EP2862203A2

EP2862203A2 - Method and production system for producing a photovoltaic module, and photovoltaic module

Info

Publication number: EP2862203A2
Application number: EP13731090.0A
Authority: EP
Inventors: Wilhelm Stein
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-06-19
Filing date: 2013-06-18
Publication date: 2015-04-22
Also published as: WO2013189932A2; WO2013189932A3; DE202013012571U1

Abstract

A method for producing a photovoltaic module (100) comprises: - providing a layer stack (101), comprising a first electrically conductive layer (102), an absorber (103), and a second electrically conductive layer (104) on a substrate (105), and the following: - cutting through the first layer (102), the absorber (103), and the second layer (104) and forming a first trench (106) in the process, - cutting through the second layer (104) and the absorber (103), - cutting through at least the second layer (104) again and forming a third trench (108) in the process, so that the second trench (107) lies between the first trench (106) and the third trench (108), - filling the first trench (106) with an electrically insulating material (109), - overwriting the filled first trench (106) and filling the second trench (108) with an electrically conductive material (110) for electrically contacting the second layer (104) and the first layer (102).

Description

description

Method and production plant for producing a photovoltaic module and photovoltaic module

The invention relates to a method for producing a photovoltaic module. The invention further relates to a photovoltaic module having a plurality of electrically connected in series segments. The invention further relates to a manufacturing plant for producing a photovoltaic module.

Photovoltaic modules can be designed as so-called crystalline photovoltaic modules. The monocrystalline photovoltaic cells used for this purpose, for example, are produced from monocrystalline silicon wafers. Polycrystalline photovoltaic cells consist of disks that do not all have the same crystal orientation. They can be produced by casting. Quasicrystalline photovoltaic cells have mono- and polycrystalline regions.

Thin-film solar cell modules, also called thin-film photovoltaic modules, have photoactive layers with layer thicknesses in the order of micrometers. The semiconductor material used in the photoactive layer or layers may be amorphous or microcrystalline. A combination of layers of amorphous and layers of microcrystalline semiconductor material within a cell is also possible, for example in the so-called tandem cells and the so-called triple cells. The semiconductor materials used are Si, Ge and compound semiconductors such as CdTe or Cu (In, Ga) Se2 (abbreviated CIS or CIGS) and polymers.

In so-called crystalline thin-film photovoltaic modules, first of all a large amount of a semiconductor material, for example silicon, is deposited on a substrate, for example by evaporation, CVD or another deposition method. The semiconductor material is then recrystallized. This happens for example by means of laser or thermally. The layer thicknesses are, for example, in the range of 3 to 50 μm. In order to be able to use economic modules with the largest possible area without the current dissipated laterally in the electrodes of the solar cells becoming so large that high ohmic losses occur, thin-film photovoltaic modules are usually divided into a plurality of segments. The strip-shaped and generally a few millimeters to centimeters wide segments usually run parallel to an edge of the module. The segments are formed by individual layers of the layer structure of the solar cell are interrupted by thin dividing lines in continuous substrate. On the one hand, the separating lines lead to the fact that identical layers of adjacent segments are electrically insulated from one another and, on the other hand, that subsequently applied layers can be electrically connected along a contact with underlying layers. With a suitable arrangement of the separating lines can be achieved in this way a series connection of the individual segments. No electrical current is generated in the area of the dividing lines. In the case of crystalline thin-film photovoltaic modules, the series connection is carried out, for example, in a manner comparable to that of thin-film photovoltaic modules. In this case, it is possible for a highly doped region of the absorber to serve as an electrically conductive layer for current transport instead of a separate front-side contact layer. It is also possible for crystalline thin-film photovoltaic modules to be contacted only from the rear side. At first an emitter is produced. The emitter and exposed base areas are alternately contacted. There is no series connection here and the voltage remains the same. This contacting is produced for example by laser radiation and printing techniques. According to further embodiments, a series connection of emitter-to-base is made comparable to the series connection in the case of thin-film photovoltaic modules, except that the first conductive layer is not exposed and the complete interconnection takes place from the rear.

It is desirable to provide a method of manufacturing a photovoltaic module that enables easy and effective fabrication. It is also desirable to provide a corresponding photovoltaic module that is efficient. It is desirable to provide a manufacturing facility that allows easy and effective production of photovoltaic modules. The invention is characterized by a method for producing a photovoltaic module as well as a manufacturing plant which is suitable for carrying out the method. In accordance with at least one embodiment of the invention, a layer stack is provided on a substrate for producing a photovoltaic module. The layer stack has a first electrically conductive layer, an absorber and a second conductive layer. The first layer, the absorber and the second layer are severed to form a first trench. The second layer and the absorber are severed to form a second trench. In particular, the second trench is spaced from the first trench. At least the second conductive layer is severed again, thereby forming a third trench. The second trench is arranged between the first and the third trench. The first trench is filled with an electrically insulating material. The filled-in first trench is overwritten with an electrically conductive material. The second trench is filled with the electrically conductive material. The electrically conductive material, which bridges the first trench and fills the second trench, electrically contacts the second layer and the first layer.

By forming the trenches, segments of the photovoltaic module are formed. In particular, the first layers of adjacent segments are insulated from one another by forming the first trench. In particular, the second layers of adjacent segments are electrically insulated from one another by the formation of the third trench. By means of the electrically conductive material in the second trench, the first layer and the second layer of adjacent segments are electrically connected to one another. Thus, the adjacent segments are electrically connected in series.

