DE102016216378A1 - Thin-film solar module with light emission channels - Google Patents

Abstract

The present invention relates to a photovoltaic thin film solar module comprising a substrate layer, a back electrode layer, a semiconductor absorber layer, a transparent or semi-transparent front electrode layer, further comprising spaced first insulating trellis filled with an insulator material defining adjacent solar cells, the first trimming trenches extending from the substrate layer in the direction the front electrode layer and a conductive bridge across the first pattern trench (s) extending from the direction of the back electrode layer to the front electrode layer, wherein the conductive bridge is or comprises conductive material and wherein the insulator material is in the first pattern trenches or the conductive pattern Material of the conductive bridge are transparent or semi-transparent and form light emission channels. Furthermore, the invention relates to a lighting device comprising a thin-film solar module according to the invention. Moreover, the invention relates to a facade with a thin-film solar module according to the invention or with a lighting device according to the invention and the use of the thin-film solar module according to the invention for lighting devices for facade lighting. Furthermore, the invention relates to a method for energy production or illumination with a thin-film solar module according to the invention and to a method for producing a thin-film solar module according to the invention.

Description

The present invention relates to a thin film solar module having light emission channels. The invention further relates to a method for energy production and to a method for producing the thin-film solar module. The invention also relates to a lighting surface and a facade with the thin-film solar module.

Thin film solar modules have long been known and commercially available. In this case, usually a glass substrate is used, on which rests a molybdenum back electrode layer. This is usually converted into suitable CIS or CIGS systems.

The efficiency of the thin-film solar modules often depends on the purity of the materials used in the layers used. This is particularly affected by the internal diffusion of components, dopants or impurities. In particular, the substrate and the semiconductor absorber layer may contain dopants or impurities. For example, dopants of the semiconductor layer may diffuse into the back electrode layer, thus lowering the efficiency.

Also, solar cells are known which are transparent as a whole. This may be a solar cell sheet, which can be placed on a conventional display, without significantly affecting the appearance of the conventional display. A disadvantage of the solutions known in this context is the very low efficiency of such solar cells. The object of the present invention is to overcome the disadvantages of the prior art and, in particular, to provide an integrated lighting system which simultaneously serves to generate energy. In particular, it is the object to provide a system which is characterized in that the ratio of energy production to energy consumption is better than in conventional solutions. Further, it is an object of the present invention to provide a system which focuses light. In particular, it is an object to provide a system that can be produced inexpensively and structurally relatively simple.

The object is achieved by a photovoltaic thin-film solar module comprising at least one substrate layer, at least one back electrode layer, at least one semiconductor absorber layer, at least one transparent or semitransparent front electrode layer, further comprising spaced first filled with at least one insulator material first Patterning trenches defining adjacent solar cells, the first pattern trenches extending from the substrate layer or a second barrier layer toward the front electrode layer, and at least one conductive bridge across the first pattern trenches extending from the direction of the back electrode layer to the front electrode layer; wherein the conductive bridge is or comprises conductive material, wherein the insulator material in the first pattern trenches and / or the conductive material of the conductive bridge, and optionally the substrate layer or portions thereof, form or are part of light emitting channels. In this case, the first patterning trench is expediently formed prior to the formation of the front electrode layer.

The object is also achieved by a photovoltaic thin-film solar module comprising, preferably in this order, preferably at least one conductive first barrier layer immediately adjacent to the substrate layer, in particular transparent or semitransparent first barrier layer, at least one substrate layer, preferably at least one conductive layer located between the substrate layer and back electrode layer Second barrier layer, in particular transparent or semitransparent second barrier layer, at least one, in particular at a barrier layer and / or the substrate layer adjacent, back electrode layer, in particular a bulk back electrode layer, preferably at least one on the back electrode layer directly adjacent conductive third barrier layer, preferably at least one, in particular the third barrier layer directly adjacent, contact layer, in particular ohmic contact layer, at least one, i nsbesondere directly to the contact layer or back electrode layer directly adjacent, semiconductor absorber layer, in particular chalcopyrite or kesterite semiconductor absorber layer, preferably at least one, in particular directly adjacent to the semiconductor absorber layer, first buffer layer containing or substantially of CdS or a CdS-free layer, in particular containing or im Substantially of Zn (S, OH) or In ₂ S ₃ , preferably at least one, in particular on the semiconductor absorber layer or the first buffer layer immediately adjacent, second buffer layer containing and consisting essentially of intrinsic zinc oxide and / or high-resistance zinc oxide, at least one, in particular the semiconductor absorber layer, the first buffer layer and / or the second buffer layer directly adjacent, transparent or semi-transparent front electrode layer, in particular containing or substantially of n-doped zinc oxide, further comprising beabs tanded first patterning trenches filled with at least one insulator material defining adjacent solar cells, the first patterning trenches extending from the substrate layer or the second barrier layer toward the front electrode layer, and at least one conductive bridge over the first or the first pattern trenches extending from the direction of the back electrode layer extends to the front electrode layer, wherein the conductive bridge consists of or comprises conductive material, wherein the insulator material and / or the conductive material, in particular both the insulator material and the conductive material, and optionally the substrate layer or portions thereof and optionally the second barrier layer are transparent or semitransparent and form or are part of light emission channels, in particular through the first structuring trenches.

It has surprisingly been found that thin film solar modules can be modified so that a high efficiency and at the same time light emission channels can be provided. Said light emission channels make it possible to irradiate light into the substrate or into the substrate layer which is emitted at the side of the thin-film solar module opposite the substrate or the substrate layer. It is particularly advantageous that the light emission channels simultaneously comprise an insulator material and / or conductive material, which separates individual solar cells on the same substrate due to its electrical properties in the case of the insulator material or connects in the case of the conductive material via a conductive bridge. Although structuring trenches and conductive bridges are not entirely unknown in themselves, a dual function as electron and photon conductors could now be used to enable efficient energy generation and light emission.

In the context of the present invention, transparent means that a corresponding transparent substance has a transmittance> 0.5, ie transmits more than 50% of the incident visible light. The transmittance T is defined as the quotient between the light intensity I behind an obstacle and the light intensity I _{0 in} front of an obstacle.

