CN109754902A - Glass composition for conducting composition - Google Patents

Abstract

The present invention relates to the glass compositions for being used to form conducting composition.It include conducting metal particles, organic carrier and glass composition comprising tellurium oxide (TeO2), zinc oxide (ZnO) and lithia (Li2O) for the conducting composition in solar panel technology in one aspect of the present invention.

Description

Glass composition for conducting composition

Technical field

The present invention relates to the glass compositions for being used to form conducting composition.In one aspect of the present invention, it to be used for the sun Conducting composition in energy panel technology comprising conducting metal particles, organic carrier and includes tellurium oxide (TeO2), oxygen Change the glass composition of zinc (ZnO) and lithia (Li2O).

Background

Solar battery is the device that luminous energy is converted to electricity using photovoltaic effect.Solar energy is attractive green energy Source, because it is sustainable and only generates on-contaminated by-product.Therefore, numerous studies have been put at present to develop to have and mention High efficiency, while persistently reducing the solar battery of material and production cost.In operation, when light hits solar battery When, a part of incident light is by surface reflection, and remaining is transmitted in solar battery.The photon of transmitted light is by usually by semiconductor Material solar battery as made of silicon absorbs.The electronics for carrying out the energy excitation semiconductor material of self-absorption photon leaves its original Son generates electron-hole pair.Then these electron-hole pairs are separated and be applied in solar cell surface by p-n junctions Conductive electrode is collected.

Solar battery usually has the electroconductive paste for being applied to it on the front and back.Typical electroconductive paste includes conductive gold Metal particles, frit and organic carrier.The positive batter for generally comprising silver is applied on the front of matrix for use as preceding electrode.One In a little situations, frit is etched through the anti-reflection coating such as silicon nitride coating on Si-substrate surface when firing, and help is being led Electrical contact is established between electric particle and silicon matrix.On the other hand, it is desirable that frit will not so aggressivity so that it is burning P-n junction is shunted after system.For example, the frit of the lead comprising relatively high amount and bismuth oxide may damage anti-reflecting layer and make base The p-n junction of matter is degraded.Accordingly, it is possible to endanger the electrical property of solar battery.Additionally, it is known that frit has wide melting temperature model It encloses, so that they depend strongly on its composition and machined parameters and behavior.Thus, joined using the prediction glass processing of known glass material Several and the behavior under quick method for cooking ability is difficult.Further, since lead and bismuth are the elements toxic to environment, reason What is thought is to reduce or eliminate its use in electroconductive paste.Conventional electroconductive paste must also adhere well in following matrix with It is mechanically and structurally upper reliable.

Therefore, it is necessary to improve the electrical contact between electroconductive paste and following matrix by improvement transmitting weight to change to realize Into solar battery efficiency glass composition.Improved total battery performance is also by for example higher short-circuit voltage, lower The preferable adhesive force and higher electric current of series resistance, electrode in matrix indicate.The glass composition should not so be corroded Property so that they damage anti-reflecting layers and p-n junction.In addition, reducing or eliminating toxic lead and bismuth oxygen for environment and health The existing glass composition of compound is ideal.In addition, it is desirable to which there is wider process window and more predictable melt row For frit.Finally, the frit for improving the adhesive force on electroconductive paste silicon matrix below is ideal.

It summarizes

One aspect of the present invention is related to conducting composition, it includes conducting metal particles, at least one glass composition and organic Carrier, the glass composition include that the total weight based on glass composition has the tellurium oxide for being at least about 70 weight % altogether (TeO2), zinc oxide (ZnO) and lithia (Li2O),.At least one glass composition preferably comprises less than about 5 weight %'s Bismuth oxide (Bi2O3) and lead oxide (PbO).When Bi2O3 is present in glass composition, the weight ratio of Bi2O3 and ZnO are preferred Less than about 0.15.It is at least 2 weight % that at least one glass composition, which preferably comprises the total weight based on glass composition, Li2O。

Another aspect of the present invention is related to conducting composition, it includes conducting metal particles, at least one glass composition, And organic carrier, the glass composition include tellurium oxide (TeO2), zinc oxide (ZnO) and the total weight based on glass composition Lithia (Li2O) more than about 1 weight %.The total amount of TeO2, ZnO and Li2O are based on glass at least one glass composition The total weight of glass composition is at least about 70 weight %, and the weight ratio of (a) TeO2 and (b) ZnO and Li2O is about 1-25, preferably About 2-15.At least one glass composition preferably comprises less than about 5 weight % bismuth oxides (Bi2O3), more preferably less than about 2.5 weights Measure % (such as less than about 2.0 weight %) and lead oxide (PbO).At least one glass composition is preferably comprised based on glass The total weight of composition is the Li2O of at least 2 weight %.

Another aspect of the present invention is related to conducting composition, it includes conducting metal particles, at least one glass composition, And organic carrier, the glass composition include tellurium oxide (TeO2), zinc oxide (ZnO) and the total weight based on glass composition Lithia (Li2O) more than about 1 weight %.The total amount of TeO2, ZnO and Li2O are based on glass at least one glass composition The total weight of glass composition is at least about 70 weight %, and the weight ratio of ZnO and Li2O is about 0.5-25, preferably from about 1-20.? In one preferred embodiment, glass composition include more than 1.0 weight %Li2O (for example, at least 1.1,1.2,1.5,1.6, 1.7,1.8,1.9 or 2.0 weight %).In one embodiment, the weight ratio of ZnO and Li2O is about 1-25, preferably from about 2- 15.The combined amount of bismuth oxide (Bi2O3) and lead oxide (PbO) is based on glass composition in at least one glass composition 100% total weight is preferably less than about 5 weight %, more preferably less than about 2.5 weight % (such as less than about 2.0 weight %).

Another aspect of the present invention is conducting compositions, it includes conducting metal particles, at least one glass composition, and Organic carrier, the glass composition include tellurium oxide (TeO2), zinc oxide (ZnO) and lithia (Li2O).(a) Li2O with (b) weight ratio of the combined amount of TeO2 and Li2O is about 0.001-0.3 (preferably from about 0.001-0.15), and (a) ZnO and (b) The weight ratio of the combined amount of TeO2 and ZnO is about 0.001-0.35, preferably from about 0.005-0.35.At least one glass composition The combined amount of middle bismuth oxide (Bi2O3) and lead oxide (PbO) is preferably less than about 5 weight %, more preferably less than about 2.5 weight % (such as less than about 2.0 weight %).In a preferred embodiment, glass composition includes to be more than 1.0 weight %Li2O (examples Such as at least 1.1,1.2,1.5,1.6,1.7,1.8,1.9 or 2.0 weight %).

The present invention also provides what is produced and conducting composition of the present invention is applied on silicon wafer and fires silicon wafer Solar battery.Another aspect of the present invention is the solar cell modules that solar battery is electrically interconnected comprising the present invention.

The present invention further provides the methods of production solar battery comprising step: providing has front and back Electroconductive paste of the present invention is applied on silicon wafer (such as front of chip), and silicon wafer is fired by silicon wafer.

It is described in detail

The present invention relates to the glass compositions preferably with low lead and/or bi content or without lead and/or bismuth.Preferably at one In embodiment, glass composition is unleaded and/or without bismuth.While not limited to the application, glass composition of the present invention is available In conducting composition, such as in those of the electrode that is used to form on solar battery.Conducting composition of the present invention is preferred Include conducting metal particles, organic carrier and the glass composition.Conducting composition can further include one or more Additive.

Conducting composition may include glass composition (preferably unleaded and/or without bismuth glass composition) or add in physics Work (such as mechanochemistry processing, crush or grinding) or chemical process (such as fire, thermal decomposition or light or radiation chemistry point Solution) during formed glass compound (such as organo-metallic compound, salt) combination.In other embodiments, glass is formed The element of glass composition be may be present in one-component or be distributed in two or more components, and the component can be nothing Setting, crystallization or partially crystallizable.

When be applied to silicon solar cell when, it is this kind of paste can be used on the front or the back side of silicon wafer formed electric contacting layer or Electrode.In a preferred embodiment, electroconductive paste is in the front of the silicon wafer for solar battery, and includes silver-colored conductive Particle, glass composition of the present invention and organic carrier.

Glass composition

Glass composition of the present invention is used as multiple functions when in conducting composition.Firstly, glass mentions for conductive particle For pumped (conveying) medium, them is allowed to migrate from paste to the interface of semiconductor substrate.Glass also for paste component provide reaction medium with Physical and chemical reaction is subjected on interface when being subjected to raised temperature.Physical reactions include but is not limited to melt, dissolution, expand It dissipates, sintering, precipitate and crystallize.Chemical reaction includes but is not limited to synthesize (forming new chemical bond) and decomposition, reduction and oxidation, And phase transformation.In addition, glass acts also as adhesion medium, the combination between conductive particle and semiconductor substrate is provided, is thus improved Electrical contact performance during the service life of solar device.It is existing due to the insulation performance of glass although being intended to realize same effect Glass composition can generate high contact resistance on the interface of electroconductive paste and silicon wafer.Glass composition of the present invention is defeated needed for providing It send, reactive and adhesion medium, and reduces contact resistance and improve total battery performance.Improved total battery performance is also by for example The preferable adhesive force and higher electric current of higher short-circuit voltage, lower series resistance, electrode in matrix indicate.