According to embodiments, the trenches are spaced from one another. According to further embodiments, the trenches adjoin one another directly, in particular firstly the first and the third trench are formed adjacent to one another. Subsequently, for example, the first and third trenches are filled with the electrically insulating material and the second trench is inserted next to the first trench in the electrically insulating material to expose the first electrically conductive layer in the region of the second trench. The formation of the first trench and the subsequent filling with the insulating material allow a reliable formation of the insulation of the first layer, so that there can be no short circuits in the first layer between adjacent segments. By forming the third trench spaced from the second trench, reliable isolation of the second layers from adjacent segments is possible. When applying the electrically conductive material thus greater tolerances can be allowed and at the same time shorts are reliably avoided in the second layer.

According to embodiments, to form the third trench, the second layer and the absorber are severed. Thus, the same process parameters can be used to form the second and third trenches. For example, all three trenches are formed by laser beaming. According to further embodiments, a mechanical structuring is possible in which the three trenches are each formed by scratching. According to other embodiments, structuring by etching is possible, in which the three trenches are each formed by printing on etching inks. For example, an ink based on potassium hydroxide is printed. In particular, the etching ink selectively etches the layer stack in such a way that the etching removes predetermined layers and stops at a predetermined layer. It is also possible a combination of mechanical structuring, laser structuring and / or etching or another layer removal method.

According to embodiments, the electrically insulating material is introduced into the first trench by means of an inkjet printing process. For example, electrically insulating ink or a polymer is printed in the first trench. According to further embodiments, the electrically conductive material is applied by an ink jet printing method. The electrically conductive material comprises in particular a silver-containing ink. According to further embodiments, another electrically conductive material is printed, for example aluminum or copper. The electrically insulating material and / or the electrically conductive material are applied according to further embodiments by means of a screen printing method or another method for structured application. According to further embodiments, a plurality of conductive regions are formed, which are arranged spaced apart along the first trench. The conductive regions each comprise the conductive material for electrical contacting of the second layer and the first layer. The second layer is free of the electrically insulating material in further areas between the line regions. The electrical contact between the second layer and the first layer is thus only partially. Thus, it is possible to save conductive material. In addition, based on the photovoltaic module requires less surface for contacting. If the module size remains the same, the efficiency of the photovoltaic module is thus increased.

According to further embodiments, a plurality of isolation regions are formed, which are spaced apart along the first trench. The isolation regions each include the electrically insulating material. The first trench is free of the electrically insulating material in a wider area. The isolation areas correspond to the line areas. Thus, electrically insulating material can be saved and yet a reliable insulation of the first layer can be realized. Only in the areas in which the electrically conductive material is applied, the electrically insulating material is introduced into the first trench. In other embodiments, the filled-in first trench is overwritten with the conductive material such that a surface of the conductive material has a predetermined roughness to scatter radiation incident during operation. The internal reflection of the incident radiation on the highly reflective conductive material reflects the radiation from the contacting region of the trenches into the segments. Thus, it is possible to at least partially convert this radiation into electrical energy. Due to the predetermined roughness, which is predetermined for example by suitable deposition conditions, the proportion of radiation is increased, which is converted into electrical energy. Thus, the efficiency of the photovoltaic module is increased. According to further embodiments, the conductive material is applied such that a

Most of the absorber facing away from the surface of the second layer is covered by the conductive material. An area adjacent to the third trench remains free of the conductive material. This is particularly useful when the conductive material is in is applied to the spaced line regions. By covering almost the entire surface of the second layer with the electrically conductive layer, the conductivity of the second layer is increased. Thus, it is possible to make the individual segments wider than conventional. This means fewer contacting areas and thus higher efficiency.

According to further embodiments, the layer stack is provided with the first electrically conductive layer and the absorber without the second electrically conductive layer.

Subsequently, the first layer and the absorber are severed, thereby forming the first trench. The absorber is severed, thereby forming the second trench. In particular, the second trench is spaced from the first trench. The first trench is filled with the electrically insulating material. A side of the absorber facing away from the first electrically conductive layer is printed with a second electrically conductive layer of the conductive material so that the filled-in first trench is overwritten and the second trench is filled up with the electrically conductive material and a third trench is freed in the second layer remains of the electrically conductive material, wherein the second trench between the first trench and the third trench is arranged.

According to a further aspect, the invention relates to a photovoltaic module with a plurality of electrically connected in series segments. The photovoltaic module is produced in particular by a method according to the application. According to embodiments, the photovoltaic module comprises a layer stack arranged on a substrate. The layer stack has a first electrically conductive layer, a photoactive absorber and a second electrically conductive layer. A first trench interrupts the absorber and the first electrically conductive layer. In the first trench an electrically insulating material is arranged. A second trench interrupts the absorber. A third trench interrupts at least the second conductive layer. The first, the second and the third trench are in particular each spaced from each other. The photovoltaic module has a contact. The contacting electrically couples the second layer to the first layer for series connection of the segment te. The contacting is applied on a side of the absorber remote from the first conductive layer for electrical bridging of the first trench. The contacting is electrically coupled in the second trench to the first layer. The contacting is in the second trench in contact with the first layer.

