CN102332484A

CN102332484A - Metallization method for solar cell fabrication

Info

Publication number: CN102332484A
Application number: CN2010102259474A
Authority: CN
Inventors: 哈特穆特·纳斯鲍墨尔
Original assignee: Rena GmbH
Current assignee: Rena GmbH
Priority date: 2010-07-14
Filing date: 2010-07-14
Publication date: 2012-01-25

Abstract

The invention provides a metallization method for solar cell fabrication, which comprises the steps of: one layer of dopant-containing mediums (56) is coated (30) at positions which are on a solar cell substrate (2) and are to be metallized; carrying out locally heating (32) on the positions which are on the solar cell substrate (2) and are to be metallized, so as to enable dopant to be locally diffused to the internal part of the solar cell substrate (2) from the dopant-containing mediums (56); and conducting electro-deposition processing (34) on metals (12) at the positions (60a and 60b) which are to be metallized and are at a position (32) on which local doped diffusion processing is conducted, wherein the positions (60a and 60b) which are to be metallized are used as electrodes for the electro-deposition processing (34).

Description

Be used for the method for metallising that solar cell is made

Technical field

The present invention relates to a kind of method for metallising of making solar cell.

Background technology

An overriding concern of metallization (plating) technology of the solar cell substrate when making solar cell is the cost problem.In the commercial production of solar cell, on the optical receiving surface of solar cell, use printing process usually such as silk screen printing, intaglio printing or roll printing, be covered with special metal thickener.Because the characteristic of metal thickener and various printing process are to all restrictions of process system, the size of printed size of component, especially metal electrode finger or line (bus-bar connecting line) can't be little of desirable scope.In addition, when coating processing, utilize photoetching process (photolithographic) to add mask earlier with appropriate configuration.Utilize these methods, not only can reduce the needs of metalized surface, and when commercial production, can reduce production costs.

Summary of the invention

Therefore, in order to overcome the problems referred to above of prior art, a main purpose of the present invention provides a kind of method for metallising of making solar cell, and this method can reduce cost and reduce required metallization area.

The invention provides the technical scheme that realizes above-mentioned purpose.

Another object of the present invention, providing can be with the solar cell of lower cost manufacturing.The invention provides and realized this purpose solar cell.

The present invention also provides other relevant technical schemes.

A kind of method according to the present invention comprises that a medium that contains alloy is coated in the solar cell substrate and will carries out on the part of metalized.What the said medium that contains alloy not necessarily only limited to be applied to the solar cell substrate will carry out on the part of metalized; But also can be applied on other parts, especially can on the one side of solar cell substrate, carry out smooth coating and handle.In addition; The part that will carry out metalized at solar cell substrate need be carried out local heat treatment; So that will contain alloy local diffusion in the medium of alloy in solar cell substrate; Carry out the electro-deposition of metal then at local dopant place and handle, and will locate a electrode as electro-deposition.

The diffusion process of alloy in solar cell substrate that contains in the medium of alloy depends on temperature.General alloy, the especially boron that adopts or the mixture of phosphorus or these elements, its diffusion velocity increases with the rising of temperature.Therefore, can heat local alloy partly, and carry out doping treatment, and not have in the alloy entering solar cell substrate of significant quantity because temperature is significantly lower around.Localized heating can realize by the for example local electric heating wire that is provided with.Localized heating also can realize by laser.Solar cell substrate is carried out this type localized heating with the method for local diffusion alloy therein, an explanation that combines emitter structure is arranged in European patent EP 1738402B1.

According to the present invention, contain the concentration of dopant of the medium of alloy, with the temperature of localized heating (temperature that promptly should the place produces), need suitably to be selected, from but the part of alloy infiltrate and can reach required scope.At this; The infiltration of alloy is according to following selection: the position that will carry out metalized at solar cell substrate; Promptly carry out the position of local dopant, high concentration of dopant is provided, thereby make this position in electro-deposition is subsequently handled, can be used as electrode.At this, preferably adopt and the identical concentration of dopant of highly doped emitter structure that adopts usually.

Utilize localized heating, especially adopt laser technology, can form more careful doped structure at lower cost.The cost that the electro-deposition of subsequent metal or alloy is handled is than lower such as the cost of vapor deposition method.Therefore, utilize method of the present invention, can form very careful metallization structure with lower cost, thereby carry out metallization process, and reduce demand electroplating surface to solar cell with lower cost.

