JP6635924B2 - Method for thin film via segment of photovoltaic device - Google Patents

Description

  [0001] The present invention relates to vias and monolithic interconnects in thin-film optoelectronic devices, such as between cells of a photovoltaic module.

  [0002] Thin-film photovoltaic modules typically consist of a number of electrically interconnected optoelectronic components. Such components may be optoelectronic devices such as photovoltaic cells, or any additional components such as diodes and other electronic devices. Photovoltaic modules typically also include electrical interconnect components such as inter-battery connectors and busbars.

[0003] Multilayer thin-film technology allows for monolithic integration and interconnection of several optoelectronic and related components on the same substrate. This integration is produced in situ using a series of layer deposition and scribing techniques. A thin-film photovoltaic or photovoltaic component or device is basically composed of three material layers: a conductive back contact electrode layer, a semiconductor photovoltaic material layer known as an absorber, and another conductive front contact electrode. Consisting of a stack with layers, the front front contact layer is usually transparent. Cu (In, Ga) to be abbreviated as CIGS photovoltaic cells based on semiconductor material ₂ such as Se, as compared to silicon photovoltaic device or solar cell of the conventional wafer-based, solar electric charges becomes cheaper, energy recovery It shows a high possibility that the period is shortened and the life cycle impact is improved.

  [0004] Compared to wafer-based photovoltaic devices, monolithic photovoltaic modules use less material to form thin films that form part of photovoltaic components, and labor costs of monolithic integration And the ease of automated production of large numbers of photovoltaic modules using, for example, roll-to-roll manufacturing techniques. For example, the relative area of the photovoltaic component exposed to light by reducing the area occupied by the front contact grid, the electrical interconnect between the optoelectronic components, and the busbars on the front contact electrodes of the photovoltaic cell Further savings are obtained by increasing. The production yield of photovoltaic modules may also be improved by reducing the number of manufacturing steps, for example, the number of scribing operations required to delineate and build optoelectronic interconnects in thin-film monolithic photovoltaic modules. .

  [0005] Patent Document 1 describes, for example, optoelectronic device modules connected in series by forming a wrap-through via using laser ablation, and the addition of a conductive material for driving current between electrodes and to adjacent modules. Has been described. Wrap-through vias typically require drilling and subsequent metallization. This adds cost and requires additional manufacturing steps that can reduce yield. When using the monolithic photovoltaic module production method of Patent Document 2 which describes that a via hole is formed by a copper-rich CIGS type wall obtained from partial dissolution of the CIGS material of the absorber layer, Avoid some of the steps.

  [0006] For some applications, there is a need for a method of forming a thin film optoelectronic device and a thin film optoelectronic device with via holes formed as line segments and variations thereof.

US Patent No. 7,276,724 International Publication No. 2011/148346 pamphlet

  [0007] A problem in the field of monolithic photovoltaic module production relates to reliably producing highly conductive via hole interconnects between photovoltaic components such as photovoltaic cells. The embodiments provided herein can include a method for reliably interconnecting the batteries of a thin-film monolithic photovoltaic module device with reduced cost and high production yield. The method can also be used to fabricate interconnects between various components of a monolithic photovoltaic module, which can include photovoltaic cells, diodes, grids, and busbars. The speed and large processing window of this method is advantageous for industrial production of monolithic photovoltaic module devices using a roll-to-roll production method. Embodiments of the present disclosure provided herein may further include thin film optoelectronic devices having via hole line segments and methods for reliably manufacturing such line segments at high speed.

  [0008] A problem in the field of manufacturing monolithic interconnects using lasers is that the processing window is very sensitive to laser scribing parameters, especially when the laser scribing photovoltaic material is formed on a flexible substrate. This means that adjustment is required.

  [0009] A further problem that is noticeable when laser scribing photovoltaic materials are formed on flexible substrates is that monolithic interconnects can exhibit variations in the manufacturing repeatability of their conductivity. That is.

  [0010] Yet another problem is that laser scribing can damage various layers of the photovoltaic material, causing cracking and local delamination of the material from the flexible substrate. This is especially true when scribing with a pulsed laser.

  [0011] Embodiments of the present disclosure can thus utilize a scribing method, preferably using a laser, wherein the heat generated by the scribing process is used to increase the conductivity of the scribing process. The material layer surrounding the isolated cavity is locally varied, which allows for the design and production of cost-effective series interconnect optoelectronic components and subsequent monolithic optoelectronic module devices.

  [0012] One embodiment of the present invention provides a thin film photovoltaic material, such as a CIGS battery or module, wherein the back contact layer is patterned with a battery, wherein a portion of the back contact layer and a portion of the front contact layer are provided. Constructed by scribing line segment via holes into a thin film material to form at least one conductive monolithic interconnect therebetween.

[0013] Embodiments of the present disclosure thus includes forming a line segment via holes in the region of the thin-film CIGS devices were monolithically integrated, including a method of forming at least one thin film CIGS devices A method for manufacturing an optoelectronic module can be provided. The device, CFCs preparative contact layer, the semi-conductor optoelectronic active layer, Ba click contact layer consists及beauty board, element line segment via holes during drilling of the line segments via holes, with respect to the line segments via hole Te, from a first power level is formed by drilling a continuous wave laser to apply the laser power progressively increases to a second power level, CFCs preparative contact layer及beauty semiconductors optoelectronic active layer at least a penetrates the parts, elements by drilling by Les Za, form a C IGS type wall-rich CIGS type alloy prior to Kira in segments via hole inner surface of the covering Ushirube conductive permanent metallized copper, The CIGS type alloy is a CIGS semiconductor optoelectronic active layer in which holes are drilled. Resulting from permanent changes in the chemical composition, form at least a portion Ba Tsu least a portion of the conductive path between the click contact layer description of front contact layer, the front contact layer along the edge of the inner surface of said line segments via hole And a raised portion of the back contact layer rising toward the front contact layer is formed at the base of the inner surface of the line segment via hole.