Without being bound by any particular theory, it is believed that glass provides conductive particle and semiconductor substrate (example in solar battery Such as silicon matrix) between improved ohm and Schottky contacts.Glass is the reaction-ability medium relative to silicon and produces on silicon matrix Liveliness proof area, which improve total contacts, such as by directly contacting or tunnelling.Improved contact performance provides better ohm Contact and Schottky contacts, and therefore better total solar cell properties.It is provided in addition, glass ingredient is combined with specific quantity With widen the glass transition temperature of range, softening temperature, melting temperature, crystallization temperature and flowing temperature paste, therefore open up The process window that wide gained is pasted.This allows gained electroconductive paste to have the improved compatibility with a variety of matrix.

According to a preferred embodiment, glass composition has suboxides lead content.According to another preferred embodiment, Glass composition is unleaded.As described herein, term " low lead content ", which refers to, has at least 0.5 weight % and less than about 5 weights Measure %, such as less than about 4 weight %, less than about 3 weight %, less than about 2 weight %, less than about 1 weight % and less than about 0.8 weight Measure the composition of the oxidation lead content of %.As described herein, term " unleaded " refers to having less than about 0.5 weight %, preferably less than About 0.4 weight %, more preferably less than about 0.3 weight %, more preferably less than about 0.2 weight %, most preferably less than about 0.1 weight % The composition of the oxidation lead content of lead oxide (100% total weight based on glass composition).In a more preferred embodiment, Glass composition includes less than about 0.01 weight % lead oxide, can be used as the incidental impurities from other glass ingredients and exists. In a preferred embodiment, glass composition does not include any lead oxide being deliberately added.

According to another preferred embodiment, glass composition has low bismuth oxide content.According to another preferred embodiment For no bismuth.As described herein, term " low bi content ", which refers to, has at least 0.5 weight % and less than about 5 weight %, such as less than The bismuth oxide of about 4 weight %, less than about 3 weight %, less than about 2 weight %, less than about 1 weight % and less than about 0.8 weight % The composition of content.As described herein, term " no bismuth " refers to having less than about 0.5 weight %, preferably less than about 0.4 weight %, More preferably less than about 0.3 weight %, more preferably less than about 0.2 weight %, most preferably less than about 0.1 weight % (are based on glass group Close object 100% total weight) oxidation bi content composition.In a more preferred embodiment, glass composition includes few In about 0.01 weight % bismuth oxide, it can be used as the incidental impurities from other glass ingredients and exist.A preferred implementation side In case, glass composition does not include any bismuth oxide being deliberately added.

In one embodiment, 100% total weight of the total amount of Bi2O3 and PbO together based on glass composition is preferred For less than 5 weight %, more preferably less than 3 weight %, more preferably less than 2.5 weight %, most preferably in less than 2.0 weight %.Most In preferred embodiment, glass composition is unleaded and without bismuth.

Glass composition includes tellurium oxide (TeO2), lithia (Li2O) and zinc oxide (ZnO).In an embodiment In, glass composition also includes sodium oxide molybdena (Na2O).

In at least one embodiment, 100% total weight of the total amount of TeO2, Li2O and ZnO based on glass composition It is at least 50 weight %, preferably at least 60 weight %, most preferably at least 70 weight %.In other embodiments, the weight of component Measuring ratio can be one of the following or any combination:

● Bi2O3:ZnO is less than about 0.15 preferably less than about 0.13；

● TeO2:(ZnO+Li2O) it is about 1-25, preferably from about 2-15, more preferably from about 3-15, most preferably from about 3.5-15；

● ZnO:Li2O is about 0.5-25, preferably from about 1-20, more preferably from about 1-15；

● Li2O:(TeO2+Li2O) it is about 0.001-0.3, preferably 0.001-0.15；With

● ZnO:(TeO2+ZnO) it is about 0.001-0.35, preferably 0.005-0.35.

In another embodiment, the weight ratio of component can be one of the following or any combination:

● TeO2:(ZnO+Li2O) it is about 1-35, preferably from about 2-20 (such as 4-11)；

● ZnO:Li2O is about 0.2-25, preferably 0.5-20, more preferable 1-20 (such as 1-7)；

● Li2O:(TeO2+Li2O) it is about 0.001-0.3, preferably 0.01-0.2 (such as 0.02-0.06)；With

● ZnO:(TeO2+ZnO) it is about 0.005-0.5, preferably 0.02-0.3 (such as 0.07-0.15).

It is about 50-99.4 weight % that glass composition, which preferably comprises 100% total weight based on TeO2, ZnO and Li2O, TeO2, more preferably from about 65-97 weight %, most preferably from about 74-95 weight %.In a preferred embodiment, glass composition Include the no more than about 95 weight %TeO2 of 100% total weight based on entire glass composition, preferably no more than about 93 weight % TeO2, most preferably no more than about 90 weight %TeO2.In another preferred embodiment of the present, glass composition includes to be based on entire glass 100% total weight of glass composition is at least 40 weight %TeO2, preferably at least about 50 weight %TeO2, most preferably at least about 60 Weight %TeO2.

In another embodiment, the amount of Li2O is preferably more than about 1 based on 100% total weight of TeO2, ZnO and Li2O Weight %.It is about 0.1-15 weight %Li2O that glass composition, which preferably comprises 100% total weight based on TeO2, ZnO and Li2O, More preferably from about 1-10 weight %Li2O, most preferably from about 1-7 weight %Li2O.In a preferred embodiment, glass composition Comprising 100% total weight based on entire glass composition be at least 1 weight %Li2O (for example, at least about 1.0,1.1,1.2, 1.5,1.6,1.7,1.8 and 1.9 weight %), preferably at least 2 weight %Li2O.In another embodiment, glass composition is excellent Choosing includes 100% total weight based on entire glass composition no more than about 15 weight %Li2O, preferably no more than about 12 weights Measure %, most preferably no more than about 10 weight %.

Glass composition preferably comprises 100% total weight based on TeO2, ZnO and Li2O more than about 1 weight %ZnO.? In one embodiment, glass composition includes the 100% total weight about 0.5-35 weight % based on TeO2, ZnO and Li2O ZnO, preferably from about 2-25 weight %ZnO, most preferably from about 4-19 weight %ZnO.

In another embodiment, glass composition further includes 100% total weight based on glass composition at least About 0.1 weight %Na2O.In one embodiment, glass composition includes about 0.1-5 weight %Na2O, preferably from about 0.1-4 Weight %Na2O, most preferably from about 0.1-3 weight %Na2O.In one embodiment, glass composition does not include Na2O.

Glass composition may include glass material, ceramic material, form reaction at elevated temperatures as is generally known in the art Any other compound of property matrix.In one embodiment, glass composition may include at least one essentially amorphous glass Glass material.In another embodiment, glass composition in combination with crystalline phase or compound or amorphous, partially crystallizable and/or The mixture of crystalline material.Glass composition also may include other oxide or compound as known in the art.For example, can make With boron, aluminium, gallium, silicon, nickel, tungsten, gadolinium, tantalum, antimony, cerium, zirconium, titanium, manganese, tin, ruthenium, cobalt, iron, copper and chromium or its at least two it is any The oxide for combining (preferably calcium halophosphate activated by antimony andmanganese, nickel, tungsten and ruthenium or its at least two combination) can produce those metal oxygens when firing At least two mixture in the compound of compound or above-mentioned metal, at least two mixture, is burning in above-mentioned oxide Any two kind are can produce in the above compound of those metal oxides at least two mixture or said components when processed Or more mixture.Other glass matrix forming agents or glass modifier, such as germanium oxide, vanadium oxide, molybdenum oxide, niobium Oxide, indium oxide, phosphorous oxides, rare-earth oxide, alkali metal oxide, alkaline earth oxide, metal tripolyphosphate Salt and metal halide (such as zinc fluoride) and chalcogenide also can be used as additive for adjusting total glass composition Performance, such as glass transition temperature.In one embodiment, glass composition may include at least one glass and at least A kind of combination of oxide or additive.In one embodiment, glass composition includes 100% based on glass composition The total weight other oxides of at least about 0.1 weight % and/or additive and no more than about 50 weight %, preferably no more than about 40 weights Measure %, more preferably no more than about 30 weight %, most preferably no more than about 20 this type oxide of weight % and/or additive.For example, In one embodiment, glass composition may include MgO, TiO2, SiO2, B2O3, Na2O, K2O, CaO, SrO, BaO, V2O5, MoO3, Cr2O3, WO3, MnO, Al2O3, P2O5, CdO, Ag2O, AgI, AgBr, AgCl or combinations thereof.