According to embodiments, the contacting is formed directly by parts of the second electrically conductive layer. On a separately formed to the second electrically conductive layer contacting is particularly omitted. The contacting is applied to the surface of the absorber facing away from the first conductive layer.

According to further embodiments, the contacting and the second electrically conductive layer are formed separately from one another. In particular, the second electrically conductive layer is applied to the surface of the absorber facing away from the first conductive layer and in each case penetrated by the first, the second and the third trench. The contacting is arranged on the surface of the second layer facing away from the absorber.

According to embodiments, the contacting has a predetermined roughness on a surface facing away from the absorber, in order to scatter radiation arriving during operation. Thus, a large part of the incoming radiation is converted into electrical energy. The photovoltaic module is efficient.

According to embodiments, the contacting is formed in a plurality of spaced-apart line regions along the first trench, and in particular the electrically insulating material is arranged in the first trench only in the line regions. As a result, the photovoltaic module is inexpensive to produce and efficient in operation. The manufacturing plant according to further aspects of the invention is configured according to embodiments for producing a photovoltaic module having a plurality of segments by structuring a large-area photovoltaic cell into the plurality of segments and by metallizing for the series connection of the segments. According to further embodiments, the production system is designed for structuring and interconnecting crystalline photovoltaic cells by a sequence of structuring steps and metallization steps without the production of a series interconnection. The photovoltaic cells are then rather functional and electrically contactable for processing to the photovoltaic module.

The described advantages of the manufacturing process apply mutatis mutandis to the manufacturing plant and / or the photovoltaic module and vice versa.

Further advantages, features and developments emerge from the examples explained below in connection with the figures. In the figures, the same or equivalent components may each be provided with the same reference numerals. The illustrated elements and their proportions to each other are not to scale. Rather, individual elements such as layers,

Structures, areas and components for better representability and / or for better understanding to be shown exaggerated thick or large dimensions.

Show it

1 shows a schematic representation of a photovoltaic module according to embodiments,

FIG. 2 shows a schematic representation of a photovoltaic module according to embodiments,

3 shows a schematic illustration of a cross section of a photovoltaic module according to embodiments, FIG. 4 shows a schematic representation of a cross section of a photovoltaic module according to embodiments, FIG. 5 a schematic representation of a cross section of a photovoltaic module according to embodiments,

FIG. 6 shows a schematic representation of a cross section of a photovoltaic module according to embodiments,

7 shows a schematic illustration of a cross section of a photovoltaic module according to embodiments,

8 shows a schematic illustration of a cross section of a photovoltaic module according to embodiments,

FIGS. 9A to 9C are schematic representations of a cross-section of a photovoltaic module at various steps during manufacture according to embodiments;

Figure 10 is a schematic representation of a manufacturing plant according to embodiments, and

Figure 11 is a schematic representation of a manufacturing plant according to embodiments.

FIG. 1 schematically shows a photovoltaic module 100 in a top view. The photovoltaic module 100 is set up to convert radiant energy into electrical energy when ready for operation. According to embodiments, the photovoltaic module 100 is of the type of a thin-film photovoltaic module. According to further embodiments, the photovoltaic module 100 is of the type of a crystalline thin-film photovoltaic module.

The photovoltaic module 100 has a plurality of segments 120, 122, which are arranged on a common substrate 105 (FIGS. 2 to 7). Each directly juxtaposed segments are separated by a contacting region 121 from each other. For example, between the segments 120 and 122, the contacting arranged area 121. In the exemplary embodiments according to FIG. 1, the contacting region 121 runs uniformly along the entire module 100.

According to further exemplary embodiments, as shown schematically in FIG. 2, the contacting regions 121 are formed only in line regions 112 spaced apart from one another. A dividing line, for example in the form of a trench 106, runs along the entire module 100 to form the segments 120 and 121. Only in the line regions 112 are the adjacent segments 120 and 122 electrically coupled to each other to connect in series the adjacent segments 120 and 122 realize. In the further regions 113 between the line regions 112, the adjacent segments 120 and 122 are not electrically connected to one another. According to embodiments, isolation regions 114 are provided, which correspond to the conduction regions 112. In regions 115 between the isolation regions, the trench 106 is free of insulating material according to embodiments. For example, the lines are approximately 50μιη wide and arranged at a distance of about 200μιη to each other.

FIG. 3 shows a schematic representation of a cross section through the photovoltaic module 100 during production.

Transverse to the flat main propagation direction of the photovoltaic module 100, a layer stack 101 is arranged on the substrate 105. A first electrically conductive layer 102 of the layer stack 101 faces the substrate 105. A second electrically conductive layer 104 of the layer stack 101 faces away from the substrate 105. Between the first layer 102 and the second layer 104, a photoactive absorber 103 is arranged.

According to embodiments, in operation, the first conductive layer 102 faces the sun, so that the radiation strikes the layer stack 101 through the substrate 105. According to further embodiments, during operation, the substrate 105 faces away from the sun, so that the second layer 104 faces the sun during operation.

For example, the layer of the electrically conductive layers 102 and 104, which faces the incident radiation during operation, is transparent, for example a TCO (TCO = Transparent Conductive Oxide Layers; Transparent Conductive Oxide Layer). The layer which is arranged facing away from the incident radiation is in particular metallic and, for example, reflective. The absorber 103 comprises, for example, a layer sequence with typically at least one p- and one n-doped semiconductor layer. In the case of silicon-based thin film solar cells, the p- and n-doped layers are usually separated by an extended substantially intrinsic (ie undoped) layer (i-layer).

