TWI498213B - Photovoltaic module with stabilized polymer - Google Patents

Description

Photovoltaic module with stabilized polymer

The present invention is in the field of photovoltaic modules, and more particularly, the invention pertains to the field of thin film photovoltaic modules incorporating a polymer layer and a photovoltaic device on a suitable thin film photovoltaic substrate.

Two common types of photovoltaic (solar) modules are used today. The first type of photovoltaic module uses a semiconductor wafer as a substrate and the second type of photovoltaic module uses a semiconductor film deposited on a suitable substrate.

Semiconductor wafer type photovoltaic modules typically include crystalline germanium wafers commonly used in various solid state electronic devices, such as computer memory chips and computer processors.

Thin film photovoltaics can be incorporated into one or more conventional semiconductors (such as amorphous germanium) on a suitable substrate. Unlike wafer applications where wafers are cut from an ingot, thin-film photovoltaic systems use relatively simple deposition techniques such as sputter coating, physical vapor deposition (PVD), or chemical vapor deposition (CVD). ) formed.

Thin film photovoltaic modules are typically incorporated into an ethylene vinyl acetate (EVA) layer or a poly(vinyl butyral) (PVB) layer to seal and protect the underlying photovoltaic device. The long-term reliability of the photovoltaic module (of course) is critical, and therefore, the stability of the polymer layer is a critical factor for any particular photovoltaic device.

As described in detail in U.S. Patent Publication No. 2007/0259998, although EVA has been widely used in photovoltaic modules, since poly(vinyl butyral) does not have the same disadvantages as EVA (such as degradation of acetic acid), Very suitable for use with poly(vinyl butyral).

Although poly(vinyl butyral) is generally preferred, it has been observed that poly(vinyl butyral) turns yellow when contacted with a silver-containing element.

Accordingly, what is needed in the art is a poly(vinyl butyral) composition suitable for stable, long-term use in photovoltaic modules having several metal components.

The present invention provides a photovoltaic device comprising a metal and a poly(vinyl butyral) layer incorporating a suitable amount of 1H-benzotriazole. When a bias voltage is applied to the photovoltaic device, 1H-benzotriazole forms a barrier layer on the metal/poly(vinyl butyral) interface, which, for example, virtually unintentionally eliminates the inclusion of silver components. Yellowing of poly(vinyl butyral) in photovoltaic devices.

The thin film photovoltaic device of the present invention comprises a poly(vinyl butyral) layer formulated according to the description herein, which provides excellent adhesion, electrical resistivity, sealing, processability and durability to photovoltaic devices, and Contains 1H-benzotriazole.

An embodiment of a thin film photovoltaic module of the present invention is shown generally at 10 in FIG. As shown in the figure, a photovoltaic device 14 is formed on a base substrate 12, which may be, for example, glass or plastic. A protective substrate 18 is bonded to the photovoltaic device 14 using a poly(vinyl butyral) layer 16.

As used herein, "1H-benzotriazole" refers to a compound as shown in the following formula:

1H-benzotriazole may be included in the poly(vinyl butyral) layer in any suitable amount, and in various embodiments, the weight percentage of 1H-benzotriazole contained is 0.001 to 5%, 0.01 to 5 %, 0.1 to 5%, 1 to 5%, 2 to 5%, or 0.1 to 0.4%.

Preferably, the 1H-benzotriazole is included in the poly(ethylene condensate) by melt-mixing 1H-benzotriazole with a poly(vinyl butyral) resin and any other additives to form a polymer layer. In the aldehyde). 1H-benzotriazole can also be provided in the form of a salt such as sodium, potassium, and ammonium.

1H-benzotriazole is a known corrosion inhibitor for copper, silver, cobalt, aluminum and zinc. It is commercially available from PMC Specialties Group and sold under the trade name Cobrate-99. Other corrosion inhibitors suitable for use in the photovoltaic device of the present invention include: derivatives of 1H-benzotriazole such as 5-methyl-1H-benzotriazole, 5-carboxybenzotriazole, and 1H-benzene Other alkyl derivatives of triazole; imidazole and imidazole derivatives such as benzimidazole, 5,6-dimethylbenzimidazole, 2-mercaptobenzimidazole, and 4,5-dihydro-1H-imidazole a fatty acid derivative; an alkyl derivative of thiadiazole and thiadiazole, such as 2-mercaptobenzothiazole, 1,2-bis(phenylthio)ethane, 2,5-bis(n-octyl) Sulfur)-1,3,4-thiadiazole, 2-amino, 5-mercapto, 1,3,4-thiadiazole, 2-mercaptopyrimidine, 2-mercaptobenzoxazole; histamine; histamine Acid; and 2-aminopyrimidine.

