KR20150132804A - Composition for forming solar cell electrode and electrode prepared using the same - Google Patents

Abstract

Embodiments of the present invention relate to a composition for forming a solar cell electrode and a solar cell electrode produced from the same. The composition for forming a solar cell electrode includes silver (Ag) powder, glass frit, and an organic vehicle. The glass frit includes at least one element selected from the group consisting of silver (Ag), tellurium (Te), lithium (Li), sodium (Na), and potassium (K). A mole ratio of Ag : Te included in the glass frit is 1 : 0.1-50. A mole ratio of Ag : Li, Na, or K is 1 : 0.01-10. The solar cell electrode produced by using the composition has minimized contact resistance (Rc) and series resistance (Rs) and thus has an excellent fill factor and excellent conversion efficiency.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for forming a solar cell electrode, and an electrode made therefrom. BACKGROUND ART [0002]

The present invention relates to a composition for forming a solar cell electrode and an electrode made therefrom.

Solar cells convert photons of sunlight into electrical energy using the photoelectric effect of PN junctions. The solar cell may be, for example, a structure in which a front electrode and a rear electrode are formed on the surface of a semiconductor wafer or substrate on which a PN junction is formed. In the solar cell having such a structure, the photoelectric effect is induced in the PN junction by the sunlight incident on the semiconductor wafer, and the electrons generated from the PN junction flow to the outside through the electrode.

An electrode of a solar cell can be formed by applying a composition for forming a solar cell electrode to a wafer or a substrate, and patterning and firing the same.

In recent years, in order to increase the efficiency of the solar cell, it is required that the thickness of the emitter included in the electrode is thinned. However, if the thickness of the emitter is reduced, it may cause a shunting phenomenon that may degrade the performance of the solar cell. In addition, the area of the solar cell is becoming wider to improve the photoelectric conversion efficiency. However, in this case, the contact resistance of the solar cell is increased and the efficiency of the solar cell can be reduced.

Therefore, it is urgently required to develop a composition for forming a solar cell electrode capable of improving the contact property with a wafer, making the emitter thin, and minimizing the contact resistance (Rc) and the series resistance (Rs) have.

It is an object of the present invention to provide a composition for forming a solar cell electrode that is excellent in contact properties between an electrode and a wafer surface.

Another object of the present invention is to provide a composition for forming a solar cell electrode capable of minimizing contact resistance and series resistance.

It is another object of the present invention to provide a solar cell electrode having excellent fill factor and conversion efficiency.

It is another object of the present invention to provide an electrode made of the composition.

The above and other objects of the present invention can be achieved by the present invention described below.

An embodiment of the present invention includes a silver frit containing a silver (Ag) element, a tellurium (Te) element and a periodic table 1A group element, wherein the silver The Group 1A element of the periodic table includes at least one element selected from the group consisting of lithium (Li), sodium (Na), and potassium (K); Wherein the molar ratio of the silver (Ag) to tellurium (Te) element contained in the glass frit is 1: 0.1 to 1:50, and the lithium (Li), sodium (Na ) Or potassium (K) is in a molar ratio of 1: 0.01 to 1:10.

The glass frit may be a glass frit containing at least one element selected from the group consisting of Pb, Bi, P, Ge, Ga, Ce, (Ti) element, a tin (Sn) element, a tin (W) element, a magnesium element, a cesium element, a strontium element, a molybdenum element, A metal element such as indium (In), vanadium (V), ruthenium, barium, nickel, copper, arsenic, cobalt, The second metal element may further include at least one second metal element selected from the group consisting of a Zr element, a Mn element, a Neod element, a Cr element, an Sb element, and an Al element. have.

The glass frit may contain 0.1 mol% to 65 mol% of silver (Ag) element relative to the total molar amount of the glass frit.

The silver (Ag) element contained in the glass frit may be formed from a silver compound having an ion decomposition temperature of 1100 ° C or lower.

The silver compound may include at least one member selected from the group consisting of silver cyanide, silver nitrate, silver halide, silver carbonate, silver acetate, silver sulfate and silver oxide.

The glass frit may be a silver compound; Tellurium oxide; And a compound containing at least one element of the periodic table 1A group selected from the group consisting of lithium (Li), sodium (Na), and potassium (K).

Wherein the metal precursor is selected from the group consisting of Pb, Bi, P, Ge, Ga, Ce, (Ti) oxide, tin (Sn) oxide, tin (W) oxide, magnesium (Mg) oxide, cesium (Cs) oxide, strontium (Sr) oxide, molybdenum A metal oxide such as indium oxide, vanadium oxide, ruthenium oxide, barium oxide, nickel oxide, copper oxide, arsenic oxide, cobalt oxide, zirconium oxide, (Zr) oxide, manganese (Mn) oxide, neodymium (Nd) oxide, chromium (Cr) oxide, antimony (Sb) oxide and aluminum have.