According to a preferred embodiment of the present invention; It is that extra thin emitter diffusion of carrying out is handled that the local diffusion of alloy is handled; The identical alloy of type dopant (p type or n type) with the medium that contains alloy; With a lower concentration, will spread in the metallized scope at least.Utilize this thin emitter diffusion to handle, can handle, form a two-stage type emitter (being referred to as selective emitter usually) with alloy local diffusion that will the metalized place.The emitter diffusion process that this is thin is decided according to the infiltration of alloy, for example decides according to the infiltration of alloy in the whole front of solar cell substrate (photoirradiated surface when promptly working).In addition, the surface of solar cell substrate might be exposed to thin emitter diffusion.And thin emitter diffusion is handled, and can before or after the alloy local diffusion is handled, carry out in principle.Yet it is according to above-mentioned thin emitter diffusion that preferred alloy local diffusion is handled.

According to another preferred embodiment of the invention, utilize laser to carry out localized heating; In this way, can limit the position that to carry out metalized more easily during heating.Adopt in the preferred version of laser at this, operating in the solution of laser beam carried out.In other words, laser beam is because the total reflection at the interface between solution and the adjoiner, and in solution, works.

More preferably, use the solution that contains alloy, and in containing the solution of alloy, operate with laser beam as the medium that contains alloy.In addition, by this method, can guarantee when localized heating that will the metalized position, to have the alloy of requirement all the time.

According to a preferred embodiment of the present invention, a branch of at least laser beam, the part surface of the solar cell substrate through will carrying out metalized, and carry out the localized heating operation.Will carry out the position of metalized, and utilize laser beam to handle equally.At this, laser beam can utilize the light refraction device to guide.Perhaps, also can make laser or the fiber waveguide that links to each other with laser relatively mobile with the solar cell substrate surface that institute will carry out metalized.Obviously, also can make solar cell substrate go up mobile at a LASER Light Source or a laser emitting part (the for example opening of a fiber waveguide).

Method according to another embodiment of the invention comprises an electrode network is set that this electrode network comprises electrode metal finger and at least one busbar, and this busbar comprises the busbar metal finger of a plurality of sections at least compartment of terrain configuration.In addition; In order to form the busbar metal finger of a plurality of section arranged spaced, in each required course of processing, laser beam is on the solar cell substrate surface that will carry out metalized; In the metal finger of these a plurality of section arranged spaced each is operated.Moreover laser beam at the busbar metal finger place that forms a plurality of section arranged spaced, with the mode of no repetition, is operated on the solar cell substrate surface.

Above-mentioned electrode network of the present invention is the metallization element with opening, and incident light can pass through metallization element and is radiated on the solar cell surface.This electrode network is generally become grid (grid) again and is set at usually on the plane of illumination of solar cell substrate under in working order.Above-mentioned electrode metal finger of the present invention refers to the metal wire of electrode network, and the purpose that this metal wire is set is to collect the electric current that solar cell produces and this is fed current to a busbar.

Busbar among the present invention refers to a metallization structure, and this metallization structure is used to export by the collected at least a portion electric current of electrode metal finger.For this reason, a busbar is connected with a plurality of electrode metal fingers.The sectional area of the busbar sectional area than electrode metal finger usually is big, and the electric charge carrier that passes through every electrode metal finger because the electric charge carrier of process busbar is more respectively is less.Therefore, busbar is wideer than electrode metal finger usually.

Busbar metal finger refers to a plating line, and it is the element of busbar.Electric current is transported in the busbar through each busbar metal finger.

The no repetitive operation of laser beam refers to, and does not have any part on the surface of the solar cell substrate of this no repetitive operation and handles through laser beam irradiation repeatedly.This no repetitive operation is only at the busbar metal finger position that forms a plurality of section arranged spaced.In principle, for example also can consider to adopt the busbar metal finger of chi structure.

The advantage of the electrode network of above-mentioned and other embodiment can contrast existing electrode network and obtains understanding.Fig. 1 is the sketch map of the solar cell with electrode network 1 of prior art.This electrode network comprises respectively a plurality of electrode metal fingers 3 that link to each other with 5b with busbar 5a; In principle, busbar more than two also can be set.Because thereby solar radiation produces electric charge carrier on active solar cell surface 7; The electric charge carrier that produces in the close region of busbar 5a and 5b is directly collected by busbar 5a and 5b, and the electric charge carrier elder generation of generation is collected and be transferred to busbar 5a and 5b subsequently by electrode metal finger 3 in the zone beyond the close region of busbar 5a and 5b.Then, these electric charge carriers are through busbar 5a and 5b and exported by solar cell.Therefore, the electric current that the current ratio that is delivered to busbar 5a and 5b is delivered to electrode metal finger 3 is big.So for fear of current loss, the cross-sectional area of busbar 5a and 5b is also bigger, this also is the general obvious reason bigger than the width of electrode metal finger 3 of width of why busbar.