its He additive

Other additives, which may be included in the polymer layer of the invention to improve stability and performance, comprise a metal deactivator such as Irganox MD- (CAS 32687-78-8) and Naugard XL- (CAS 70331-94-1); hindered amine light stabilizers such as Tinuvin (CAS129757-67-1); and phenolic antioxidants such as Anox (2,2'-thiodiethyl bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] CAS 41484-35-9).

It is expected that any combination of any of the above polymeric stabilizers with benzotriazole will result in further stability of the poly(vinyl butyral) at the poly(vinyl butyral)-metal interface and the inner side of the polymer. Experimental data has suggested: adding benzotriazole and Anox The poly(vinyl butyral) formulation does further reduce polymer fading and protect the structure of the thin film solar panel. In various embodiments of the invention, 1H-benzotriazole and a phenolic antioxidant are incorporated into a poly(vinyl butyral) layer, and in some embodiments, 1H-benzotriazole and 2, 2'-Thionodiethyl bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] is incorporated into a poly(vinyl butyral) layer.

Poly(vinyl butyral) layer

The thin film photovoltaic module of the invention adopts a poly(vinyl butyral) layer as a laminating adhesive for sealing the photovoltaic device on a protective substrate, thereby forming the photovoltaic mold of the invention. group.

The poly(vinyl butyral) of the present invention can be produced by an acetalization process, as is known to those skilled in the art (see, for example, U.S. Patent Nos. 2,282,057 and 2,282,026). In one embodiment, the Encyclopedia of Polymer Science & Technology, Third Edition, Volume 8, pages 381 to 399, BE Wade (2003), acetal vinyl (vinyl acetal) can be used. The solvent method described in the polymer. In another embodiment, the hydration process described therein can be used. Poly (vinyl butyral) is commercially available from a variety of forms (e.g.) Solutia Inc., Missouri, St. Louis, as Butvar ^TM resins.

In various embodiments, poly(vinyl butyral) comprises from 10 to 35 weight percent (wt.%) hydroxyl groups calculated from polyvinyl alcohol, from 13 to 30 wt.% hydroxyl groups calculated as polyvinyl alcohol or as polyethylene. The alcohol has 15 to 22 wt.% of hydroxyl groups. The polymer layer resin may also include less than 15 wt.% of residual ester groups, 13 wt.%, 11 wt.%, 9 wt.%, 7 wt.%, 5 wt.%, or Less than 3 wt.% of residual ester groups, the remainder being an acetal, preferably butyraldehyde acetal, but optionally containing minor amounts of other acetal groups (for example) 2-ethylhexanal (for example, see U.S. Patent No. 5,137,954).

In various embodiments, the poly(vinyl butyral) has at least 30,000, 40,000, 50,000, 55,000, 60,000, 65,000, 70,000, 120,000, 250,000, or at least 350,000 grams (g/mole or dalton) per mole. Molecular weight. A small amount of dialdehyde or trialdehyde may also be added during the acetalization step to increase the molecular weight to at least 350,000 g/mole (see, for example, U.S. Patent Nos. 4,902,464, 4,874,814, 4,814,529, and 4,654,179). . As used herein, the term "molecular weight" means a weight average molecular weight.

A variety of adhesion control agents can be used in the polymer layer of the present invention, including sodium acetate, potassium acetate, and magnesium salts. Magnesium salts which can be used with such embodiments of the invention include, but are not limited to, those disclosed in U.S. Patent No. 5,728,472, such as magnesium salicylate, magnesium nicotilate, bis(2-aminobenzoic acid). Magnesium, magnesium bis(3-hydroxy-2-naphthoate), and magnesium bis(2-butyrate) (Chemical Abstract No. 79992-76-0). In various embodiments of the invention, the magnesium salt is magnesium bis(2-butyrate).

