coating 10 that obtains is microdot/adhesive ratio with the ratio of adhesive: 2/1.In addition, about temperature when burning sticky, measure 4 temperature at the angle of 10cm square glass plate, be set to mean value design temperature ± 5 DEG C within the scope of condition.

In addition, by the Ag colloidal dispersions of spin-coating method coating 0.03 μm of average grain diameter on formed side, the inside nesa coating 10 in the Ag nanometer ink of ethanol solvent, so that the thickness after burning till becomes 200nm, and at 200 DEG C, burn snearing film 30 minutes, thus form conductive reflecting film 20, the back electrode strap without strengthening membrane of (F) of construction drawing 2 thus, then, as shown in (G) of Fig. 2, carry out laser scribing P3 processing, obtain and evaluate with many maqting type thin film silicon solar cell.In addition, the Ag nanometer ink used consist of the Ag colloid of 10 mass parts and the ethanol of 90 mass parts.

[table 1]

[table 2]

As from table 1,2, in all embodiments 1 ~ 45, back electrode strap all can be used to make thin-film solar cells, and conversion efficiency is up to 7.23 ~ 7.87%.In contrast, in comparative example 1, namely use the operation more complicated than embodiment 1 ~ 45 to make, conversion efficiency is also lower than embodiment 1 ~ 45.Due in embodiment 1 ~ 45, shorten the heat treatment process in manufacturing process, and realize low temperature, therefore conversion efficiency uprises.

As more than, the backplate of the application of the invention can bring simplification and the efficient activity of the manufacturing process seeking backplate.And a part for the laser scribing process for the manufacture of general thin-film solar cells can be omitted.And by shortening heat processing procedure and the fire damage alleviated due to low temperature photoelectric conversion layer, conversion efficiency can be improved thus.

Claims

1. a thin-film solar cells back electrode strap, is characterized in that,

Be laminated with transparent electrode thin film and reflecting electrode film, and transparent electrode thin film has caking property,

Barrier film is laminated with further in reflecting electrode film side,

The mineral-type barrier layer of alternately stacked more than 1 layer or 2 layers of barrier film and the organic barrier layer of more than 1 layer or 2 layers are formed, wherein, described mineral-type barrier layer uses the barrier film composition containing the mineral-type basic material of polymer type adhesive or the mineral-type basic material of non-polymeric adhesive, and described organic barrier layer uses the barrier film composition of the organic basic material containing polymer type adhesive.

2. thin-film solar cells back electrode strap as claimed in claim 1, wherein,

Carrier band is laminated with further at the opposing face of transparent electrode thin film.

3. thin-film solar cells back electrode strap as claimed in claim 2,

It is the thin-film solar cells back electrode strap comprising base material, transparent electrode layer, photoelectric conversion layer, transparent electrode thin film and reflecting electrode film, and it forms transparent electrode thin film and reflecting electrode film in the region opposed with described photoelectric conversion layer.

4. a manufacture method for thin-film solar cells, is characterized in that,

Comprise successively: (A) prepares to be formed with the operation of the material to be bonded of base material, transparent electrode layer and photoelectric conversion layer; (B) operation of the transparent electrode thin film of the thin-film solar cells back electrode strap according to any one of the photoelectric conversion layer laminating claims 1 to 3 of described material to be bonded.

5. the manufacture method of thin-film solar cells as claimed in claim 4, wherein,

Transparent electrode thin film and reflecting electrode film hardening is made again after (B) operation.

6. a thin-film solar cells, it comprises the thin-film solar cells back electrode strap according to any one of claims 1 to 3.