Selective emitter solar cell electrode and solar cell comprising the same

Abstract

Disclosed are a selective emitter solar cell electrode including a conductive powder and a glass frit, the glass frit including: 15 to 40 mole percent of lead (Pb) oxide; 0.1 to 40 mole percent of tellurium (Te) oxide; 0.1 to 3 mole percent of tungsten (W) oxide; and greater than or equal to 0.1 and less than 25 mole percent of silicon (Si) oxide, the total mole percent of the lead (Pb) oxide, the tellurium (Te) oxide, and the silicon (Si) oxide being 75 mole percent or less, and a selective emitter solar cell including the same.

Description

Technical Field

[0001] This invention relates to a selective emitter solar cell electrode and a selective emitter solar cell including the same. More specifically, it relates to a selective emitter solar cell electrode that minimizes damage caused by pn junctions and achieves excellent conversion efficiency, and a selective emitter solar cell including the same. Background Technology

[0002] Silicon-based solar cells consist of a substrate comprising a p-type silicon semiconductor and an emitter layer comprising an n-type silicon semiconductor, with a pn junction formed between the p-type substrate and the n-type emitter layer. When sunlight is incident on a solar cell with this structure, electrons are generated as multiple carriers on the emitter layer comprising the n-type silicon semiconductor, and holes are generated as multiple carriers on the substrate comprising the p-type silicon semiconductor, through the photovoltaic effect. The electrons and holes generated by the photovoltaic effect move to the front electrode and the rear electrode, which are respectively bonded to the upper part of the emitter layer and the lower part of the substrate. If these electrodes are connected by wires, current flows.

[0003] For solar cells with this structure, the efficiency is affected by the concentration of the dopant in the emitter. For example, when the concentration of the dopant in the emitter is low, i.e., when the emitter is formed with a low concentration of dopant, the recombination of electrons and holes is reduced, resulting in increased short-circuit current density and open-circuit voltage. However, this also results in increased contact resistance and a reduced fill factor (FF). Conversely, when the concentration of the dopant is high, i.e., when the emitter is formed with a high concentration of dopant, the contact resistance is reduced, resulting in increased fill factor. However, this also results in reduced short-circuit current density and open-circuit voltage.

[0004] Therefore, in the past, when forming the emitter layer of a solar cell, the portion forming the electrode was selectively doped with a high concentration only on the emitter, which was doped with a low concentration. This has led to the development of solar cells with structures that can obtain the advantages of both low-concentration and high-concentration doped portions, such as solar cells with selective emitter structures (hereinafter, selective emitter solar cells). Summary of the Invention

[0005] The purpose of this invention is to provide a selective emitter solar cell electrode suitable for selective emitter solar cells.

[0006] Another object of the present invention is to provide a selective emitter solar cell electrode that minimizes damage caused by pn bonding and has excellent conversion efficiency.

[0007] Another object of the present invention is to provide a solar cell comprising the above-described selective emitter solar cell electrode.

[0008] 1. According to one embodiment, a selective emitter solar cell electrode is provided. The electrode comprises conductive powder and a glass frit.

[0009] The aforementioned glass frit comprises:

[0010] Lead (Pb) oxides ranging from 15 mol percent to 40 mol percent;

[0011] Tellurium (Te) oxides ranging from 0.1 mol% to 40 mol%;

[0012] 0.1 mol percent to 3 mol percent tungsten (W) oxide; and

[0013] Silicon (Si) oxide with a mole percentage greater than or equal to 0.1 mol% and less than 25 mol%.

[0014] The total molar percentage of lead (Pb) oxide, tellurium (Te) oxide, and silicon (Si) oxide can be less than 75 molar percentages.

[0015] 2. In 1 above, the glass frit may further contain one or more elements selected from bismuth (Bi), lithium (Li), phosphorus (P), germanium (Ge), gallium (Ga), cerium (Ce), iron (Fe), zinc (Zn), magnesium (Mg), cesium (Cs), strontium (Sr), molybdenum (Mo), titanium (Ti), tin (Sn), indium (In), vanadium (V), barium (Ba), nickel (Ni), copper (Cu), sodium (Na), potassium (K), arsenic (As), cobalt (Co), zirconium (Zr), manganese (Mn), boron (B), and aluminum (Al).