Glass composition can be formed by any method known in the art, including solid-state is synthesized, melts and is quenched or it Its ChimieDouce (softening is learned) method.In typical melting and method of quenching, first step is that suitable raw material is (logical Often it is powder type) mixing.The mixture is heated in air or in oxygen-containing atmosphere to form melt.Melt is rapid It is cold, then by its grinding, ball milling and/or screening, to provide the mixture with required granularity.For example, can be by powder type Component is mixed together in V-comb mixing machine.Then by mixture heating (such as to about 800-1200 DEG C) about 30-40 minutes So that raw material can react to form single glass system.Then the system is quenched, sand shape consistency is presented.The corase meal is for example in ball milling It is ground in machine or jet mill, until generating fine powder.Glass particle can be ground to about 0.01-20 μm, preferably from about 0.1-5 μm flat Equal granularity (d50).In one embodiment, glass particle can form the nano-scale particle of the d50 with about 1 to about 100nm.

ChimieDouce (softening learn) method about 20 DEG C to about 500 DEG C at a temperature of carry out.ChimieDouce reaction For topotactic reaction, it is intended that the structural element of reactant is kept in the product, but is formed and changed.Such methods include but unlimited In sol-gel process, precipitating, the hot method of hydrothermal/solvent and pyrolysis.Conventional solid synthesis can also be used for preparing glass described herein Glass composition.In the method, coarse raw materials are sealed under vacuum in vitreosil pipe or tantalum or platinotron, are then heated to About 700-1200 DEG C.Material keeps about 12-48 hours at the raised temperature, and then Slow cooling (about 0.1 DEG C/min) is extremely Room temperature.In some cases, solid-state reaction can carry out in air in alumina crucible.Prepare the another side of glass composition Method is co-precipitation.In the method, by adjusting pH it is horizontal or and being incorporated to reducing agent by metallic element reduction and and its Its metal oxide or hydroxide co-precipitation are to form the solution comprising metal cation.Then by these metals, metal oxygen Compound or the drying precipitate of hydroxide are simultaneously fired under vacuum at about 400-800 DEG C to form fine powder.

According to an embodiment of the invention, glass composition has the required firing temperature glass below in electroconductive paste Change transformetion range (Tg).Preferred glass composition is at least about 150 DEG C, preferably at least 180 DEG C, most preferably at least 210 DEG C of Tg range.Meanwhile when being measured using thermodynamic analysis, preferred glass material has no more than about 750 DEG C, excellent Choosing is not greater than about 700 DEG C, most preferably no greater than about 650 DEG C of Tg range.Specifically, DSC can be used in glass transition temperature Equipment, such as TAInstrumentsSDTQ600SimultaneousTGA/DSC (TAInstruments) measurement.For measurement And data assessment, using Survey Software TAUniversalAnalysis2000, V4.5A.As the disk for reference and sample, Use the alumina sample cup (commercially available by TAInstruments) of the volume of the diameter with 6.8mm and about 90 μ l.By about 20- The sample of the amount of 50mg is put into tray sample with the accuracy weighing of 0.01mg.Empty reference dish and tray sample are put into equipment, Stove is closed and starts to measure.The heating of 10-50 DEG C/min is used to 1000 DEG C of final temperature from 25 DEG C of initial temperature Rate.Always the surplus in instrument is cleaned with nitrogen (N25.0), and with synthesis of air, (80%N2 and 20%O2 come by stove It is cleaned from Linde) with the flow velocity of 50ml/min.The first step of DSC signal is glass transition using above-mentioned software evaluation, and is surveyed Fixed initial value is considered the temperature of Tg.

Glass particle well known in the art can show various shapes, size and coating.For example, a large amount of shapes of glass particle It is as known in the art.Some examples include (plate, the piece) of spherical, angular, elongated (stick or needle-shaped) peace.Glass The combination that particle also can be used as the particle of different shape (such as ball and piece) exists.It is preferred that having to the advantageous of generated electrode The glass particle for helpful shape or the combination of shapes of adhering.

Median particle diameter d50 is particle characteristic well known in the art.D50 is the intermediate value of median diameter or size distribution.It It is in cumulative distribution 50% particle size values.Size distribution can by laser diffraction, dynamic light scattering, imaging, electrophoretic light scattering or Any other method measurement known in the art.The HoribaLA-910 being connected on the computer with LA-910 software program Laser diffraction particle size analyzer is used to measure the size distribution of frit.Artificial selection frit glass particles is opposite from LA-910 Refractive index simultaneously enters in software program.The appropriate filler line that will be filled in test cabinet in deionized water to tank.Then by using Circulation and agitating function in software program recycle solution.After 1 minute, solution is discharged.This repeat in addition once with Ensure that room removes any residual materials.Then deionized water third time in room is filled and it is made to recycle and stir 1 minute.It is logical Cross any background particle eliminated in solution using the blank function in software.Then start ultrasonic agitation, and by frit It is slowly added in the solution in test cabinet until transmissivity item is in the suitable area in software program.When transmissivity is correct horizontal When, laser diffraction analysis is run, the size distribution of glass is measured and is provided as d50.In a preferred embodiment, glass The median particle diameter d50 of particle is at least about 0.1 μm, and is preferably no greater than about 20 μm, more preferably not greater than about 10 μm, more preferably not Greater than about 5 μm, most preferably no greater than about 3 μm.

Specific surface area is also particle characteristics well known in the art.As described herein, the measurement of all surface product uses BET (Brunauer-Emmett-Teller) method by operated according to SMART method MonosorbMS-22 analyzer (by QuantachromeInstrumentsofBoyntonBeach, Florida production) it carries out.It prepares and is used in built-in degasification station The sample of analysis.Flowing gas removes impurity, generates the clean surface that can be adsorbed on it.Sample can be added with what is provided Heat cover is heated to the selectable temperature of user.Digital temperature control and display are mounted on instrument panel.It is complete in degasification After, sample cell is transferred to analysis station.Quick coupling fittings automatically seal sample cell during transfer.With single button It pushes, starts to analyze.Dewar flask filled with coolant automatically increases, and impregnates sample cell and causes to adsorb.Instrument detection It arrives, when (2-3 minutes) are completed in absorption, automatically reduces Dewar flask, and leniently will examination using built-in hot air blowers Heat back room temperature in sample pond.Therefore, desorption gas signal is shown on digital instrument, and surface area is directly displayed and shown in front panel Show on device.Entire measurement (the absorption and desorption) period usually needs to be less than 6 minutes.The technology is detected using highly sensitive thermal conductivity Device measurement adsorbate/inert carrier gas mixture concentration when inspiration row is conciliate in absorption changes.When pass through airborne electronic equipment device When part is integrated and compared with calibration, detector provides the volume of absorption or desorption gas.Built-in miniature processor ensures linearly simultaneously The BET surface area for automatically calculating sample, is indicated with m2/g.In one embodiment, glass particle has at least about 0.1m2/g and be not greater than about 15m2/g, preferably at least about 1m2/g and be not greater than about 10m2/g specific surface area.

Conducting composition

One aspect of the present invention is related to conducting composition.Required electroconductive paste is for highly conductive so that the electrical property of gained solar battery It can optimized electroconductive paste.Conducting composition generally comprises metallic particles, organic carrier and at least one glass described herein Composition.According to an embodiment, electroconductive paste includes: (i) at least about 50 weight % and no more than about 95 weight % metals Grain；(ii) at least about 0.1 weight % and no more than about 10 weight % glass；(iii) at least about 1 weight % and no more than about 25 Weight % organic carrier (100% total weight based on paste).

In a preferred embodiment, conducting composition includes at least about 0.1 weight % glass composition, preferably extremely Few about 0.5 weight %.Meanwhile paste includes the no more than about 10 weight % glass compositions of 100% total weight based on paste, preferably not More than about 8 weight %, most preferably no more than about 6 weight %.

Conducting metal particles

Electroconductive paste includes conducting metal particles.Electroconductive paste may include at least about 50 weight % metals of 100% total weight based on paste Particle, preferably at least about 60 weight %, more preferably at least about 70 weight %, most preferably at least about 80 weight %.Meanwhile paste is preferred Include the no more than about 95 weight % metallic particles of 100% total weight based on paste.

It can be used as is generally known in the art and think all metallic particles suitable for electroconductive paste.Preferably metallic particles is It shows those of high conductivity, generates the electricity with high efficiency and fill factor and low series resistance and grid resistance Pole.Preferred metallic particles is metal element, alloy, metal derivative, the mixture of at least two metals, at least two alloys Mixture or at least one metal and at least one alloy mixture.Preferred metal includes silver, aluminium, gold, copper and mickel And its at least one of alloy or mixture.In a preferred embodiment, metallic particles includes silver.In another preferred reality It applies in scheme, metallic particles includes silver and aluminium.Suitable silver derivative includes such as silver alloy and/or silver salt, such as silver-colored halogenation Object (such as silver chlorate), silver nitrate, silver acetate, silver trifluoroacetate, silver orthophosphate and combinations thereof.In one embodiment, golden Metal particles include the metal or alloy for being coated with one or more kinds of different metals or alloy, such as are coated with Argent grain or the painting of aluminium There is the copper particle of silver.