The metal precursor may comprise from 1 wt% to 45 wt% of silver compounds, from 20 wt% to 75 wt% of tellurium oxide, and from 1 wt% to 35 wt% of a compound comprising Group 1A elements.

The metal precursor may include 1 wt% to 40 wt% of the second metal oxide.

Another embodiment of the present invention is a powder composition comprising 60% to 95% by weight of said silver powder; 0.1% to 20% by weight of said glass frit; And 1% by weight to 30% by weight of the organic vehicle.

The glass frit may have an average particle diameter (D50) of 0.1 占 퐉 to 10 占 퐉.

The composition for forming a solar cell electrode may further include at least one of a dispersing agent, a thixotropic agent, a plasticizer, a viscosity stabilizer, a defoamer, a pigment, a UV stabilizer, an antioxidant and a coupling agent.

Another embodiment of the present invention relates to a solar cell electrode made of a composition for forming a solar cell electrode.

The composition for forming a solar cell electrode of the present invention improves the contact property between the electrode and the wafer by introducing a silver compound having an ion decomposition temperature of 1100 DEG C or lower into a glass frit.

In addition, the contact resistance (Rc) and the series resistance (Rs) of the solar cell electrode made of the composition are minimized, and the fill factor and conversion efficiency are excellent.

1 is a schematic view briefly showing a structure of a solar cell according to an embodiment of the present invention.

Composition for forming solar cell electrode

One embodiment of the present invention relates to a composition for forming a solar cell electrode (hereinafter sometimes referred to simply as " composition "). The composition for forming a solar cell electrode in one embodiment includes silver (Ag) powder, glass frit, and organic vehicle. The glass frit may include a silver (Ag) element; Tellurium (Te) element; And Periodic Table 1A Group Elements. At this time, the Group 1A element of the periodic table includes at least one element selected from the group consisting of lithium (Li), sodium (Na), and potassium (K); . Wherein the molar ratio of silver (Ag): tellurium element (Te) contained in the glass frit is 1: 0.1 to 1:50 and silver element (Ag): lithium element (Li), sodium element (Na) (K) is from 1: 0.01 to 1:10.

In the present specification, the molar ratio means a molar ratio of each metal element to an atom. Hereinafter, the present invention will be described in detail.

(A) is powder

The composition for forming a solar cell electrode of the present invention uses silver (Ag) powder as the conductive powder. The silver powder may be a powder having a nano-sized or micro-sized particle diameter. For example, the silver powder may be a silver powder in the size of tens to hundreds of nanometers or a silver powder in the range of several to several tens of micrometers. Two or more kinds of silver powders having different sizes may be mixed and used.

The particle shape of the silver powder may be, for example, spherical, plate-like, amorphous, and the like.

The silver powder may have an average particle diameter (D50) of, for example, 0.1 탆 to 10 탆 or 0.5 탆 to 5 탆. Within this range, the contact resistance and line resistance can be lowered.

The average particle size was measured using a particle size analyzer 1064LD model manufactured by CILAS after dispersing the conductive powder in isopropyl alcohol (IPA) by ultrasonication at 25 캜 for 3 minutes.

Silver powder may be contained in an amount of 60% by weight to 95% by weight based on the total weight of the composition for forming a solar cell electrode. Within the above range, it is possible to realize an effect of improving conversion efficiency and an effect of making paste. More specifically, the silver powder may be contained in an amount of 70% by weight to 90% by weight based on the total weight of the composition for forming a solar cell electrode.

(B) glass frit

The glass frit can lower the resistance by forming silver crystal grains in the emitter region by etching the antireflection film during the baking process of the composition for forming the solar cell electrode. In addition, glass frit improves the adhesion between the conductive powder and the wafer and softens at the time of sintering to induce an effect of further lowering the firing temperature.

Increasing the area of the solar cell can increase the contact resistance of the solar cell. Therefore, the damage to the pn junction due to the increase of the area of the solar cell must be minimized, and the series resistance must be minimized. In addition, it is required that the vitreous frit be sufficiently secured in thermal stability even at a wide range of firing temperatures.

The glass frit of the present invention is a silver (Ag) compound; Tellurium (Te) oxide; And a metal precursor comprising a compound comprising a Group 3A element of the Periodic Table of Elements.

At this time, the compound containing the Group IA element in the periodic table may be a lithium (Li) compound, a sodium (Na) compound, a potassium (K) compound or a mixture thereof.

For example, the glass frit of one embodiment comprises a silver (Ag) compound; Tellurium (Te) oxide; And lithium (Li) compounds, sodium (Na) compounds, potassium (K) compounds, or mixtures thereof; And then melting and pulverizing the metal precursor. Thus, the glass frit of one embodiment includes a silver (Ag) element; Tellurium (Te) element; And at least one element of the periodic table 1A group selected from the group consisting of lithium (Li) element, sodium (Na) element and potassium (K) element.