The obstacle in the sense of the abovementioned definition is a flat, planar layer of the transparent material with a layer thickness of 10 μm, preferably 100 μm, on which the light beam impinges perpendicularly. For the purposes of the present invention, the transmittance of a transparent substance determined in this way is preferably ≥ 0.8, in particular ≥ 0.9. The degree of transmission or the light intensities is determined at a wavelength of 470 nm, 550 nm or 650 nm. It is sufficient for the definition or invention if the transparency characteristic is fulfilled for at least one of said wavelengths, but preferably at least for the wavelength 650 nm. It is particularly preferred if the transmittance for all three wavelengths has said transmittances.

For the purposes of the present invention semitransparent means that a corresponding transparent substance has a transmittance of 0.1 to 0.5. In the context of the present invention, the transmittance of a semi-transparent substance determined in this way is preferably 0.2 to 0.5, in particular 0.4 to 0.5. The determination of the transmittance is analogous to transparent substances. The degree of transmission or the light intensities is determined at a wavelength of 470 nm, 550 nm or 650 nm. It is sufficient for the definition or invention if the semitransparent property is satisfied for at least one of said wavelengths, but preferably at least for the wavelength 650 nm. It is particularly preferred if the transmittance for all three wavelengths has said transmittances. If a substance has transmittances of semitransparency on and for other wavelengths of transparency for some wavelengths, then the substance is to be regarded as transparent, although preferably the determination at the wavelength 650 nm is decisive.

Light emission channels in the sense of the present invention are channels, preferably in the form of trenches, in particular comprising structuring trenches, through which visible light can be transmitted. Said light emission channels extend between substrate layer and front electrode layer. In a particularly suitable embodiment, the channels are transparent or semitransparent over their entire extension, wherein the transmittance is determined orthogonal to the front electrode layer. In this special case, the transmittance is thus not determined over a layer thickness of 10 .mu.m, preferably 100 .mu.m, but across the depth of the channels, wherein the depth is preferably determined orthogonal to the front electrode layer. Preferably, said transmittance at a wavelength of 470 nm, 550 nm or 650 nm ≥ 0.5, in particular ≥ 0.7, or corresponds to one of the preferred transmission levels described above.

In a particularly suitable embodiment, it is provided that the photovoltaic thin-film solar module spaced from each other with at least one conductive material filled or provided second structuring trenches which extend to the contact layer or to the back electrode layer or to the third barrier layer, in particular to the third barrier layer or to the back electrode layer, and in each case adjacent to a filled first structuring trench, and the photovoltaic thin film solar module further includes spaced third structuring trenches, for example third structuring trenches filled with an ink, which extend to the contact layer or to the back electrode layer or to the second or third barrier layer, in particular to the third barrier layer or to the back electrode layer, and in each case adjacent to a second structuring trench, beyond the first structuring trench the second patterning trench adjacent, are present, and wherein at least one conductive bridge is formed by conductive material, which extends through second structuring trenches filled or provided with said conductive material and over adjacent first structuring trenches to the front electrode layer of the adjacent solar cell. The conductive material of the conductive bridge can also be accessed using a conductive ink.

In a suitable further embodiment of the thin-film solar module according to the invention, it is provided that this contains spaced fourth structuring trenches extending to the contact layer or to the back electrode layer or to the second or third barrier layer, in particular to the third barrier layer or to the back electrode layer, and respectively adjacent to a filled first patterning trench and having a first volume region extending along the trench wall adjacent the first pattern trench and filled or provided with the at least one conductive material, and a second volume region adjacent thereto from the contact layer or the back electrode layer or from the third barrier layer, in particular from the third barrier layer, extends to the front electrode layer, and wherein the at least one conductive bridge is formed by conductive material which extends through first volume areas of the fourth patterning trenches filled or provided with said conductive material and over adjacent first patterning trenches to the front electrode layer of the adjacent solar cell.

Surprisingly, it has been found that the above-described first and / or second structuring trenches are suitable for forming light emission channels if the insulator material and / or the conductive material present therein is transparent or semitransparent. For example, in one embodiment, only the conductive material may be transparent or semi-transparent. In this case, it is advantageous if the second patterning trenches pierce the back electrode layer and form light emission channels in this way.

In an alternative embodiment, the conductive material is not transparent and the insulator material is transparent or semitransparent. In this case, it may be provided that the conductive material forms conductive bridges across the first patterning trenches, but is used so thin that the non-transparent conductive material is nevertheless translucent to a certain extent. In particular, if the thickness of the conductive material in the region of the first patterning trench is only a few nanometers, non-transparent materials also have a certain translucence with sufficient conductivity. Thus, a light emission channel can be created by the insulator material and the conductive bridge only a few nanometers thick.

However, a further embodiment is very particularly preferred, with both the insulator material and the conductive material being transparent or semitransparent. In this embodiment, it is conceivable to produce one or even two types of light emission channels. In any case, the first patterning trenches form light emission channels, since the filling used is transparent and also the conductive bridge can be made transparent. For the second structuring trenches it is ultimately decisive whether they pierce the back electrode layer. In this case, the second patterning trenches form a second type of light emitting channel. In the embodiment mentioned, it is preferable if this is not the case and the second patterning trenches thus do not form light emission channels. It has been found that a second type of light emission channel is often dispensable and the conductivity of the back electrode layer is better if it is not pierced by the second patterning trenches. However, a second type of light emission channels may be preferable if the light transmission of the thin film solar module is to be further improved.

Preferably, the conductive material of the conductive bridge is transparent or semi-transparent. It has been found that it is particularly preferred if the conductive bridge consists of transparent material at least in the region which lies above the first structuring trench. For example, it may be provided in that the conductive bridge consists of a first and a second conductive material, wherein the second structuring trenches and / or the first volume regions of the fourth structuring trenches are filled with the first conductive material, which is transparent, semitransparent or opaque (opaque is called a transmittance ≤ 0.2 in analogous conditions, as described above for the transparency definition, or no light transmission under said conditions), and the area of the bridge which lies above the first patterning trench, in particular the predominant or entire area of the bridge, which is above the front electrode layer with conductive material is filled, which is transparent or semitransparent, in particular transparent.