Such as glass particle, metallic particles can show a variety of shapes and sizes.Metallic particles also can be used as different shape The combination of the particle of (such as ball and piece) exists.It is preferred that having the metal to the advantageous shape of improved conductivity or combination of shapes Particle.A kind of method for characterizing surface nature of this kind of shape without considering particle is by following parameter: length, width and thickness Degree.In the context of the present invention, the length of particle is provided by the length of longest space displacement vector, two endpoint is included in In particle.The width of particle is provided by the length of the longest space displacement vector perpendicular to length vector defined above, Two endpoint is included in particle.The thickness of particle by perpendicular to length vector defined above and width vector most Long spacing displacement vector provides, two endpoint is included in particle.In one embodiment, it is preferred to have as far as possible uniformly Shape (i.e. wherein about length, width and thickness ratio as close possible to 1；Preferably at least 0.7, more preferably at least 0.8, most Preferably at least 0.9, and preferably no greater than about 1.5, preferably no greater than about 1.3, most preferably no greater than about 1.2 shape) metal Particle.In this embodiment, the example of the preferable shape of metallic particles is spherical and cube or combinations thereof or it is a kind of Or a variety of and other shapes of combination.In another embodiment, preferably there is the metallic particles of the shape of low uniformity, preferably About length, the size of width and thickness than at least one of be about 1.5 or more, more preferably from about 3 or more, most preferably from about 5 with On.It is piece type, stick or needle-like or piece type, stick or needle-like and other shapes of combination according to the preferable shape of the embodiment.

It is preferred that the median particle diameter d50 (use is measured with the identical method described in glass particle) of metallic particles is at least About 0.1 μm, and it is preferably no greater than about 10 μm, preferably no greater than about 8 μm, more preferably not greater than about 7 μm, most preferably no greater than about 5 μ m.In addition, metallic particles have at least about 0.1m2/g and no more than about 10m2/g specific surface area (use with about glass particle The identical method measurement).According to a preferred embodiment, using at least about 0.2m2/g, preferably at least 0.5m2/ G, and the silver powder of the specific surface area no more than about 5m2/g simultaneously.

It is preferred that contributing other components of more favorable contact performance and conductivity.For example, metallic particles can have surface painting Layer.As is generally known in the art and it is considered suitable to this any type coating in the context of the invention and can be used on metallic particles.Preferably Coating is those of the adhesiveness for promoting gained electroconductive paste coating.If there is the coating, then preferred coatings are based on metal 100% total weight of grain is no more than about 10 weight %, preferably no more than about 8 weight %, most preferably no more than about 5 weight %.

Organic carrier

Electroconductive paste of the present invention also may include organic carrier.In one embodiment, organic carrier is with 100% gross weight based on paste Measure at least about 0.01 weight % and no more than about 50 weight %, preferably no more than about 30 weight %, most preferably no more than about 20 weights The amount of amount % is present in electroconductive paste.

In the context of the present invention preferred organic carrier be based on one or more solvents, preferable organic solvent it is molten Liquid, lotion or dispersion, ensure the component of electroconductive paste with dissolve, emulsify or discrete form exist.Preferably organic carrier is The optimum stabilization of the component of electroconductive paste is provided and assigns those of the viscosity that paste allows effective printing.

In one embodiment, organic carrier includes organic solvent and optional adhesive (such as polymer), surface One of activating agent and thixotropic agent are a variety of.For example, in one embodiment, organic carrier includes in organic solvent One or more adhesives.

Preferred adhesive is to contribute to form with favourable stability, impressionability, viscosity in the context of the present invention Those of with the electroconductive paste of sintering character.As is generally known in the art and think that all adhesives suitable for the context of the invention can As the adhesive in organic carrier.Preferred adhesive (its classification for generally falling into referred to as " resin ") is polymer-bonded Agent, monomeric cement and the combined adhesive for polymer and monomer.Polymer adhesive can also be wherein at least two A different monomeric unit includes the copolymer in single molecule.Preferred polymer adhesive is band in the polymer backbone There is in those of those of functional group, main chain tyre functional group and main chain and all has outside main chain those of functional group.It is preferred that Main chain in the polymer with functional group be such as polyester, replace polyester, polycarbonate, replace polycarbonate, band in main chain There is the polymer of cyclic group, glycan, replaces glycan, polyurethane, replace polyurethane, polyamide, replace polyamide, phenolic aldehyde tree Rouge, substituted phenolic resin, one or more aforementioned polymers monomer optionally with the copolymer of other comonomers or its at least Two kinds of combination.According to an embodiment, adhesive can be polyvinyl butyral or polyethylene.Band in preferred main chain The polymer for having cyclic group be such as polyvinyl butyl alcohol ester (PVB) and its derivative and poly- terpineol and its derivative or its Mixture.Preferred glycan is such as cellulose and its alkyl derivative, preferably methylcellulose, ethyl cellulose, ethoxy Cellulose, propyl cellulose, hydroxypropyl cellulose, butyl cellulose and its derivative and its at least two mixture.It is other Preferred polymer is cellulose ester resin, such as cellulose-acetate propionate, cellulose acetate-butyrate and any combination thereof.It is preferred that Host polymer chain outside have functional group polymer be with those of amide group, with acid and/or those of ester group, Commonly referred to as acrylic resin, or the combined polymer with above-mentioned functional group, or combinations thereof.It is had outside preferred main chain The polymer of amide is such as polyvinylpyrrolidone (PVP) and its derivative.Acid and/or ester group are had outside preferred main chain Polymer be such as polyacrylic acid and its derivative, polymethacrylates (PMA) and its derivative or polymethylacrylic acid Or mixtures thereof methyl esters (PMMA) and its derivative,.Preferred monomeric cement is ethylene glycol monomer, terpin alcohol resin or pine Or mixtures thereof fragrant derivative,.Be preferably based on ethylene glycol monomeric cement be with those of ether group, ester group, or Person has those of ether group and ester group, and preferred ether group is methyl, ethyl, propyl, butyl, amyl, hexyl and higher Grade alkyl ether, preferred ester group are acetic acid esters and its alkyl derivative, preferably ethylene glycol monobutyl ether monoacetate or it is mixed Close object.Alkylcellulose, preferred, ethyl, its derivative and its with from aforementioned listed adhesive or other adhesives The mixture of other adhesives is most preferred adhesive in the context of the invention.Adhesive can be based on organic carrier The amount of 100% total weight at least about 0.1 weight %, preferably at least about 0.5 weight % exist.Meanwhile adhesive can be to be based on 100% total weight of organic carrier no more than about 10 weight %, preferably no more than about 8 weight %, more preferably no more than about 7 weights The amount for measuring % exists.

Preferred solvent is the component removed from paste to obvious degree during firing.It is preferred that they are after firing To reduce at least about 80% than before with firing, the absolute weight for preferably reducing at least about 95% than before with firing is deposited ?.Preferred solvent is to contribute those of advantageous viscosity, impressionability, stability and sintering characteristic.As is generally known in the art and Being considered suitable to all solvents in the context of the invention can be used as solvent in organic carrier.Preferred solvent is in standard environment Temperature and pressure (SATP) (298.15K, 25 DEG C, 77 °F) exists as liquid under 100kPa (14.504psi, 0.986atm) Those of, preferably there is those of the fusing point of about 90 DEG C or more of -20 DEG C of boiling point peace treaty.Preferred solvent is polarity or nonpolarity , proton or non-proton, aromatics or non-aromatic.Preferred solvent be single methanol, glycol, polyalcohol, monoesters, diester, polyester, Monoether, diether, polyethers, at least one of functional group comprising these classifications or a variety of optionally include the function of other classifications Alcohol groups that group, preferably cyclic group, aromatic group, unsaturated bond, one or more O atom are exchanged for heteroatoms, one or The solvent for the ester group that ether group that multiple O atoms are exchanged for heteroatoms, one or more O atoms are exchanged for heteroatoms, and The mixture of two or more in above-mentioned solvent.Preferred ester is the dialkyl ester of adipic acid herein, wherein preferably Alkyl component is the group of methyl, ethyl, propyl, butyl, amyl, hexyl and more advanced alkyl or two different this kind of alkyl It closes, preferably the mixture of dimethyl adipate and two or more adipate esters.Preferred ether is diether herein, excellent The dialkyl ether of ethylene glycol is selected, wherein preferred alkyl component is methyl, ethyl, propyl, butyl, amyl, hexyl and more advanced The combination of alkyl or two different this kind of alkyl and the mixture of two kinds of diether.Preferred alcohol is primary, secondary and tertiary herein Alcohol, the preferably tertiary alcohol, wherein it is preferred that the mixture of terpineol and its derivative or two or more alcohol.Preferred combination is more In a different functional groups solvent be 2,2,4- trimethyl -1,3- pentanediol mono isobutyrates, commonly referred to as texanol, and Its derivative, 2- (2- ethoxy ethoxy) ethyl alcohol, commonly referred to as carbitol, alkyl derivative, preferably methyl, ethyl, third Base, butyl, amyl and hexyl Carbitol, preferably hexyl Carbitol or butyl carbitol and its acetic ester derivative, preferably butyl Carbitol acetate, or at least two mixture among the above.Organic solvent can be with 100% gross weight based on organic carrier At least about 60 weight % are measured, the amount of more preferably at least about 70 weight %, most preferably at least about 80 weight % exist.Meanwhile it is organic Solvent can with the no more than about 99 weight % of 100% total weight based on organic carrier, more preferably no more than about 95 weight %'s Amount exists.