If electrode metal finger 3 is to make with method of the present invention,, need with laser at the surperficial enterprising line operate of solar cell substrate then for the purpose of localized heating.Therefore apparently, often must be in order to form this laser of busbar 5a and 5b at the surperficial enterprising line operate of solar cell substrate, so that busbar can form proper width as shown in Figure 1.In addition, need to form the multi-stripe laser light beam to make busbar 5a and 5b; The number of laser beam depends on the circumstances; When forming similar traditional busbar shown in Figure 1, laser need be operated through a certain the repetition at substrate surface, so that can produce the metallization of one of busbar subsequently.

Unexpected is that evidence on the metalized portion of making according to the method for the invention, must not used broad busbar as shown in Figure 1, just can guarantee fully big current delivery.It is emphasized that in addition to comprise the busbar of using a plurality of sections metal finger at interval of processing according to the method for the invention described above, can guarantee sufficient current delivery, and required laser can obtain obviously reducing.In other words, operate continually on the solar cell substrate surface with laser beam need not resembling in the prior art manufacture method of wide busbar as shown in Figure 1.

This has obtained clear and definite demonstration in Fig. 2; Shown that in Fig. 2 this metalized portion comprises electrode metal finger 3 and busbar 15a and 15b according to the metalized portion of above-mentioned preferred feature preparation.The busbar metal finger 9a that each root busbar 15a in an illustrated embodiment and 15b comprise the section arranged spaced, and the busbar more than two can be set in principle.Can obviously find out from the comparison of Fig. 1 and Fig. 2, because structure according to the method for the invention needs less laser radiation, so can make solar cell with lower cost.Confirmable is that structure of the present invention can provide good equally electric current supply, and the solar cell of producing has identical fill factor.

Another advantageous feature of the present invention, in the scope of the busbar metal finger that forms a plurality of section arranged spaced, laser beam does not have operation repeatedly, thereby can reduce production costs significantly.As shown in Figure 2, all busbar metal fingers all are to utilize the no repetitive operation of laser beam to form.Yet; Compare with the making of broad busbar as shown in Figure 1; Though much narrower metal fingers are not to utilize no repetition laser operations making but every busbar metal finger utilizes the laser rays of two repetitions to process, its cost of manufacture is still more to one's profit.Certainly, also can make by three, four even the busbar metal finger that constitutes of more repetition laser rays at this, but its cost advantage will reduce like this.

In addition, utilize another favorable characteristics of the present invention, the efficient of solar cell also can be provided, because under the activity coefficient of identical electric current input quality and identical solar cell, can reduce electrode network surperficial the covering of active solar cell.

According to a preferred embodiment of the present invention, when forming at least one busbar, the busbar metal finger at a distance from configuration is local repeated configuration therebetween.

According to a preferred embodiment of the present invention, in order to form the electrode metal finger, laser beam in the course of processing along the electrode metal finger to carry out the enterprising line operate in solar cell substrate surface of metalized.

Solar cell of the present invention comprises an electrode network; This electrode network comprises electrode metal finger and at least one busbar; A plurality of electroplax metal fingers are electrically connected by this at least one busbar, and said at least one busbar is suitable for exporting the electric current that a plurality of electrode metal fingers are produced.In addition; At least one busbar has the busbar metal finger of a plurality of sections at least ground each interval configuration, and these busbar metal finger section are made up of and are up to respectively ten times of width of an electrode metal finger not at least in part the electro-deposition metal.

So-called " electro-deposition metal " refers to the metal or metal alloy through chemistry or physical coating, especially vapour deposition.The preferably metal of chemical deposition, more preferably electro-deposition metal.

Solar cell of the present invention can utilize laser chemistry to handle, and makes at lower cost, especially utilizes method of the present invention.This can give the credit to busbar can be with less laser radiation manufacturing; In other words; Laser beam only need just have the advantage of saving time with cost in the less operation of the solar cell substrate enterprising line length in surface like this on solar cell is made in the process of making busbar.Especially significantly be that evidence, the present invention can realize the above-mentioned reduction of solar cell cost of manufacture and the good electric current conveying of electrode network simultaneously.Therefore, can when reduce cost of manufacture, not cause the deterioration of the fill factor of solar cell, thereby can not influence efficient.