In a preferred embodiment, the conductive material corresponds to the material of the front electrode layer. In particular, it is preferable if the conductive bridge is formed integrally with the front electrode layer. Here, for example, the second structuring trenches may be filled with the material of the front electrode layer, which extends to the back electrode layer.

In a suitable embodiment, it is provided that the back electrode layer contains or is essentially formed from V, Mn, Cr, Mo, Ti, Co, Zr, Ta, Nb and / or W and / or contains or is essentially formed from an alloy containing V, Mn, Cr, Mo, Ti, Co, Fe, Ni, Al, Zr, Ta, Nb and / or W. The back electrode layer according to the present invention can also be used as a bulk back electrode layer and the system of bulk back electrode layer or Back electrode layer, second barrier layer and contact layer are referred to as a multi-layer back electrode layer.

Furthermore, it is preferred if the back electrode layer is thicker than, in particular at least twice as thick as, the contact layer, the second barrier layer, the third barrier layer, the first buffer layer and / or the second buffer layer. It is particularly preferred if the back electrode layer is thicker than the contact layer, the second barrier layer, the third barrier layer, the first buffer layer and the second buffer layer - if these are present. It has been found that a comparatively thicker back electrode layer is associated with a better efficiency.

In this case, it can also be provided that the first, second and / or third barrier layer in each case represents a barrier, in particular a bidirectional barrier, for migrating, in particular diffusing or diffusible components, in particular for alkali ions or compounds containing alkali metal ions, preferably sodium ions. For example, the second barrier layer prevents the depletion of the semiconductor layer on a dopant forming this layer, eg. As sodium, whereby an unimpaired efficiency can be maintained.

The first, second and / or third barrier layer is expediently a barrier for alkali ions, in particular sodium ions, or compounds containing alkali metal ions, selenium or selenium compounds, sulfur or sulfur compounds and / or metals, in particular Cu, In, Ga, Fe, Ni, Ti, Zr, Hf, V, Nb, Ta, Al and / or W.

In a further embodiment, it is provided that the contact layer contains or is essentially formed from Mo, W, Ta, Nb, Zr and / or Co, in particular Mo and / or W, and / or contains or at least essentially forms a metal chalcogenide and / or at least one first layer, adjacent to the third barrier layer, containing or consisting essentially of Mo, W, Ta, Nb, Zr and / or Co, in particular Mo and / or W, and at least one second layer, not adjacent to the third Barrier layer comprising or consisting essentially of at least one metal chalcogenide. In one embodiment, the metal of the first layer and the metal of the second layer of the contact layer coincide. It can also be provided that the metal of the first layer and / or the metal of the second layer of the contact layer coincide with the metal of the bulk back electrode layer and / or that the metal of the contact layer coincide with the metal of the bulk back electrode layer.

In a further embodiment, it is provided that the semiconductor absorber layer comprises a quaternary IB-IIIA-VIA chalcopyrite layer, in particular a Cu (In, Ga) Se 2 layer, a pentanary IB-IIIA-VIA chalcopyrite layer, in particular a Cu (In, Ga) (Se _1-x , S _x ) ₂ layer, or a kesterite layer, in particular a Cu ₂ ZnSn (Se _x , S _1-x ) ₄ layer, for example a Cu ₂ ZnSn (Se) ₄ - or a Cu ₂ ZnSn (S) ₄ layer, where x takes values from 0 to 1.

Furthermore, it is preferred if the substrate comprises a glass pane, in particular sodalime float glass, borosilicate glass, quartz glass, rotosil, glass ceramic, rolled glass, low-alkali glass or a plastic pane, in particular with a width greater than 0.2 m, in particular greater than 1.0 m, and a length greater than 0.6 m, in particular greater than 1.5 m. The thickness is usually comparatively low.

In a preferred embodiment, it is provided that the back electrode layer molybdenum and / or tungsten, in particular molybdenum, contains or is formed from this, the conductive barrier layer TiN contains or is formed substantially from this, and the contact layer MoSe ₂ contains or is formed substantially from this.

The first, second, third and / or fourth structuring trenches preferably have, at least in sections, in particular completely, an average width of not more than 50 μm, in particular not more than 30 μm and preferably not more than 10 μm. Furthermore, it is preferred if adjacent first structuring trenches and / or adjacent second structuring trenches and / or adjacent third structuring trenches and / or adjacent fourth structuring trenches at least partially have an average spacing in the range from 3 mm to 10 mm, in particular from 4 mm to 8 mm ,

It is also preferred if second and third structuring trenches adjacent to first structuring trenches and / or adjacent first and fourth structuring trenches have at least sections, in particular completely, an average spacing in the range of 5 μm to 100 μm, in particular in the range of 10 μm to 50 μm. to each other. In one embodiment, it is possible for the first patterning trenches to be filled with the insulator material beyond the level of the contact layer, in particular beyond the level of the second buffer layer, with the insulator material.

Particularly preferred is a thin-film solar module, which comprises a plurality of, in particular monolithically integrated serienverschalteten, solar cells, which are each separated by the spaced first structuring trenches, in particular wherein between the solar cells, the light emission channels are present, i. the first structuring trenches form the light emission channels and / or are part of the light emission channels.

In a very particularly preferred embodiment, it is provided that the thin-film solar module comprises lighting means, in particular LEDs, OLEDs or halogen lamps, which are arranged on a side of the substrate layer facing away from the back electrode layer. It has been shown that light can be irradiated homogeneously or inhomogeneously through the thin-film solar module. The light intensity of this system makes it possible to create an illuminated surface on the front electrode layer side.