Organic carrier also may include one or more surfactants and/or additive.Preferred surfactant is to have Help to be formed those of the electroconductive paste with advantageous stability, impressionability, viscosity and sintering character.As is generally known in the art and Being considered suitable to all surface activating agent in the context of the invention can be used as surfactant in organic carrier.Preferred surface Activating agent is based on those of linear chain, branch, chains of aromatic, fluorination chain, siloxane chain, polyether chain and combinations thereof.Preferred table Face activating agent is including but not limited to single-stranded, double-strand or multichain polymer.Preferred surfactant can have nonionic, yin from Son, cation, amphiphilic or zwitterionic head.Preferred surfactant can for polymerization and monomer or mixtures thereof. Preferred surfactant can have pigment affinity group, hydroxyl-functional carboxylate preferably with pigment affinity group (such as Produced by BYKUSA, Inc.), the acrylate copolymer (such as being produced by BYKUSA, Inc.) with pigment affinity group, tool There is the modified polyether (such as DISPERS655, produced by EvonikTegoChemieGmbH) of pigment affinity group, there is Gao Yan Expect other surfactants (such as DISPERS662C, produced by EvonikTegoChemieGmbH) of affinity group.Do not exist Other preferred polymers in above-listed include but be not limited to polyethylene glycol oxide, polyethylene glycol and its derivative and alkyl carboxylic acid and Or mixtures thereof its derivative or salt,.Preferred polyethyleneglycol derivative is poly(ethylene glycol) acetic acid.Preferably alkyl carboxylic acid is With those of fully saturated alkyl chain and with those of single or multiple unsaturated alkyl chain or its mixture.Preferably have The carboxylic acid of saturated alkyl chain be those of the alkyl chain length with about 8 to about 20 carbon atoms, preferably C9H19COOH (capric acid), C11H23COOH (lauric acid), C13H27COOH (myristic acid), C15H31COOH (palmitinic acid), C17H35COOH are (stearic Acid) or its salt or mixture.The preferred carboxylic acid with unsaturated alkyl chain is C18H34O2 (oleic acid) and C18H32O2 (linoleic acid).Preferred monomcric surfactant is benzotriazole and its derivative.If it exists, surfactant can base In organic carrier 100% total weight be at least about 0.01 weight %.Meanwhile surfactant based on organic carrier 100% Total weight preferably no more than about 10 weight %, preferably no more than about 8 weight %, more preferably no more than about 6 weight %.

Additive in preferred organic carrier be different from said components and contribute to the advantageous property of electroconductive paste if any Those of sharp viscosity, impressionability, stability and sintering characteristic material.It can be used as is generally known in the art and be considered suitable to the present invention Additive in context.Preferred additive include but is not limited to thixotropic agent, viscosity modifier, stabilizer, inorganic additive, Thickener, emulsifier, dispersing agent and pH adjusting agent.Preferred thixotropic agent includes but is not limited to carboxylic acid derivates, preferred fatty acid Derivative or combinations thereof.Preferred derivative of fatty acid includes but is not limited to C9H19COOH (capric acid), C11H23COOH (laurel Acid), C13H27COOH (myristic acid), C15H31COOH (palmitinic acid), C17H35COOH (stearic acid), C18H34O2 (oil Acid), C18H32O2 (linoleic acid) and combinations thereof.Herein, preferably the group comprising fatty acid is combined into castor oil.

Additive

According to another embodiment, electroconductive paste may include the additive different from conductive particle, glass and organic carrier.Preferably Additive contributes to the raising performance of electroconductive paste, its electrode generated or gained solar battery.As is generally known in the art and think It can be used as the additive in electroconductive paste suitable for all additives in the context of the invention.Preferably additive includes but is not limited to Thixotropic agent, viscosity modifier, emulsifier, stabilizer or pH adjusting agent, inorganic additive, thickener and dispersing agent or its at least Two kinds of combination.Most preferably inorganic additive.Preferred inorganic additive includes but is not limited to alkali and alkaline-earth metal, transition gold Belong to, such as nickel, zirconium, titanium, manganese, tin, ruthenium, cobalt, iron, copper and chromium, tungsten, molybdenum, zinc；Late transition metal, for example, boron, silicon, germanium, tellurium, gadolinium, Antimony, rare earth metal, such as lanthanum, cerium oxide, mixed-metal oxides, complex compound, or it is fixed by the nothing that those oxides are formed Shape or partially crystallizable glass or its at least two combination, preferably bismuth, zinc, calcium halophosphate activated by antimony andmanganese, magnesium, nickel, tungsten, alkali metal and alkaline earth gold Category, tellurium and ruthenium or its at least two combination, oxide can produce the chemical combination of those metal oxides or glass when firing At least two mixture in object or above-mentioned metal, at least two mixture in above-mentioned oxide, it is above-mentioned can when firing It generates in those metal oxides, mixed-metal oxides, compound or amorphous or partially crystallizable glass compound extremely Few two kinds of mixture or two or more above-mentioned any mixture.

In one embodiment, conducting composition includes selected from by Li3PO4, MnO, MnO2, Ag2MoO4 and its group The independent and unique additive for the group being combined into.Term " independence " and " uniqueness " indicate the additive and remaining paste component (i.e. Conducting metal particles, glass composition, organic carrier) it is dividually added in paste and is separated with paste component chemical before firing.

If it exists, conducting composition may include at least about 0.1 weight % of 100% total weight based on paste addition Agent.Meanwhile paste preferably comprises the no more than about 10 weight % of 100% total weight based on paste, preferably no more than about 5 weight %, more Preferably no more than about 2 weight % additives.

Form conducting composition

To form conducting composition, it can be used any method known in the art for being used to prepare paste composite by glass composition In conjunction with conducting metal particles and organic carrier.Preparation method be not it is crucial, condition is that it generates evenly dispersed paste.It can incite somebody to action Component is for example mixed with mixing machine, then for example, by three roller mills, to prepare finely dispersed paste.

Solar battery

On the one hand, the present invention relates to solar batteries.In one embodiment, solar battery is by semiconductor substrate such as silicon wafer It is formed with according to the conducting composition of any of embodiment described herein.

On the other hand, the present invention relates to the solar batteries being prepared via a method which, the method includes will be according to this The conducting composition of any of the text embodiment is applied on semiconductor substrate and fires semiconductor substrate.

Silicon wafer

Other than other areas of solar battery, preferred chip has can be with high efficiency absorption light to obtain electron-hole To and with high efficiency on boundary, by hole and the region being electrically separated preferably on p-n junction boundary.Preferred chip be comprising Those of the monolithic entity being made of front doped layer and back side doped layer.

It is preferred that chip includes quadrivalent element, binary compound, ternary compound or the alloy suitably adulterated.Herein, Preferred quadrivalent element is silicon, Ge or Sn, preferably silicon.Preferred binary compound is the group of two or more quadrivalent elements Close, the binary compound of group-III element and V group element, II race element and VI race element binary compound or IV race element With the binary compound of VI race element.The group of preferred quadrivalent element is combined into two or more members selected from silicon, germanium, tin or carbon The combination of element, preferably SiC.The binary compound of preferred group-III element and V group element is GaAs.It is preferably implemented according to one Scheme, chip are silicon.The foregoing description for wherein specifically mentioning silicon is also applied for other wafer compositions described herein.

The position that p-n junction boundary is located at the front doped layer of chip and back side doped layer meets.In N-shaped solar battery In, back side doped layer is doped with electron n-type dopant and front doped layer is doped with receiving electronics or to hole p-type doping Agent.In p-type solar battery, back side doped layer is doped with p-type dopant and front doped layer is doped with n-type dopant.Root According to a preferred embodiment, the chip with p-n junction boundary by providing doping silicon matrix first, then by opposite type Doped layer is applied in the one side of matrix and prepares.