[0014] In the above method, by forming the via hole, a part of the back contact layer in the via hole can be removed, thereby exposing a part of the substrate. Still further, forming a via hole may remove a portion of the back contact layer in the via hole, thereby exposing a portion of the substrate, where the back contact is raised toward the front contact layer. Forming the raised portion of the layer forms a gutter-like curl-up . Rather, the gutter curl-up includes a portion of the back contact layer that curls over a portion of the CIGS-type wall. In the above method, the substrate may be polyimide. More specifically, the drilling of the via holes can be with a continuous wave laser. Still further, forming a via hole can be with the thin film CIGS device by at least one laser forming a laser spot having an asymmetric laser spot diagram. More precisely, increasing the laser power during drilling of the via hole by the laser involves a gradual increase in the laser power during the movement of the laser spot from the laser towards the via hole. The drilling of the via hole is performed by microscopic inspection when viewed from the light-exposed side of the device, the end corresponding to the start of drilling of the line segment via hole (first end) rather than at the end (second end). ) Can form the inner surface of a CIGS type alloy having an elliptical pattern having a small radius of curvature. In practice, drilling a via hole with a laser may include moving a laser spot of a continuous wave laser such that the laser energy supplied to at least a portion of the via hole is between 1 J / m and 8 J / m. . More specifically, drilling of via holes with a laser can include time intervals where the laser supply fluence is in the range of 5 × 10 ⁸ J / m ^{2 to} 41 × 10 ⁸ J / m ² . More precisely, laser drilling of via holes can include time intervals where the laser fed steady state fluence is in the range of 7.5 × 10 ⁸ J / m ^{2 to} 11 × 10 ⁸ J / m ^2. . For greater manufacturing throughput, drilling of via holes can be performed simultaneously with laser scribing of adjacent ablating lines to the front contact layer. Forming the thin-film CIGS device in a broader manner can include forming a dashed line of a plurality of the line segment via holes in a region of the thin-film CIGS device.

Embodiments of the present disclosure also relate to a method of forming a thin-film CIGS device that includes at least one line segment via hole in a region of the thin-film CIGS device, the device comprising a substrate and a front contact layer disposed on the substrate. And a back contact layer disposed on the substrate, and a semiconductor optoelectronic active layer disposed between the front contact layer and the back contact layer, and the line segment via hole is drilled by using a laser output. Conductive, permanently metallized copper formed through the front contact layer and at least a portion of the semiconductor optoelectronically active layer and by laser drilling covering the inner surface of the at least one line segment via hole Rich CIGS type alloy CIGS A back contact layer is formed along the line segment via hole, forming a conductive path between a part of the front contact layer and a part of the back contact layer, and rising toward the front contact layer. Forming a raised portion of the gutter to form a gutter-like curl-up .

In the method, a gutter curl-up is formed by a change in power applied by a laser during drilling of a line segment via hole. A gutter-like curl-up is formed by a gradual increase in laser power applied to the line segment via hole from a first power level to a second power level during drilling of the line segment via hole. A gutter-shaped curl-up is formed by a gradual increase in laser power applied to the line segment via hole from a first power level to a second power level during movement of the laser spot from the laser directed to the via hole. Is done. The gutter curl up includes a portion of the back contact layer that curls over a portion of the CIGS type wall. The CIGS type wall includes a portion extending above the front contact layer. The CIGS-type wall includes a portion extending above the front contact layer, and a portion of the front contact layer is disposed between the portion of the semiconductor photoelectrically active layer and the CIGS-type wall extending above the front contact layer. The gutter curl up includes a portion of the back contact layer that curls over a portion of the CIGS type wall.

  [0017] Embodiments of the present disclosure also provide for non-shadowing busbars, various sizes and numbers of current collection grids, encapsulation materials, and via depth and / or shape and / or location and / or number of vias. Monolithically integrated optoelectronic modules including variations can also be included.

[0018] Embodiments of the present disclosure provided herein relate to the manufacture of thin film photovoltaic devices, and more particularly, to photovoltaic devices for interconnected optoelectronic components such as flexible photovoltaic modules. Alternatively, some problems in the field of roll-to-roll production of modules can be advantageously solved. For thin-film flexible photovoltaic devices manufactured using one or more of the embodiments or methods described herein, advantages obtained over conventional devices can include:
Enlarged laser scribing window Greater reproducibility of laser scribing process Higher photovoltaic conversion efficiency Greater strength of monolithic interconnect Greater production yield Greater design range Greater photovoltaic module reliability Lower manufacturing costs

  [0019] The advantages listed above should not be deemed necessary for use with one or more of the embodiments described herein, but should be considered with respect to the scope of the invention described herein. It is not intended to be limiting.

  [0020] One of the advantages of the embodiments described herein includes the formation of line segment via holes, which not only provide connections to busbars and even to busbars that do not shadow. , May be particularly useful for monolithic interconnection of thin film devices.

