A photovoltaic device showing improved efficiency in the case of light shielding, and a method for manufacturing such a photovoltaic device

Abstract

The present invention relates to a photovoltaic device (1) comprising at least one photovoltaic cell (2) having a base electrode (3), a top electrode (4) and a layer system (5) comprising at least one photoactive layer (6) arranged between the base electrode (3) and the top electrode (4). At least one photovoltaic cell (2) is at least partially segmented into segments (7), and the segmentation is designed so that at least the upper electrode (4) and layer system (5) of one segment (7) are separated from the upper electrode (4) and layer system (5) of another segment (7) by at least one cavity (8) to prevent mutual contact, or so that the upper electrode (4), layer system (5) and at least partially the base electrode (3) of one segment (7) are separated from the upper electrode (4), layer system (5) and at least partially the base electrode (3) of another segment (7) by at least one cavity (8) to prevent mutual contact, and the at least one cavity (8) is formed in a direction at least substantially perpendicular to the layer system (5) of the at least one photovoltaic cell (2), and the segments (7) of the at least one photovoltaic cell (2) are electrically conductively connected in parallel to each other so that the flow of current through the at least one photovoltaic cell (2) is distributed to the individual segments (7).

Description

Technical Field

[0001] The present invention relates to a photovoltaic device including at least one photovoltaic cell, a photovoltaic system including at least two such photovoltaic devices, and a method for manufacturing such a photovoltaic device.

Background Art

[0002] Photovoltaic devices, particularly those incorporated into building structures, are temporarily shaded. The photovoltaic device consists of at least one photovoltaic cell including at least one photoactive layer, which can be connected in series or in parallel.

[0003] Photovoltaic devices or their photovoltaic cells connected in series are not necessarily shaded to the same extent, and some continue to be partially exposed to sunlight. In this case, the shaded photovoltaic cell connected in series with others generates an opposing voltage compared to the unshaded photovoltaic cell, restricting or blocking the flow of current from other photovoltaic cells to that photovoltaic cell.

[0004] Prior art methods for avoiding the problem of partial shading employ bypass diodes to ensure that current continues to flow from series-connected photovoltaic cells and to prevent damage to partially shaded photovoltaic cells. In the case of shaded or defective photovoltaic cells, by connecting a bypass diode in parallel with the photovoltaic cell, power loss is reduced. When a photovoltaic device, particularly a photovoltaic cell of a photovoltaic device, is at least partially shaded, this photovoltaic cell does not generate a voltage or generates a low voltage, and the generated current by the photovoltaic cells connected in series upstream thereof cannot be conducted, damaging the at least partially shaded photovoltaic cell. In such a case, the bypass diode can take over the conduction of the generated current from the photovoltaic cell connected upstream through the bypass diode to the photovoltaic cell connected downstream, thus preventing damage to the shaded photovoltaic cell. Thus, the photovoltaic device can continue to function in at least partially shaded photovoltaic cells. However, such a solution is very costly and requires a high degree of complexity, which leads to high additional costs.

[0005] U.S. Patent Application Publication No. 20150349164A1 discloses a solar cell with an integrated bypass diode, where the bypass diode and the solar cell include different regions adjacent to each other on a substrate and are separated by a gap.

[0006] European Patent No. EP 1 920 468 B1 discloses an organic photovoltaic cell including a bypass diode.

[0007] International Publication Pamphlet No. 2014 / 051889A1 discloses a solar cell including a number of photovoltaic cells, where the photovoltaic cells have a specific arrangement of intermediate spaces, and as a result, the area of the resulting cell allows only a maximum opposing voltage and the number of bypass diodes can be reduced.

[0008] However, it has been found that a drawback of the prior art is that it is complex to incorporate a complete bypass diode into a photovoltaic cell during manufacturing. The bypass diode requires a large area that cannot generate electricity, resulting in a large power loss in the photovoltaic element. Furthermore, known methods are not particularly suitable for roll-to-roll processes, especially for the manufacture of photovoltaic elements. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0009] Accordingly, the present invention is based on the object of providing a photovoltaic element that exhibits better efficiency in the case of at least partial shading of individual photovoltaic cells or cell regions, improves the service life of the shaded photovoltaic cells, does not exhibit the aforementioned drawbacks, and in particular is not damaged in the case of at least partial shading of the photovoltaic cells. In particular, the loss of the active region is minimized as much as possible, and the impact on performance is also minimized.

[0010] This object is achieved by the subject matter of the independent claims. Advantageous configurations become apparent from the dependent claims.