In principle; Compare with the big busbar (busbar 5a and 5b as shown in Figure 1) of prior art; Also can be implemented in the busbar of making busbar metal finger under the situation about reducing cost, and the width of these busbar metal fingers is 10 times of the electrode metal finger with a plurality of sections at least ground arranged spaced.Yet; The influence that the reduction of cost can be increased by the width of busbar metal finger; Because increase along with width; Just more frequent for form the laser beam operation that corresponding busbar metal finger need carry out on the solar cell substrate surface, and to repeat this operation toward contact, cover the slit to avoid in busbar metal finger, producing.

In addition; A remarkable part is that the geometrical construction of electrode metal finger and busbar metal finger is suitably selected in evidence; Can not worsen electric current conveying quality or reduce under the situation of fill factor, reduce surperficial the covering of active solar cell solar cell.In other words, can improve the efficient of solar cell.

According to a further advantageous embodiment of the invention, a busbar has the busbar metal finger that a plurality of each intervals dispose at least.These busbar metal fingers are section ground but also each interval configuration fully not only.According to a particularly advantageous embodiment of the present invention, busbar comprises the busbar metal finger of configuration fully at each interval and is made up of these fingers.

According to a further advantageous embodiment of the invention, at least one busbar comprises the local busbar metal finger of assembling arranged spaced.At this, the meaning of " the local gathering " is meant that the electric charge carrier that is produced passes through the surface that electrode network is assembled, and typically refers to the active solar cell surface.Therefore, busbar is at a plurality of busbar metal fingers of local convergence collection arranged spaced.

On the contrary, in an alternate embodiment, busbar metal finger mainly is to be evenly distributed on the active solar cell surface.Therefore, in the case all busbar metal fingers all as an independent busbar.

According to another preferred solar battery structure of the present invention; At the position of solar cell substrate in abutting connection with busbar metal finger; With at the position of solar cell substrate adjacent electrode metal finger, have the doping content higher than peripheral part of solar cell substrate.

In this way, can form a kind of emitter of two stepwises, often become selective emitter.This emitter can be collected the charging carrier that is produced effectively when electroplating, on the contrary, the zone charging carrier that causes owing to doping content is lower being produced is compound less around, thereby can increase the efficient of solar cell on the whole.If the busbar metal finger of solar cell substrate is higher than the doping content of peripheral region with the doping content in all of its neighbor zone of electrode metal finger, then can realize maximum improvement.If have only the element of adjacent range to compare high-concentration dopant, also can improving action.

According to another preferred embodiment of the invention, this busbar metal finger, and this electrode metal finger at least, preferably depositing metal forms, or is formed by depositing metal fully.At this, chemical deposition metal preferably.This type chemical deposition can be adopted electrochemical deposition, claims galvanoplastic again, or claims the no current sedimentation.

According to another preferred embodiment of the invention, said electrode network has at least one smooth contact surface, is used to collect the electric current that is produced; And this contact surface and a plurality of electrode metal finger and/or the direct adjacency of busbar metal finger.In this way, can make a plurality of solar cells connected to one another easily, wherein each electrode network can connect via at least one smooth contact surface respectively, rather than the electrode contact of narrow busbar metal finger individually.

According to another preferred embodiment of the invention, there is the metal finger of varying number to be electrically connected to each other respectively through at least two busbar metal fingers and electrode metal finger.At this, the direct-connected meaning is meant that the metal finger and the electrode metal finger of the affiliated quantity of the relevant busbar metal finger of independent utilization are connected to each other, and does not need other electrical connection.Therefore, the first busbar metal finger in these at least two busbar metal fingers than the second busbar metal finger more can with the metal finger of another quantity directly and the electrode metal finger be electrically connected to each other.

According to another preferred embodiment of the invention, each root busbar utilize its varying number respectively busbar metal finger directly and the electrode metal finger be electrically connected to each other.According to this preferred embodiment of the invention, can reduce capture-effect and can provide gratifying electric current to carry through busbar simultaneously through electrode network.

Description of drawings

Fig. 1 is a kind of sketch map with solar cell of electrode network of prior art.

Fig. 2 is the sketch map according to the solar cell of one first embodiment of the present invention.

Fig. 3 is the phantom along the A-A line among Fig. 2.