[0021] FIG. 3 illustrates a cross-sectional view of an embodiment of a line segment via hole of a thin film CIGS device having elevated CIGS type via hole walls. FIG. 4 shows a cross-sectional view of an embodiment of a line segment via hole of a thin film CIGS device having a raised CIGS type via hole wall surface. [0022] FIG. 2 illustrates a cross-sectional view of a thin film CIGS module comprised of a plurality of line segment via holes. FIG. 3 shows a top view of the thin film CIGS module comprising a plurality of line segment via holes shown in FIG. 2, ie, a view on the side exposed to light. [0024] FIG. 4 shows a top view of a line segment via hole, ie, a view of the side exposed to light, and a graph of the corresponding laser power used to laser scribe the line segment via hole. FIG. 3 shows a top view of a line segment via hole, ie, a view of the side exposed to light, and a graph of the corresponding laser power used to laser scribe the line segment via hole. 5 is a graph of laser power versus time used to scribe a series of line segment via holes. [0026] Variations of FIGS. 2, 1A, 1B, and 4A are shown, where the elevated CIGS-type via hole walls are wider and form on the front contact layer. 2, 1A, 1B, and 4A are shown, wherein the elevated CIGS type via hole wall is wider and forms on the front contact layer. 2, 1A, 1B, and 4A are shown, wherein the elevated CIGS type via hole wall is wider and forms on the front contact layer. 2, 1A, 1B, and 4A are shown, wherein the elevated CIGS type via hole wall is wider and forms on the front contact layer. 2, 1A, 1B, and 4A are shown, wherein the elevated CIGS type via hole wall is wider and forms on the front contact layer.

  [0027] FIGS. 1A-1B depict exemplary embodiments of the present disclosure provided herein, each of which illustrates a method of forming a line segment via hole for forming a monolithically integrated optoelectronic module. Represents a technical variation on how it is performed. Those skilled in the art will appreciate that the scales of the various components shown in the figures have been adjusted to improve clarity and therefore are not intended to limit the scope of the invention provided herein. You will recognize. Further, the number and area of the components in the figures are shown schematically and can therefore be further adjusted and configured to form an integrated optoelectronic module suitable for industrial production. Most of the features described with respect to FIGS. 1A and 1B also apply to FIGS. 6B and 6C, the difference being that the embodiment of FIGS. 6B and 6C makes the embodiment of the CIGS type at least partially cover the surface of the front contact layer 150. It is to include at least one raised portion of the alloy 155 ', and that the bumps of the raised portion 155 of the front contact of FIGS. 1A and 1B are numbered 157 in FIGS. 6B and 6C.

  [0028] FIG. 1A shows a cross-section of a portion of a thin-film device 100 where a line segment via hole 165 has been scribed, preferably using a laser. The thin film device comprises at least one electrically insulating substrate 110, at least one conductive back contact layer 120, at least one absorber layer 130, optionally at least one buffer layer 140, and at least one conductive front contact layer 150. Become.

  [0029] The electrically insulating substrate 110 may be rigid or flexible, and may comprise a variety of materials or coating materials, for example, glass, coated metal, metal coated with plastic, plastic, coated plastic such as metal-coated plastic, or the like. Flexible glass may be used. Polyimide is very flexible and sustains the temperatures needed to produce high efficiency optoelectronic devices, requires less processing than coated metal substrates, and is compatible with those of the photovoltaic material layers deposited on it A preferred flexible substrate material is polyimide because it exhibits a characteristic thermal coefficient of thermal expansion. Industrially available polyimide substrates are typically available in thicknesses of 7 μm to 150 μm and can sustain temperatures of about 400 to 600 ° C., enabling roll-to-roll production.

[0030] At least one conductive back contact layer 120 coats the substrate 110. The back contact layer 120 preferably has a high light reflectivity, and may have some other thin film material, such as metal chalcogenide, molybdenum chalcogenide, molybdenum selenide (eg, MoSe ₂ ), sodium (Na) doped Mo , Potassium (K) doped Mo, Na and K doped Mo, transition metal chalcogenide, tin doped indium oxide (ITO), doped or undoped indium oxide, doped or undoped zinc oxide, zirconium nitride, Tin oxide, titanium nitride, titanium (Ti), tungsten (W), tantalum (Ta), gold (Au), silver (Ag), copper (Cu), and niobium (Nb) can also or advantageously be used. It is generally made of molybdenum (Mo), although it can be included.

[0031] At least one absorber layer 130 coats the conductive layer 120. The absorber layer 130 is typically made of an ABC material, where A is a periodic table of chemical elements defined by the International Union of Pure and Applied Chemistry including copper (Cu) or silver (Ag). Represents an element of group 11; B represents an element of group 13 of the periodic table including indium (In), gallium (Ga), or aluminum (Al); and C represents sulfur (S), selenium ( Se) or an element belonging to Group 16 of the periodic table including tellurium (Te). An example of an ABC material, such as an ABC ₂ material, is a Cu (In, Ga) Se ₂ semiconductor (also known as CIGS).

  [0032] Optionally, at least one semiconductor buffer layer 140 coats the absorber layer 130. The buffer layer typically has an energy bandgap higher than 1.5 eV, for example, CdS, Cd (S, OH), CdZnS, indium sulfide, zinc sulfide, gallium selenide, indium selenide, It is made of (indium, gallium) sulfur compound, (indium, gallium) selenium compound, tin oxide, zinc oxide, Zn (Mg, 0) S, Zn (0, S) material, or a variation thereof.