For better utilization of the wavelength spectrum, a plurality of pin layer sequences with different absorption spectra can be provided one above the other in the absorber 103. Such a tandem cell has, for example, a pin layer sequence of amorphous silicon and a pin layer sequence of microcrystalline silicon. It is also possible to provide a further pin layer sequence of amorphous silicon germanium. In this case one speaks of triple cells.

Typically, in operation of the photovoltaic module, the p-doped layer faces the sun. It is also possible that the n-doped layer faces the sun. As a growth substrate 105 glass or a (metal) film is used. The film is transparent according to embodiments. A cover element 125 (FIG. 6), through which sunlight is incident during operation, is laminated to the module only at the end of the production process when a (metal) film is used. The layer stack remains connected to the growth substrate 105.

As active semiconductor material for the absorber 103, amorphous or microcrystalline group IV semiconductors, for example a-Si, a-SiGe, μ ^ 8ί, or compound semiconductors such as CdTe or Cu (In, Ga) Se2 (abbreviated CIS or CIGS) ) are used. Furthermore, the absorber may comprise organic material configured to convert radiant energy into electrical energy. It can in the absorber

103 also layers of different materials can be combined. Furthermore, partially reflective layers (intermediate reflectors) made of a conductive oxide and / or a conductive semiconductor layer may be provided in the absorber 103. In the contacting region 121, a first trench 106 is formed. The first trench 106 is formed in the stacking direction of the layer stack 101 through the entire layer stack 101. The first trench 106 breaks through the layer stack 101 beginning at a surface 118 of the second layer 104 facing away from the absorber 103 up to the substrate 105. The first layer 102 of the segment 120 is electrically separated from the first layer 102 of the second segment 122 by the trench 106 isolated.

In the contacting region 121, a second trench 107 is introduced. The second trench 107 divides the second layer 104 and the absorber 103. The second trench 107 extends to the first layer 102, so that the first layer 102 remains electrically conductive in the region of the trench 107. The second trench 107 is arranged at a distance from the first trench 106. The second trench 107 is arranged between the first trench 106 and a third trench 108.

In particular, the third trench 108 electrically isolates the second layer 104 of the segment 120 from the second layer of the segment 122. The third trench 108 in the illustrated exemplary embodiments cuts through the second layer 104 and the absorber 103. According to further embodiments, the third trench 108 only cuts through the second layer 104 and the absorber 103 remains at least partially in the region of the third trench 108.

The first trench 106, the second trench 107 and the third trench 108 are in particular introduced into the layer stack 101 after the first layer 102, the absorber 103 and the second layer 104 have been deposited continuously onto the substrate 105. The first trench 106, the second trench 107 and the third trench 108 are introduced into the layer stack 101 in particular by laser radiation.

FIG. 4 shows a schematic representation of the photovoltaic module 100 after the electrical series connection of the segments 120 and 122.

For electrical series connection of the segments 120 and 122, an electrically insulating material 109 is first introduced into the trench 106. For example, the electrical introduced electrically insulating material 109 along the entire trench 106 (see Figure 1). According to further embodiments, the electrically insulating material 109 is only partially introduced into the trench 106 (FIG. 2). In particular, the electrically insulating material 109 is introduced only in the insulating regions 114 in the trench 106, and the regions 115 between the insulating regions are free of insulating material 109. The electrically insulating material 109 comprises in particular an electrically insulating ink or an electrically insulating polymer. The electrically insulating material 109 is, in particular, a material that can be deposited by means of an ink jet method.

After the electrically insulating material 109 has been introduced into the trench 106, an electrically conductive material 110 is applied in the contacting region 121. The electrically conductive material 110 is applied such that an electrically conductive connection is formed between the second layer 104 of the segment 120 and the first layer 102 of the segment 122.

The electrically conductive material 110 is applied to the surface 118 on both sides of the trench 106, so that the trench 106 and the electrically insulating material 109 is bridged. The electrically conductive material 110 is applied so that it extends into the second trench 107 and in particular completely fills it. By the electrically conductive material 110 is an ohmic contact between the second electrically conductive layer 104 and the first electrically conductive layer 102. The electrically conductive material 110 extends from the surface facing away from the substrate 118 to the layer 102. The arrows in the layer stack 101 and The electrically conductive material 110 symbolize the current flow and the series connection of the segments 120 and 122 during operation.

The electrically conductive material 110 comprises in particular Al, Ag, Cu or another electrically conductive material. In particular, the electrically conductive material 110 comprises a material which can be deposited by means of an inkjet printing process.

In the region of the third trench 108, the current flows through the first layer 102, since the second layer 104 is electrically insulated by the trench 108. To the risk of a Short circuit in the region of the third trench 108 of the layer 104 on, according to embodiments, an electrically insulating material 111 in the third trench 108 is provided. According to further embodiments, the electrically insulating material 111 in the third trench 108 is dispensed with. The electrically insulating material 111 can be deposited in particular by means of an inkjet printing process.