The silver (Ag) compound may be decomposed into silver (Ag) ions at a temperature of 1100 ° C or less. When a silver compound having a decomposition temperature in the above range is used, contact between the electrode and the wafer can be improved.

Specifically, the silver compound is an ion-binding compound such as silver cyanide (AgCN), silver nitrate (AgNO ₃ ), silver halide (Ag-X), silver carbonate (Ag ₂ CO ₃ ), silver acetate (AgC ₂ H ₃ O ₂ ) , Silver sulfate (Ag ₂ SO ₄ ) and silver oxide (Ag ₂ O) may be used singly or in combination. In the silver halide (Ag-X), X may be iodine, fluorine, chlorine or bromine.

The silver element present in the glass frit derived from the silver compound described above can control the conductivity of the glass at the interface of the electrode formed in the order of silver-glass-wafer. Further, the silver element derived from the silver compound is excellent in the effect of filling the isolated pore or void formed on the glass frit. In this case, the glass frit can reduce the contact resistance and series resistance between the wafer and the electrode.

The solar cell electrode made of the glass frit of the present invention can further precipitate silver crystals on the glass frit after firing. At this time, the silver crystals precipitated further mean silver crystals other than Ag crystalline formed by the conductive powder after firing. Further, the silver element present in the glass frit derived from the above-mentioned silver compound imparts conductivity to the glass between the interfaces of the electrodes formed in the order of silver-glass-wafer, Or an isolated pore or void formed in the substrate. In this case, the glass to which conductivity is imparted acts as an insulator between the silver crystal and the wafer. In this case, the silver element present in the glass frit can reduce the contact resistance and series resistance of the wafer-silver electrode.

The tellurium oxide may be, for example, tellurium monoxide, tellurium dioxide, tellurium trioxide, and the like.

The lithium compound may be, for example, lithium carbonate, but lithium cyanide, nitrate, halogen salt, acetate, sulfate, lithium oxide, or the like may be used.

The sodium compound may be, for example, sodium carbonate, but a cyanide salt, a nitrate salt, a halogen salt, a nitrate salt, a sulfate salt, a sodium oxide or the like of sodium may be used.

The potassium compound may be, for example, potassium carbonate, but a cyanide salt, a nitrate salt, a halogen salt, a nitrate salt, a sulfate salt, a potassium oxide, or the like of potassium may be used.

In one embodiment, the metal precursor may comprise from 1 wt% to 45 wt% of silver compounds, from 20 wt% to 75 wt% of tellurium oxide, and from 1 wt% to 35 wt% of a compound comprising Group 3A elements .

The molar ratio of the silver element: tellurium element (Ag: Te) present in the glass frit of one embodiment may be from 1: 0.1 to 1:50, for example from 1: 0.5 to 1:40. When the molar ratio of Ag: Te exceeds 1: 50 and Te is contained in an excess amount (when the molar ratio of Te exceeds 50 times of Ag), the effect of Ag is small and the effect of Ag is small. When the molar ratio of Ag: Te is more than 1: 0.1 and Ag is contained in an excess amount (when the molar ratio of Te is less than 0.1 times of Ag), the inherent properties of glass may be deteriorated.

The molar ratio (Ag: Li, Ag: Na or Ag: K) of the silver element, the lithium element, the sodium element or the potassium element present in the glass frit is 1: 0.01 to 1: 10, for example from 1: 0.01 to 1: 5. When the molar ratio of Li, Na or K to Ag is more than 1:10 (the molar ratio of Li, Na or K is more than 10 times of Ag), the content of silver (Ag) The effect is negligible. In addition, lithium (Li), sodium (Na), or potassium (K) may penetrate into the wafer and lower the open-circuit voltage (Voc). Further, when the molar ratio of Ag to Li, Na or K is more than 1: 0.01 and the amount of silver (Ag) is excessive (the molar ratio of Li, Na or K is less than 0.01 times of Ag) .

The glass frit may be a glass frit containing at least one element selected from the group consisting of Pb, Bi, P, Ge, Ga, Ce, (Ti) element, a tin (Sn) element, a tin (W) element, a magnesium element, a cesium element, a strontium element, a molybdenum element, A metal element such as indium (In), vanadium (V), ruthenium, barium, nickel, copper, arsenic, cobalt, Further includes at least one second metal element selected from the group consisting of elements of Zr, Mn, neodymium, chromium, antimony, and aluminum . In this specification, any one of the above-mentioned metal elements is referred to as a second metal element in order to distinguish it from the above-mentioned silver element, tellurium element, periodic table 1A group element and the like.