  [0033] At least one transparent conductive layer 150 coats the buffer layer 140. The transparent conductive layer (also known as front contact) is typically a transparent conductive oxide (TCO) layer made of a doped or undoped variation of a material such as, for example, indium oxide, tin oxide, or zinc oxide. Consists of

  [0034] Line segment via hole 165 is a thin film microstructure typically formed after deposition of front contact layer 150. The line segment via holes 165 are preferably scribed using at least one laser, preferably with at least one continuous wave laser. As a result, the local heat generated by the scribing makes the CIGS material at the level of the CIGS absorber layer 130 that covers the inner surface of the line segment via hole 165 permanently conductive, thereby forming a CIGS type wall 134. The material of the CIGS type wall 134 results from local heat-induced alteration of the CIGS material of the absorber layer 130. Heat induced alteration can be described as partial melting and partial evaporation of the chemical components of the CIGS material, thereby resulting in the CIGS type wall 134 being formed from a copper-rich CIGS type alloy. It becomes as.

  [0035] One skilled in the art can observe and quantify the distribution of thin film microstructures and materials using scanning electron microscopy, energy dispersive X-ray spectroscopy (EDS), and image processing software. Characterization of the copper-rich CIGS type alloy by energy dispersive X-ray spectroscopy (EDS) suggests that it contains at least copper selenide and copper.

[0036] The CIGS type alloy thus forms a metallized CIGS type wall 134 of the line segment via hole 165. The metal-coated CIGS type wall 134 extends in the direction of the thin film thickness from the back contact layer 120 to at least the front contact layer 150 in the line segment via hole 165. The metallized CIGS type wall 134 thus provides a conductive path between the back contact layer 120 and the front contact layer 150. The resistivity of the CIGS type wall 134 is typically about 1.68 × 10 ⁸ Ω. At the same about 2 × ¹⁰ 2 2 [Omega copper having a resistivity of m. m, a satisfactory value is about 1.9 × 10 ³ Ω. m to 2.1 × 10 ³ Ω. m.

  [0037] Thus, by controlling the energy supplied during the laser scribing process, segment via holes 165 can be desirably formed. The local heating generated by the scribing process using at least one laser, preferably at least one continuous wave laser, also causes at least one raised portion 125 of the back contact layer 120 to rise toward the front contact layer 150. Form. Raised portion 125 can provide improved mechanical and electrical contact with CIGS type wall 134.

[0038] Furthermore, a portion 155 having a higher front contact can be arbitrarily formed on the surface of the front contact layer 150 by local heat generated by the scribing process. The raised portion of the front contact typically resembles a bump along most of the periphery of the via hole. The shape of the bumps typically fuses to the inner surface 135 of the CIGS type wall 134 of the via hole and outwardly, it can progressively fuse to the front contact layer or form an obtuse joint 159. The outer cross section of the bump can be modeled, for example, by an arbitrarily truncated bump function. That is, when | x | <1 (or when | x | << 1), y = exp (−1 / (l−x ² )), otherwise y = 0. The raised portion 155 of the front contact may include indium diffused from the underlying absorber layer 130. The indium is a result of both thermal radiation and diffusion from the location where the laser energy is applied and from thermal radiation due to the hot plate effect due to the presence of the underlying back contact layer 120 during the laser scribing process. Can exist. As a result, indium is diffused from the absorber layer 130 to the front contact layer 150.

  [0039] FIG. 1B shows a cross section of a variation of FIG. 1A, wherein a portion of the substrate 110 is exposed in the via hole 165 'and at least one raised portion of the back contact layer 120 is exposed to the substrate. Gutter-shaped curl-ups 127 and 127 'are formed around the exposed portion 117. Exposing the substrate 110 to form the gutter-shaped curls 127, 127 'of the back contact layer 120 requires a greater laser scribing fabrication window, greater production yield, and mechanical resistance than the embodiment shown in FIG. 1A. Can be given. FIG. 1B shows two variations of the CIGS type walls 134, 134 'and the corresponding raised portions of the gutter-shaped curl-ups 127, 127' of the back contact layer 120. The variation in the height of the back contact of the CIGS type wall 134 and the gutter-shaped curl-up 127 is that the raised portion curls up and curls backward, thereby forming a curl-up curl-up and back 127 type. The material of the inner surface 134 is then surrounded and possibly locally fused to form a heterogeneous composite of copper, copper selenide, and molybdenum. The variation in the height of the back contact of the inner surface 134 'and the gutter-shaped curl-up 127' is such that the raised portion curls up, but does not curl backward, thereby providing a curl-up only 127 'type of curl-up. Formed and comprises less material fusion than in curl up and back 127.

  [0040] The elevated portions of the two CIGS type wall variations 134, 134 'and the gutter curls 127, 127' may be in separate via holes or in the same via hole. For example, at least a portion of one long side of via hole 165 'can represent variations 134, 127, while at least a portion of the other long side can represent variations 134', 127 '. Forming the raised portions of the gutter-like curl-ups 127, 127 'of the back contact layer 120, as compared to FIG. 1A, may in some embodiments raise the inner surfaces 134, 134' relatively higher. And optionally higher elevations of the raised portion 155 of the front contact.

  [0041] The gutter curls 127, 127 'can be advantageous to increase the conductivity of the via holes and the strength against thin film delamination. In effect, the gutter curls 127, 127 'form a weld, usually consisting of a non-uniform distribution of molybdenum, copper, and possibly copper selenide, which bonds the thin film layers to one another, especially the back contact molybdenum. Locally reinforce bonding of the nearby unfused CIGS semiconductor optoelectronic active layer to the layer. Via holes or monolithically interconnecting trenches manufactured according to the prior art, especially those manufactured using pulsed lasers instead of continuous wave lasers, are capable of delamination, flaking and cracking in thin film layers of photovoltaic devices. Thus, a smaller mechanical strength, which can be usually determined, can be exhibited.