It is well known in the art for adulterating silicon matrix.Doping silicon matrix can be by as is generally known in the art and being considered suitable to this hair Bright any method preparation.Preferred silicon matrix source is monocrystalline silicon, polysilicon, amorphous silicon and high-grade metalluragical silicon, optimal Menu crystal silicon or polysilicon.Doping and form doping silicon matrix and can be added dopant during the preparation in silicon matrix simultaneously into It goes or it can be carried out in a subsequent step.Doping can be orientated for example, by gas diffusion and give birth to after the preparation of silicon matrix It grows and carries out.Doping silicon matrix be also be easy it is commercially available.According to an embodiment, the initial dopant of silicon matrix can be by that will mix It is formed in miscellaneous dose of addition silicon mixture to carry out simultaneously.According to another embodiment, front doped layer and if there is The application for talking about the back layer of high doped can be carried out by gas phase oriented growth.Preferably at least about 500 DEG C of gas phase oriented growth, It is carried out at a temperature of preferably at least about 600 DEG C, most preferably at least about 650 DEG C.Meanwhile gas phase oriented growth is preferably being not greater than about 900 DEG C, more preferably not greater than about 800 DEG C carry out at a temperature of most preferably no greater than about 750 DEG C.Oriented growth is further preferably extremely Few 2kPa, preferably at least about 10kPa, most preferably at least about carry out under the pressure of 30kPa.Meanwhile oriented growth is being not greater than about 100kPa, preferably no greater than about 80kPa are most preferably no greater than about carried out under the pressure of 70kPa.

Various shapes, surface texture and size may be present in silicon matrix as is generally known in the art.For some examples, the shape of matrix It may include cube, disk, chip and irregular polyhedrons.According to a preferred embodiment, chip is with similar, preferably Identical two peacekeepings are significantly less than the cube of the third dimension of other two dimensions.The third dimension can be tieed up small at least than the first two 100 times.

In addition, a variety of surface types are as known in the art.In one embodiment, it is preferred to rough surface Silicon matrix.A kind of method for assessing the roughness of matrix is to assess the surface roughness ginseng of matrix sub-surface (sub-surface) Number, with the total surface area of matrix compared be it is small, preferably total surface area less than about 1%, and it is flat substantially.Table The value of surface roughness parameter is provided by the ratio of the area of subsurface and the area of theoretical surface, and the area of the theoretical surface is logical It crosses and the subsurface is projected and is formed and minimizing mean square displacement in the plane of subsurface best fit.Higher table Surface roughness parameter value indicates rougher, more irregular surface, and lower surface roughness parameter value indicates more smooth, relatively equal Even surface.It is preferred that the surface roughness of silicon matrix is modified to generate multinomial factor (including but not limited to light absorption and in table Adhesive force on face) between optimum balance.

The larger dimension of two of changeable silicon matrix is to be suitble to application required by gained solar battery.It is preferred that the thickness of silicon wafer Degree is at least about 0.01mm.Meanwhile thickness is preferably not greater than about 0.5mm, more preferably not greater than about 0.3mm, most preferably less In about 0.2mm.According to an embodiment, silicon wafer can have the minimum thickness of 0.01mm.

It is preferred that front doped layer is thin compared with the doped layer of the back side.Further preferably front doped layer has at least about 0.1 μm, And it is not greater than about 10 μm, and preferably no greater than about 5 μm, most preferably no greater than about 2 μm of thickness.

High doped layer can be applied to the back side of silicon matrix overleaf between doped layer and any other layer.This is highly mixed Diamicton have doping type identical with back side doped layer, and the layer usually with+indicates (n+ type layer applied to the N-shaped back side doping On layer and p+ type layer is applied on the doped layer of the p-type back side).The high doped back layer is used to help the electric conductivity that metallizes and improve Energy.It is preferred that if it exists, high doped back layer have at least about 1 μm, and be not greater than about 100 μm, preferably no greater than about 50 μm, most preferably no greater than about 15 μm of thickness.

Dopant

Preferred dopant is to form p-n junction boundary and electronics or hole are introduced into band structure when being added in silicon wafer Those of.It is preferred that specifically selecting characteristic and the concentration of these dopants to adjust the band structure feature of p-n junction and according to need Light absorption and conductivity feature are set.Preferred p-type dopant is will be those of in hole addition silicon wafer band structure.Ability Domain is known and is considered suitable to all dopants in the context of the invention and can be used as p-type dopant.Preferably p-type dopant includes But it is not limited to triad, especially those of 13 race of periodic table.Preferred 13 race's element of periodic table include but is not limited to boron, Aluminium, gallium, indium, thallium or in which at least two combination, wherein particularly preferred boron.

Preferred n-type dopant is will be those of in electronics addition silicon wafer band structure.It is known in the art and be considered suitable to All dopants in the context of the invention can be used as n-type dopant.Preferred n-type dopant includes but is not limited to periodic table 15 The element of race.Preferred 15 race element include but is not limited to nitrogen, phosphorus, arsenic, antimony, bismuth or in which at least two combination, wherein special Not preferred phosphorus.

As described above, the various doped levels of p-n junction can be changed to adjust the required performance of gained solar battery.

According to certain embodiment, semiconductor substrate (i.e. silicon wafer), which has, is greater than about 60 Ω/, such as greater than about 65 Ω/ , 70 Ω/, 90 Ω/, 95 Ω/ or 100 Ω/ sheet resistance.

Solar battery structure

One aspect of the present invention is can solar battery obtained by the method for the present invention.Preferred solar battery is to be converted to electricity Can output total incident optical energy ratio in terms of, have it is efficient those.Further preferably light-weight and durable solar battery. At least, solar battery generally comprises: electrode before (i), the front (ii) doped layer, (iii) p-n junction boundary, the back side (iv) doping Layer and (v) weld pad (solderingpad).Solar battery also may include other layers for chemical/mechanical protection.

Anti-reflecting layer

Anti-reflecting layer can be used as outer layer application before by front of the application of electrode in solar battery.Preferably anti-reflecting layer is It reduces the incident light ratio by head-on reflection and improves those of the incident light ratio for crossing front to be absorbed by chip.Have The absorption/reflection ratio of benefit is easy to etch by electroconductive paste, or resistant to temperature needed for electroconductive paste firing, and not tribute It is preferred for offering the anti-reflecting layer for the electrons and holes recombination that electrode interface nearby improves.It can be used as is generally known in the art and think Suitable for all anti-reflecting layers in the context of the invention.Preferred anti-reflecting layer include but is not limited to SiNx, SiO2, Al2O3, The mixture of TiO2 or in which at least two and/or its at least two layers combination.According to a preferred embodiment, antireflection Layer is SiNx, wherein using especially such if silicon wafer.

The thickness of anti-reflecting layer is suitable for the wavelength of appropriate light.A preferred embodiment according to the present invention, anti-reflecting layer tool There are at least about 20nm, preferably at least about 40nm, the most preferably at least about thickness of 60nm.Meanwhile thickness is preferably not greater than about 300nm, preferably no greater than about 200nm, most preferably no greater than about 90nm.

Passivation layer

One or more passivation layers can be used as outer layer applied on the front and/or the back side of silicon wafer.Passivation layer can be electric before formation It is applied before extremely or before application anti-reflecting layer (if there is one).Preferred passivation layer is to reduce electrode interface Those of neighbouring electron/hole recombination rate.It can be used as is generally known in the art and be considered suitable to any in the context of the invention Passivation layer.Preferred passivation layer includes but is not limited to silicon nitride, silica and titanium dioxide.According to a preferred implementation side Case uses silicon nitride.Preferred passivation layers have at least 0.1nm, preferably at least about 10nm, the most preferably at least about thickness of 30nm. Meanwhile passivation layer is preferably not greater than about 2 μm, more preferably not greater than about 1 μm, most preferably no greater than about 200nm.

Other protective layers

In addition to the above-mentioned layer of major function for directly contributing solar battery, it can be added other for what is mechanically and chemically protected Layer.

It can be by cell package to provide chemoproection.Encapsulation is well known in the art and usable suitable for times of the invention What is encapsulated.According to a preferred embodiment, if there is the encapsulation, then transparent polymer, commonly referred to as transparent thermoplastic tree Rouge is used as encapsulating material.Preferred transparent polymer includes but is not limited to silicon rubber and polyethylene vinylacetate (PVA).

Transparency glass plate can also be added in the front of solar battery to provide the mechanical protection to battery front side.Transparent glass Glass plate is well known in the art, and suitable any suitable translucent glass plate can be used.

Back-protective material can be added in the back side of solar battery to provide mechanical protection.Back-protective material is ability Known in domain, and any suitable back-protective material can be used.Preferred back-protective material is with good mechanical Those of energy and resistance to weathering.Preferred back-protective material is the polyethylene terephthalate with polyvinyl fluoride layer. It is preferred that back-protective material is present in below encapsulated layer (there are back-protective layer and encapsulation).

Frame material can be added to the outside of solar battery to obtain mechanical support.Frame material is well known in the art , and any frame material being considered suitable in the context of the invention can be used.Preferred frame material is aluminium.