At this time, the glass frit may contain the silver (Ag) compound described above; Tellurium (Te) oxide; And Periodic Table 1A Group Elements; (P) oxide, bismuth (Bi) oxide, phosphorus (P) oxide, germanium (Ge) oxide, gallium (Ga) oxide, cerium (Ce) oxide, iron (Fe) oxide, Zinc oxide, tungsten oxide, magnesium oxide, cesium oxide, strontium oxide, molybdenum oxide, titanium oxide, tin oxide, indium oxide, (Zr), zirconium (Zr), zirconium (Zr), zirconium (Zr), tin oxide Further comprises at least one second metal oxide selected from the group consisting of oxides, manganese (Mn) oxides, neodymium (Nd) oxides, chromium (Cr) oxides, antimony (Sb) oxides and aluminum .

The metal precursor may further comprise, for example, from 1 wt% to 40 wt% of the second metal oxide.

In one embodiment, the metal precursor comprises 1 to 30% by weight of a silver compound, 20 to 70% by weight of tellurium oxide, 1 to 20% by weight of a compound containing a Group 1A element and 5 to 40% by weight of bismuth oxide %. ≪ / RTI >

Other Embodiments The metal precursor may comprise from 1 to 30% by weight of silver compounds, from 20 to 70% by weight of tellurium oxide, from 1 to 20% by weight of compounds containing Group 1A elements and from 10 to 40% .

In another embodiment, the metal precursor comprises 1 to 30% by weight of silver compound, 20 to 70% by weight of tellurium oxide, 1 to 20% by weight of compound containing Group 1A element and 1 to 10% by weight of neodymium oxide can do.

The glass frit may contain from 0.1 mol% to 65 mol%, for example, from 1 mol% to 50 mol%, of the silver (Ag) component relative to the total molar amount of the glass frit. Within this range, it is possible to maintain excellent properties as an insulator of the glass frit, while improving the conductivity of the electrode. In the specific example, the silver (Ag) component of the total molar amount of the glass frit is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 mol%.

In the present specification, the content of each metal component contained in the glass frit is measured by an inductively coupled plasma-atomic emission spectroscopy (ICP-OES: Inductively Coupled Plasma-Optical Emission Spectrometer). The inductively coupled plasma-atomic emission spectrometry (ICP-OES) uses a very small amount of sample, which can shorten sample preparation time. In addition, ICP-OES can reduce errors through sample preprocessing and has an advantage of excellent analytical sensitivity.

Specifically, the ICP-OES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) method comprises steps of: pre-treating a sample, preparing a standard solution, measuring and converting an element concentration of a metal component to be measured, And calculating the element content of the component. In this case, the content of each metal component contained in the glass frit can be precisely measured.

In the step of pretreating the sample, the sample may be carbonized by dissolving an appropriate amount of the sample using an acidic solution capable of dissolving the metal component to be analyzed of the glass frit as a sample and heating the mixture. As the acidic solution, for example, a sulfuric acid (H ₂ SO ₄ ) solution or the like may be used.

The carbonized sample can be appropriately diluted to a range of analytical concentration of the metal component to be analyzed with a solvent such as distilled water and hydrogen peroxide (H ₂ O ₂ ). The above analytical concentration range can be used diluted to 10,000 times in consideration of the element detection capability of the applied ICP-OES instrument.

The preprocessed sample can be calibrated with a standard solution, for example, a standard solution of a metal component to be analyzed for elemental measurement when measured with an ICP-OES instrument.

As an example, the standard solution is introduced into an ICP-OES measuring instrument and a calibration curve is created by an external standard method. Then, the content (ppm) of the analyte metal component of the sample pretreated with the ICP-OES measuring instrument is measured and then converted to calculate the content and the molar ratio of each metal component in the glass frit.

In the solar cell electrode made of the glass frit of the present invention, silver crystals can be precipitated not only on the Ag crystalline formed by the conductive powder after firing but also on the glass frit.

The glass frit may have an average particle diameter (D50) of 0.1 占 퐉 to 10 占 퐉. The shape of the glass frit may be spherical or irregular. Within the above range, the effect of improving the conductivity of the electrode and the effect of reducing the contact resistance are excellent.

The content of the glass frit may be, for example, 0.1% by weight to 20% by weight or 0.5% by weight to 10% by weight based on the total weight of the composition for forming a solar cell electrode. Within the above range, the PN junction stability can be secured even under a wide range of sheet resistance conditions. Also, within the above range, the series resistance value of the solar cell can be minimized, and the efficiency of the solar cell can be improved.

The glass frit can be prepared as described above using conventional methods. For example, the silver (Ag) compound; Tellurium (Te) oxide; And lithium (Li) compounds, sodium (Na) compounds, potassium (K) compounds, or mixtures thereof; Are mixed in a predetermined composition to prepare a metal precursor. The blend can be mixed using a ball mill or a planetary mill. The prepared metal precursor is melted at a temperature of 800 to 1300 占 폚 and quenched at 25 占 폚. The resulting product is pulverized by a disk mill, a planetary mill or the like to obtain a glass frit.