[0011] This object is achieved in particular by providing a photovoltaic element comprising at least one photovoltaic cell having a base electrode, a top electrode, and a layer system comprising at least one photoactive layer, the layer system being arranged between the base electrode and the top electrode. The at least one photovoltaic cell is at least partially segmented into segments, the segmentation being designed such that at least the top electrode and the layer system of one segment are separated from the top electrode and the layer system of another segment, or the top electrode, the layer system, and at least partially the base electrode of one segment are separated from the top electrode, the layer system, and at least partially the base electrode of another segment, in each case being separated by at least one cavity so as to prevent contact with each other, the at least one cavity being formed at least substantially perpendicular to the layer system of the at least one photovoltaic cell, and the segments of the at least one photovoltaic cell being electrically conductively connected in parallel to each other such that the flow of current through the at least one photovoltaic cell is distributed to the individual segments.

[0012] In a preferred embodiment, the base electrode, the layer system, and the top electrode are structured by a laser. In a preferred embodiment, the base electrode forms the cathode and the top electrode forms the anode.

[0013] In a preferred embodiment of the invention, the base electrode is arranged on a substrate, in particular a film.

[0014] The cavity is in particular a space between at least two segments, separating the segments from each other at least in sections, such that there is no at least electrically conductive connection between the at least two segments via such a section, and / or the segments do not contact each other in this section area. The cavity forms a specific distance horizontally with respect to the layer system between two segments, one of which is below the other. The cavity is in particular an intermediate space.

[0015] In particular, the present invention discloses a technical solution for avoiding damage to a photovoltaic device, particularly an organic photovoltaic device, caused by what is known as a so-called hot spot. By implementing this solution, a photovoltaic device composed of a plurality of photovoltaic cells can continue to function without damage even when one or more photovoltaic cells are shaded.

[0016] Segmentation means, in particular, at least partial separation of the upper electrode of the photovoltaic cell and the layer system, or of the upper electrode, the layer system, and at least part of the base electrode, such that, as a result, when at least one photovoltaic cell has at least partial shading and / or defects, the current of each individual segment obtained is of a magnitude that does not damage the photovoltaic cell. Depending on the desired limitation of the current density in each segment, the segments can be segmented depending on the cross-sectional area of the segment, in particular the width and length of the segment, and the current density in the individual segments is lower compared to a non-segmented photovoltaic cell. In a preferred embodiment of the present invention, the current decreases in the individual segments, in particular the current density is very low, and at least partially shaded photovoltaic cells, in particular completely shaded photovoltaic cells, can still conduct the current of adjacent non-shaded photovoltaic cells without damage.

[0017] Shading means, in particular, at least partial reduction of the incidence of light on the photovoltaic device, in particular a state where at least an essentially opaque object casts its shadow based on the sun on the components of the photovoltaic device. In a shaded cell or at least partially shaded cell, either no current is generated in the at least partially shaded cell itself or less current is generated, so that when light is irradiated, there is a counter voltage compared to non-shaded cells. As a result, there is a risk that at least partially shaded cells connected in series with other non-shaded cells will be damaged.

[0018] A defect is understood to mean, in particular, a fault in the layer system of a photovoltaic cell or a fault in the electrical conductive connection of a layer system including at least one electrode.

[0019] A photovoltaic device is understood to mean, in particular, a solar cell, and the photovoltaic device has at least one photovoltaic cell. The photovoltaic cells may be arranged and / or connected in various ways within the photovoltaic device. Preferably, the photovoltaic device is composed of a plurality of photovoltaic cells connected in series.

[0020] Possible structures of the layer system of a photovoltaic cell are described in WO 2004 / 083958 A2, WO 2011 / 013219 A1, WO 2011 / 138021 A2, WO 2011 / 161108 A1. For the specific applications identified herein, layer systems in which the photoactive layer is vaporizable and applied by physical vapor deposition (PVD), or which contain an applied absorber material, are preferably used. For this purpose, materials belonging to the group of "low molecules" are used, which are described in particular in WO 2006 / 092134 A1, WO 2010 / 133208 A1, WO 2014 / 206860 A1, WO 2014 / 128278 A1, WO 2017 / 114937 A1, and WO 2017 / 114938 A1. The photoactive layer forms an acceptor / donor system and can be in the form of a plurality of individual layers or a mixed layer, as a planar heterojunction, preferably a bulk heterojunction. A layer system that can be completely applied by physical vapor deposition is preferred.

[0021] The layer system may be in the form of a single cell, tandem cell, or multi-cell, the name of which is determined by the number of sub-cells, and each sub-cell is preferably separated by a transport layer and an optional recombination layer and includes at least one photoactive layer that may itself be composed of multiple layers. A p-layer system or an n-layer system, also simply called a p-layer or an n-layer, may be composed of multiple layers, and at least one of the layers of the p-layer system or the n-layer system is preferably p-doped or n-doped as a p-doped or n-doped wide-gap layer. An i-layer system, also called an i-layer, is undoped or doped less, i.e., has a weaker doping, compared to the p- and n-layers within a sub-cell and is in the form of a photoactive layer. Each of these n-, p-, i-layers may be composed of further layers, where the n- and p-layers are each composed of at least one doped n- and p-layer that contribute to the increase in charge carriers as a result of their doping. That is, the layer stack of the photovoltaic cell is composed of a convenient combination of p-, n-, and i-layer systems, i.e., each sub-cell includes an i-layer system and at least one p- or n-layer system.