Fig. 4 is the sketch map according to the solar cell of one second embodiment of the present invention.

Fig. 5 is the sketch map according to the solar cell of one the 3rd embodiment of the present invention.

Fig. 6 is the phantom of the solar cell of the 3rd embodiment.

Fig. 7 is the schematic diagram according to manufacture method of the present invention.

Fig. 8 is the sketch map of method according to an embodiment of the invention, wherein in a kind of solution, operates a laser beam and on a solar cell substrate surface, does not have repetitive operation.

Fig. 9 is the sketch map of method according to another embodiment of the invention, wherein in a kind of fiber waveguide, operates a laser beam and on a solar cell substrate surface, does not have repetitive operation.

Embodiment

As shown in Figure 2, be the sketch map of first embodiment of solar cell 10 of the present invention.This solar cell 10 has an electrode network, and this electrode network comprises electrode metal finger 3 and busbar (busbar) 15a, 15b.This busbar 15a, 15b comprise busbar metal finger 9a, the 9b of a plurality of arranged spaced respectively.Every busbar 15a, 15b comprise busbar metal finger 9a, the 9b of local gathering and arranged spaced respectively.

Compare with the prior art solar cell with electrode network shown in Figure 1, according to the advantage of the solar cell of the present invention of the embodiment of Fig. 2, being that made solar cell has covers less active solar cell surface 7.In the present embodiment, what it was less covers, and mainly is owing to busbar 15a, 15b are made up of busbar metal finger 9a, the 9b of each interval configuration respectively.As stated, this less not covering can worsen fill factor, thereby can raise the efficiency.

In addition, solar cell as shown in Figure 2 has the advantage that reduces production costs.Because compare with roomy thick busbar 5a, the 5b of prior art shown in Figure 1; In the making of the busbar 15a that comprises five busbar metal fingers respectively of the present invention as shown in Figure 2,15b, obviously do not need laser to operate on the solar base plate surface continually.

Shown in Figure 3, be solar cell of the present invention 10 as shown in Figure 2 phantom along the A-A line.Visible from Fig. 3, except a back electrode 11 that entirely is provided with, busbar metal finger 9a has electro-deposition metal 12.In addition, the doping content of the adjacent part 13 of busbar metal finger 9a is higher than the doping content of peripheral part 14, wherein in this peripheral part 14, has only rare emitter diffusion to mix.Therefore, the adjacent part 13 of high-concentration dopant has constituted one two stepwise emitter with rare emitter part 14 of mixing.

Fig. 4 is the sketch map according to the solar cell 10 ' of one second embodiment of the present invention.This embodiment is except the structure of

busbar metal finger

17a, 17b, 17c, 17d, 17e, 18a, 18b, 18c, 18d, 18e, and all the embodiment with shown in Figure 2 is identical for all the other.Present embodiment also is to have two

busbar

16a, 16b, also can adopt the busbar of other quantity in principle.These

busbars

16a, 16b also are that the

busbar metal finger

17a, 17b, 17c, 17d, 17e, 18a, 18b, 18c, 18d, the 18e that utilize a plurality of each interval configurations respectively constitute.In Fig. 2, the metal busbar finger 9a of busbar 15a, 15b, the length of 9b is identical and this busbar metal finger 9a, 9b with identical length directly and electrode metal finger 3 be electrically connected to each other.By contrast, in the embodiment shown in fig. 4, each root busbar metal finger 17a of

busbar

16a, 17b, 17c, 17d, 17e are electrically connected to each other with different length and electrode metal finger 3.The busbar metal finger 18a of

busbar

16b, 18b, 18c, 18d, 18e also constitute in the same manner.

Fig. 5 is the sketch map according to the solar cell 20 of one the 3rd embodiment of the present invention.Wherein electrode network comprises electrode metal finger 3 and busbar metal finger 19.At this, busbar metal finger 19 evenly is arranged on the active solar cell surface 7.All busbar metal fingers 19 can be considered to a busbar 25 on the whole.Undoubtedly, such electrode network especially can avoid electroplating the local flaw in the net.

Embodiment as shown in Figure 5 has

smooth contact surface

23a and 23b; And contacting of the electrode network that its flat structures helps being made up of busbar metal finger 19 and electrode metal finger 3, and be convenient to be connected into a solar module to more this solar cell.Plural

smooth contact surface

23a, 23b can be set in principle, yet must consider that the increase of covering owing to active solar cell surface 7 influences the problem of efficient.In addition, also can consider only to be provided with single smooth contact surface, yet this may carry adverse effect arranged according to the size of solar cell to electric current.At present when solar cell is made in industry, the size of its solar cell substrate is proved and can has preferable efficient having two smooth contact surface 23a, 23b.Certainly, smooth contact surface also can be used in embodiment as shown in Figure 2.