(C) Organic vehicle

The organic vehicle is mechanically mixed with the inorganic component of the composition for forming a solar cell electrode to give the composition suitable viscosity and rheological properties for printing.

The organic vehicle may be an organic vehicle ordinarily used in a composition for forming a solar cell electrode. In addition, the organic vehicle may generally contain a binder resin, a solvent, and the like.

As the binder resin, an acrylate-based or cellulose-based resin can be used, and ethylcellulose is generally used. However, it is preferable to use a mixture of ethylhydroxyethylcellulose, nitrocellulose, a mixture of ethylcellulose and phenol resin, an alkyd resin, a phenol resin, an acrylic ester resin, a xylene resin, a polybutene resin, a polyester resin, Based resin, a rosin of wood, or a polymethacrylate of alcohol may be used.

Examples of the solvent include 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, hexylene glycol, terpineol, methyl ethyl ketone, benzyl alcohol, gamma butyrolactone or ethyl lactate alone Or two or more of them may be used in combination.

The organic vehicle may be contained in an amount of 1 to 30% by weight based on the total weight of the composition for forming a solar cell electrode. Within this range, sufficient adhesive strength and excellent printability can be ensured.

(D) Additive

The composition for forming a solar cell electrode of the present invention may further contain usual additives as required. The additive may be used alone or as a mixture of two or more of a dispersing agent, a thixotropic agent, a plasticizer, a viscosity stabilizer, a defoaming agent, a pigment, an ultraviolet stabilizer, an antioxidant and a coupling agent. In this case, it is possible to further improve the flow characteristics, process characteristics and stability of the composition for forming a solar cell electrode. The additive may be contained in an amount of 0.1% by weight to 5% by weight based on the total weight of the composition for forming a solar cell electrode, but the content may be changed if necessary.

Solar cell electrode and solar cell comprising same

Another aspect of the present invention relates to an electrode formed from the composition for forming a solar cell electrode and a solar cell including the same.

1 shows a structure of a solar cell according to an embodiment of the present invention.

Referring to Fig. 1, a wafer 100 or a substrate 100 includes a p-layer (or n-layer) 101 and an n-layer (or p-layer) 102 as an emitter. The rear electrode 210 and the front electrode 230 may be formed on the wafer 100 or the substrate 100 by printing and firing the composition for electrode formation.

For example, the electrode forming composition may be applied to the backside of the wafer by printing, followed by drying at a temperature of about 200 캜 to 400 캜 for about 10 seconds to about 60 seconds to perform a preliminary preparation step for the rear electrode. In addition, a preparation step for the front electrode can be performed by printing a composition for electrode formation on the entire surface of the wafer and then drying it. Thereafter, the front electrode and the rear electrode can be formed by baking the wafer or the substrate coated with the electrode forming composition at 400 ° C to 950 ° C or 750 ° C to 950 ° C for 30 seconds to 180 seconds.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Examples 1 to 50 and Comparative Examples 1 to 4

Example 1

3.0 wt% of ethyl cellulose (STD4) as an organic binder was sufficiently dissolved in 6.5 wt% of butyl carbitol as a solvent at 60 캜, and spherical silver powder (Dowa High Tech CO. Ltd., AG-4-8), 3.1% by weight of glass frit prepared by using the silver carbonate (Ag ₂ CO ₃ , manufactured by Acros) as a silver compound and having the composition shown in the following Table 1, BYK 102 (BYK- chemie) and 0.3 wt% thixotropy ST (Elementis co.) were added, mixed and dispersed by a 3 roll kneader to prepare a composition for forming a solar cell electrode.

Examples 2 to 9

A composition for forming a solar cell electrode was prepared in the same manner as in Example 1, except that the glass frit prepared in the composition shown in the following Table 1 was used.

Examples 10 to 15

A composition for forming a solar cell electrode was prepared in the same manner as in Example 1, except that silver iodide (AgI, Sigma-Aldrich) was used as a silver compound and glass frit prepared in the following Table 2 was used.

Examples 16 to 24

A composition for forming a solar cell electrode was prepared in the same manner as in Example 1, except that silver nitrate (AgNO ₃ , Daejung Co.) was used as a silver compound and glass frit prepared in the following Table 3 was used.

Examples 25 to 33

A composition for forming a solar cell electrode was prepared in the same manner as in Example 1, except that silver oxide (Ag ₂ O, Acros) was used as the silver compound and glass frit prepared in the composition shown in the following Table 4 was used.

Comparative Examples 1 to 2

A composition for forming a solar cell electrode was prepared in the same manner as in Example 1, except that the glass frit prepared in the composition shown in the following Table 5 was used.