In various embodiments of the polymer layer of the present invention, the polymer layer may comprise from 20 to 60, from 25 to 60, from 20 to 80, from 10 to 70, or from 10 to 100 parts of plasticizer. Of course, other quantities can be used as long as they are suitable for a particular application. In some embodiments, the plasticizer has a hydrocarbon segment of less than 20, less than 15, less than 12, or less than 10 carbon atoms. The amount of plasticizer can be adjusted to affect the glass transition temperature ( _Tg ) of the poly(vinyl butyral) layer. In general, larger amounts of plasticizer can be added to lower the _Tg .

To form the polymer layer, any suitable plasticizer can be added to the polymer resins of the present invention. The plasticizer used in the polymer layer of the present invention may contain a polybasic acid ester or a polyhydric alcohol therein. Suitable plasticizers include, for example, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexanoate), triethylene glycol diheptanoate, Tetraethylene glycol diheptanoate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, a mixture of heptyl adipate and decyl ester, adipic acid diiso a mercaptoester, a heptyl adipate, a dibutyl sebacate, a polymeric plasticizer such as an oil-modified azelaic acid, such as the phosphate disclosed in U.S. Patent No. 3,841,890 Mixtures of adipates, such as adipates disclosed in U.S. Patent No. 4,144,217, and mixtures and compositions of the foregoing. Other plasticizers which may be used are mixed adipates made of C ₄ to C ₉ alkanols and C ₄ to C ₁₀ cycloalkanols (as disclosed in U.S. Patent No. 5,013,779), and C ₆ to C ₈ adipate, such as hexyl adipate. In various embodiments, the plasticizer used is dihexyl adipate and/or triethylene glycol di-2-ethylhexanoate.

The poly(vinyl butyral) polymer, plasticizer, and any additives can be heat treated and configured in sheet form according to methods known to those of ordinary skill in the art. An exemplary method of forming a poly(vinyl butyral) sheet comprises extruding molten poly(vinyl butyral) by forcing the melt through a mold (eg, a mold having a dimension substantially larger than the opening of the vertical dimension) (It includes resins, plasticizers, and several additives). Another exemplary method of forming a poly(vinyl butyral) sheet comprises casting a melt from a mold into a roll, curing the resin, and substantially removing the cured resin in the form of a sheet. In various embodiments, the polymeric layer can have a thickness of, for example, 0.1 to 2.5 mm, 0.2 to 2.0 mm, 0.25 to 1.75 mm, and 0.3 to 1.5 mm.

The poly(vinyl butyral) layer of the present invention may comprise a low molecular weight epoxy resin additive. Any suitable epoxy resin can be used with the present invention as is known in the art (for example, see U.S. Patent Nos. 5,529,848 and 5,529,849).

Other additives can be incorporated into the polymer sheet to enhance its performance in the final product. As is known in the art, such additives include, but are not limited to, dyes, pigments, stabilizers (eg, UV stabilizers), antioxidants, anti-blocking agents, additional infrared absorbers, flame retardants, combinations of the foregoing. And similar.

Typical UV stabilizers include substituted 2H-benzotriazoles, such as those by Ciba Specialty Company. Trade name is sold, for example , as shown in Equation II:

Base substrate

The base substrate of the present invention (which is shown in Figure 1 as component 12) can be any suitable substrate on which the photovoltaic device of the present invention can be formed. Examples include, but are not limited to, glass, and rigid plastic glass materials (which produce "hard" film modules), and thin plastic films such as polyethylene terephthalate, polyimine, fluoropolymers, and Analogs (which produce "flexible" film modules). It is generally preferred that the base substrate allows for most of the incident radiation penetration in the range of 350 to 1200 nm, although those skilled in the art will recognize that there are several variations, including variations in the entry of light into the photovoltaic device via the protective substrate.

Thin film photovoltaic device

The thin film photovoltaic device of the present invention (which is shown in Figure 1 as component 14) is formed directly on the base substrate. A typical device fabrication includes depositing a first conductive layer; etching the first conductive layer; depositing and etching a semiconductor layer; depositing a second conductive layer; etching the second conductive layer; and applying a busbar conductor and a protective layer depending on the application. An electrically insulating layer is optionally formed on the base substrate between the first conductive layer and the base substrate. This optional layer can be, for example, a layer of germanium.