  [0042] Forming variations 134, 127 and 134 ', 127' can be a local adaptation of the via hole segment conductivity or, if the via hole segment is sufficiently long, the curl up height 1273 and width 1275, copper The width 1345 of the rich CIGS type alloy, as well as the local adaptation of the conductivity along the length of the via-hole segment by varying the amount of indium diffused into the bump-shaped raised portion 155 of the front contact 150. Can be advantageous for For example, one surface of the via hole segment, eg, the surface closest to the majority of the front contact area exposed to the light of the battery, may be moved from the other surface, eg, the surface closest to the front contact layer groove 151 (shown in FIGS. 2 and 3). Making it also conductive may be advantageous in some embodiments. It is also possible to adjust the conductivity of the surface of the via segment to show compatibility with variations in local conductivity on the surface of the battery, for example, variations caused by the presence, proximity, or proximity of front contact conductive grid components. Can be advantageous. Embodiments can include, for example, via hole segments of various lengths, possibly curvilinear via hole segments, wherein any one of the faces of any one of the via segments has variations 134, 127 and 134 ', 127'.

  [0043] A method of manufacturing at least one via hole line segment comprising at least one of the above variations can include using a laser spot, wherein a laser spot diagram of a laser scribing device surface. , The region of the highest laser light intensity of the laser spot is not located symmetrically with respect to the center of the laser spot diagram. The asymmetry of the laser spot diagram can be obtained, for example, by adjusting a laser beam shaper or a laser beam expander arranged in the optical path of the laser beam. By choosing or controlling the location of the region of highest laser intensity within the laser spot, one skilled in the art can select or control the formation of curl-up variations 127 and 127 '. One of ordinary skill in the art will appreciate that the highest laser intensity in the laser spot can be altered to alter the formation of the line segment via hole, for example, to form multiple gutter curls of various features within the at least one line segment via hole. The location of the region can be changed as desired.

  FIG. 2 shows a cross section of a thin-film CIGS photovoltaic module 200 comprising a plurality of line segment via holes 163, 165, 165 ', 167. Line segment via holes 165 allow for serial monolithic interconnection between adjacent cells of the photovoltaic module. Line segment via holes 163, 167 allow for electrical interconnection of front contact or back contact layer components to underlying busbars 182, 188. The at least one line segment via hole 163, 165, 165 ', 167 is a copper-rich CIGS resulting from heat-induced alteration of the CIGS material of the absorber layer described in at least one of FIGS. 1A-1B. Type walls 132, 134, 136, 138 and at least one raised portion 125, 127 of the back contact layer. Any one of the via holes 163, 165, 165 'and 167 has a height of at least one front contact formed over the front contact layer component 156, as shown in FIGS. 1A-1B. A portion 155 can optionally be provided. Any one of the via holes 163, 165, 165 ', 167 optionally includes at least one back contact layer component 128 formed with gutter curls 127, 127', as also shown in FIG. 1B. be able to.

  [0045] Similar to the description of FIG. 1A, the photovoltaic module 200 includes at least one conductive back, represented by at least one electrically insulating substrate 110, here a back contact layer component 124, 126, 128, 129. A contact layer, optionally at least one buffer layer, represented by at least one absorber layer 130, here buffer layer components 142, 144, 146, 148, and here front contact layer components 152, 154, 156, 158 And at least one conductive front contact layer represented by The back contact layer grooves 121 that form the electrically isolated back contact layer components are typically laser scribed prior to the absorber layer deposition. The front contact layer groove 151, which forms at least the electrically isolated front contact layer component, is usually laser scribed, preferably by a pulsed laser, more preferably by a picosecond pulsed laser, so that the groove is formed in the back contact layer component. It can extend deep to the surface.

  [0046] Line segment via holes 165 establish a monolithic interconnect between at least one first front contact layer component 154, 156 and at least one second back contact layer component 126, 128. The via hole may be scribed before, after, or simultaneously with the scribing of the front contact layer groove 151. Furthermore, the same laser source can be used to scribe via hole 165 and front contact layer groove 151.

  [0047] Line segment via holes 163, 167 enable electrical contact to at least one busbar 182, 188. The via holes 163 and 167 can be scribed deeper than the via holes 165 and 165 'so as to ablate a part of the substrate 110. The conductive pastes 172 and 178 can be used to establish electric paths between the thin film layers of the via holes 163 and 167 and the busbars 182 and 188, respectively. The conductive paste may include at least one via hole 163, 165, 165 'to increase the conductivity of the connection provided by the inner surfaces 132, 134, 136, 138 within the via holes 163, 165, 165', 167. , 167 as a filler.