Measurement of molar ratio of Ag: Te, Ag: Li, Ag: Na and Ag: K in glass frit using inductively coupled plasma-atomic emission spectrometry (ICP-OES)

Pretreatment of samples: 0.5 g of glass frit as a sample to be analyzed is weighed accurately into 0.0001 g unit. 5 ml of sulfuric acid (H ₂ SO ₄ ) was added to the beaker containing the sample and heated at 220 ° C. for 3 hours using a hot plate to fully carbonize the sample. Hydrogen peroxide (H ₂ O ₂ ) was added to complete the pretreatment until the beaker containing the carbonized sample became transparent.

Preparation of Standard Solution: A standard solution of the metal component to be analyzed was prepared.

Measurement of molar ratio of metal components: HNO 3 was added to the beaker containing the pretreated sample, and the mixture was heated for 5 minutes and then air-cooled. The prepared standard solution was introduced into an ICP-OES measuring instrument (PerkinElmer) and a calibration curve was prepared by an external standard method. Then, the ICP-OES measuring instrument was used to measure the concentration of silver (Ag (Ag): Te, Ag: Li, Ag: Na, and Na in the glass frit were measured after measuring the concentrations (ppm) of the elements of the tellurium (Ta), lithium (Li), sodium The mole ratio of Ag: K was calculated. The results are shown in Table 6 below.

The content of each metal component (%) = the element concentration of each metal component (ppm) x Dilution Factor (DF) / 10000

Mole of each metal component = content of each metal component / molecular weight of each metal component

Mole% of each metal component = mole of each metal component / mole sum of all metal components

Composition of glass frit (unit: wt%) room
city
Yes Ag ₂ CO ₃ PbO Bi ₂ O ₃ TeO ₂ P ₂ O ₅ Li ₂ CO ₃ Na ₂ CO ₃ K ₂ CO ₃ SiO ₂ ZnO WO ₃ Nd ₂ O ₃ MgO SnO SrO Sb ₂ O ₃ Cr ₂ O ₃ One 5 - 30 42 - - 12 - - 5 3 - - - 3 - - 2 10 - 30 42 - - 5 - - 10 3 - - - - - - 3 30 - 20 32 - 5 One 3 - 2 - 3 4 - - - - 4 5 32 - 48 - - 10 - 2 3 - - - - - - 5 10 - 10 67 - - 5 - 3 5 - - - - - - 6 27 20 - 40 - - 2 - 5 3 - - - - - - 3 7 7 - 14 47 3 3 8 - 3 5 - 2 5 3 8 14 - 27 42 - - 9 - 3 - 3 2 - - - - 9 25 - 20 37 - - 11 - 7 - - - - - - - -

Composition of glass frit (unit: wt%) room
city
Yes Agi PbO Bi ₂ O ₃ TeO ₂ P ₂ O ₅ Li ₂ CO ₃ Na ₂ CO ₃ K ₂ CO ₃ SiO ₂ ZnO WO ₃ Nd ₂ O ₃ MgO SnO SrO Sb ₂ O ₃ Cr ₂ O ₃ 10 3 35 - 41 - 3 - 13 3 - 2 - - - - - 11 13 35 - 33 - 2 - 7 3 2 - 3 2 - - - - 12 22 20 - 29 - 3 - 3 8 5 - 3 3 4 - - - 13 4 13 - 62 - 2 One 2 - 3 - 6 - 3 2 - 2 14 21 - 5 45 2 2 - 4 3 5 - 3 2 8 - - - 15 29 13 - 39 - 2 - 2 8 5 - 2 - - - - -

Composition of glass frit (unit: wt%) room
city
Yes AgNO ₃ PbO Bi ₂ O ₃ TeO ₂ P ₂ O ₅ Li ₂ CO ₃ Na ₂ CO ₃ K ₂ CO ₃ SiO ₂ ZnO WO ₃ Nd ₂ O ₃ MgO SnO SrO Sb ₂ O ₃ Cr ₂ O ₃ 16 5 38 - 40 - 12 - - 2 3 - - - - - - - 17 15 - 21 49 - 10 - - - 2 3 - - - - - - 18 30 - 12 48 - One - - 5 4 - - - - - - - 19 3 - 36 42 - 9 - - 2 5 - - 3 - - - - 20 16 - 21 42 - 11 - - 2 3 3 - - 2 - - - 21 28 - 18 32 - 6 - - 8 5 - 3 - - - - - 22 4 17 7 53 - 13 - - - 3 - - - 3 - - - 23 16 19 - 45 - 7 3 - - - 3 - 2 - 5 - - 24 31 16 - 41 - 9 - - - 3 - - - - - - -