Although the 1H-benzotriazole agent of the present invention can be added to a polymer layer for use in a photovoltaic device without any silver, in a preferred embodiment, 1H-benzotriazole is used for poly(ethylene tributyl) In the aldehyde) layer, the layer is used in a photovoltaic module having a photovoltaic device comprising silver. Examples of silver components include, but are not limited to, conductive layers or elements such as wire grids or reflective layers (see, for example, US 2006/0213548).

In other embodiments, the 1H-benzotriazole agent of the present invention may be added to a polymer layer for use on a photovoltaic device comprising other metals that have been degraded, wherein the metals include, for example, antimony, copper, Cadmium, lead, tin, zinc, gold, indium, palladium, platinum, aluminum, ruthenium, chromium, iron, nickel, ruthenium, osmium, titanium, or vanadium.

Those skilled in the art will recognize that the above-described device fabrication is only one known method and is merely an embodiment of the invention. Many other types of thin film photovoltaic devices are within the scope of the present invention. Examples of forming methods and apparatus include such forming methods and apparatus as described in U.S. Patent Nos. 2003/0180983, 7,074,641, 6,455,347, 6,500,690, 2006/0005874, 2007/0235073, 7,271,333, and 2002/0034645.

The various components of the thin film photovoltaic device can be formed by any suitable method. In various embodiments, chemical vapor deposition (CVD), physical vapor deposition (PVD), and/or sputtering can be used.

The two conductive layers are used as electrodes to carry the current generated by the intervening semiconductor material. One of the electrodes is generally transparent to allow solar radiation to reach the semiconductor material. Of course, both conductors may be transparent, or one of the conductors may be reflective such that light that has passed through the semiconductor material is reflected back into the semiconductor material. The conductive layer may comprise any suitable conductive oxide material, such as tin oxide or zinc oxide, or if transparency, such as is not critical to the "back" electrode, a metal or metal alloy layer may be used, such as aluminum or Silver. In other embodiments, a metal oxide layer and a metal layer may be combined to form an electrode, and the metal oxide layer may be doped with boron or aluminum and deposited using low pressure chemical vapor deposition. The conductive layers may have a thickness of, for example, 0.1 micrometers to 10 micrometers.

The photovoltaic cell of the thin film photovoltaic device can include, for example, a hydrogenated amorphous germanium of the conventional PIN or PN structure. The crucible typically has a thickness of up to about 500 nanometers and typically comprises a P-layer having a thickness of 3 to 25 nanometers, an i-layer of 20 to 450 nanometers, and a n- of 20 to 40 nanometers. Floor. For example, as described in U.S. Patent No. 4,064,521, it can be deposited by means of a glow discharge in a mixture of decane or decane and hydrogen.

Alternatively, the semiconductor material may be micro-amorphous germanium, cadmium telluride (CdTe or CdS/CdTe), copper indium diselenide (CuInSe ₂ , or "CIS", or CdS/CuInSe ₂ ), copper indium gallium selenide (CuInGaSe) ₂ or "CIGS", or other photovoltaic active materials. The photovoltaic device of the present invention may have an additional semiconductor layer, or a combination of the above semiconductor types, and may be a series, triple junction or heterojunction structure.

Etching the layers to form individual components of the device can be performed using any conventional semiconductor fabrication technique including, but not limited to, screen printing using a photoresist mask, using positive or negative light. Etch etching, mechanical scribing, discharge scribing, chemical etching, or laser etching. Typically, etching various layers will result in the formation of individual photovoltaic cells within the device. The devices can be electrically connected to other devices using bus bars that are inserted or formed at any suitable stage of the process.

A protective layer may optionally be formed on the photovoltaic cell prior to assembly with the poly(vinyl butyral) layer and the protective substrate. The protective layer can be, for example, sputtered aluminum.

The photovoltaic cells of the present invention are formed from the electrically interconnected photovoltaic cells formed from the optional insulating layer, the conductive layers, the semiconductor layers, and the protective layer.

Protective substrate

The protective substrate of the present invention (which is shown in Figure 1 as element 18) can be any suitable substrate that can be used to bond the polymer layer and adequately protect the underlying device. Examples include, but are not limited to, glass, rigid plastic, and thin plastic films such as poly(ethylene terephthalate), polyimine, fluoropolymers, and the like. It is generally preferred that the protective substrate allows for most of the incident radiation penetration in the range of 350 to 1200 nm, but those skilled in the art will recognize that there may be several variations, including all of the light entering the photovoltaic device entering through the substrate. A variation. In such embodiments, the protective substrate need not be transparent, or mostly such, and may be, for example, a reflective film that blocks light from exiting the photovoltaic module via the protective substrate.

assembly

The final assembly of the thin film photovoltaic module of the present invention comprises providing a poly(vinyl butyral) layer which is contacted with a thin film photovoltaic device using a plurality of bus bars (if available) formed on a base substrate; A protective substrate in contact with the poly(vinyl butyral) layer is disposed, and the assembly is laminated to form the module.