In one embodiment of the photovoltaic thin-film solar modules according to the invention, a second conductive barrier layer may be present on the substrate layer, followed by the back electrode layer, then the contact layer, then the semiconductor absorber layer, optionally the first or second buffer layer, and then the front electrode layer. In a further embodiment on the substrate layer, first a second conductive barrier layer, then the back electrode layer, then the third conductive barrier layer, then the contact layer, then the semiconductor absorber layer, optionally the first or second buffer layer, and then the front electrode layer. Furthermore, in the thin-film solar modules according to the invention, in a further embodiment, which is preferred, the back electrode layer is present on the substrate layer, then the conductive barrier layer, then the contact layer thereon, the semiconductor absorber layer, optionally the first or second buffer layer, and then the front electrode layer. Further preferred layer sequences result from the exemplary embodiments.

In a suitable embodiment of the present invention, the thin-film solar module comprises light sources, in particular LEDs, OLEDs or halogen lamps, which are arranged on a side of the substrate layer facing away from the back electrode layer and / or in at least one edge region of the substrate layer, preferably circumferential, in particular fixed the edge region preferably extends between two mutually plane-parallel opposite sides of the substrate layer, in particular wherein a full-area and / or partial illumination of the substrate layer takes place. The arrangement of the bulbs allows optimal use of the thin-film solar module as a lighting device or surface. In principle, however, it is also conceivable not to integrate the bulbs in the thin-film solar module and instead to provide another illumination, for example by artificial light or sunlight, which is directed via reflectors to the substrate side.

For the purposes of the present invention, the solar module preferably comprises a front side, which is to be found in the direction of the front electrode layer, and an opposite rear side, which is to be found in the direction of the substrate layer. The light sources are preferably located on the rear side and / or on an edge region of the substrate. In this case, it is preferred if the lighting means, in particular LEDs, OLEDs or halogen lamps, are arranged such that light from the lighting means couples in through the edge region, wherein a side of the substrate layer facing away from the back electrode layer has a reflector layer, in particular in the form of a reflective metallic Thin film, comprises, or is immediately adjacent to one such. This allows a higher light output. The reflector layer can also be designed in the form of a first barrier layer. In this case, the first barrier layer should have reflective properties. For example, light can be coupled in an edge region of the substrate layer and reflected within the substrate until the light escapes through the light emission channels. The reflections take place at the reflector layer and optionally the back electrode layer or the second barrier layer. It is the back exit of light reduced, in particular completely suppressed, and increases the luminous efficacy.

In one embodiment, it is provided that the luminous means are provided by a luminous means surface, in particular flat illuminant matrix with discrete illuminants or a continuous luminous surface. It may, for example, be an LED matrix or OLED surface.

In another embodiment, on the other hand, it is provided that bulbs or illuminant surfaces arranged linearly or in strips are used. In particular, marginal arrangements of LED rows or parallel multiple rows, which form light lines or light strips, are preferred. It is preferably provided that the thin-film solar module comprises a second barrier layer, which is transparent or semi-transparent, and / or that the first structuring trenches extend as far as the substrate layer. It has been found that such solar modules allow a particularly simple construction of the light emission channels.

In preferred embodiments, bulbs according to the invention are not an isolated, single point source of illumination. For the purposes of the present invention, illuminants are preferably a multiplicity of illuminants which are arranged in a line or a surface, or a luminous surface, in particular a luminous strip, the entire surface or the entire strip illuminating continuously. This means that several light sources, for example several LEDs, halogen lamps or light bulbs, are used. Alternatively, it can also be, for example, an OLED surface or a halogen lamp with a longitudinal extent.

In a further embodiment, the thin-film solar module comprises at least one weather protection layer between the carrier layer and the lighting means. Alternatively or additionally, the thin-film solar module comprises at least one diffuser layer between the carrier layer and the lighting means.

Preferably, the display surface is designed and arranged to absorb light, in particular sunlight, and to emit light, in particular artificial light. In a particularly suitable embodiment, the thin-film solar module according to the invention and / or the display surface comprises absorption areas and emission areas, the latter occupying less than 20%, in particular less than 10%, preferably less than 5%, of the area of the absorption areas. In this case, it is preferred if absorption regions and emission regions are arranged alternately, in particular wherein each absorption region is to be assigned a solar cell.

The invention further relates to a method for obtaining energy with a thin-film solar module, in particular a thin-film solar module according to the invention, wherein the thin-film solar module comprises on a rear side lighting means, which couple light into a substrate layer at the back and emits at the front, wherein the thin-film solar module from a front side opposite the back Energy from light, especially sunlight, wins, which is radiated from the front.

The invention further relates to a method for obtaining energy and / or illumination with a thin-film solar module, in particular a thin-film solar module according to the invention, wherein the thin-film solar module comprises on a rear side lighting means which couple light into a substrate layer at the rear and emit energy at a front side opposite the rear side Light, especially sunlight, wins, which is radiated from the front.