[0016] 3. In either 1 or 2 above, the glass melt may further contain 1 to 20 molar percentages of bismuth (Bi) oxide.

[0017] 4. In any one of 1 to 3 above, the glass melt may further contain 1 to 20 mole percent of lithium (Li) oxide.

[0018] 5. In any one of 1 to 4 above, the glass melt may further contain 0.1 mol% to 10 mol% magnesium (Mg) oxide.

[0019] 6. In any one of 1 to 5 above, the glass melt may further contain 0.1 mole percent to 10 mole percent of zinc (Zn) oxide.

[0020] 7. In any one of 1 to 6 above, the glass melt may further contain 0.1 mol% to 5 mol% sodium (Na) oxide.

[0021] 8. In any one of 1 to 7 above, the glass melt may further contain 0.1 mol% to 5 mol% of boron (B) oxide.

[0022] 9. In any one of 1 to 8 above, the electrode may be formed from a composition comprising the conductive powder, the glass frit, and the organic carrier.

[0023] 10. In step 9 above, the composition may comprise:

[0024] The above-mentioned conductive powder comprises 60 to 95% by weight;

[0025] 0.1% to 20% by weight of the above-mentioned glass frit; and

[0026] The above-mentioned organic carriers are used in amounts ranging from 1 to 30% by weight.

[0027] 11. In 9 or 10 above, the composition may further include one or more of the following: dispersant, thixotropic agent, plasticizer, viscosity stabilizer, defoamer, pigment, ultraviolet stabilizer, antioxidant, and coupling agent.

[0028] 12. According to another embodiment, a selective emitter solar cell is disclosed. The selective emitter solar cell includes:

[0029] The substrate is doped with a first conductivity type dopant;

[0030] A selective emitter layer is formed on the front of the substrate and includes a high-concentration doped portion and a low-concentration doped portion doped with a second conductivity type dopant.

[0031] The first electrode is formed on the aforementioned highly concentrated doped portion; and

[0032] The second electrode is formed on the back of the aforementioned substrate.

[0033] The first electrode mentioned above can be any one of the electrodes in 1 to 11 mentioned above.

[0034] The present invention provides a selective emitter solar cell electrode that minimizes damage caused by pn bonding and has excellent conversion efficiency, as well as a selective emitter solar cell including the same. Attached Figure Description

[0035] Figure 1 The structure of a selective emitter solar cell, an example of the present invention, is briefly shown. Detailed Implementation

[0036] In this specification, singular expressions include plural expressions, provided there is no clear difference in context.

[0037] The terms "include" or "have" in this specification mean the presence of the features or structural elements described in the specification, but do not preclude the possibility of adding more than one other feature or structural element.

[0038] The terms "first," "second," etc., used in this specification may be used to describe various structural elements, but structural elements are not limited to these terms. Terms are used only for the purpose of distinguishing one structural element from others.

[0039] In this specification, the term "to" in "a to b" indicating a numerical range is defined as ≥ a and ≤ b.

[0040] Selective emitter solar cell electrode

[0041] According to one embodiment, a selective emitter solar cell electrode includes a conductive powder and a glass frit, wherein the glass frit comprises: 15 to 40 mol% lead (Pb) oxide; 0.1 to 40 mol% tellurium (Te) oxide; 0.1 to 3 mol% tungsten (W) oxide; and greater than or equal to 0.1 mol% and less than 25 mol% silicon (Si) oxide, wherein the total molar percentage of lead (Pb) oxide, tellurium (Te) oxide, and silicon (Si) oxide can be less than 75 mol%. In this case, damage caused by pn junctions can be minimized, resulting in excellent open-circuit voltage, series resistance, and / or fill factor, and thus, superior conversion efficiency.

[0042] The aforementioned electrodes can be formed from a selective emitter solar cell electrode composition, which may include conductive powder, glass frit, and organic carrier.

[0043] conductive powder

[0044] The conductive powder may contain, for example, one or more metal powders of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), aluminum (Al), and nickel (Ni), but is not limited thereto. According to one example, the conductive powder may contain silver powder.