The second trench 107 and the third trench 108 are introduced into the layer stack 101 under the same process conditions, according to embodiments. Thus, the formation of the trenches 107 and 108 is simplified. By completely filling the second trench 107 with the electrically conductive material 110, a good ohmic contact between the electrically conductive material 110 and the first layer 102 is ensured. The region of the absorber 103 and the second layer 104 between the second trench 107 and the third trench 108 serves to compensate manufacturing tolerances during the application of the electrically conductive material 110. The third trench 108, which is formed separately from the second trench 107, is sufficiently good ensures electrical isolation of the second layer 104 and short circuits in the second layer

104 can be prevented. Thereby, it is possible to make the contacting area 121 between the adjacent segments 120 and 122 relatively thin. Thus, the efficiency of the photovoltaic module 100 is increased.

According to further embodiments, the trench 108 is introduced into the layer stack 101 after the application of the electrically conductive material 110. This eliminates the possibility that conductive material may enter the trench 108 during application of the electrically conductive material 110. This further reduces the possibility of an unintentional short circuit. This sequence is particularly suitable for photovoltaic modules in which the radiation through the substrate during operation

105 passes to the layer stack 101, for example, absorbers made of CdTe or amorphous silicon. However, it is also possible to apply this order to absorbers from CIGS, for example when structuring mechanically.

For example, the region 121 has a width of 150 μιη or less, for example, a width of 100 μιη. The first trench 106 has, for example, a width of 20 μm. The second trench 107 has, for example, a width of 20 μm. Of the third trench 108 has, for example, a width of 40 μm. The region between the first trench 106 and the second trench 107 has, for example, a width of 10 μm. The area between the second trench 107 and the third trench 108 has, for example, a width of 10 μm. According to further embodiments, the contacting region 121 has a width of less than 60 μm, for example 50 μm.

According to further embodiments, the trench 108 is completely filled with the insulating material 111 (FIG. 4). This is particularly advantageous in CdTe photovoltaic modules. In the case of CIGS photovoltaic modules, for example, transparent material is used for this purpose. The reflective conductive material 110 is applied throughout the bonding area 121 (see description of FIGS. 6 and 7). Thus, almost the entire contacting region 121 is mirrored, so that almost all of the radiation that strikes the entire surface of the photovoltaic module 100 during operation can be converted into electrical energy.

FIG. 5 shows a schematic illustration of a cross section of the photovoltaic module 100 according to further embodiments, which are particularly suitable for a-Si and CdTe photovoltaic modules. In contrast to the photovoltaic module 100 according to the exemplary embodiments of FIG. 4, the electrically conductive material 110 covers almost the entire surface 118 of the second layer 104. Only a region 119 of the surface 118 is free of electrically conductive material 110. The region 119 immediately adjoins to the third trench 108. The region 119 ensures the electrical insulation of the second layer 104 in the region of the third trench 108. Due to the large-area coverage of the layer 104 with the electrically conductive material, a particularly good conductivity is made possible on the side of the absorber 103 facing away from the substrate 105. It is possible to strip the electrically conductive material 110 and thus to support the layer 104. In particular, the electrically conductive material 110 covers the surface 118 of the layer

104 within the conduit areas 112 except for the area 119 completely. In the areas 113 between the line region 112, the surface 118 is not covered with the electrically conductive material 110. FIG. 6 shows a schematic representation of the photovoltaic module 100 according to further embodiments. In addition to the embodiments of FIGS. 4 and 5, a surface 116 of the electrically conductive material 110 facing away from the absorber 103 is rough. A lamination film 123 is applied to the side of the layer stack 101 and the electrically conductive material 110 facing away from the substrate 105. In addition, the cover element 125 is arranged, for example a glass. The arrows symbolize the incident radiation 124 in operation. The rough structure of the surface 116, the incoming radiation 124 is reflected and scattered. The electrically conductive material 110 reflects incoming radiation very well. Due to the rough structure of the surface 116, the incident radiation is additionally scattered. After reflection and scattering on the electrically conductive material 110, the radiation is reflected at the transition between the cover element 125 and the atmosphere. As a result, the radiation which strikes the photovoltaic module 100 in the region of the electrically conductive material 110 reaches the segment 122, so that this radiation can also be converted into electrical energy.

The cover member 125 is, for example, glass having a refractive index of about 1.5. Outside the photovoltaic module 100 is in operation air with a refractive index of about 1. The refractive index jump, the radiation at the transition between the cover member 125 and the air is reflected. As a result, the efficiency of the photovoltaic module 100 is further increased. Almost all of the radiation impinging on the photovoltaic module 100 is used for conversion to electrical energy, including some of the radiation impinging on the contacting region 121. Only radiation which strikes the photovoltaic module 100 between the electrically conductive material and the segment 122 in the region of the third trench 108 is not or only barely converted into electrical energy. FIG. 7 shows a schematic representation of the photovoltaic module 100 according to others

Embodiments. In contrast to the embodiments of FIG. 6, the radiation 124 strikes the layer stack 101 during operation through the substrate 105. In order to be able to at least partially convert the radiation into electrical energy, which in the context of FIG. 1, the contacting region 121 is formed such that the radiation is reflected and / or scattered into the segments 120 and 122. For this purpose, in addition to the rough surface 116 of the electrically conductive material 110, a texture of the electrically insulating material 109 is also provided. In addition, the electrically insulating material 109 is transparent. The arrows symbolize the path of radiation.