The method for preparing solar battery

Solar battery can be by the anti-reflection coating that is applied to conducting composition on the front of semiconductor substrate such as silicon wafer As prepared on silicon nitride, silica, titanium oxide or aluminium oxide with forming front electrode.Then back side electroconductive paste is applied to too The back side of positive energy battery is to form weld pad.Electroconductive paste can with as is generally known in the art and be considered suitable in the context of the invention appoint Where formula applies.Example include but is not limited to impregnate, submerge, pouring into, drop coating, injection, spraying, blade coating, curtain coating, brushing or print Brush or its at least two combination.Preferred printing technology is ink jet printing, silk-screen printing, bat printing (tamponprinting), hectographic printing, letterpress or stencil printing or its at least two combination.It is preferred that conductive Paste is preferably applied by silk-screen printing by printing.Specifically, it is at least about 10 μm that network optimization choosing, which has diameter, more preferably extremely It is about 15 μm few, more preferably at least about 20 μm, most preferably at least about 25 μm of finger line opening.Refer to line opening diameter preferably not simultaneously Greater than about 100 μm, more preferably not greater than about 80 μm, most preferably no greater than about 70 μm.

Then aluminium paste is applied to the back side of matrix, be overlapped the edge of the weld pad formed by back side electroconductive paste to form BSF. Then matrix is fired according to the suitable profile determined that forms by matrix and electroconductive paste.

Firing is by the electrode of printing and weld pad sintering to be formed necessary to solid conduction body.Firing is ripe in this field Know, and can be to be considered suitable to carry out in a manner of any in the context of the invention.It is preferred that fire glass material Tg with Upper progress.

Being arranged for the maximum temperature of firing is about 900 DEG C hereinafter, preferably from about 860 DEG C or less.About 820 DEG C of firing temperature For obtaining solar battery.Usually setting firing temperature profile is can burn out the organic bond from conducting composition Material and existing any other organic material.The firing step is usually in band oven in air or in oxygen-containing atmosphere It carries out.It is preferred that firing with quick method for cooking with about 30 seconds to about 3 minutes, more preferably from about 30 seconds to about 2 minutes, most preferably from about 40 Total firing time of second to about 1 minute carries out.It is selected as about 3-7 seconds in 600 DEG C or more of time optimals.Matrix can reach about 700- 900 DEG C of peak temperature about 1-5 seconds.Firing can also be carried out with high delivery rate, for example, about 100-500cm/min, be generated about 0.05-5 minutes retention times.Hot profile needed for multiple humidity provinces, such as 3-12 area can be used to control.

Electroconductive paste firing on the front and back can be carried out simultaneously or sequentially.If being applied to the conduction on two faces Paste has similar, preferably identical best firing condition, then it is suitable for firing simultaneously.If applicable, preferably simultaneously into Row is fired.If firing sequentially carries out, preferably applies and fire back side electroconductive paste first, be thereafter applied to electroconductive paste just On face and fire.

Measure the performance of electroconductive paste

For the performance for measuring solar battery, standard electric test is carried out.Use the business IV from HalmElektronikGmbH Testing machine " cetisPV-CTL1 " characterization is printed on the sample solar battery of front and back paste thereon.It will be surveyed during electrical measurement All components and solar battery to be tested for measuring equipment are maintained at 25 DEG C.The temperature always during actual measurement It is measured simultaneously on battery surface by temperature probe.With the known AM1.5 of 1000W/m2 on Xe arc lamp simulated battery surface The daylight of intensity.To make simulator reach the intensity, flash lamp in a short time several times until it reaches by IV testing machine The maintenance level that " PVCTControl4.260.0 " software supervision arrives.HalmIV testing machine measures electric current using Multi-contact method (I) and voltage (V) is to measure the IV curve of battery.For doing so, by solar battery so that probe refers to the main grid with battery The mode of line contact is placed between Multi-contact probe.The number of contact probe line is adjusted to the number of main gate line on battery surface Mesh.All electricity values are directly automatically measured by the curve by the software package executed.As reference standard, test by same area Size, same wafer material form and use the calibration solar battery from ISEFreiburg of identical front wiring processing And data and validation value are compared.The chip that measurement at least five is processed in much the same way, data are by calculating each value Average value and embody.Software PVCTControl4.260.0 provide about efficiency, fill factor, short circuit current, series resistance and The value of open-circuit voltage.

The adhesive performance of solar battery, which can be used, comes from SomontGmbH, German commercially available welding bench M300-0000- 0901 test.Sample is fixed on the platform first, the welding (ECu+62Sn-36Pb-2Ag) from BrukerSpalek is used FluxKester952S (come from Kester) coating, and the power by applying 12 heat burnings needle (heatedpin) be adhered to On the finger line (fingerline) or main gate line of test, the heat, which burns needle and is pressed in welding, to be referred in line or main gate line.Heat burns needle set There is 280 DEG C of set temperature and sample welding preheating table placed on it is set as to 175 DEG C of temperature.Be cooled to room temperature with Afterwards, sample is mounted in GPStable-TestPro testing machine (GPSolarGmbH, Germany).It secures the strap on measuring head And by the speed of 100mm/s and in a manner of so that the band part being fixed on battery surface and the band part of pull is surrounded angle at 45 ° Pull.Power needed for taking out main gate line/refer to line is measured with newton.At along finger 10 same intervals points of line/main gate line Contact, this method is repeated, including in one of every one end measurement.Take the average value of 10 results.

Specific contact resistivity can measure in the air conditioning room with 22 ± 1 DEG C, wherein will own before measuring Equipment and Material Balance.The specific contact resistivity of the firing silver electrode on the doped layer of front to measure silicon solar cell, can make With " GP4-TestPro " for being equipped with " GP-4Test1.6.6Pro " software package from GPSolarGmbH.The device applies 4 Point measuring principle simultaneously assesses specific contact resistivity by transmission length method (TLM).Printing to measure specific contact resistivity, with chip Refer to that line vertically cuts the wafer strip of 2 one (1) cm wide.By micrometer with the precision measurement of 0.05mm each definite width Degree.It is equipped with wide scope zoom lens VH-Z100R's with from KeyenceCorp at a difference in three (3) on this The width that silver refers to line is fired in digital microscope " VHX -600D " measurement.On each point, width 10 is measured by 2 mensurations It is secondary.Refer to that line width angle value is the average value of all 30 times measurements.Software package is using referring to that line width, width and printing refer to that line is mutual Distance calculates specific contact resistivity.Measurement electric current is set as 14mA.Installation is adapted for contact with a adjacent more contact measurements for referring to line in six (6) Head (Part No. 04.01.0016) is simultaneously contacted with a adjacent finger line in six (6).It is a to measure five (5) being equally distributed on each It is carried out on point.Specific contact resistivity value (m Ω * cm2) after starting measurement, in software measurement strip at each point.Take all 10 The average value of a point is as specific contact resistivity value.

Solar cell module

Another aspect of the present invention is the solar cell module formed by solar battery of the present invention.It can be by multiple solar batteries Space arrangement and the collectivity arrangement for being electrically interconnected to form referred to as module.Preferred module can have multiple arrangements, preferably be known as The rectangular arrangement of solar panel.It arranges and consolidates by a variety of methods of solar battery electrical connection and by this kind of battery machine Determine to form a variety of methods of collectivity arrangement to be well known in the art.It can be used as is generally known in the art and be considered suitable to this hair Any such methods in bright context.Preferred method is to generate low quality: power output ratio, low volume: power output ratio Those of with high-durability.Aluminium is the preferred material being mechanically fixed for solar battery.Embodiment

Embodiment 1

Respectively prepared by the preparaton according to the following table 1 for one group of 3 kinds of exemplary glass composition (G1-G3).All amounts are based on glass group 100% total weight of object is closed with weight % offer.

The preparaton of 1. glass G1-G3 of table

G1G2G3TeO₂85.88177.6Li₂ O3.54.55.3Na₂O12.12.7ZnO9.712.414.4

Glass is formed using melting and method of quenching, wherein raw material is mixed in powder form with predetermined amount.Then by mixture It heats in air or in oxygen-containing atmosphere to form melt, is then quenched.Then the glass of quenching is crushed, ball milling And it sieves to provide the mixture with required granularity.

Then each exemplary glass composition of about 2.5 weight % and about 88 weight % silver powder and about 9.5 weight % is organic Carrier (100% total weight based on paste composite) is combined to form example paste P1-P3.When will paste mix to homogeneous consistency when, They are screen printed into 90 Ω/ thin-layer electric with about 16 μm of silk diameters and 15 μm of EOM using with 360 mesh stainless steel wires On the front of the blank polysilicon chip of resistance.Commercially available back side paste is used to form weld pad, extend throughout battery whole length and It is about 4mm wide.Then, commercially available aluminium back side paste is printed on all remaining areas of cell backside to form aluminium BSF.Then Battery is dried at a suitable temperature.Then will there is peak of the silicon matrix of printing front and back paste at about 700-975 DEG C It is fired at a temperature of value.