Composition of glass frit (unit: wt%) room
city
Yes Ag ₂ O PbO Bi ₂ O ₃ TeO ₂ P ₂ O ₅ Li ₂ CO ₃ Na ₂ CO ₃ K ₂ CO ₃ SiO ₂ ZnO WO ₃ Nd ₂ O ₃ MgO SnO SrO Sb ₂ O ₃ Cr ₂ O ₃ 25 4 8 30 43 - 7 - 2 - - - 2 3 One - - - 26 8 3 35 36 - 5 - - 3 - - 3 5 - - - 2 27 11 14 17 29 - 3 - - 8 13 - - 3 2 - - - 28 2 5 5 61 - 14 - - 3 4 2 - 4 - - - - 29 5 32 13 37 - 8 - - - - - - - 5 - - - 30 10 30 12 21 2 6 3 - - 5 - 2 3 3 - - 3 31 5 2 35 47 - 5 - - - - 3 - - - 3 - - 32 7 7 35 39 - 7 - - - - 3 2 - - - - - 33 12 22 13 34 - 3 - - 8 5 - 3 - - - - -

Composition of glass frit (unit: wt%) ratio
School
Yes Agi PbO Bi ₂ O ₃ TeO ₂ P ₂ O ₅ Li ₂ CO ₃ Na ₂ CO ₃ K ₂ CO ₃ SiO ₂ ZnO WO ₃ Nd ₂ O ₃ MgO SnO SrO Sb ₂ O ₃ Cr ₂ O ₃ One - - 36 51 - 7 - - 4 - - 2 - - - - - 2 10 - 19 54 - - - - - 7 - 5 3 2 - - -

Mole ratio Te / Ag Li / Ag Na / Ag K / Ag Example 1 7.25 - 6.25 - Example 2 3.62 - 1.30 - Example 3 0.92 0.62 0.09 0.20 Example 4 8.28 - 5.21 - Example 5 5.78 - 1.30 - Example 6 1.28 - 0.19 - Example 7 5.79 1.60 2.98 - Example 8 2.59 - 1.67 - Example 9 1.28 - 1.15 - Example 10 20.07 6.35 - 14.55 Example 11 3.73 0.98 - 1.81 Example 12 1.94 0.87 - 0.46 Example 13 22.77 3.18 1.11 1.68 Example 14 3.15 0.60 - 0.64 Example 15 1.98 0.44 - 0.23 Example 16 8.50 11.03 - - Example 17 3.47 3.06 - - Example 18 1.70 0.15 - - Example 19 14.88 13.78 - - Example 20 2.79 3.16 - - Example 21 1.21 0.98 - - Example 22 14.08 14.93 - - Example 23 2.99 2.01 0.60 - Example 24 1.41 1.33 - - Example 25 7.79 5.49 - 0.83 Example 26 3.26 1.96 - - Example 27 1.91 0.86 - - Example 28 22.11 21.95 - - Example 29 5.37 5.02 - - Example 30 1.52 1.88 0.66 - Example 31 6.82 3.14 - - Example 32 4.04 3.14 - - Example 33 2.05 0.78 - - Comparative Example 1 - - - - Comparative Example 2 7.93 - - -

How to measure Fill Factor and Efficiency

The composition for forming a solar cell electrode according to the above-described Examples and Comparative Examples was screen-printed on a crystal mono wafer in a predetermined pattern, and dried using an infrared drying furnace. Thereafter, aluminum paste was printed on the rear side of the wafer and then dried in the same manner. The cells thus formed were fired at 700 ° C. to 950 ° C. for 30 seconds to 210 seconds using a belt-type sintering furnace. The thus-prepared cells were measured using a solar cell efficiency measuring apparatus (Pasan, CT-801) The series resistance (Rs), fill factor (FF,%) and conversion efficiency (%) of the solar cells of the solar cell were measured and shown in Tables 7 and 8, respectively.

Series resistance
(Rs, m?) Fill Factor (FF,%) Conversion efficiency
(%) Example 1 2.579 78.820 17.752 Example 2 2.430 79.203 17.882 Example 3 2.244 79.555 17.971 Example 4 2.606 78.731 17.748 Example 5 2.429 79.212 17.883 Example 6 2.237 79.587 17.974 Example 7 2.547 78.905 17.817 Example 8 2.352 79.262 17.902 Example 9 2.253 79.528 17.963 Example 10 2.642 78.520 17.687 Example 11 2.422 79.215 17.883 Example 12 2.281 79.516 17.959 Example 13 2.575 78.846 17.770 Example 14 2.404 79.218 17.890 Example 15 2.293 79.460 17.942 Example 16 2.626 78.651 17.717 Example 17 2.371 79.257 17.899