The radiation is partially reflected and scattered at the junction between substrate 105 and electrically insulating material 109. Another part of the radiation is reflected and scattered at the transition between electrically insulating material 109 and electrically conductive material 110. In addition, it is possible to roughen the layer 102 in the region of the second trench 107 and in the region of the third trench 108, so that scattering of the radiation also takes place here. The radiation which strikes the photovoltaic module 100 in the region 121 is thus reflected and scattered at least partially into the adjacent segments 120 and 122 and can there be converted into electrical energy. Thus, the efficiency of the photovoltaic module is further increased.

FIG. 8 shows a schematic representation of a cross section of the photovoltaic module 100 according to further embodiments, which are particularly suitable for CdTe photovoltaic modules. In contrast to the photovoltaic module 100 according to the exemplary embodiments of FIGS. 3 to 7, the first electrically conductive layer 102 and the absorber 103 are first applied to the substrate 105 for the production. Subsequently, the trench 106 is introduced into the first electrically conductive layer 102 and the absorber 103, so that the first electrically conductive layer 102 and the absorber 103 are interrupted. The trench 107 is introduced into the absorber 103, so that the electrically conductive

Layer 102 is exposed. The first trench 106 is filled with the electrically insulating material 109.

Subsequently, the second electrically conductive layer 104 is printed on one of the first electrically conductive layer 102 opposite side 126 of the absorber 103. The electrically conductive material 110 is printed on the side 126 so that almost the entire surface of the absorber 103 is covered by the electrically conductive material 110. Only the area 119 is released and thus already at printing the third Trench 108 formed. The second electrically conductive layer 104 is already printed structured. The conductive material 110 forms the second electrically conductive layer 104. The conductive material 110 comprises in particular graphite. The conductive material 110 is applied by an ink jet printing method.

The conductive material 110 bridges the trench 106 and is in contact with the first electrically conductive layer 102 in the trench 107. In addition to the trench 107, the layer 104 is electrically insulated by the trench 108. As a result, the current flow symbolized by the arrows is possible for series connection of the segments 120 and 122.

FIGS. 9A to 9C show the photovoltaic module 100 according to further embodiments during production. In contrast to the embodiments of FIGS. 3 to 7, initially only the first trench 106 and the third trench 108 are introduced into the layer stack 101, as shown in FIG. 9A. Before the second trench 107 is formed, the electrically insulating material 109, 111 is printed. The electrically insulating material 109 and 111 are printed together in one step and are in particular made of the same material. The electrically insulating material 109, 111 is printed so that it fills the two trenches 106 and 108. According to embodiments, the electrically insulating material is printed only in the contacting region 121. According to further embodiments, the electrically insulating material is printed on the entire surface 118 of the layer 104, for example by means of a roller printing method.

Subsequently, as shown in Fig. 9B, the trench 107 is formed. The trench 107 extends through the electrically insulating material 109, 11 as well as through the layer 104 and the absorber 103 up to the layer 102. The trench 107 is arranged between the trench 106 and the trench 108.

Subsequently, as shown in FIG. 9C, the electrically conductive material 110 is printed. The electrically conductive material 110 is printed in such a way that it is in contact with the layer 104 in the region of the segment 120, bridges the trench 106 and makes contact with the layer 102 in the trench 107. The electrically conductive material 110 does not extend to the segment 122, so that the layer 104 of the segment 120 is electrically is isolated from the layer 104 of the segment 122. The arrows in the layer stack 101 and the electrically conductive material 110 symbolize the current flow and the series connection of the segments 120 and 122 during operation. In the order of patterning and metallization according to the embodiments of Figures 9A to 9C, a reliable formation of the series connection is possible because the trench 108 is completely electrically isolated. In addition, it is possible to make the trench 107 very narrow, since fewer tolerances must be taken into account. Thus, the contacting area 121 becomes very narrow. For example, in the case of a transparent insulating material 109, 111, as explained in connection with FIG. 7, full mirroring of the contacting region 121 is also possible. For this purpose, the insulating material 111 in the region of the trench 108 is also covered with the reflective conductive material 110. According to further embodiments, the trenches 106 and 108 are introduced directly adjacent to one another in FIG. 9A. The complaint by parts of the layers 103 and 104 between the trenches 106 and 108 is omitted. The following manufacturing steps are correspondingly explained as in connection with FIGS. 9B and 9C. By directly adjoining the trenches 106 and 108, it is possible to further reduce the contacting area 121.

According to further embodiments, the insulating material 109, 111 is already applied in a structured manner. For example, the insulating material 109, 111 is applied after the trench 107 has been introduced into the layers 103 and 104. The insulating material 109, 111 is applied so that it fills the trenches 106 and 108 and a

Access to the trench 107 leaves free to subsequently fill the trench 107 with the electrically conductive material 110 can.

FIG. 10 shows a schematic representation of a production facility 200. The production facility 200 is in particular set up in a single process step

Series connection of the photovoltaic module 100 by means of a combination of structuring steps and metallization steps form. The substrate 105 with the unstructured layer stack 101 would be in operation with a small electrical energy Supply voltage and a large current. This is not conventionally desired. The production plant 200 divides the layer stack 101 into the segments 120 and 122. The manufacturing plant 200 forms the contacting region 121 for the series connection of the segments 120 and 122. Thus, the photovoltaic module produced by the manufacturing plant 200 in operation supply electrical energy having a higher voltage and a lower current than the unstructured layer stack 101.