Fig. 6 is the phantom of the solar cell of a third embodiment in accordance with the invention.Can have the structure of flush type contact according to solar cell of the present invention, promptly so-called " flush type contact solar cell " (buried contact solar cell).Representational busbar metal finger and electrode metal finger are electro-deposition metal 12 as shown in Figure 5.In other words, busbar metal finger and electrode metal finger can constitute with mode as shown in Figure 6.

According to Fig. 6, electro-deposition metal 12 is embedded in the solar cell substrate.Its method of imbedding in solar cell substrate, normally for example metal 12 by electro-deposition to opening in before utilize the etching method of laser ablation method or laser work.With the adjacent zone 13 ' of the electro-deposition metal section and part of busbar metal finger or contacting metal finger 12 and its opposite around part 14; The emitter diffusion that must have higher concentration is mixed; Thereby, had two stepwises or selective emitter as such among the embodiment shown in Figure 3.

In addition, the surface of solar cell substrate 2 as shown in Figure 6 has through superficial makings (surface texturing) handles the pyramid structure that forms, so that increase coupling efficiency.For same purpose can be covered with one deck anti-reflection layer 27 on its surface.Pyramid structure and anti-reflection layer that this type has surface texture formation obviously can be used among all embodiment of solar cell of the present invention.

It is obvious that to those skilled in the art, can implement with the mode of flush type contact like electrode metal finger and the busbar metal finger of Fig. 4 and embodiment shown in Figure 5.

Fig. 7 is a schematic diagram of making the method for metallising of solar cell of the present invention.According to the method, a kind of medium that contains alloy is overlayed on the position (30) that will be electroplated of solar cell substrate.In addition, localized heating (32) is carried out at the position that will be metallized processing to this solar cell substrate, so that the alloy local diffusion is doped to solar cell substrate inside.Then, carry out metal electric deposit (34) at the position that receives the processing of alloy local diffusion, wherein an electrode is served as at this position when carrying out electro-deposition (34).Fig. 7 does not also mean that in the preceding processing (30) that must be covered with doped dielectric of localized heating (32).Can certainly so do, yet also can utilize laser 53 to be covered with the processing (30) of doped dielectric and the processing (32) of localized heating simultaneously like for example Fig. 8 or method shown in Figure 9.

Utilizing laser to be covered with doped dielectric (30) can be as shown in Figure 8 with the process of carrying out localized heating.As shown in Figure 8, this method comprises that the laser beam 54 that utilizes a laser 53 operates in a solution containing phosphate especially phosphoric acid solution 56.Phosphoric acid solution utilizes a nozzle 58 as shown in the figure to be sprayed on the surface 52 of solar cell substrate 2, and this nozzle is worked with laser beam 54.In this way, can guarantee that 2 of solar cell substrates are heated at position that it has the medium (being phosphoric acid solution in this embodiment) that contains alloy.

Fig. 8 is used for the course of processing of example description metal finger 60a and 60b.Can relate to electrode metal finger and busbar metal finger at this.Process operation and the phosphorus in this position phosphoric acid solution that laser beam 54 has been accomplished metal finger 60a mixed by the part be diffused in the solar cell substrate 2 after, just carry out the phosphorus doping local diffusion processing of metal finger 60b.Therefore, Fig. 8 illustrate brief description laser beam 54 on the surface 52 of solar cell substrate 2, do not have the process of repetitive operation 36.The real time operation direction of laser beam 54 is as shown in arrow 64.Therefore, in processing procedure subsequently, this laser beam 54 will carry out the doping treatment on the unprocessed portion still 62 of busbar metal finger 60b.

As shown in Figure 8, the width of

metal finger

60a, 60b should be the width of enough laser beam 54 operations of ability in each metal finger course of processing in principle.Therefore, 54 needs of laser beam carry out single treatment respectively to metal finger 60a, 60b.Therefore, the described laser beam 54 of embodiment as shown in Figure 8 with the mode of no repetition on the surface of solar cell substrate 2 52 enterprising line operates.Therefore, have no on the surface 52 of solar cell substrate 2 part received laser beam 54 repeat repeatedly handle.On the contrary, laser beam 54 is handled along metal finger 60a earlier, carries out the processing to metal finger 60b then as illustrated in fig. 8 again.