• a) Zurverfügungstellung einer, insbesondere flächigen, Substratschicht,
• b) subsequentes Aufbringen der Schichten, welche zwischen Substratschicht und Frontelektrodenschicht anzutreffen sind, einschließlich der Rückelektrodenschicht, der Halbleiterabsorberschicht, insbesondere in der Schichtfolge wie sie vorstehend für das erfindungsgemäße Dünnschichtsolarmodul beschrieben wurde, sowie Aufbringen der Frontelektrodenschicht,
• c) mindestens einen ersten Strukturierungsschritt, umfassend Entfernen der auf die Substratschicht aufgebrachten Schichten entlang voneinander beabstandeter Linien mittels Laserablation, insbesondere mit Laserlichtpulsen mit einer Pulsdauer im Bereich von 1 pico-Sekunden bis 1 nano-Sekunde, unter Ausbildung erster Strukturierungstrenngräben, welche benachbarte Solarzellen trennen,
• d1) mindestens einen zweiten Strukturierungsschritt und einen nachfolgenden dritten Strukturierungsschritt unter Ausbildung der zweiten und dritten Strukturierungstrenngräben oder aber einen vierten Strukturierungsschritt unter Ausbildung der vierten Strukturierungstrenngräben, wobei der zweite, dritte und vierte Strukturierungsschritt durch Entfernung der Schichten im Bereich der zweiten und dritten bzw. der vierten Strukturierungstrenngräben mittels Laserablation, insbesondere mit Laserlichtpulsen mit einer Pulsdauer im Bereich von 1 pico-Sekunden bis 1 nano-Sekunde, oder mechanisch, insbesondere mittels Nadelritzens, erfolgt,
• e1) Füllen der ersten Strukturierungstrenngräben mit mindestens einem Isolatormaterial, das nach der Befüllung transparent oder semitransparent in dem ersten Strukturierungstrenngraben vorliegt,
• f1) Füllen der zweiten Strukturierungstrenngräben oder des ersten Volumenbereichs der vierten Strukturierungstrenngräben unter Nichtbefüllung des hierzu benachbarten zweiten Volumenbereichs mit einem leitfähigen Material, insbesondere einem transparenten oder semitransparenten Material,
• g1) Ausbilden mindestens einer leitfähigen Brücke umfassend das leitfähige Material zwischen dem Substrat oder der dritten Barriereschicht und der Frontelektrodenschicht der hierzu benachbarten Solarzelle, so dass benachbarte Solarzellen elektrisch serienverschaltet werden, oder als Alternative zu den Schritten d1) bis g1)
• d2) mindestens einen zweiten Strukturierungsschritt und einen nachfolgenden dritten Strukturierungsschritt unter Ausbildung der zweiten und dritten Strukturierungstrenngräben, wobei der zweite Strukturierungsschritt durch die chemische Phasenumwandlung und/oder thermischer Zersetzung und/oder Laserablation der Schichten im Bereich der zweiten Strukturierungstrenngräben unter Ausbildung linienförmiger leitfähiger Bereiche mit einem leitfähigen Material erfolgt, wobei der dritte Strukturierungsschritt durch Entfernung der Schichten im Bereich der dritten Strukturierungstrenngräben mittels Laserablation, insbesondere mit Laserlichtpulsen mit einer Pulsdauer im Bereich von 1 pico-Sekunden bis 1 nano-Sekunde, oder mechanisch, insbesondere mittels Nadelritzens, erfolgt,
• e2) Füllen der ersten Strukturierungstrenngräben mit mindestens einem Isolatormaterial, das nach der Befüllung transparent oder semitransparent in dem ersten Strukturierungstrenngraben vorliegt,
• g2) Ausbilden mindestens einer leitfähigen Brücke umfassend das leitfähige Material zwischen dem Substrat oder der dritten Barriereschicht und der Frontelektrodenschicht der hierzu benachbarten Solarzelle, so dass benachbarte Solarzellen elektrisch serienverschaltet werden.

In der letztgenannten Ausführungsform ist von besonderem Vorteil, dass, anders als bei den Schritten f1) und g1), in Schritt g2) die Verschaltung in einem Schritt stattfindet. Mit der vorliegenden Erfindung konnte ein Dünnschichtsolarmodul entwickelt werden, welches sich nutzen lässt, um neben der herkömmlichen Absorption von Licht zur Energiegewinnung auch Licht zu emittieren. Hierbei kann das emittierte Licht für Beleuchtungszwecke genutzt werden. Bei der Beleuchtung kann es sich um einfarbiges Licht oder alternierende Farbkombinationen handeln. Beispielsweise kann das eingestreute Licht farbig sein. Auch können Farbmuster sowie eine zeitliche Abfolge an Farbmustern vorgesehen sein, und zwar auch auf einem einzelnen Dünnschichtsolarmodul. Der Wechsel der Farbmuster kann dabei in einer weiteren Ausgestaltung im Einklang mit den benachbarten Dünnschichtsolarmodulen erfolgen. Insbesondere hat sich gezeigt, dass mit dem erfindungsgemäßen Dünnschichtsolarmodul ein verbesserter Wirkungsgrad der Solarzellen erzielt werden kann, als dies bei herkömmlichen Solarmodulen der Fall ist, wenn versucht wird eine Beleuchtung zu integrieren. Ein besonderes Anliegen der vorliegenden Erfindung ist es, Fassadenbeleuchtungen bzw. Fassaden, welche mit den erfindungsgemäßen Dünnschichtsolarmodulen ausgestattet sind, bereitzustellen. Es hat sich überraschenderweise gezeigt, dass die verwendeten Dünnschichtsolarmodule hinreichend robust sind, um an Außenfassaden verwendet zu werden.The invention further relates to the use of the thin-film solar module according to the invention for lighting devices and for facade lighting. The invention also relates to a method for producing a thin-film solar module according to the invention, comprising:

• a) providing a, in particular flat, substrate layer,
• b) subsequent application of the layers which are to be found between substrate layer and front electrode layer, including the back electrode layer, the semiconductor absorber layer, in particular in the layer sequence as described above for the thin layer solar module according to the invention, and application of the front electrode layer,
• c) at least one first structuring step, comprising removing the layers applied to the substrate layer along spaced-apart lines by means of laser ablation, in particular with laser light pulses having a pulse duration in the range of 1 pico-seconds to 1 nanosecond, forming first structuring trenches separating adjacent solar cells,
• d1) at least one second structuring step and a subsequent third structuring step to form the second and third structuring trenches or a fourth structuring step to form the fourth structuring trenches, the second, third and fourth structuring steps by removing the layers in the region of the second and third and fourth structuring trenches by means of laser ablation, in particular with laser light pulses having a pulse duration in the range of 1 pico-seconds to 1 nano-second, or mechanically, in particular by Nadelritzens takes place,
• e1) filling the first structuring trenches with at least one insulator material that is transparent or semi-transparent in the first structuring trench after filling,
• f1) filling the second structuring trenches or the first volume region of the fourth structuring trenches while not filling the second volume region adjacent thereto with a conductive material, in particular a transparent or semitransparent material,
• g1) forming at least one conductive bridge comprising the conductive material between the substrate or the third barrier layer and the front electrode layer of the adjacent thereto solar cell, so that adjacent solar cells are electrically series-connected, or as an alternative to the steps d1) to g1)
• d2) at least one second structuring step and a subsequent third structuring step to form the second and third structuring trenches, wherein the second structuring step comprises chemical phase transformation and / or thermal decomposition and / or laser ablation of the layers in the region of the second structuring trenches to form linear conductive regions conductive material takes place, wherein the third structuring step takes place by removal of the layers in the region of the third structuring trenches by means of laser ablation, in particular with laser light pulses having a pulse duration in the range of 1 pico-seconds to 1 nano-second, or mechanically, in particular by Nadelritzens
• e2) filling the first structuring trenches with at least one insulator material that is transparent or semi-transparent in the first structuring trench after filling,
• g2) forming at least one conductive bridge comprising the conductive material between the substrate or the third barrier layer and the front electrode layer of the adjacent thereto solar cell, so that adjacent solar cells are electrically series-connected.