[0022] The horizontal extent of the layer system is understood to mean, in particular, the direction essentially parallel to the substrate and / or the layers of the layer system.

[0023] In a preferred embodiment, the photovoltaic device has a cell comprising at least one photoactive layer, in particular a CIS-, CIGS-, GaAs- or Si-cell, a perovskite cell or an organic photovoltaic device (OPV), so-called organic solar cell. The organic photovoltaic device is understood in particular to mean a photovoltaic device having at least one layer of organic photoactive layer, in particular a polymer organic photovoltaic device, or an organic photovoltaic device based on small molecules. Polymers are characterized by not being vaporizable and thus can only be applied from solution, while small molecules can usually be vaporized, so they can be applied as a solution like polymers, but can also be applied by vapor deposition techniques, in particular vapor deposition from vacuum. In particular, the photovoltaic device is preferably a flexible organic photovoltaic device based on small molecules.

[0024] In a preferred embodiment of the present invention, the photoactive layer of the layer system contains small molecules that can be vaporized in a vacuum. In a preferred embodiment of the present invention, at least the photoactive layer of the layer system is vapor deposited in a vacuum.

[0025] Small molecules are understood in particular to mean non-polymeric organic molecules with a monodisperse molar mass of 100 to 2000 g / mol that are present in the solid phase at normal pressure (the atmospheric pressure of the ambient air) and room temperature. In particular, small molecules are photoactive, and "photoactive" is understood to mean that the charge state and / or polarization state of the molecule changes when exposed to light.

[0026] In a preferred embodiment of the present invention, the top electrode comprises silver or a silver alloy, aluminum or an aluminum alloy, gold or a gold alloy, or a combination of these materials, preferably containing Ag:Mg or Ag:Ca as a silver alloy.

[0027] The photovoltaic device according to the present invention has advantages over the prior art. Advantageously, it is possible to protect the photovoltaic device against hot spots, in particular to divide at least partially the current generated in an unshaded cell between the individual segments of a cell that is at least partially shaded, thereby preventing damage to the at least partially shaded cell. For this reason, the photovoltaic device can continue to generate electricity using other unshaded cells. Advantageously, at least one photovoltaic cell is not damaged in the case of at least partial shading and / or in the case of a defect of the photovoltaic cell. Advantageously, when the individual photovoltaic cells of the photovoltaic device are shaded, the efficiency is improved and the service life of the photovoltaic device is improved. Advantageously, there is no loss or at least substantially no loss of the area of the photovoltaic cell and / or there is no loss or at least substantially no loss of the function of the photovoltaic cell. Advantageously, the flow of current from a preceding photovoltaic cell is distributed to the individual segments of a photovoltaic cell that is at least partially shaded. Advantageously, the segmentation can be incorporated particularly easily into current manufacturing methods, in particular with only little effort for programming the laser structuring. Advantageously, this manufacturing can be integrated into a roll-to-roll process. The segmentation can be incorporated directly into the layer system during manufacturing without using additional external components, in particular diodes. Advantageously, the segmentation of the photovoltaic cells is cost-effective compared to other solutions, in particular bypass diodes. Advantageously, the flow of current through the individual segments is smaller.

[0028] According to a development of the invention, the photovoltaic device comprises at least a first photovoltaic cell and a second photovoltaic cell, the at least first photovoltaic cell and the second photovoltaic cell being connected in series, the top electrode of the first photovoltaic cell being electrically conductively connected to the base electrode of the second photovoltaic cell, preferably the base electrodes of the photovoltaic cells being horizontally separated from each other with respect to the layer system and the top electrodes of the photovoltaic cells being horizontally separated from each other with respect to the layer system.

[0029] According to a development of the present invention, the cross-sectional areas of the segments of at least one photovoltaic cell are equal to each other based on the horizontal extent of the layer system, preferably, the sizes of the cross-sectional areas of the segments are equal depending on the flow of current through at least one photovoltaic cell. The smaller the flow of current through an individual segment, the lower the current density, and the larger the flow of current through an individual segment, the higher the current density.

[0030] The cross-sectional area is understood to mean, in particular, the area of the segment in the horizontal extent of the layer system, in particular along the layer of the layer system.

[0031] According to a development of the present invention, the width of the segment is from 1 cm to 2 m, preferably from 5 cm to 1 m, and / or the distance between individual segments in the horizontal direction with respect to the layer system is in the range from 10 nm to 200 nm, preferably from 40 nm to 80 nm. The distance between individual segments is provided to be formed by at least one cavity, in particular.