[0045] The particle shape of conductive powder is not particularly limited, and a variety of particle shapes can be used, such as spherical, plate-shaped or amorphous particles.

[0046] Conductive powders can be powders with nano-sized or micro-sized particles, such as conductive powders with a size of tens or hundreds of nanometers or conductive powders with a size of several to tens of micrometers. Furthermore, two or more conductive powders of different sizes can be used in combination as conductive powders.

[0047] The average particle size (D) of the conductive powder50 The particle size can range from 0.1 μm to 10 μm, for example, from 0.5 μm to 5 μm. Within this range, contact resistance and series resistance may decrease. After ultrasonically dispersing the conductive powder in isopropanol (IPA) at 25°C for 3 minutes, the average particle size (D) can be determined using a 1064LD model manufactured by CILAS. 50 ).

[0048] The amount of conductive powder used is not particularly limited; for example, it can contain 60 to 95% by weight of conductive powder relative to the total weight of the composition for forming the selective emitter solar cell electrode. Within this range, the solar cell exhibits excellent conversion efficiency and can be readily paste-coated. According to one example, it can contain 70 to 95% by weight of conductive powder relative to the total weight of the composition for forming the selective emitter solar cell electrode; according to another example, it can contain 80 to 95% by weight of conductive powder.

[0049] glass frit

[0050] Glass frit is used in the sintering process of a composition for forming electrodes in a selective emitter solar cell to etch an anti-reflection film, thereby melting conductive powder and generating crystalline particles of conductive powder in the emitter region. Furthermore, the glass frit improves the adhesion between the conductive powder and the wafer, and softens during sintering, inducing a further reduction in the sintering temperature.

[0051] The glass frit, based on its total molar percentage, contains 15 to 40 mol% lead (Pb) oxide; 0.1 to 40 mol% tellurium (Te) oxide; 0.1 to 3 mol% tungsten (W) oxide; and ≥0.1 mol% but <25 mol% silicon (Si) oxide. The total molar percentage of lead (Pb) oxide, tellurium (Te) oxide, and silicon (Si) oxide can be less than 75 mol%. In this case, the damage caused by pn bonding can be minimized, resulting in excellent open-circuit voltage, series resistance, and / or fill factor, leading to superior conversion efficiency.

[0052] For example, a glass frit may contain 20 to 40 mole percent of lead (Pb) oxide based on the total mole percentage of the glass frit, and as another example, it may contain 30 to 40 mole percent, but is not limited to this.

[0053] For example, a glass melt may contain 5 to 40 moles of tellurium (Te) oxide based on the total number of moles of the glass melt, and as another example, it may contain 10 to 40 moles, but is not limited to this.

[0054] For example, the glass frit may contain 0.5 mol% to 3 mol% of tungsten (W) oxide based on the total number of moles of the glass frit, and as another example, it may contain 1 mol% to 3 mol%, but is not limited thereto.

[0055] For example, the glass frit may contain 1 to 20 mole percent of silicon (Si) oxide based on the total mole percentage of the glass frit, and as another example, it may contain 5 to 20 mole percent, but is not limited to this.

[0056] For example, the glass frit may contain 50 to 75 mole percent of lead (Pb) oxide, tellurium (Te) oxide and silicon (Si) oxide, based on the total number of moles of the glass frit, and may contain 55 to 75 mole percent, or even 60 to 75 mole percent of the total number of moles, but is not limited to these.

[0057] According to one example, the glass frit may also contain one or more elements selected from bismuth (Bi), lithium (Li), phosphorus (P), germanium (Ge), gallium (Ga), cerium (Ce), iron (Fe), zinc (Zn), magnesium (Mg), cesium (Cs), strontium (Sr), molybdenum (Mo), titanium (Ti), tin (Sn), indium (In), vanadium (V), barium (Ba), nickel (Ni), copper (Cu), sodium (Na), potassium (K), arsenic (As), cobalt (Co), zirconium (Zr), manganese (Mn), boron (B), and aluminum (Al).