In the last-mentioned embodiment, it is of particular advantage that, unlike steps f1) and g1), in step g2), the interconnection takes place in one step. With the present invention, a thin-film solar module could be developed, which can be used to emit light in addition to the conventional absorption of light for energy production. Here, the emitted light can be used for lighting purposes. The lighting can be monochromatic light or alternating color combinations. For example, the interspersed light can be colored. Also, color patterns as well as a temporal sequence of color patterns can be provided, even on a single thin-film solar module. The change of the color pattern can be done in a further embodiment in accordance with the adjacent thin-film solar modules. In particular, it has been shown that with the thin-film solar module according to the invention an improved efficiency of the solar cells can be achieved, as is the case with conventional solar modules, when an attempt is made to integrate lighting. A particular concern of the present invention is to provide facade lighting or facades, which are equipped with the thin-film solar modules according to the invention. It has surprisingly been found that the thin-film solar modules used are sufficiently robust to be used on external facades.

Further features and advantages of the invention will become apparent from the following description, are explained in the preferred embodiments of the invention by way of example with reference to schematic drawings. Showing:

1 a schematic cross-sectional view of a first embodiment of the thin-film solar module according to the invention with first, second and third structuring trenches.

2 a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention with first, second and third structuring trenches.

3 a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention with first, second and third structuring trenches.

4 a schematic cross-sectional view of another embodiment of the Thin-film solar module according to the invention with first and fourth structuring trenches.

5 a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention with first, second and third structuring trenches and a first arrangement of the lighting means and a possible beam path.

6 a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention with a further arrangement of the lamps.

1 If one takes a schematic cross-sectional view of a first embodiment of the thin-film solar module according to the invention 1 , The photovoltaic thin film solar module includes one on a substrate layer 4 immediately adjacent conductive transparent first barrier layer 2 , a bulk back electrode layer abutting on the substrate layer 6 , one at the back electrode layer 6 immediately adjacent conductive third barrier layer 8th , an ohmic contact layer directly adjacent to the third barrier layer 10 , a semiconductor absorber layer immediately adjacent to the contact layer 12 , in particular chalcopyrite or kesterite semiconductor absorber layer, a first buffer layer directly adjacent to the semiconductor absorber layer 14 , one at the first buffer layer 14 immediately adjacent second buffer layer 16 , one at the second buffer layer 16 directly adjacent transparent front electrode layer 18 spaced first structuring trenches filled with at least one insulator material 28 . 40 , which neighboring solar cells 30 . 42 defining the first patterning trenches 28 . 40 from the substrate layer 4 in the direction of the front electrode layer 18 extend, and each a conductive bridge 26 . 38 arising from the direction of the back electrode layer 6 up to the front electrode layer 18 extends, wherein the conductive bridges 26 . 38 consist of conductive material or include this. Here, the insulator material and the conductive material are transparent. Light emission channels are formed within the first patterning trench such that light coupled into the substrate layer passes through the insulator material and through the conductive bridge 26 . 38 is emitted to the front. Second structuring trenches 24 . 36 are with conductive material 22 . 34 filled. In the present case, it is the same material as the conductive bridge. Third structuring trenches 20 . 32 are present unfilled, but can also be filled with Isoliermetrial.

The ohmic contact layer 10 consists in the embodiment of a metal chalcogenide such as molybdenum selenide. It can be obtained in different ways, as previously explained in general terms. In one embodiment, for example, molybdenum selenide has been sputtered from a molybdenum selenide target. Alternatively, first of all a metal layer can be applied, which is then converted into the corresponding metal chalcogenide before and / or during the formation of the semiconductor absorber layer. The contact layer 10 In this case, in a preferred embodiment, it may also be mixed with at least one dopant, for example sodium ions or a sodium compound, in particular sodium sulfite or sodium sulfide.

The layer 12 represents the semiconductor absorber layer and may be present, for example, as a chalcopyrite or as a kesterite semiconductor absorber layer. Methods of applying these semiconductor absorber layers are known to those skilled in the art. If a dopant is present in the contact layer, it usually diffuses into the latter under the conditions of formation of the semiconductor absorber layer. Thin-film deposition is then applied to the semiconductor absorber layer 12 first the first buffer layer 14 from eg CdS, Zn (S, OH) or In ₂ S ₃ and the second buffer layer 16 have been applied from intrinsic zinc oxide and then the transparent front electrode layer 18 from n-doped zinc oxide. In the 1 Layer sequence shown 2 . 4 . 6 . 8th . 10 12 . 14 . 16 and 18 can also differ significantly. For example, the sequence of layers is also 4 . 6 . 10 . 12 . 14 . 18 or 4 . 6 . 8th . 12 . 14 . 16 . 18 conceivable, not mentioned layers omitted.

2 If one takes a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention 1 , where the reference numbers are analogous to 1 were awarded. In contrast to 1 is the second barrier layer 44 represented by the first structuring trenches 28 . 40 is broken. The second barrier layer 44 therefore need not be transparent to light emission channels through the first patterning trenches 28 . 40 to enable.

3 If one takes a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention 1 , where the reference numbers are analogous to 1 and 2 were awarded. In contrast to 2 is the second barrier layer 44 Although also reproduced, but not by the first structuring trenches 28 . 40 breached. The second barrier layer 44 should therefore be transparent or semitransparent to light emission channels through the first patterning trenches 28 . 40 to enable.