The production facility 200 has a structuring device 201. The structuring device 201 has a process head 202. According to embodiments, three laser beam devices 203, 204 and 205 are arranged on the process head 202. In addition, two ink jet printing devices 206 and 207 are disposed on the same process head 202. According to further embodiments, fewer laser beam devices, for example two laser beam devices, are provided. In other embodiments, three ink jet printing devices are provided on the process head 202. In other embodiments, the laser beam devices 203, 204 and 205 are disposed on a common process head and the ink jet printing devices 206 and 207 are disposed on a separate common process head. According to further embodiments, laser beam devices 203, 204 and 205 are arranged on both sides of the substrate. In particular for structuring CIGS photovoltaic modules, laser radiation is radiated onto the layer stack 101 both from below and from above. According to further embodiments, alternatively or additionally, mechanical structuring devices and / or etching devices for forming a trench in the layer stack 101 are provided on the process head 202. The substrate 105 is moved by the structuring device 201 after the layer stack 101 has been completely deposited. The process head 202 is moved relative to the layer stack 101, and the contacting regions 121 are formed by the laser beam devices 203, 204 and 205 and the ink jet printing devices 206 and 207. For example, the first trench 106 is formed by the laser beam device 203. For example, the second trench 107 is formed by the laser beam device 204. For example, the third trench 108 is formed by the laser beam device 205. In particular, it is possible that the laser beam devices 203, 204 and 205 simultaneously form the first trench 106, the second trench 107 and the third trench 108 per contacting region 121.

The inkjet printing device 206 serves, for example, for introducing the electrically insulating material 109 into the first trench 106. The inkjet device 207 serves for example for applying the electrically conductive material 110. The structuring steps are thus possible in a common structuring device 201 with a single process head 202. According to embodiments, two process heads are provided. For example, the laser beam devices 203, 204 and 205 are disposed on a common process head and the ink jet printing devices 206 and 207 are disposed on a separate common process head. By applying the laser beam devices 203, 204 and 205 on a single common process head, the trenches 106, 107 and 108 are correctly positioned with little tolerance to each other. In addition, the electrically insulating material 109 and the electrically conductive material 110 are positioned as closely as possible to the trenches 107, 108 and 109 within narrow tolerances. This makes it possible to make the contacting area 121 narrow. Thus, the efficiency of the photovoltaic module is increased during operation.

As schematically illustrated in FIG. 11, in the structuring device 201, the laser beam devices 203, 204 and 205 are arranged, for example, on the side of the substrate 105. According to further embodiments, in particular if the substrate 105 for the laser beams is not transparent, the laser beam devices 203, 204, 205 are arranged wholly or partially on the side of the layer stack 101. The laser beam devices 203, 204 and 205 are configured, for example, to emit laser beams having mutually different wavelengths.

The ink jet printing devices 206 and 207 are arranged on the side of the layer stack 101 facing away from the substrate in order to be able to introduce the electrically insulating material 109 into the first trench 106 and to introduce the electrically conductive material 110 onto the surface 118 and into the second trench 107 can.

By combining the structuring steps into the common structuring device 201, the manufacturing plant requires less area than conventional needed. This leads to a cost saving. Because structuring is possible after the complete deposition of the layer stack 101, the conventional necessary cleaning steps between the individual coating processes of the first layer 102, the absorber 103 and the second layer 104 can be dispensed with. Thus, it is also possible to dispense with the conventionally necessary production facilities.

The quality of the layer stack 101 is improved due to the eliminated vacuum-lock steps during the production of the layer stack 101.

Due to the deliberate reflection and scattering of the radiation in the contacting region 121, the efficiency of the photovoltaic module 100 increases. The effective range in which the radiation passes through the module 100 as far as possible without conversion into electrical energy can be reduced to the region of the third trench 108, for example to a width of 50 μιη.

Consequently, it is possible to reduce the investment cost and the manufacturing cost. In addition, it is possible to increase the efficiency of the photovoltaic modules 100. The trench 108, which is formed separately in addition to the second trench 107, increases the process reliability. The third trench 108 may be made relatively narrow depending on the tolerances in the application of the electrically conductive material 110. As a result, the efficiency of the photovoltaic module is high with good prevention of short circuits. The arrangement of the laser beam devices 203, 204 and 205 and the inkjet printing devices 206 and 207 in the common structuring device 201, no tolerances between the conventionally existing multiple structuring must be taken into account. Therefore, the areas between the trenches 106, 107 and 108 can be set narrow.

The invention is not limited by the description based on the embodiments of these. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments. For example, one is Combination of the electrically insulating material 111 (Figure 4) and almost complete coverage of the surface 118 by the electrically conductive material 110 (Figure 5) possible.

Claims

claims

A method of making a photovoltaic module (100) comprising:

- Providing a layer stack (101) having a first electrically conductive layer (102), an absorber (103) and a second electrically conductive layer (104) on a substrate (105), and below:

- severing the first layer (102), the absorber (103) and the second layer (104) and thereby forming a first trench (106),

- severing the second layer (104) and the absorber (103) and thereby forming a second trench (107),

- Re-cutting at least the second layer (104) and thereby forming a third trench (108) so that the second trench (107) between the first (106) and the third (108) trench is arranged,

- filling the first trench (106) with an electrically insulating material (109), - overwriting the filled-in first trench (106) and filling up the second trench (108) with an electrically conductive material (110) for electrical contacting of the second layer (104 ) and first layer (102).