Fig. 9 is the sketch map of method according to another embodiment of the present invention.The method of Fig. 9 is most of identical with the method for Fig. 8, and unique difference is that laser beam 54 is not in phosphoric acid solution 56, to operate in the embodiment of Fig. 9, but in a fiber waveguide, operates, and this fiber waveguide can comprise for example optical fiber.The part of this fiber waveguide 66 is set in the nozzle 58, so that phosphoric acid solution 56 can flow through around fiber waveguide.Therefore, the fiber waveguide 66 of embodiment as shown in Figure 9 is set in the phosphoric acid solution 56.The explanation of its remaining operation is with the explanation to Fig. 8 embodiment.

Like the solar cell of the embodiment of Fig. 2 to Fig. 6, can both use according to the method for the invention, especially according to the method for the embodiment of Fig. 7 or Fig. 8, and obtain making.

The medium that can adopt all to contain alloy in principle according to the method for the invention, especially, the embodiment of Fig. 8 or Fig. 9 can adopt the solution of boron-containing solution or boron-containing compound as the alloy medium.When adopting solution containing phosphate, Fig. 8 or 9 embodiment obviously are not limited to phosphoric acid solution.Other phosphorus compounds also can be used as the alloy medium.

The critical piece label declaration:

1: solar cell 2-solar cell substrate 3: electrode metal finger

5a: busbar 5b-busbar 7: active solar energy

Battery surface

9a: busbar metal finger 9b: busbar metal finger 10: solar cell

10 ': solar cell 11: back electrode 12: the electro-deposition metal

13: the adjacent part of busbar metal finger

13 ': the adjacent part of busbar metal finger or contacting metal finger

14: peripheral part 15a: busbar 15b: busbar

16a: busbar 16b: busbar 17a: busbar metal finger

17b: busbar metal finger 17c: busbar metal finger 17d: busbar metal finger

17e: busbar metal finger 18a: busbar metal finger 18b: busbar metal finger

18c: busbar metal finger 18d: busbar metal finger 18e: busbar metal finger

19: busbar metal finger 20: solar cell 23a: smooth contact surface

23b: smooth contact surface 25: busbar 27: anti-reflection layer

28: emitter diffusion mixes 29: the surface receives the pyramid structure that veining is handled

30: be covered with doped dielectric 32: utilize the local laser heating

34: electro-deposition handles 36: laser beam no reprocessing from the teeth outwards

52: solar cell substrate surface 53: laser

54: laser beam 56: phosphoric acid solution 58: nozzle

60a: metal finger course of processing 60b: the metal finger course of processing

64: laser beam direction of operating 66: fiber waveguide.

Claims

1. manufacturing solar cells (1; 10; 20) method for metallising comprises:

The position (60a, 60b) that on a solar cell substrate (2), will carry out metalized is covered with the medium (56) that (30) one deck contains alloy;

On solar cell substrate, will carry out the position (60a, 60b) of metalized and carry out localized heating (32) so that alloy from the medium (56) that contains alloy local diffusion to the inside of solar cell substrate (2); And

At the position that will carry out metalized at the position (32) that will carry out local doping DIFFUSION TREATMENT (60a, 60b); Carry out the electro-deposition of metal (12) and handle (34), and the said position (60a, 60b) that will carry out metalized is used as the electrode that electro-deposition is handled (34).

2. the method for claim 1, wherein said localized heating (32) is undertaken by laser (53).

3. method as claimed in claim 2, wherein with a kind of solution (56) that contains alloy as the medium (56) that contains alloy, and the laser beam (54) of said laser (53) is operated in the said solution (56) that contains alloy.

4. the method for claim 1; Wherein said localized heating (32) is undertaken by laser (53); And the laser beam (54) of said laser (53) is operated in a fiber waveguide (66); Said fiber waveguide is set in a kind of solution (56) that contains said alloy at least in part, and the said solution that contains said alloy is used as the medium (56) that contains alloy.

5. like any one the described method in the aforementioned claim, wherein use a kind of phosphoric acid solution (56) as the medium (56) that contains alloy.

6. like any one the described method in the aforementioned claim, (52) enterprising line operate (36) carries out localized heating (32) at least a portion surface of the solar cell substrate (2) that will carry out metalized wherein to use at least one laser beam (54).