[0032] According to a development of the present invention, the length of the segment, in particular the length of at least one photovoltaic cell, is from 1 mm to 1 m, preferably from 5 mm to 5 cm, and the segments are preferably formed at least substantially parallel to each other.

[0033] According to a development of the present invention, the individual segments are each formed over the entire direction of the photovoltaic cell, and the shapes of the segments are preferably of different designs.

[0034] According to a development of the present invention, the segments are at least substantially parallel, preferably formed in a strip shape, and preferably, the segments of subsequent photovoltaic cells are offset parallel to each other compared to the preceding photovoltaic cell.

[0035] According to a development of the present invention, the photovoltaic cells of the photovoltaic device are electrically conductively connected by at least one bus bar.

[0036] The photovoltaic cell is divided into single, tandem, or multi-cells depending on the transport of the layer structure between two bases and top contacts and the number of photoactive layer systems by other layers. Tandem and multi-cells are composed of at least two sub-cells arranged vertically between the electrodes, and each sub-cell includes at least one photoactive layer system.

[0037] According to the development of the present invention, the layer system includes at least two photoactive layers, where the photovoltaic cell is a tandem cell, the layer system preferably includes at least three photoactive layers, where the photovoltaic cell is a triple cell, and / or the layer system further includes at least one charge carrier transport layer, where at least one charge carrier transport layer is arranged between the base electrode or the top electrode and the photoactive layer, and the layer system preferably includes at least a first charge carrier transport layer and a second charge carrier transport layer, where the first charge carrier transport layer is arranged between the base electrode and at least one photoactive layer, and the second charge carrier transport layer is arranged between at least one photoactive layer and the top electrode.

[0038] According to the development of the present invention, the photovoltaic device is an organic photovoltaic device, preferably a flexible organic photovoltaic device, and preferably at least one photoactive layer of the organic photovoltaic device has a low molecule as the absorbing material.

[0039] In particular, the flexible photovoltaic property is understood to mean, in particular, a photovoltaic device that can be bent and / or stretched within a certain range.

[0040] According to the development of the present invention, it is provided that the photovoltaic device does not include a bypass diode.

[0041] The object of the present invention is also achieved by providing a photovoltaic system comprising at least two photovoltaic elements, in particular according to one of the exemplary embodiments described above. With respect to this photovoltaic system, this brings about the advantages already described in particular in relation to a photovoltaic element comprising at least one photovoltaic cell. In this case, at least two photovoltaic elements are connected in series. The photovoltaic element preferably consists of photovoltaic cells connected in series with each other. The photovoltaic cells are preferably connected in series by electrically conducting the upper electrode of one photovoltaic cell to the base electrode of the subsequent photovoltaic cell.

[0042] The object of the present invention is also a method for manufacturing a photovoltaic element, in particular a flexible photovoltaic element, comprising at least two photovoltaic cells, each having a base electrode, an upper electrode, and a layer system arranged between the base electrode and the upper electrode, and in particular according to one of the exemplary embodiments described above, the layer system having at least one photoactive layer. With respect to this method, this brings about the advantages already described in particular in relation to a photovoltaic element comprising at least one photovoltaic cell and in combination with a photovoltaic system. The method comprises the following steps: a) providing a base electrode layer on a substrate; b) structuring the base electrode layer with a laser such that the base electrode layer is divided into individual base electrodes; c) applying a layer system having at least one photoactive layer to the structured base electrode and forming at least one opening in the layer system associated with the individual base electrodes by laser ablation, the base electrode being at least partially exposed at the at least one opening; d) applying an upper electrode layer to the at least one opening and / or on the layer system by the at least one opening, the at least one opening being filled; e) Structuring the upper electrode layer and the layer system with a laser such that individual upper electrodes and individual layer systems are formed, wherein the upper electrode of the first photovoltaic cell is electrically conductively connected to the base electrode of the second photovoltaic cell, and f) Segmenting at least one photovoltaic cell, at least the upper electrode and the layer system, or the upper electrode, the layer system and at least partially the base electrode, by laser ablation, such that segments of at least one photovoltaic cell are formed.

[0043] In a preferred embodiment of the invention, steps e) and f) are carried out simultaneously.

[0044] In a preferred embodiment of the invention, for forming the openings by laser ablation in step c), for the laser structuring in steps b) and e), and / or for the segmentation in step f), the parameters of at least one laser beam, preferably the energy density, pulse duration, pulse shape, pulse frequency and / or wavelength, are adjusted depending on the material and layer thickness of the base electrode, layer system and / or upper electrode.