The electric conductivity of paste P1-P3 is described in the following table 2.Efficiency (Eta, %), fill factor (FF, %) and 3 standards Series resistance under luminous intensity (Rs3, Ω) is all calculated according to parameter described herein.The adhesive performance of P1 is pasted also according to described herein Parameter calculates.Adhesion test result is in the following table 3 with newton (N) description.

The electrical property of 2. example of table paste P1-P3

The adhesive performance of 3. example of table paste P1

5.78 intermediate value (N) of P1 average value (N), 5.70 maximum value (N) 9.16

Embodiment 2

Respectively prepared by the preparaton according to the following table 4 for another group of exemplary glass composition (G6-G10).All amounts are based on glass group 100% total weight of object is closed with weight % offer.Glass composition is formed by 1 the method for embodiment.

The preparaton of 4. glass G6-G10 of table

G6G7G8G9G10TeO₂87.485.384.885.285.1Li_{2& lt;/sub>O3.13.53.53.53.5Na₂ O11111ZnO8.59.69.59.69.6MgO-0.6---TiO₂--1.2--SiO< sub>2}---0.7-B₂O<sub>3</sub& gt;----0.8

It then will each exemplary glass composition of about 2.5 weight % and about 88.5 weight % silver powder and about 9 weight % organic carrier knots It closes to form example paste P6-P10 and mix, print and fire as described in Example 1.

The conduction and adhesive performance of paste P6-P10 is described in the following table 5 and 6.Efficiency (Eta, %), fill factor (FF, %) It is all calculated according to parameter described herein with the series resistance under 3 etalon optical powers (Rs3, Ω).Adhere to force data according to implementation Identical parameter described in example 1 calculates.

The electrical property of 5. example of table paste P6-P10

P6P7P8P9P10Eta17.77617.72017.70417.53117.693FF78.67178.59178.55078.36077. 959Rs30.00300.00300.00300.00320.0027

The adhesive performance of 6. example of table paste P6-P10

Embodiment 3

Respectively prepared by the preparaton according to the following table 7 for another group of exemplary glass composition (G11-G16).All amounts are based on glass group 100% total weight of object is closed with weight % offer.Glass composition is formed by 1 the method for embodiment.

The preparaton of 7. glass G11-G16 of table

G11G12G13G14G15G16TeO₂84.282.685.284.683.686.7Li& lt;sub>2</sub>O3.53.44.24.94.13.6Na₂O11111- ZnO11.313.09.69.511.39.7

It then will each exemplary glass composition of about 2.5 weight % and about 88.5 weight % silver powder and about 9 weight % organic carrier knots It closes to form example paste P11-P16 and mix, print and fire as described in Example 1.

The electric conductivity of paste P11-P16 is described in the following table 8.Efficiency (Eta, %), fill factor (FF, %) and 3 marks Series resistance under quasi-optical intensity (Rs3, Ω) is all calculated according to parameter described herein.

The electrical property of 8. example of table paste P11-P16

P11P12P13P14P15P16Eta17.58817.60817.53217.53017.59217.552FF79.34179.25479 .27179.05979.40779.115Rs30.00250.00260.00250.00270.00260.0028

Embodiment 4

One group of example paste composite (P17-P20) uses the G1 glass from embodiment 1, the about 88.5 weight % of about 2.5 weight % Silver powder and the preparation of about 9 weight % organic carriers.Paste composite is formed by 1 the method for embodiment.Each example is pasted Other oxides as described in the following table 9 of about 0.2 weight %.

Table 9. pastes unique oxide addition in P17-P20

The electric conductivity of paste P17-P20 is described in the following table 10.Efficiency (Eta, %), fill factor (FF, %) and 3 standard light Series resistance under intensity (Rs3, Ω) is all calculated according to parameter described herein.

The electrical property of 10. example of table paste P17-P21

P17P18P19P20Eta16.33917.51717.44917.549FF73.17478.62478.25578.567Rs30.008 00.00300.00310.0030

Embodiment 5

Other three kinds of exemplary glass compositions (G21-G23) are prepared to measure the performance for changing Li2O content to gained electroconductive paste It influences.The preparaton of glass G21-G23 is described in the following table 4.All amounts are based on 100% total weight of glass composition with weight % is measured to provide.Glass composition is formed by method described in embodiment 1.

The preparaton of 11. glass G21-G23 of table

G21G22G23TeO₂85.886.987.69Li<sub>2</sub& gt;O3.52.41.45Na₂O111ZnO9.79.79.86

One group of example paste composite (P21-P23) with each glass G21-G23 of about 2.5 weight %, about 88.5 weight % silver powder and The preparation of about 9 weight % organic carriers.Paste composite and example solar cell are formed by 1 the method for embodiment, and are made Solar battery is also subjected to the electrical performance test of the parameter according to embodiment 1.As a result it is described in the following table 12.

The electrical property of 12. example of table paste P21-23

P21P22P23Eta19.02418.81117.868FF78.83078.08174.147Rs30.003280.003920.0072 6

As can be seen that the example paste comprising 2.4 and 3.5 weight %Li2O in table 12 and only included 1.45 weight %Li2O Paste P23, which is compared, shows better efficiency, fill factor and series resistance.

These and other advantage of the invention is that those skilled in the art learn from previous specification.Therefore, this field Technical staff, which recognizes, can make being altered or modified without departing from wide creative concept of the invention to the embodiment above.It retouches The specific scale for stating any specific embodiment is merely to illustrate.It is therefore understood that the present invention is not limited to described herein specific Embodiment, but it is intended to cover in all changes in scope and spirit of the present invention and improvement.

Claims (10)

1. conducting composition, it includes:

Conducting metal particles；

At least one glass composition, it includes the total weights based on glass composition to have the oxidation for being at least about 70 weight % altogether Tellurium (TeO2), zinc oxide (ZnO) and lithia (Li2O)；With

Organic carrier,

Wherein at least one glass composition includes the less than about bismuth oxide (Bi2O3) of 5 weight % and lead oxide (PbO), And when there are Bi2O3, the weight ratio of Bi2O3 and ZnO are less than about 0.15.

2. conducting composition, it includes:

Conducting metal particles；

At least one glass composition, it includes tellurium oxide (TeO2), zinc oxide (ZnO) and based on the gross weight of glass composition Amount is more than the lithia (Li2O) of about 1 weight %, and wherein the total amount of TeO2, ZnO and Li2O are at least about 70 weight % and (a) The weight ratio of TeO2 and (b) ZnO and Li2O is about 1-25, preferably from about 2-15；With

Organic carrier,

Wherein at least one glass composition includes the less than about bismuth oxide (Bi2O3) of 2.5 weight % and lead oxide (PbO)。

3. conducting composition according to claim 2, wherein the weight ratio of (a) TeO2 and (b) ZnO and Li2O is about 3-15, Preferably from about 3.5-15.

4. conducting composition, it includes:

Conducting metal particles；

At least one glass composition, it includes tellurium oxide (TeO2), zinc oxide (ZnO) and based on the gross weight of glass composition Amount is more than the lithia (Li2O) of about 1.0 weight %, and wherein the total amount of TeO2, ZnO and Li2O are at least about 70 weight % and ZnO Weight ratio with Li2O is about 0.5-25, preferably from about 1-20；With

Organic carrier,

Wherein the combined amount of bismuth oxide (Bi2O3) and lead oxide (PbO) is based on glass group at least one glass composition Close the 100% total weight less than about 2.5 weight % of object.

5. conducting composition, it includes:

Conducting metal particles；

At least one glass composition, it includes tellurium oxide (TeO2), zinc oxide (ZnO) and lithias (Li2O), wherein (a) The weight ratio of the combined amount of Li2O and (b) TeO2 and Li2O is about 0.001-0.15, and the group of (a) ZnO and (b) TeO2 and ZnO The weight ratio of resultant is about 0.001-0.35, preferably from about 0.005-0.35；With

Organic carrier,

The wherein combined amount of bismuth oxide (Bi2O3) and lead oxide (PbO) less than about 2.5 weights at least one glass composition Measure %.

6. conducting composition according to claim 5, wherein when bismuth oxide (Bi2O3) and lead oxide (PbO) are all present in institute When stating at least one glass composition, the weight ratio of Bi2O3 and ZnO are less than about 0.13.

7. conducting composition as claimed in one of claims 1-6, wherein glass composition include based on TeO2, ZnO and 100% total weight of Li2O is the TeO2 of about 50-99.4 weight %.

8. conducting composition as claimed in one of claims 1-7, wherein glass composition include based on TeO2, ZnO and 100% total weight of Li2O is the Li2O of about 0.1-15 weight %.

9. conducting composition as claimed in one of claims 1-8, wherein glass composition include based on TeO2, ZnO and 100% total weight of Li2O is the ZnO of about 0.5-35 weight %.

10. conducting composition as claimed in one of claims 1-10 is applied on silicon wafer；With

Silicon wafer is fired.