  [0048] FIG. 3 is a schematic top or plan view of a thin film CIGS module 200 including a plurality of line segment via holes 163, 165, 165 ', 167 having staggered directions, ie, a view on the side exposed to light. And its cross section is shown in FIG. The lines 210 of the line segment via holes 163, 165 'were scribed in the direction 101, and the line segment via holes 165, 167 were scribed in the opposite direction 102. The direction of scribing is recognizable in that the end corresponding to the start 105 of the drilling of the line segment via hole has a smaller radius of curvature than the end 106. The edge length and shape corresponding to the start 105 of the drilling is the result of the movement of the laser and the progressive increase in laser power. Gradual laser power increases are preferred for making conductive CIGS type alloys, while minimizing the risk of unnecessary cracks and delamination that often occur when using pulsed lasers. For some laser scribing parameters and thin film CIGS devices, the direction of scribing is such that the CIGS type walls 132, 134, 136, at the end corresponding to the start 105 of drilling correspond to the end corresponding to the end 106 of drilling. It can also be recognized in that it has 138 longer inner surfaces 135. The line segment via holes 163, 165, 165 ', 167 are characterized in that a part of the via hole length at the end corresponding to the start 105 of drilling is smaller than the average width of the via hole except for the end 106. It is possible. Line segment via holes 165 ′ are also illustrated in the top view of the gutter-shaped curl-up 127 or 127 ′ of the back contact layer component 128 and the visible portion of the substrate 110. The front contact layer groove 151 reveals a part of the absorber layer 130. The front contact layer grooves 151 that separate the front contact components can be manufactured in the same production process used to produce the line segment via holes, thereby increasing production complexity, time, cost, and tools. Advantageously reduce the number of

  [0049] Although the line segment via hole can be scribed in any direction, the first line of the line segment via hole is in the first direction 101, and then the second line of the line segment via hole, For example, scribing adjacent lines in a second opposite direction 102 may be advantageous to increase manufacturing speed. Furthermore, the line segment via holes may have various dimensions, such as various variations, lengths and / or widths, as shown in the description of FIGS. 1A-1B, FIGS. 2 and 3, and for a given line. It is possible to have various separations between the upper line segment via holes, ie between the lines of the line segment via hole.

  [0050] FIG. 4A shows a top view of an embodiment of a line segment via hole 165 ', ie, a view on the side exposed to light, and FIG. 4B shows the corresponding laser used to laser scribe the line segment via hole. It is a graph of power 400. Line segment via hole 165 ′ is laser scribed in direction 101 with thin film device 100. In FIG. 4A, the laser power used forms a via hole with a raised trough-shaped curl-up 127 in the back contact layer 120 around the exposed portion 117 of the substrate. The curl up 127 may include a curl up variation of the curl up and back 127 or curl up only 127 'shown in FIG. 1B. The underlying substrate 110 is also visible as a result of partial ablation of the back contact layer 120. FIG. 4A also illustrates a CIGS-type wall 134 covered by at least one raised portion 155 of the front contact covering a portion of the front contact layer 150. Also, in FIG. 4A, within the laser power increase distance portion 405, the inner surface 135 of the CIGS type wall 134 that is narrower than the rest around the via hole is visible. It is in the laser power increase distance portion 405 following the edge corresponding to the start 105 of drilling that the portion of the via hole is typically less than the average width of the via hole, except for the edge length 406 leading to the end 106.

  [0051] The graph of FIG. 4B shows how a plot 400 of laser power versus distance typically comprises a laser power increase portion 415. The laser power augmentation portion starts at a power level with no power and a power level that does not form any scribing traces, and forms any via hole segments similar to those shown in the description for FIGS. 1A, 1B, 6B, and 6C. Ends with the level of laser power you can. The increase in laser power is usually controlled by a laser controller, but can also be obtained with a mechanical or optoelectronic shutter. The increase in laser power as a function of distance is usually gradual and is typically shaped as a ramp or step response of a damped first or second order system model. The laser spot typically moves a distance 405 during the laser power increase distance portion. However, the laser power can be arbitrarily set to increase without moving the laser spot. The laser power increase distance section is usually followed by a section of constant power, where the laser spot can travel any length and scribe or trace any pattern on the thin film photovoltaic device 100, 200. . The pattern usually consists of at least one line segment, but can also consist of a connected sequence of turns, segments or can be curved. The scribing of the via hole ends with a laser power reduction step 416 that forms the end 106 of the line segment via hole. The laser power is then reduced, usually abruptly, to a level below the ablation threshold power, which does not form any scribing of via holes, and preferably no scribing traces.

  [0052] In summary, the laser power reduction step 416 forms the end 106, while the laser power increase portion 415 forms the beginning 105 of the drilled end. The rate at which energy is supplied during the laser power augment 415 is an important parameter for successfully forming via holes with highly conductive CIGS type walls 134, 134 'and gutter curls 127, 127'. . Examples of some desirable laser scribing processing parameters are described in further detail below. Too high a rate results in delamination, excessive layer ablation, and unusual via holes, which reduce the overall photovoltaic efficiency of the device, cause flaking of the thin film layers, create breakpoints, and Life may be shortened. The sudden laser power reduction step 416 typically allows the conductive end 106 to be successfully formed. Sudden laser power reduction is not a requirement, but is advantageous when the power of the laser is controlled by an electronic controller or switch capable of forcing a minimum period between levels of laser power output allowing scribing, for example, a simmer period. It can be.

  FIG. 5 is a graph of laser power versus time, where two line segment via holes are scribed, for example, to various portions of a thin film CIGS module 200. The scale of the graph is different from that of FIG. 4B. The graph illustrates a line segment via hole scribing sequence for scribing at least one line segment via hole. As shown in laser power plot 500, the sequence of scribing at least one line segment via hole comprises at least one laser power increase time portion 515, where the laser power starts scribing the first line segment via hole. To increase progressively. The increase in laser power as a function of time is preferably gradual and is usually shaped as a ramp or step response of a damped first or second order system model. The laser power increase time portion 515 can be used to form a starting portion that is similar in shape to the laser power increase distance portion 405 shown in FIGS. 3 and 4A. The laser power then optionally reaches a steady state. The sequence then includes a laser power reduction portion 516, typically by a laser power reduction step, usually abrupt, to a laser power level below the normal ablation threshold power. This is followed by a reduced power level portion 517, which is typically maintained at a level that does not form via holes, or preferably any scribing traces. The line segment via hole scribing sequence is then repeated for as many line segments as needed. With a large processing window, the laser power level, laser scribing period, laser power increase and decrease sub-periods and profile need not be the same from one line segment via hole to the other, as shown in FIG.