[0045] In a preferred embodiment of the invention, the base contact and the layer system, the individual layers of the layer system, and / or the layer system and the upper electrode are electrically conductively connected by means of a suitable structuring, in particular laser structuring.

[0046] In a preferred embodiment of the invention, the layers are applied by means of a printing method, preferably an inkjet method, a screen printing method, and / or a flexographic printing method, and / or by evaporation of the material to be applied.

[0047] In a preferred embodiment of the present invention, the wavelength range of the laser in the laser ablation in step c), the laser structuring in steps b) and e), and / or the segmentation in step f) is from 300 nm to 1200 nm, preferably from 400 nm to 1000 nm, or preferably from 450 nm to 800 nm.

[0048] In a preferred embodiment of the present invention, the energy density of at least one laser beam in the laser ablation of step c) and / or the segmentation of step f) is adjusted during ablation as a function of the removal depth of the layer system.

[0049] In a preferred embodiment of the present invention, the layer system is electrically conductively connected to the base electrode and / or the top electrode by laser structuring.

[0050] According to a development of the present invention, it is provided that the top electrode layer is horizontally divided with respect to the layer system of at least one photovoltaic cell such that a top electrode is obtained, and the base electrode layer is horizontally divided based on the layer system of at least one photovoltaic cell such that a base electrode is obtained.

[0051] According to a development of the present invention, it is provided that the method is used in a roll-to-roll process.

[0052] In a preferred embodiment of the present invention, the structuring is carried out during the application of the individual layers of the layer system. In an alternatively preferred embodiment of the present invention, the structuring is carried out after the application of the individual layers of the layer system.

[0053] Hereinafter, the present invention will be described in more detail with reference to the drawings.

Brief Description of the Drawings

[0054]

Figure 1

Figure 2

Figure 3

DETAILED DESCRIPTION OF THE INVENTION

[0055] FIG. 1 shows a schematic view of the structure of a layer system 5 including electrodes 3 and 4 of a photovoltaic cell 2.

[0056] The photovoltaic device 1, particularly an organic photovoltaic device 1, consists of a series of thin layers, a layer system 5 having at least one photoactive layer 6, and at least one photoactive layer 6 is preferably deposited in a vacuum or processed from a solution. Electrical connection can be implemented by a metal layer, a transparent conductive oxide, and / or a transparent conductive polymer. Vacuum deposition of the organic layer is particularly advantageous when manufacturing multilayer solar cells, particularly tandem cells or triple cells. Such a layer system 5 of the photovoltaic cell 2 is shown in one exemplary embodiment in FIG. 1.

[0057] In this exemplary embodiment, the photovoltaic cell 2 has glass as the substrate 13, a transparent base electrode 3 made of ITO(M) 14, a layer 15 of fullerene C60, a photoactive layer 16 containing at least one absorbing material and fullerene C60, and a p-doped hole transport layer 17 made of Di-NPB and NDP9, and an upper electrode 4 made of gold 18.

[0058] FIG. 2 schematically represents the photovoltaic device 1 in a side view to clarify the problems of the photovoltaic cell 2 that is at least partially shaded. For the same and functionally equivalent elements, the previous description may be referred to.

[0059] The problem with the series-connected photovoltaic cells 2 in the case of at least partial shading 12 of the photovoltaic cell 2 is that the shaded photovoltaic cell 2 is a diode reverse-biased with respect to the non-shaded or less-shaded series-connected photovoltaic cells 2. Therefore, they impede the outflow of the photo-generated current and have an adverse effect on the efficiency. There is also a risk that current concentration may occur in the photovoltaic cell 2 shaded due to a defect site, which can lead to local overheating and ultimately irreversible degradation of the photovoltaic cell 2, and thus loss of efficiency of the photovoltaic device 1.

[0060] An example of the degradation of the photovoltaic cell 2 due to at least partial shading 12 is shown in FIG. 2. The at least partial shading 12 results in this case in undesirable local damage to the photovoltaic cell 2.

[0061] FIG. 3 schematically shows an exemplary embodiment of the segmented photovoltaic device 1 in side view and top view. For the same and functionally equivalent elements, the same reference numerals are used, so refer to the previous description in this regard.

[0062] The photovoltaic device 1 has at least one photovoltaic cell 2 having a base electrode 3, a top electrode 4, and a layer system 5 including at least one photoactive layer 6, and the layer system 5 is disposed between the base electrode 3 and the top electrode 4. The at least one photovoltaic cell 2 is at least partially segmented into segments 7, and the segmentation is designed such that at least the top electrode 4 and the layer system 5 of one segment 7 are separated from the top electrode 4 and the layer system 5 of another segment 7, or the top electrode 4, the layer system 5, and at least partially the base electrode 3 of one segment 7 are separated from the top electrode 4, the layer system 5, and at least partially the base electrode 3 of another segment 7, and in each case are separated by at least one cavity 8 so as to prevent mutual contact, and the at least one cavity 8 is formed at least substantially perpendicular to the layer system 5 of the at least one photovoltaic cell 2, and the segments 7 of the at least one photovoltaic cell 2 are designed to be electrically conductively connected in parallel to each other such that the flow of current through the at least one photovoltaic cell 2 is distributed among the individual segments 7.