[0058] For example, the glass frit may also contain 1 to 20 mole percent of bismuth (Bi) oxide, based on the total mole percentage of the glass frit. In this case, it can have the effect of reducing contact resistance and increasing bond strength. According to one example, the glass frit may contain 5 to 20 mole percent of bismuth (Bi) oxide, and according to another example, it may contain 10 to 20 mole percent, but is not limited thereto.

[0059] As another example, the glass frit may also contain 1 to 20 molar percentages of lithium (Li) oxide, based on the total molar number of the glass frit. In this case, an improvement in open-circuit voltage may be achieved. According to one example, the glass frit may contain 5 to 20 molar percentages of lithium (Li) oxide; according to another example, it may contain 5 to 15 molar percentages; and according to yet another example, it may contain 10 to 15 molar percentages, but is not limited to these.

[0060] As another example, the glass frit may also contain 0.1 mol% to 10 mol% magnesium (Mg) oxide, based on the total molar number of the glass frit. In this case, it can have the effect of improving contact resistance and increasing bond strength. According to one example, the glass frit may contain 1 mol% to 10 mol% magnesium (Mg) oxide; according to another example, it may contain 2 mol% to 10 mol%; according to yet another example, it may contain 5 mol% to 10 mol%, but is not limited thereto.

[0061] As another example, the glass frit may also contain 0.1 mol% to 10 mol% of zinc (Zn) oxide, based on the total molar number of the glass frit. In this case, it can have an effect of improving contact resistance. According to one example, the glass frit may contain 1 mol% to 10 mol% of zinc (Zn) oxide; according to another example, it may contain 2 mol% to 10 mol%; according to yet another example, it may contain 5 mol% to 10 mol%, but is not limited to these.

[0062] As another example, the glass frit may contain 0.1 to 5 mol% sodium (Na) oxide, based on the total molar number of the glass frit. In this case, improved contact resistance and fill factor (FF) can be achieved. According to one example, the glass frit may contain 0.5 to 5 mol% sodium (Na) oxide; according to another example, it may contain 1 to 5 mol%; and according to yet another example, it may contain 2 to 5 mol%, but is not limited to these.

[0063] As another example, the glass frit may contain 0.1 to 5 moles of boron (B) oxide, based on the total mole count of the glass frit. In this case, improved contact resistance and flyback effect can be achieved. According to one example, the glass frit may contain 0.5 to 5 moles of boron (B) oxide; according to another example, it may contain 1 to 5 moles; and according to yet another example, it may contain 2 to 5 moles, but is not limited thereto.

[0064] The shape and size of the glass molten ingot are not subject to special restrictions. For example, the shape of the glass molten ingot can be spherical or amorphous, and the average grain size (D) of the glass molten ingot can be... 50 The particle size can range from 0.1 μm to 10 μm. After ultrasonically dispersing the glass frit in isopropanol for 3 minutes at 25 °C, the average particle size (D) can be determined using a 1064LD model manufactured by CILAS. 50 ).

[0065] Glass frit can be obtained using conventional methods from the aforementioned elements and / or oxides of those elements. For example, the aforementioned elements and / or oxides of those elements can be mixed using a ball mill or planetary mill, and the resulting mixture can be melted and mixed at 800°C to 1300°C, quenched at 25°C, and then pulverized using a disk mill, planetary mill, or similar method.

[0066] The amount of glass frit used is not particularly limited; for example, it can be 0.1 to 20% by weight relative to the total weight of the composition for forming the selective emitter solar cell electrode. Within this range, damage caused by pn bonding can be minimized, resulting in excellent open-circuit voltage, series resistance, and / or fill factor, and thus, superior conversion efficiency. According to one example, it can be 0.5 to 10% by weight relative to the total weight of the composition for forming the selective emitter solar cell electrode; according to another example, it can be 0.1 to 5% by weight.

[0067] organic carrier

[0068] The organic carrier is mechanically mixed with the inorganic components of the composition for forming selective emitter solar cell electrodes, thereby giving the composition viscosity and rheological properties suitable for printing.

[0069] Organic carriers can typically be the same organic carriers used in compositions for forming solar cell electrodes, and may include binder resins and solvents, etc.