[0054] Although this is not necessary to fabricate line segment via holes for thin film photovoltaic devices, those skilled in the art who want to tailor the fabrication process will now require a large number of line segment via holes. It can be manufactured at high speed and keeps measuring the specific resistance of each via hole. Those skilled in the art will also appreciate the specific resistance, e.g., curl-up, to measure the specific resistance of the via hole portion and then select the optimal laser spot shape and location of the region of highest laser intensity within the laser spot. A curl-up variation of ANDBACK 127 or curl-up only 127 ', a via-hole portion having a curl-up height 1273 and width 1275, and a copper-rich CIGS type alloy 1345 in-layer size are prepared and cut out. You can also. A satisfactory process has a standard deviation of 0.06 with an average value of 3.2 ^x 10-3 Ω. m, more preferably 2 ^× 10-3Ω. Get m.

[0055] For example, a laser power increase time portion 515 using a continuous wave laser that supplies a laser spot of 6 W and 50 μm diameter to the surface of the device is preferably 10 μs to 4 μs at a laser scan speed of 3 m / s to 5 m / s. And preferably at a laser scanning speed of 0.5 m / s to 3 m / s for 50 μs to 7 μs. The corresponding laser power increase measured at the surface of the device is therefore about 1 ^× 10 8 W ^{/ m 2} . s− ^{2 to} 17 ^× 10 ⁸ W ^{/ ms2} . For a preferred laser scanning speed of about 3.7 m / s, the preferred laser power increase time portion 515 lasts about 7 μs, and the laser power increase is shaped as a step response of a damped first or second order system model. A preferred laser power reduction step 416 is a sudden reduction in laser power to a level below the ablation threshold power.

  [0056] The laser power increase distance portions 405, 415 are typically at least 5 μm in length. The steady state or laser constant power portion can be set at a measured power of, for example, about 7 W and a laser scanning speed of, for example, about 3.7 m / s at the surface of the device to be scribed. In this case, the laser power is measured at the surface of the laser scribed device using a laser power meter with a thermopile sensor capable of measuring from 10 μW to 30 kW. One skilled in the art can choose a higher laser power, probably in combination with a higher speed of the laser scribing spot. The steady state laser power is typically set to a measured power in the range of 0.2W to 20W, preferably 2W to 10W, more preferably 5W to 8W. The wavelength of the laser is usually in the range of 532 nm to 1064 nm. The diameter of the laser scribing spot is usually in the range of 5 μm to 1000 μm, preferably 5 μm to 300 μm, more preferably 30 μm to 50 μm.

  [0057] The line segment via hole scribing sequence preferably has a line segment length of about 200 μm, for example, having a separation of about 50 μm between the end of the first via hole and the start end of the second via hole. Via holes can be formed. Typically, the length 410 of the via hole is in the range 50 μm to 0.1 μm, preferably in the range 50 μm to 1000 μm, more preferably in the range 180 μm to 220 μm, and in the range 10 μm to 1000 μm, preferably in the range 10 μm to 100 μm. , More preferably in the range of 40 μm to 60 μm. One of skill in the art may prefer to specify a scribing to non-scribe length ratio ranging from 1: 1 to 100: 1, preferably 4: 1. The line segment width 411, consisting of the raised portion 155 of the front contact covering the inner surface 135 of the CIGS type wall 134 and the front contact layer 150, is typically in the range of 10 μm to 100 μm, preferably in the range of 25 μm to 75 μm; More preferably, it is in the range of 45 μm to 55 μm, for example, about 50 μm micrometer. Referring to FIG. 1B, the bumps in the raised portion 155 of the front contact on the surface of the front contact layer 150 are formed from the front contact end near the inner surface of the CIGS type wall and the outer fusion or blunt shape where it meets the front contact layer. And typically has a cross-sectional width of 1555, measured to the joint of 、, typically in the range of 3 μm to 25 μm, preferably in the range of 10 μm to 15 μm, for example about 12 μm. The thickness 1553 of the raised portion of the front contact above the flat surface of the front contact layer is in the range of 0.5 μm to 6 μm, preferably in the range of 1 μm to 3 μm, more preferably in the range of 1.5 μm to 2.5 μm, For example, it is about 2 μm. The height 1273 of the gutter-shaped curl-up 127, 127 ′ of the back contact layer measured from the surface of the substrate 110 is usually in the range of 0.5 μm to 10 μm, preferably in the range of 0.5 μm to 5 μm, more preferably 2 μm.範 囲 4 μm, for example, about 3 μm.

[0058] The laser scanning speed is usually in the range of 0.1 m / s to 200 m / s, preferably in the range of 0.5 m / s to 100 m / s, more preferably in the range of 0.5 m / s to 6 m / s. It is. The energy supplied by drilling at steady state laser power typically ranges from 1 J / m to 8 J / m, preferably from 1.5 J / m to 2.2 J / m. The steady state laser fluence is usually in the range of 5 × 10 ⁸ J / m ^{2 to} 41 × 10 ⁸ J / m ² , preferably 7.5 × 10 ⁸ J / m ^{2 to} 11 × 10 ⁸ J / m ² . is there. Although line segment via holes are preferably scribed using a continuous wave laser, those skilled in the art can use a pulsed laser, for example a picosecond laser.