[0063] As a result, the at least one photovoltaic cell 2 is not damaged, especially not by hot spots, in the case of at least partial shading 12 and / or in the case of defects in the photovoltaic cell 2. Furthermore, since the efficiency is improved when the individual photovoltaic cells 2 of the photovoltaic device 1 are shaded 12, the service life of the photovoltaic device is concomitantly improved. Advantageously, there is no loss or at least substantially no loss in the area of the photovoltaic cell 2 and / or at least substantially no loss in the performance of the photovoltaic cell 2. The segmentation can be incorporated particularly easily into current manufacturing methods, in particular requiring only little effort for programming laser structuring.

[0064] In one configuration of the present invention, the photovoltaic device 1 includes at least a first photovoltaic cell 2 and a second photovoltaic cell 2. At least the first photovoltaic cell 2 and the second photovoltaic cell 2 are connected in series. The upper electrode 4 of the first photovoltaic cell 2 is electrically conductively connected to the base electrode 3 of the second photovoltaic cell 2. Here, the base electrodes 3 of the photovoltaic cells 2 are preferably separated from each other in the horizontal direction with respect to the layer system 5, and the upper electrodes 4 of the photovoltaic cells 2 are separated from each other in the horizontal direction with respect to the layer system 5. Preferably, in each case, the upper electrode 4 of the preceding photovoltaic cell 2 is electrically conductively connected to the base electrode 3 of the subsequent photovoltaic cell 2.

[0065] In a further configuration of the present invention, based on the horizontal extent of the layer system 5, the cross-sectional areas 9 of the segments 7 of at least one photovoltaic cell 2 are equal to each other. Preferably, the size of the cross-sectional area 9 of the segment 7 is designed depending on the flow of the current passing through at least one photovoltaic cell 2.

[0066] In a further configuration of the present invention, the width 10 of the segment 7 is 1 cm to 2 m, preferably 5 cm to 1 m, and / or the distance between the individual segments 7 in the horizontal direction with respect to the layer system 5 is in the range of 10 nm to 200 nm, preferably 40 nm to 80 nm.

[0067] In a further configuration of the present invention, the length 11 of the segment 7, particularly the length 11 of at least one photovoltaic cell 2, is 1 mm to 1 m, preferably 5 mm to 5 cm. The segments 7 are preferably formed at least substantially parallel to each other.

[0068] In a further configuration of the present invention, the individual segments 7 are each formed over the entire direction of the photovoltaic cell 2. Preferably, the shapes of the segments 7 are of different designs.

[0069] In a further configuration of the present invention, segment 7 is formed at least substantially parallel, preferably in strip form, and preferably, the segments 7 of the subsequent photovoltaic cell 2 are offset parallel to each other compared to the preceding photovoltaic cell 2.

[0070] In a further configuration of the present invention, the photovoltaic cells 2 of the photovoltaic device 1 are electrically conductively connected by at least one bus bar.

[0071] In a further embodiment of the present invention, the layer system 5 includes at least two photoactive layers 6, where the photovoltaic cell 2 is a tandem cell, and the layer system 5 preferably includes at least three photoactive layers 6, where the photovoltaic cell 2 is a triple cell, and / or the layer system 5 further includes at least one charge carrier transport layer, where at least one charge carrier transport layer is disposed between the base electrode 3 or the top electrode 4 and the photoactive layer 6, and the layer system 5 preferably includes at least a first charge carrier transport layer and a second charge carrier transport layer, the first charge carrier transport layer being disposed between the base electrode 3 and at least one photoactive layer 6, and the second charge carrier transport layer being disposed between at least one photoactive layer 6 and the top electrode 4.

[0072] In a further configuration of the present invention, the photovoltaic device 1 is an organic photovoltaic device 1, preferably a flexible organic photovoltaic device 1, and preferably at least one photoactive layer 6 of the organic photovoltaic device 1 has small molecules as the absorbing material.

[0073] In a further configuration of the present invention, the photovoltaic device 1 does not have a bypass diode.

[0074] A photovoltaic system is formed by connecting at least two photovoltaic devices 1 in series.