Although the subject matter of the present application has been designed using the preferred embodiments illustrated, the invention includes within its scope all photovoltaic devices including silver components and poly(vinyl butyral), including standard (non-film) Photovoltaic devices, and other multilayer laminates of polyvinyl butyral sheets that are well known in the art and that are in contact with a degradable metal component (e.g., solar glass, and mirrors).

The present invention comprises a poly(vinyl butyral) sheet having any of the components described herein incorporated into 1H-benzotriazole and optionally incorporating any of the other additives described herein.

The present invention comprises a method of manufacturing a photovoltaic module comprising the steps of: providing a base substrate; forming a photovoltaic device of the present invention thereon; and laminating a poly(vinyl butyral) layer using the present invention The photovoltaic device is mounted on a protective substrate.

The invention comprises a plurality of photovoltaic modules comprising the polymer layer of the invention.

Instance Example 1

Using a small laboratory scale extruder; 750 grams of poly(vinyl butyral) resin having a vinyl alcohol content of about 18.7 wt.% and a residual vinyl acetate content of 0.5 wt.% to 4 wt.% 285 g of triethylene glycol di-(2-ethylhexanoate) as a plasticizer, 2.63 g of UV absorber Tinuvin 328 0.19 g of magnesium (2-ethylbutyrate) as the adhesion control salt, and various additives as shown in Table 1; and extruded into a sheet having a thickness of 0.76 mm.

The sheets were used to laminate a thin film solar cell (15 x 15 cm). The laminates were exposed to 85 ° C and 85% relative humidity for 1,000 hours at a bias of 1,000 volts. The yellow index of the laminate was measured after 1,000 hours of exposure. The typical yellow index of the laminate is about 12 (between 11 and 13) prior to exposure.

Example 2

The flakes (1.14 mm thick) were prepared in a trial production scale extruder by adding 38 g of triethylene glycol di- (as a plasticizer) per 100 g of poly(vinyl butyral) resin. 2-ethylhexanoate), 0.35 g 0.025 g of magnesium (2-ethylbutyrate), as well as the various additives shown in Table 2. Glass coated with silver and other layers is used to prepare poly(vinyl butyral) laminates. The size of the coated glass was 7 x 9 cm. The laminates were tested for 670 hours at 85 ° C, 85% relative humidity (RH) and a bias of 1,000 volts.

Example 3

The concentrations of silver in Control #2 and Sample 4 of Example 1 were measured after 1000 hours of exposure. The samples are delaminated. The plasticizer was extracted from the layers by soaking and stirring in a 75:25 hexane/ethyl acetate mixture. The recovered poly(vinyl butyral) resin retained color, then dissolved in acid and analyzed for silver content using a Perkin Elmer Optima 3300 DV instrument. The silver content of a standard sheet of poly(vinyl butyral) was also analyzed.

The "yellow index" is measured on a complete glass laminate. The sample was measured by excluding the hemispherical reflectance of the specular component (and wherein the transparent glass surface was facing the source) in accordance with ASTM Test Method E 1331. Using the reflectance values of the entire visible spectrum, the yellow index value is calculated using the "C, 1931" column of "The coefficient of the yellow index equation" in Table 1 of the ASTM E313 "Standard Test Method for Plastic Yellow Index" method.

The test under bias is accomplished by first forming the following structure: electrode/glass layer/photovoltaic film/electrode/poly(vinyl butyral)/glass layer. A voltage of 1,000 volts dc is then applied, which results in a current of about 0.1 milliamperes.

As shown in these examples, as shown in Formula II The addition of the substituted 2H-benzotriazole derivative did not prevent yellowing, which highlighted the significant success of 1H-benzotriazole.

By virtue of the present invention, when a photovoltaic device containing silver is utilized, it is now possible to provide a thin film photovoltaic module having excellent poly(vinyl butyral) stability and yellowing resistance.