4 shows a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention 1 , wherein fourth structuring trenches 120 . 132 are formed, which in a first volume range with conductive material 122 . 134 are filled and are not filled in a second volume range. The structuring trenches 120 . 132 have wall areas 150 . 154 . 156 . 160 on. The first volume area is always at the interface 152 . 158 in the second volume range over. The photovoltaic thin film solar module includes one on a substrate layer 104 , a bulk back electrode layer abutting on the substrate layer 106 , one at the back electrode layer 106 immediately adjacent conductive third barrier layer 108 , an ohmic contact layer directly adjacent to the third barrier layer 110 , a semiconductor absorber layer immediately adjacent to the contact layer 112 , in particular chalcopyrite or kesterite semiconductor absorber layer, a first buffer layer directly adjacent to the semiconductor absorber layer 114 , one at the first buffer layer 114 immediately adjacent second buffer layer 116 , one at the second buffer layer 116 directly adjacent transparent front electrode layer 118 spaced first structuring trenches filled with at least one insulator material 128 . 140 , which neighboring solar cells 130 . 142 defining the first patterning trenches 128 . 140 from the substrate layer 104 in the direction of the front electrode layer 118 extend, and each a conductive bridge 126 . 138 arising from the direction of the back electrode layer 106 up to the front electrode layer 118 extends, wherein the conductive bridge consists of or comprises of conductive material. Here, the insulator material and the conductive material are transparent. Light emission channels are formed within the first patterning trench such that light coupled into the substrate layer passes through the insulator material and through the conductive bridge 126 . 138 is emitted to the front. Fourth structuring trenches 120 . 132 are partially made with conductive material 122 . 134 filled. In the present case, it is the same material as the rest of the bridge.

5 shows a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention 1 , wherein the layer sequence of 4 corresponds and in addition at the back a reflector layer 202 is applied, which is directly connected to the substrate layer. For clarity, only the newly added reflector layer 202 and the front electrode layer 204 quantified. Further, second and third patterning trenches are provided, wherein the first patterning trenches extend to the substrate layer while the second and third patterning trenches each extend to the third barrier layer. In the design of the thin-film solar module according to 5 is the front electrode layer 204 integral with the conductive bridge, so that the conductive material of the front electrode layer 204 to the second structuring trenches 206 . 208 and possibly also extending into the third structuring trenches. Furthermore, bulbs 210 . 212 reproduced, which are arranged peripherally. In the present case, this is a basic diagram, so that it should be clear to the person skilled in the art that more than four structuring trenches are usually found between the lamps due to the monolithic series connection of solar cells. For bulbs 212 is an example of a beam path reproduce, wherein the beam represented by arrows on the reflector layer 202 reflected and escaped through a light emission channel. The insulating material is presently transparent and the conductive material is at least semitransparent.

6 shows a schematic cross-sectional view of another embodiment of the thin-film solar module according to the invention 300 wherein the thin film solar module interrupted by light emission channels 300 is represented by a dashed double line. The light emission channels correspond to the breaks in said double line. Below the thin-film solar module 300 are bulbs 203 arranged in the form of an LED matrix, which by aperture 304 are delimited against each other.

The features of the invention disclosed in the foregoing description, in the claims and in the drawings may be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims (14)