[0070] Acrylic or cellulose resins can be used as bonding resins. For example, ethyl cellulose can be used as a bonding resin. Other examples include ethyl hydroxyethyl cellulose, nitrocellulose, mixtures of ethyl cellulose and phenolic resins, alkyd resins, phenolic resins, acrylic resins, xylene resins, polybutene resins, polyester resins, urea resins, melamine resins, vinyl acetate resins, polymethyl acrylate resins containing rosin or ethanol, etc.

[0071] As solvents, hexane, toluene, ethyl cellosolve, cyclohexanone, butyl cellosolve, butyl carbitol (diethylene glycol monobutyl ether), dibutyl carbitol (diethylene glycol dibutyl ether), butyl carbitol acetate (diethylene glycol monobutyl ether acetate), propylene glycol monomethyl ether, hexane, terpineol, methyl ethyl ketone, benzyl alcohol, γ-butyrolactone, ethyl lactate, or 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (e.g., ester alcohol) can be used alone or in combination.

[0072] The amount of organic carrier used is not particularly limited; for example, it can be from 1 to 30% by weight relative to the total weight of the composition for forming a selective emitter solar cell electrode. Within this range, sufficient bond strength and excellent printability can be ensured. According to one example, it can be from 3 to 20% by weight relative to the total weight of the composition for forming a selective emitter solar cell electrode; according to another example, it can be from 1 to 15% by weight.

[0073] additive

[0074] In order to improve flow characteristics, process characteristics, and stability, the composition for forming selective emitter solar cell electrodes may, in addition to the above-mentioned components, individually or as needed, contain two or more dispersants, thixotropic agents, plasticizers, viscosity stabilizers, defoamers, pigments, ultraviolet stabilizers, antioxidants, coupling agents, etc. These components may comprise 0.1% to 5% by weight of the total weight of the composition for forming selective emitter solar cell electrodes, but their content may be varied as needed.

[0075] The selective emitter solar cell electrode can be prepared by coating the above-mentioned selective emitter solar cell electrode forming composition onto a highly concentrated doped portion in the selective emitter layer, drying, and firing.

[0076] The composition for forming the electrode of a selective emitter solar cell can be applied by methods such as screen printing, gravure printing, rotary screen printing, and peeling, but is not limited to these methods.

[0077] A composition for forming a selective emitter solar cell electrode can be dried, for example, at about 200°C to about 400°C for about 10 seconds to about 60 seconds, but is not limited thereto.

[0078] For example, a firing process of about 60 seconds to about 210 seconds can be performed at about 400°C to about 950°C, but it is not limited to this.

[0079] Solar cells

[0080] According to another embodiment, a solar cell including the above-described selective emitter solar cell electrode is provided.

[0081] The selective emitter solar cell described above may include: a substrate doped with a first conductivity type dopant; a selective emitter layer formed on the front of the substrate and including a high-concentration doped portion and a low-concentration doped portion doped with a second conductivity type dopant; a first electrode formed on the high-concentration doped portion; and a second electrode formed on the back of the substrate, wherein the first electrode may be the selective emitter solar cell electrode described above.

[0082] The first conductivity type and the second conductivity type can be of different types. For example, if the substrate doped with the first conductivity type dopant is n-type, then the selective emitter layer doped with the second conductivity type dopant can be p-type; if the substrate doped with the first conductivity type dopant is p-type, then the selective emitter layer doped with the second conductivity type dopant can be n-type.

[0083] According to one example, the sheet resistance of the highly doped portion in the selective emitter layer may be less than that of the less doped portion. For example, the sheet resistance of the highly doped portion may be from 50 Ω / sq. to 100 Ω / sq., and the sheet resistance of the less doped portion may be from 85 Ω / sq. to 170 Ω / sq., but is not limited thereto.

[0084] In one example, the first electrode can be the front electrode, and the second electrode can be the rear electrode. In another example, the first electrode can be the rear electrode, and the second electrode can be the front electrode.

[0085] Figure 1 The structure of a selective emitter solar cell 100 according to an example of the present invention is briefly shown.