[0075] A method for manufacturing a photovoltaic device 1, in particular a flexible photovoltaic device 1, comprising at least two photovoltaic cells 2, each having a base electrode 3, a top electrode 4, and a layer system 5 disposed between the base electrode 3 and the top electrode 4, the layer system 5 comprising at least one photoactive layer 6, comprises the following steps: a) providing a base electrode layer on a substrate 13; b) structuring the base electrode layer by laser so that the base electrode layer is divided into individual base electrodes 3; c) applying a layer system 5 having at least one photoactive layer 6 to the structured base electrodes 3 and forming at least one opening associated with the individual base electrodes 3 in the layer system 5 by laser ablation, the base electrodes 3 being at least partially exposed by the at least one opening; d) applying a top electrode layer to at least one opening and / or on the layer system 5 by means of at least one opening, the at least one opening being filled; e) structuring the top electrode layer and the layer system 5 by laser so that individual top electrodes 4 and individual layer systems 5 are formed, the top electrode 4 of the first photovoltaic cell 2 being electrically conductively connected to the base electrode 3 of the second photovoltaic cell 2, and f) segmenting at least one photovoltaic cell 2, at least the top electrode 4 and the layer system 5, or the top electrode 4, the layer system 5 and at least partially the base electrode 3, by laser ablation, forming segments 7 of at least one photovoltaic cell 2. The layer system is preferably electrically conductively connected to the base electrode 3 and / or the top electrode 4 by laser structuring.

[0076] The laser structuring of the top electrode layer and the layer system 5 in step e) and the segmentation in step f) may be carried out simultaneously.

[0077] In the configuration of the present invention, the upper electrode layer is divided horizontally with respect to the layer system 5 of at least one photovoltaic cell 2 so that the upper electrode 4 is obtained, and the base electrode layer is divided horizontally based on the layer system 5 of at least one photovoltaic cell 2 so that the base electrode 3 is obtained.

[0078] In a further configuration of the present invention, the layer system 5 is applied at least partially by vapor deposition under vacuum.

[0079] In a further configuration of the present invention, the method is used in a roll-to-roll process.

[0080] In one exemplary embodiment, the following parameters are used in the laser ablation in step b): laser speed 4 μJ - 385 mm / s, and energy of each laser pulse 25 kHz (25 pulses per second).

[0081] In one embodiment (Figure 3), the provided substrate 13 is coated with the base electrode layer of the photovoltaic cell 2 after being provided, structured (P1), and the base electrode layer is separated into the base electrodes 3 of the individual segments 7. Subsequently, the layer system 5 is applied on the base electrode 3. The layer system 5 can be applied as a single cell, tandem cell or multi-cell, preferably by vapor deposition of low molecules. The application of the individual layers to the area of the base electrode 3 for forming the layer system 5 can be carried out at least partially by a printing process, preferably an inkjet, screen printing, gravure printing or flexographic printing process, or by vapor deposition of the applied material. The layer system 5, in particular the individual layers of the layer system 5, is preferably applied by physical vapor deposition under vacuum. Subsequently, the layer system 5 (P2) of the photovoltaic cell 2 is structured. The upper electrode layer is applied to the layer system 5, and by the final structuring (P3), the upper electrode layer is separated into the individual upper electrodes 4. The individual layers of the photovoltaic cell 2 can be structured, for example, by laser ablation, electron or ion beam ablation, or using a shadow mask.

[0082] In one exemplary embodiment, the following parameters are used for the structure P1 / P2 / P3 using a laser: P1: wavelength 1030 nm, line width 50 μm; P2: wavelength 515 nm, line width 50 μm; P3: wavelength 1030 nm, line width 100 μm. P1 / P2 / P3 are connected in series here, and each segment is connected in parallel.

[0083] FIG. 3 shows an exemplary embodiment of the laser structuring of the photovoltaic cell 2. The structure P1 / P2 / P3 is shown. The direction of current flow is indicated by the arrow. In this exemplary embodiment, the photo-generated current flows, in particular, through the upper electrode 4 of the shaded photovoltaic cell 2 divided into individual segments 7 of the photovoltaic cell 2, and can flow into the base electrode 3 to an improved extent via the additional P2 structuring there.

Claims

1. A photovoltaic device (1) comprising at least one photovoltaic cell (2) having a base electrode (3), a top electrode (4), and at least one photoactive layer (6), and a layer system (5) disposed between the base electrode (3) and the top electrode (4), wherein the photovoltaic device (1) comprises at least a first photovoltaic cell (2) and a second photovoltaic cell (2), the at least first photovoltaic cell (2) and the second photovoltaic cell (2) are connected in series, and the top electrode (4) of the first photovoltaic cell (2) is electrically conductively connected to the base electrode (3) of the second photovoltaic cell (2), wherein the at least one photovoltaic cell (2) is partially segmented into segments (7), and the segmentation is such that, by means of at least one cavity (8), the top electrode (4) and the layer system (5) of one segment (7) are separated from the top electrode (4) and the layer system (5) of another segment (7) to prevent contact therebetween, or by means of at least one cavity (8), only a portion of the top electrode (4), the layer system (5) and the base electrode (3) of one segment (7) is separated from only the portion of the top electrode (4), the layer system (5) and the base electrode (3) of another segment (7) to prevent contact therebetween, and the at least one cavity (8) is formed in a direction perpendicular to the layer system (5) of the at least one photovoltaic cell (2), wherein the plurality of segments (7) of the at least first photovoltaic cell (2) and the second photovoltaic cell (2) are arranged in a direction perpendicular to the series direction in which the first photovoltaic cell (2) and the second photovoltaic cell (2) are connected, wherein the segments (7) of the at least one photovoltaic cell (2) are electrically conductively connected to each other in parallel only by the base electrode (3) such that the flow of current through the at least one photovoltaic cell (2) is distributed among the individual segments (7), characterized in that it is a photovoltaic device (1).