Photovoltaic thin film solar module containing, in particular in this order, preferably at least one conductive first barrier layer immediately adjacent to the substrate layer, in particular transparent or semitransparent first barrier layer, at least one substrate layer, preferably at least one conductive second barrier layer lying between the substrate layer and back electrode layer, in particular transparent or semitransparent second barrier layer, at least one, in particular at a barrier layer and / or the substrate layer adjacent, back electrode layer, in particular a bulk back electrode layer, preferably at least one on at least one contact layer, in particular ohmic contact layer, directly adjacent to the third barrier layer, at least one semiconductor absorber layer directly adjacent to the contact layer or back electrode layer, in particular chalcopyrite or kesterite semiconductor absorber layer, preferably at least one, in particular on the semiconductor absorber layer immediately adjacent, first buffer layer containing or substantially of CdS or a CdS-free layer, in particular containing or substantially Zn (S, OH) or In ₂ S ₃ , preferably at least one, in particular on the semiconductor absorber layer or the first buffer layer immediately adjacent, second buffer layer containing and essentially of intrinsic zinc oxide and / or high-resistance zinc oxide, at least one, in particular on the semiconductor absorber Furthermore, the first buffer layer and / or the second buffer layer directly adjacent, transparent or semi-transparent front electrode layer, in particular containing or consisting essentially of n-doped zinc oxide, further comprising spaced apart with at least one insulator filled first structuring trenches, which define adjacent solar cells, the first Patterning trenches extending from the substrate layer or the second barrier layer toward the front electrode layer; and at least one conductive bridge across the first pattern trench (s) extending from the direction of the back electrode layer to the front electrode layer, the conductive bridge being made of conductive material characterized in that the insulator material in the first patterning trenches and / or the conductive material of the conductive bridge, in particular both the Insulator material and the conductive material, and optionally the substrate layer or portions thereof and optionally the second barrier layer are transparent or semitransparent and light emission channels, in particular through the first structuring trenches, forming, or are part of.  A photovoltaic thin-film solar module according to claim 1, comprising spaced apart second structuring trenches filled or provided with at least one conductive material, which extend as far as the contact layer or the back electrode layer or the second or third barrier layer or the substrate, in particular up to the third barrier layer or up to the third barrier layer Back electrode layer, extend and each adjacent to a filled first structuring trench, spaced third patterning trenches, which extend to the contact layer or to the back electrode layer or to the second or third barrier layer, in particular to the third barrier layer or to the back electrode layer, and each adjacent to a second patterning trench, beyond the first patterning trench to which the second patterning trench is adjacent, and wherein the mi at least one conductive bridge is formed above the first or second pattern trenches by conductive material extending through second pattern trenches filled or provided with said conductive material and over adjacent first pattern trenches to the front electrode layer of the adjacent solar cell, or fourth pattern trenches spaced apart from each other; extending to the contact layer or to the back electrode layer or to the third barrier layer, in particular to the third barrier layer or to the back electrode layer, and each adjacent to a filled first structuring trench and having a first volume region extending from the barrier layer to the front electrode layer extending to the first structuring trench adjacent Trenngrabenwand and filled with the at least one conductive material t, and a second volume region adjacent thereto, which extends from the contact layer or from the back electrode layer or from the third barrier layer, in particular from the third barrier layer, to the front electrode layer, and wherein the at least one conductive bridge is over or the first patterning trenches are formed by conductive material which extends through first volume regions of the fourth pattern trenches filled or provided with said conductive material and over adjacent first pattern trenches to the front electrode layer of the adjacent solar cell. Photovoltaic thin-film solar module according to claim 1 or 2, characterized in that it comprises a second barrier layer, which is transparent or semitransparent, and / or that the first structuring trenches extend to the substrate layer. Thin-film solar module according to one of the preceding claims, characterized in that a plurality of, in particular monolithically integrated serienverschalteten solar cells, which are separated from each other by the spaced first structuring trenches, wherein in particular, the light emission channels are present between the solar cells. Thin-film solar module according to one of the preceding claims, characterized in that this luminous means, in particular LEDs, OLEDs or halogen lamps, which are arranged on a side remote from the back electrode layer side of the substrate layer and / or in at least one edge region of the substrate layer, preferably circumferentially, wherein the edge region extends between two mutually plane-parallel opposite sides of the substrate layer, in particular wherein a full-area and / or partial illumination of the substrate layer takes place. Thin-film solar module according to claim 5, characterized in that the lighting means, in particular LEDs, OLEDs or halogen lamps, are arranged so that light of the lighting means coupled through the edge region, wherein a side remote from the back electrode layer side of the substrate layer, a reflector layer, in particular in the form of a reflective metallic thin film, comprises, or is immediately adjacent to such. Thin-film solar module according to claim 5 or 6, characterized in that the substrate layer is an optical diffuser, comprises or directly adjacent to such, in particular an optical diffuser on the reflector layer, which by roughening the side facing away from the back electrode layer of the substrate layer or by deposition of a is formed optically transparent Haze layer, and / or that a carrier layer on which the bulbs are mounted, is attached directly or indirectly to the substrate layer, in particular wherein the carrier layer comprises apertures, which limits the lateral radiation of the bulbs, and / or a liquid crystal layer is present between the luminous means and the back electrode layer, in particular adjacent to or integrated into the substrate layer.  Thin-film solar module according to one of claims 5 to 7, further comprising at least one weather protection layer and / or diffuser layer between the carrier layer and the lighting means. Lighting device with at least one thin-film solar module according to one of the preceding claims, characterized in that the thin-film solar module comprises or forms a display surface and / or an illumination surface, in particular wherein the display surface is designed and configured to absorb light, in particular sunlight, and light, in particular artificial light the light-emitting means, via the light emission channels to emit, optionally further comprising energy storage, in particular an energy storage, which is charged by the thin-film solar module. Lighting device according to claim 9, characterized in that the emitted light is monochrome or represents an alternating color combination and / or that the illumination device is set up and designed to produce color patterns or a temporal sequence of color patterns, in particular on a single thin-film solar module and / or Consistent with adjacent thin-film solar modules.  Facade with at least one thin-film solar module according to one of claims 1 to 8 and / or with at least one illumination device according to claim 9 or 10, wherein the at least one thin-film solar module, preferably substantially perpendicular to the facade fastened or fastened. Use of the thin-film solar module according to one of claims 1 to 8 for lighting devices, in particular according to claim 9 or 10, for facade lighting. Method for energy production and / or illumination with a thin-film solar module, in particular a thin-film solar module according to one of claims 1 to 8, wherein the thin-film solar module comprises at a rear side lighting means, which couple light into a substrate layer at the back and emits at a front side opposite the back. A method for producing a thin-film solar module according to one of claims 1 to 8, comprising: a) providing a, in particular flat, substrate layer, b) subsequent application of the layers which are to be found between substrate layer and front electrode layer, including the back electrode layer, the semiconductor absorber layer, in particular in FIG Layer sequence of claim 1, as well as application of the front electrode layer, c) at least one first structuring step, comprising removing the layers applied to the substrate layer along spaced lines by means of laser ablation, in particular with laser light pulses having a pulse duration in the range of 1 pico-seconds to 1 nano-second forming first patterning trenches separating adjacent solar cells; d1) at least one second patterning step and a subsequent third one Structuring step forming the second and third structuring trenches or a fourth structuring step forming the fourth structuring trenches, the second, third and fourth structuring step by removing the layers in the region of the second and third or the fourth structuring trenches by means of laser ablation, in particular with laser light pulses with a Pulse duration in the range of 1 pico-seconds to 1 nano-second, or mechanically, in particular by Nadelritzens takes place, e1) filling the first structuring trenches with at least one insulator material, which is present after filling transparent or semitransparent in the first structuring trench, f1) filling the second structuring trenches or the first volume region of the fourth structuring trenches with non-filling of the second volume region adjacent thereto with a conductive material, in particular one transparent or semi-transparent material, g1) forming at least one conductive bridge over the first or the first patterning trenches comprising the conductive material between the substrate or the third barrier layer and the front electrode layer of the adjacent solar cell such that adjacent solar cells are electrically series connected, or as an alternative to Steps d1) to g1) d2) at least one second structuring step and a subsequent third structuring step to form the second and third structuring trenches, wherein the second structuring step by the chemical phase transformation and / or thermal decomposition and / or laser ablation of the layers in the region of the second structuring trenches Formation of line-shaped conductive regions is carried out with a conductive material, wherein the third structuring step by removal of the layers in the region of the third structure e2) filling of the first structuring trenches with at least one insulator material, which is transparent or semitransparent after being filled, by means of laser ablation, in particular with laser light pulses having a pulse duration in the range from 1 pico-seconds to 1 nano-second or mechanically, in particular by Nadelritzens g2) forming at least one conductive bridge over the first patterning trench (s) comprising the conductive material between the substrate or the third barrier layer and the front electrode layer of the adjacent solar cell such that adjacent solar cells are electrically series connected.

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