[0086] Reference Figure 1 The selective emitter solar cell 100 may include a p-type (or n-type) substrate 11, an n-type (or p-type) selective emitter layer 12, a rear electrode 21, and a front electrode 23. The selective emitter layer 12 may include a low-concentration doped portion 12a and a high-concentration doped portion 12b.

[0087] The selective emitter solar cell 100 is prepared by, for example, printing a selective emitter solar cell electrode forming composition on the front of a highly concentrated doped portion 12b in the selective emitter layer 12, drying it at about 200°C to about 400°C for about 10 seconds to about 60 seconds, performing a preparation step for the front electrode 23, printing aluminum paste on the back of the substrate 10, drying it at about 200°C to about 400°C for about 10 seconds to about 60 seconds, performing a preparation step for the back electrode 21, and firing it at about 400°C to about 950°C for about 60 seconds to about 210 seconds.

[0088] The present invention will now be described in further detail with reference to specific embodiments. However, these are mentioned as preferred examples of the invention and should not be construed as limiting the invention to these embodiments.

[0089] Example

[0090] Example 1

[0091] At 60°C, 2 parts by weight of ethyl cellulose (STD4, Dow Chemical) as a binder resin were fully dissolved in 6.5 parts by weight of terpene alcohol (Nippon Terpine) as a solvent. Then, 90 parts by weight of spherical silver powder (AG-4-8F, Dowa Hightech) with an average particle size of 2.0 μm and 1.5 parts by weight of glass frit A (as shown in Table 1 below) with an average particle size of 2.0 μm were added. After uniform mixing, the mixture was dispersed using a 3-roll mill to prepare a composition for forming selective emitter solar cell electrodes.

[0092] On one side of a p-type semiconductor substrate, a 5 μm thick poly(p-380) mesh containing a doping paste (Honeywell) containing group 5 element P was first doped to form an electrode pattern. The substrate was then heat-treated at 300°C for 5 minutes and dried. A second doping was performed on the substrate in an 850°C diffusion furnace by injecting POCl3 gas, thus fabricating a selective emitter layer. After the second doping, the phospherosilicon glass (PSG) on the substrate surface was removed using HF. SiN was then coated onto the surface using PECVD to form an anti-reflection film. Next, aluminum paste was printed onto the back of the substrate, and the substrate was dried at 300°C for 30 seconds to form the back electrode. The selective emitter solar cell electrode forming composition was then printed in an array onto the electrode pattern using a Baccini printer, and finally dried at 300°C for 30 seconds to form the front electrode. Solar cells were prepared by firing the cells formed through the above process at a temperature between 640°C and 700°C for 45 seconds using a belt furnace.

[0093] Examples 2 to 8 and Comparative Examples 1 to 4

[0094] When preparing the composition for forming the electrode of a selective emitter solar cell, glass frits B to L as described in Table 1 were used instead of glass frit A. Otherwise, the solar cell was prepared by the same method as in Example 1.

[0095] Table 1

[0096] (Unit: mole percentage)

[0097]

[0098] Evaluation example: Evaluation of electrical characteristics

[0099] The open-circuit voltage (Voc, mV), series resistance (Rs, Ω), fill factor (FF, %), and conversion efficiency (Eff., %) of the solar cells prepared in Examples 1 to 8 and Comparative Examples 1 and 4 were measured using a solar cell efficiency measurement device (Halm, Fortix Tech). The leakage current (Jo2, nA / cm²) was measured using a Suns-Voc device (Sinton). 2 As an indicator of the predictive mobility and diffusion rate of metal ions within a wafer, the results are shown in Table 2 below. A lower Jo2 value indicates lower mobility and diffusion rate of the metal ions.