2. The method of claim 1, comprising:

Depositing the conductive material (110) such that a majority of an absorber-facing surface (118) of the second layer (104) is covered by the conductive material (110) and an area (119) adjacent to the third trench (108) free of the conductive material (110) remains.

3. A process for producing a photovoltaic module (100), comprising:

- Providing a layer stack (101) with a first electrically conductive layer (102) and an absorber (103), and below:

- severing the first layer (102) and the absorber (103) and thereby forming a first trench (106),

- severing the absorber (103) and thereby forming a second trench (107),

Filling the first trench (106) with an electrically insulating material (109),

- Printing one of the first electrically conductive layer (102) facing away from (126) of the absorber (103) with a second electrically conductive layer (104) of a conductive Material (110) such that the filled first trench (106) is overwritten and the second trench (108) is filled with the electrically conductive material (110) and a third trench (108) in the second electrically conductive layer (104) free remains of the electrically conductive material (110), wherein the second trench (107) is disposed between the first trench (106) and the third trench (108).

4. The method according to any one of claims 1 to 3, comprising:

- Completely filling the second trench (107) with the electrically conductive material (110).

5. The method according to any one of claims 1 to 4, comprising:

Ink jet printing of the electrically insulating material (109),

- Inkjet printing of the electrically conductive material (110).

6. The method according to any one of claims 1 to 5, comprising:

- Filling the third trench (108) with an electrically insulating material (111).

A method according to any one of claims 1 to 6, wherein the overwriting and padding comprises:

Forming a plurality of conductive regions (112) spaced apart along the first trench (106) and each having the conductive material (110) for electrically contacting the second layer (104) and the first layer (102); Layer (104) in further areas (113) between the line regions (112) is free of the electrically insulating material (109).

The method of claim 7, wherein filling the first trench (106) with the electrically insulating material (109) comprises:

Forming a plurality of isolation regions (114) spaced apart along the first trench (106) and each comprising the electrically insulating material (109), the first trench (106) being in a wider region

(115) is free of the electrically insulating material (109), wherein the insulating regions (114) correspond to the conductive regions (1 12).

The method of any one of claims 1 to 8, wherein the padded first trench (106) is over written such that a surface (116) of the conductive material (110) has a predetermined roughness to receive incident radiation (125) sprinkle.

The method of claim 9, wherein the insulating material (109) is transparent and applied to have a predetermined texture (117).

11. The method according to any one of claims 1 to 10, wherein the insulating material (109,

111) is applied so as to have a trench arranged to correspond to the location of the second trench (107).

The method of any one of claims 1 to 11, wherein the first (106) and third (108) trenches are formed such that the first (106) and third (108) trenches directly adjoin one another.

A photovoltaic module having a plurality of electrically series connected segments (120, 122), comprising:

a layer stack (101) arranged on a substrate (105) with:

a first electrically conductive layer (102),

A photoactive absorber (103),

a second electrically conductive layer (104),

a first trench interspersing the absorber and the first electrically conductive layer to form the segments and in which an electrically insulating material is arranged;

a second trench (107) which interrupts the absorber (103),

- A third trench (108) which interrupts at least the second conductive layer (104), wherein the first (106), the second (107) and the third trench (108) are arranged so that the second trench (107) between the first (106) and the third (108) trench is arranged,

- A contact (110) over which the second layer (104) electrically to the first

Layer (102) is coupled to the series connection of the segments (120, 122), which on the first layer (102) facing away from the absorber (103) is applied to the electrical see bridging the first trench (106) and being electrically coupled in the second trench (107) to the first layer (102).

14. The photovoltaic module according to claim 13, wherein the contacting (110) on a surface (116) facing away from the absorber (103) has a predetermined roughness in order to be in the

To scatter incident radiation (125).

15. Photovoltaic module according to claim 13 or 14, in which the contacting (110) is formed in a plurality of spaced-apart line regions (1 12) along the first trench (106) and in particular the electrically insulating material (110) in the first trench only in the line areas (112) is arranged.

16. Photovoltaic module according to one of claims 13 to 15, wherein in the third trench (108) an insulating material (1 11) is arranged.

17. Photovoltaic module according to one of claims 13 to 16, wherein the second electrically conductive layer is formed separately from the contact (110) and from the first trench (106) and the second trench (107) is broken.

18. Manufacturing plant (200), for producing a photovoltaic module (100) having a plurality of segments, which is designed to structure a large-area photovoltaic cell in the plurality of segments and to metallize the series connection of the segments.

19. Manufacturing plant (200) according to claim 18, which is designed for

- severing the second layer (104) and the absorber (103) and thereby forming a second trench (107), - Re-cutting at least the second layer (104) and thereby forming a third trench (108) so that the second trench (107) between the first (106) and the third (108) trench is arranged,

20. Manufacturing plant according to claim 18 or 19, with a structuring device (201), in which at least two laser beam devices (203, 204) are provided on a common process head (202) and on a further common process head two ink jet printing devices (206, 207) are provided ,