Series resistance
(Rs, m?) Fill Factor (FF,%) Conversion efficiency
(%) Example 18 2.300 79.449 17.936 Example 19 2.617 78.681 17.736 Example 20 2.545 78.939 17.822 Example 21 2.651 78.496 17.673 Example 22 2.344 79.300 17.916 Example 23 2.129 79.605 17.978 Example 24 2.564 78.869 17.785 Example 25 2.512 79.006 17.865 Example 26 2.320 79.386 17.929 Example 27 2.624 78.660 17.734 Example 28 2.717 78.310 17.628 Example 29 2.550 78.883 17.807 Example 30 2.542 78.969 17.831 Example 31 2.674 78.432 17.639 Example 32 2.526 78.989 17.843 Example 33 2.516 79.001 17.861 Comparative Example 1 3.842 77.086 17.136 Comparative Example 2 3.296 77.545 17.354

Examples 1 to 33 each contain silver elements derived from a silver compound having an ion decomposition temperature of 1100 DEG C or lower, wherein the molar ratio of Ag to Te is 1: 0.1 to 1: 50, and the molar ratio of Li, Na or K to Ag is 1: 0.01 to 1:10.

As can be seen from the results of Tables 7 and 8, the electrode made of the composition for forming a solar cell electrode using the glass frit of Examples 1 to 33 had a lower series resistance value than Comparative Examples 1 and 2, It was confirmed that the fill factor value was excellent.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (13)

Silver (Ag) powder, glass frit, and organic vehicle,
Wherein the glass frit comprises a silver (Ag) element, a tellurium (Te) element, and a periodic table 1A group element,
The Group 1A element of the periodic table includes at least one element selected from the group consisting of lithium (Li), sodium (Na), and potassium (K); / RTI >
The molar ratio of the silver element (Ag): tellurium element (Te) contained in the glass frit is 1: 0.1 to 1:50,
Wherein the molar ratio of lithium (Li), sodium (Na) or potassium (K) to the silver (Ag) is 1: 0.01 to 1:10.
The glass frit according to claim 1, wherein the glass frit includes at least one element selected from the group consisting of lead (Pb), bismuth, phosphorus (P), germanium, gallium, cerium, (Si) element, a zinc (Zn) element, a tungsten (W) element, a magnesium element, a cesium element, a strontium element, a molybdenum element, a titanium element, (Cu) element, an arsenic (As) element, a cobalt (Co) element, a cobalt (Co) element, a cobalt At least one second metal selected from the group consisting of a Co element, a Zr element, a Mn element, a Neod element, a Cr element, an Sb element and an Al element. Wherein the composition further comprises an element.
The composition for forming a solar cell electrode according to claim 1, wherein the glass frit contains 0.1 to 65 mol% of silver (Ag) element relative to the total molar amount of the glass frit.
The composition for forming a solar cell electrode according to claim 1, wherein the silver (Ag) element contained in the glass frit is formed from a silver compound having an ion decomposition temperature of 1100 캜 or lower.
The composition for forming a solar cell electrode according to claim 4, wherein the silver compound comprises at least one member selected from the group consisting of silver cyanide, silver nitrate, silver halide, silver carbonate, silver acetate, silver sulfate and silver oxide.
The method of claim 1, wherein the glass frit comprises a silver compound; Tellurium oxide; And a compound containing at least one element selected from the group consisting of lithium (Li), sodium (Na), and potassium (K).
7. The method of claim 6, wherein the metal precursor is selected from the group consisting of Pb, Bi, P, Ge, Ga, (Si) oxide, zinc (Zn) oxide, tungsten (W) oxide, magnesium oxide, cesium oxide, strontium oxide, molybdenum oxide, titanium oxide, A metal oxide such as tin (Sn) oxide, indium (In) oxide, vanadium (V) oxide, ruthenium (Ru) oxide, barium oxide, nickel oxide, copper oxide, At least one second metal selected from the group consisting of an oxide of Co, an oxide of zirconium (Zr), an oxide of manganese (Mn), an oxide of neodymium (Nd), an oxide of chromium (Cr), an oxide of antimony (Sb) Wherein the composition further comprises an oxide.
7. The method of claim 6, wherein the metal precursor comprises from 1 wt% to 45 wt% silver compound, from 20 wt% to 75 wt% tellurium oxide, and from 1 wt% to 35 wt% compound comprising Group 3A element A composition for forming a battery electrode.
The composition for forming a solar cell electrode according to claim 7, wherein the metal precursor comprises 1 wt% to 40 wt% of a second metal oxide.
The solar cell electrode composition according to claim 1,
60% to 95% by weight of the silver powder;
0.1% to 20% by weight of said glass frit; And
And 1 wt% to 30 wt% of the organic vehicle.
The composition for forming a solar cell electrode according to claim 1, wherein the glass frit has an average particle diameter (D50) of 0.1 to 10 mu m.
The solar cell electrode composition according to claim 1, wherein the composition for forming a solar cell electrode further comprises at least one additive of a dispersing agent, a thixotropic agent, a plasticizer, a viscosity stabilizer, a defoamer, a pigment, a UV stabilizer, / RTI >
A solar cell electrode made of the composition for forming a solar cell electrode according to any one of claims 1 to 12.

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