[0100] Table 2

[0101] Example 1 Glass frit A 0.6806 0.00308 78.58 21.71 7.41 Example 2 Glass frit B 0.6796 0.00303 78.68 21.75 6.81 Example 3 Glass frit C 0.6806 0.00312 78.43 21.68 7.82 Example 4 Glass frit D 0.6760 0.00297 78.73 21.61 6.26 Example 5 Glass frit E 0.6809 0.0028 78.72 21.69 7.83 Example 6 Glass frit F 0.0682 0.00287 78.83 21.76 7.85 Example 7 Glass frit G 0.0680 0.00274 78.70 21.65 7.88 Example 8 Glass frit H 0.0681 0.00272 78.80 21.72 7.55 Comparative Example 1 Glass frit I 0.6772 0.00315 78.40 21.51 8.03 Comparative Example 2 Glass frit J 0.6775 0.00320 78.23 21.52 8.56 Comparative Example 3 Glass frit K 0.6770 0.00307 78.48 21.57 8.35 Comparative Example 4 Glass frit L 0.6755 0.00299 78.51 21.54 8.74

[0102] Table 2 above confirms that the selective emitter solar cells of Examples 1 to 8, which have electrodes including the glass frit of the present invention, have excellent open-circuit voltage, series resistance, and / or fill factor compared to Comparative Examples 1 to 4, which do not have this feature. This indicates excellent conversion efficiency, low Jo2, and minimal damage caused by pn junctions.

[0103] Those skilled in the art can readily implement simple variations or modifications of the present invention, and such variations or modifications can be considered to be included within the scope of the present invention.

Claims

1. A selective emitter solar cell electrode, characterized in that, It contains conductive powder and glass frit. The above-mentioned glass frit is composed of the following components: Lead (Pb) oxides ranging from 15 mol percent to 40 mol percent; Tellurium (Te) oxides ranging from 0.1 mol% to 40 mol%; 0.1 mol percent to 3 mol percent of tungsten (W) oxide; Silicon (Si) oxides with a molar percentage greater than or equal to 0.1 and less than 25; Bismuth (Bi) oxides ranging from 1 mol percent to 20 mol percent; Lithium (Li) oxides ranging from 1 mol% to 20 mol%; Zinc (Zn) oxides ranging from 0.1 mol% to 10 mol%; The total molar percentage of lead (Pb) oxide, tellurium (Te) oxide, and silicon (Si) oxide is less than 75 mol%.

2. A selective emitter solar cell electrode, characterized in that, It contains conductive powder and glass frit. The above-mentioned glass frit is composed of the following components: Lead (Pb) oxides ranging from 15 mol percent to 40 mol percent; Tellurium (Te) oxides ranging from 0.1 mol% to 40 mol%; 0.1 mol percent to 3 mol percent of tungsten (W) oxide; Silicon (Si) oxides with a molar percentage greater than or equal to 0.1 and less than 25; Bismuth (Bi) oxides ranging from 1 mol percent to 20 mol percent; Lithium (Li) oxides ranging from 1 mol% to 20 mol%; Zinc (Zn) oxides ranging from 0.1 mol% to 10 mol%; The total molar percentage of lead (Pb) oxide, tellurium (Te) oxide, and silicon (Si) oxide is less than 75 mol%. And magnesium (Mg) oxides ranging from 0.1 mol% to 10 mol%; or Sodium (Na) oxides ranging from 0.1 mol% to 5 mol%; or Sodium (Na) oxides from 0.1 mol percent to 5 mol percent and boron (B) oxides from 0.1 mol percent to 5 mol percent.

3. The selective emitter solar cell electrode according to claim 1 or 2, characterized in that, The electrode is formed from a composition comprising the conductive powder, the glass frit, and the organic carrier.

4. The selective emitter solar cell electrode according to claim 3, characterized in that, The above composition comprises: The above-mentioned conductive powder comprises 60 to 95% by weight; 0.1% to 20% by weight of the above-mentioned glass frit; and The above-mentioned organic carriers are used in amounts ranging from 1 to 30% by weight.

5. The selective emitter solar cell electrode according to claim 3, characterized in that, The above composition also includes one or more of the following: dispersant, thixotropic agent, plasticizer, viscosity stabilizer, defoamer, pigment, ultraviolet stabilizer, antioxidant, and coupling agent.

6. A selective emitter solar cell, characterized in that, include: The substrate is doped with a first conductivity type dopant; A selective emitter layer is formed on the front of the substrate and includes a high-concentration doped portion and a low-concentration doped portion doped with a second conductivity type dopant. The first electrode is formed on the aforementioned highly concentrated doped portion; and The second electrode is formed on the back of the aforementioned substrate. The first electrode described above is the electrode as described in claim 1 or 2.

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