2. The photovoltaic device (1) according to claim 1, characterized in that the horizontal cross-sectional areas (9) of the segments (7) of the at least one photovoltaic cell (2) are equal to each other.

3. The width (10) of the segment (7) is from 1 cm to 2 m, and / or the distance between the individual segments (7) in the horizontal direction with respect to the layer system (5) is in the range of 10 nm to 200 nm, characterized in that the photovoltaic element (1) according to claim 1 or 2.

4. The length (11) of the segment (7) is from 1 mm to 1 m, characterized in that the photovoltaic element (1) according to any one of claims 1 to 3.

5. The individual segments (7) are each arranged in the horizontal direction of the photovoltaic cell (2), and the segments (7) are separated from each other in the horizontal direction with respect to the layer system (5), characterized in that the photovoltaic element (1) according to any one of claims 1 to 4.

6. A plurality of the segments (7) are parallel to each other and are formed in a strip shape, characterized in that the photovoltaic element (1) according to any one of claims 1 to 5.

7. The photovoltaic cell (2) of the photovoltaic element (1) is electrically conductively connected by at least one bus bar, characterized in that the photovoltaic element (1) according to any one of claims 1 to 6.

8. The layer system (5) includes at least two photoactive layers (6), where the photovoltaic cell (2) is a tandem cell, and / or the layer system (5) further includes at least one charge carrier transport layer, where the at least one charge carrier transport layer is arranged between the base electrode (3) or the upper electrode (4) and the photoactive layer (6), characterized in that the photovoltaic element (1) according to any one of claims 1 to 7.

9. The photovoltaic element (1) is an organic photovoltaic element (1), characterized in that the photovoltaic element (1) according to any one of claims 1 to 8.

10. The photovoltaic element (1) is a flexible organic photovoltaic element (1), characterized in that the photovoltaic element (1) according to claim 1.

11. The photovoltaic element (1) does not include a bypass diode, characterized in that the photovoltaic element (1) according to any one of claims 1 to 10.

12. A photovoltaic system including at least two photovoltaic elements (1) according to any one of claims 1 to 11, wherein the at least two photovoltaic elements (1) are connected in series.

13. A method for manufacturing a photovoltaic device (1) comprising at least two photovoltaic cells (2) according to any one of claims 1 to 11, each having a base electrode (3), a top electrode (4), and a layer system (5) disposed between the base electrode (3) and the top electrode (4) and having at least one photoactive layer (6), a) providing a base electrode layer on a substrate; b) structuring the base electrode layer with a laser such that the base electrode layer is divided into individual base electrodes (3); c) applying a layer system (5) having at least one photoactive layer (6) to the structured base electrode (3) and forming at least one opening associated with each of the individual base electrodes (3) in the layer system (5) by laser ablation, wherein the base electrode (3) is at least partially exposed at the at least one opening; d) applying a top electrode layer to the at least one opening and / or on the layer system (5) through the at least one opening, wherein the at least one opening is filled; e) structuring the top electrode layer and the layer system (5) with a laser such that individual top electrodes (4) and individual layer systems (5) are formed, and the top electrode (4) of the first photovoltaic cell (2) is electrically conductively connected to the base electrode (3) of the second photovoltaic cell (2); and f) segmenting at least one of the photovoltaic cells (2) by laser ablation only a part of the top electrode (4) and the layer system (5), or the top electrode (4), the layer system (5) and the base electrode (3), such that segments (7) of the at least one photovoltaic cell (2) are formed. A method comprising the steps above.

14. The method for manufacturing a photovoltaic device (1) according to claim 13, wherein the top electrode layer is horizontally divided with respect to the layer system (5) of the at least one photovoltaic cell (2) such that a top electrode (4) is obtained, and the base electrode layer is horizontally divided based on the layer system (5) of the at least one photovoltaic cell (2) such that a base electrode (3) is obtained.

15. The method for manufacturing the photovoltaic device (1) according to claim 13 or 14, wherein the method is used in a roll-to-roll method.

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