7. method as claimed in claim 6, wherein

Formed (20,32,34) and comprised electrode metal finger (3) and at least one busbar (15a, 15b; An electrode network 25) (3,15a, 15b; 3,25),

Said busbar has busbar metal finger (9a, the 9b of a plurality of sections at least ground each interval configuration; 19),

Laser beam (54) is on the surface (52) that will carry out metalized of solar cell substrate (2), at busbar metal finger (9a, the 9b that will form the each interval configuration of a plurality of sections at least ground; 19) position, according to the desired metal finger course of processing (60a, 60b), the enterprising line operate in surface (52) (36) in solar cell substrate (2), and

Said laser beam (54) is at busbar metal finger (9a, the 9b that will form (20,32,34) a plurality of each interval configurations; 19) (60a is 60b) with the mode of the no repetition enterprising line operate in surface (52) (36) in solar cell substrate (2) for each section.

8. method as claimed in claim 7, wherein in order to form at least one busbar, the metal finger of each interval configuration is provided with by the mode of assembling with the part.

9. method as claimed in claim 7, wherein said busbar metal finger (19) is gone up by configuration uniformly on active solar cell surface (7).

10. solar cell with an electrode network, wherein said electrode network are to utilize to process like any one the described method among the claim 7-9.

11. have an electrode network (3,15a, 15b; 3,25) solar cell (10; 20), this electrode network has electrode metal finger (3) and at least one busbar (15a, 15b; 25), and a plurality of electrode metal finger (3) through at least one busbar (15a, 15b; 25) be electrically connected to each other, and said at least one busbar (15a, 15b; 25) comprise a plurality of electrode metal fingers (3) to carry the electric current that is produced, wherein, at least one busbar (15a, 15b; 25) have busbar metal finger (9a, the 9b that a plurality of sections at least ground each interval disposes; 19) also have at least a part to constitute and have respectively the width of the width that decuples a said electrode metal finger (3) at most by electro-deposition metal (12) respectively.

12. solar cell (10 as claimed in claim 11; 20), busbar metal finger (9a, the 9b of wherein said a plurality of sections at least ground each interval configuration; 19) have the width of the width that is five times in a said electrode metal finger (3) at most respectively, and preferably have the width of the width that is three times in a said electrode metal finger (3) at most.

13. like claim 11 or 12 described solar cells (10; 20), wherein said busbar metal finger (9a, 9b; 19) having approximately and the identical width of electrode metal finger (3), preferably less than 100 microns width, more preferably is the width less than 60 microns.

14. like any one described solar cell (10 in the claim 11 to 13; 20), wherein said at least one busbar (15a, 15b; 25) have busbar metal finger (9a, the 9b that a plurality of each intervals dispose; 19), preferably constitute by these busbar metal fingers.

15. like any one described solar cell (10) in the claim 11 to 14, wherein busbar (15a, 15b) comprise local assemble and the busbar metal finger of configuration at each interval (9a, 9b).

16. like any one described solar cell (20) in the claim 11 to 14, wherein busbar metal finger (20) is configured on the active solar cell surface (7) equably.

17. like any one described solar cell (10) in the claim 11 to 16; Wherein (9a, 9b) doping content in the zone (13 ') of the zone of adjacency (13) and solar cell substrate (2) and electrode metal finger (3) adjacency is higher than the doping content in the peripheral region of solar panel with busbar metal finger for solar cell substrate (2).

18. any one described solar cell (10 in the claim 11 to 17; 20), busbar metal finger (9a, 9b at least wherein; 19) by depositing metal (12) and preferably constitute by chemical deposition metal (12), and preferably electrode metal finger (3) also by depositing metal (12) and preferably constitute by chemical deposition metal (12).

19. any one described solar cell (20) in the claim 11 to 18; Wherein said electrode network (3; 25) has a smooth contact surface (23a who is used to collect the electric current that is produced at least; 23b), and a plurality of electrode metal finger (3) and/or busbar metal finger (19) directly adjoin herein.

20. any one described solar cell (10 ') in the claim 11 to 18; Wherein through at least two busbar metal fingers (17a, 17b, 17c, 17d, 17e, 18a, 18b, 18c, 18d, 18e); Preferably through a busbar (16a; Each root busbar metal finger (17a, 17b, 17c, 17d, 17e, 18a, 18b, 18c, 18d, 18e) 16b) has the busbar metal finger of varying number directly to be electrically connected with electrode metal finger (3) respectively.