While the invention has been described with respect to the embodiments of the invention, it is understood that those skilled in the art can In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention. Therefore, the present invention is not intended to be limited to the particular embodiments of the embodiments disclosed herein.

It is to be understood that any range of values, values, or characteristics of any single component of the invention may be used interchangeably with any other range of components, values, or features of any other component of the invention to form a component definition. Examples of values, as listed throughout. For example, a film module can include a combination of poly(vinyl butyral) and several photovoltaic elements to form a plurality of arrangements within the scope of the present invention, but the listing will be extremely cumbersome.

The drawings are intended to be illustrative, and are not to be construed as limiting the invention in any particular embodiment.

The figures are not drawn to scale unless otherwise indicated.

Each of the references referred to herein, including journal articles, patents, applications, and the entire contents of the publications are hereby incorporated by reference.

10. . . Thin film photovoltaic module

12. . . Base substrate

14. . . Photovoltaic device

16. . . Poly(vinyl butyral) layer

18. . . Protective substrate

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view showing a thin film photovoltaic device of the present invention.

10. . . Thin film photovoltaic module

12. . . Base substrate

14. . . Photovoltaic device

16. . . Poly(vinyl butyral) layer

18. . . Protective substrate

Claims (15)

A photovoltaic module comprising: a base substrate; a photovoltaic device disposed in contact with the base substrate, wherein the photovoltaic device comprises a metal component; a poly(vinyl butyral) layer, Provided to be in contact with the photovoltaic device, wherein the poly(vinyl butyral) layer comprises a 1H-benzotriazole salt; and a protective substrate disposed to interface with the poly(vinyl butyral) layer contact. The module of claim 1, wherein the photovoltaic device is a thin film photovoltaic device, and the metal component is preferably used as a conductive layer. The module of claim 2, wherein the poly(vinyl butyral) layer comprises from 0.001 to 5 weight percent of the 1H-benzotriazole salt. The module of claim 2, wherein the poly(vinyl butyral) layer comprises 0.1 to 0.4 weight percent of a 1H-benzotriazole salt. The module of claim 2, wherein the poly(vinyl butyral) layer comprises from 1 to 5 weight percent of the 1H-benzotriazole salt. The module of claim 2, wherein the poly(vinyl butyral) layer additionally comprises a phenolic antioxidant. The module of claim 2, wherein the metal is tantalum, copper, cadmium, lead, tin, zinc, silver, gold, indium, palladium, platinum, aluminum, lanthanum, chromium, iron, nickel, lanthanum, cerium, titanium, Or vanadium. The module of claim 2, wherein the metal is silver. An interpolymer layer comprising a poly(vinyl butyral) sheet, the thin The sheet comprises from 0.001 to 5 weight percent of the 1H-benzotriazole salt, wherein the poly(vinyl butyral) sheet additionally comprises a phenolic antioxidant. A multilayer laminate comprising: a first substrate; a metal component disposed in contact with the first substrate; a poly(vinyl butyral) layer disposed in contact with the metal component, Wherein the poly(vinyl butyral) layer comprises a 1H-benzotriazole salt; and a second substrate disposed in contact with the poly(vinyl butyral) layer. The multilayer laminate of claim 10, wherein the poly(vinyl butyral) layer comprises 0.1 to 0.4 weight percent of a 1H-benzotriazole salt. The multilayer laminate of claim 10, wherein the poly(vinyl butyral) layer comprises from 1 to 5 weight percent of the 1H-benzotriazole salt. The multilayer laminate of claim 10, wherein the poly(vinyl butyral) layer comprises from 0.001 to 5 weight percent of the 1H-benzotriazole salt. The multilayer laminate of claim 10, wherein the poly(vinyl butyral) layer additionally comprises a phenolic antioxidant. A method for manufacturing a photovoltaic module, comprising: providing a base substrate; forming a photovoltaic device on the base substrate, wherein the photovoltaic device comprises a metal component; and providing a poly(vinyl butyral) layer Contacting the photovoltaic device, wherein the poly(vinyl butyral) layer comprises a 1H-benzotriazole salt; a protective substrate is disposed to contact the poly(vinyl butyral) layer; The base substrate, the photovoltaic device, the poly(vinyl butyral) layer, and the protective substrate are laminated to form the module.