  [0059] The configuration of the laser scribed microstructure can be analyzed using an X-ray diffraction (XRD) analysis system. The presence of back contact layer gutter curls is in the range between 58.5 26 ° and 59.5 26 °, preferably 58.7 26 °, more preferably the presence of Mo with a (220) mirror index direction. 58.66 corresponding to at least one peak of 26 ° count. The peak of count is at least 5% greater than the number of counts for thin-film CIGS devices without vias or scribing manufactured according to embodiments of the present invention. Mo films that do not curl up typically have a (111) mirror index direction. The gutter curl-up can consist of copper selenide which allows the alloy to be fused or formed by molten CIGS, thereby having a non-uniform concentration of copper in the curl-up.

  [0060] FIG. 6A is a variation of FIG. 2 and shows a cross-section of a thin-film CIGS photovoltaic module 200 comprising a plurality of line segment via holes 163, 165, 165 ', 167. Line segment via holes 165 allow for serial monolithic interconnection between adjacent cells of the photovoltaic module. Line segment via holes 163, 167 allow for electrical interconnection of front contact or back contact layer components to underlying busbars 182, 188. The at least one line segment via hole 163, 165, 165 ', 167 is a copper-rich CIGS resulting from the thermally induced alteration of the CIGS material of the absorber layer described in at least one of FIGS. 6B-6C. Type walls 132, 134, 136, 138 and at least one raised portion 125, 127 of the back contact layer. Any one of the via holes 163, 165, 165 'and 167 may have at least one higher height of the CIGS type alloy 155' formed on the front contact layer component 156, as also shown in FIGS. 6B to 6C. The changed part can be provided arbitrarily. Any of the via holes 163, 165, 165 ', 167 optionally include at least one back contact layer component 128 formed with gutter-like curl-ups 127, 127', as also shown in FIG. 1B or 6C. Can be. In other respects, FIG. 6A corresponds to the description provided for FIG. The difference between FIG. 6A and FIG. 2 is that FIG. 6A includes an elevated portion 155 ′ of a CIGS type alloy formed over the front contact layer component 156.

  [0061] FIGS. 6B and 6C depict two exemplary embodiments of a device comprising at least one elevated portion 155 'of a CIGS type alloy at least partially covering the surface of the front contact layer 150. The raised portion of the CIGS type alloy typically results in a bump in the raised portion 157 of the front contact along most of the periphery of the via hole. The bumps in the raised portion 157 of the front contact can be fused to the raised portion 155 'of the CIGS type alloy, and outwardly progressively fuse with the front contact layer or an obtuse angled joint. 159 can be formed. The raised portion 157 of the front contact in FIGS. 6B and 6C corresponds to the raised portion 155 of the front contact in FIGS. 1A and 1B. In other respects, FIG. 6B corresponds to the description provided for FIG. 1A.

  [0062] FIG. 6C shows a cross section of the variation of FIG. 6B, wherein a portion of the substrate 110 is exposed in the via hole 165 'and at least one raised portion of the back contact layer 120 is exposed in the substrate. Gutter-shaped curl-ups 127 and 127 'are formed at the periphery 117 of the portion. Exposing the substrate 110 and forming the gutter-shaped curls 127, 127 'of the back contact layer 120 provides a larger laser scribing fabrication window, greater production yield, and mechanical resistance than the embodiment shown in FIG. 6B. Can be. FIG. 6C shows two variations of the CIGS type walls 134, 134 'and the corresponding raised portions of the trough curls 127, 127' of the back contact layer 120. The variations are similar to those described for FIG. 1B, with the difference that forming the raised portions of the trough curls 127, 127 'of the back contact layer 120 may be accomplished in some implementations. In form, a raised portion 155 'of the CIGS type alloy results in a relatively higher elevation of the inner surfaces 134, 134', as well as a raised portion 157 of the front contact. Otherwise, FIG. 6C corresponds to the description provided for FIG. 1A.

  [0063] Forming variations 134, 127 and 134 ', 127' is curl-up height 1273 and width 1275, copper-rich CIGS type alloy width 1345, conductive CIGS type alloy lip width 1355. And by varying the amount of indium diffused into the bump-shaped raised portion 155 of the front contact 150, the local adaptation of the conductivity of the via-hole segment, or the length of the via-hole segment if the via-hole segment is sufficiently long. It can be advantageous to design a local adaptation of the conductivity along. For example, in one embodiment, one side of the via hole segment, eg, the side closest to the majority of the front contact area exposed to the light of the battery, is connected to the other side, eg, the front contact layer groove 151 (FIGS. 2, 3, and 6A) may be advantageous. Tailoring the conductivity on both sides of the via segment to provide compatibility with variations in local conductivity on the surface of the cell, such as the presence, proximity, or proximity of front contact conductive grid components Can also be advantageous. Embodiments include, for example, via-hole segments of various lengths, possibly curvilinear via-hole segments, wherein any one on either side of any one of the via segments has variations 134, 127 and 134 ', 127. ′.

  [0064] FIG. 6D shows a top view of the embodiment of the line segment via hole 165 'of FIG. 6C, ie, a view on the side exposed to light, and FIG. 4B shows a corresponding view used to laser scribe the line segment via hole. 6 is a graph of the laser power 400 shown in FIG. Line segment via hole 165 ′ is laser scribed in direction 101 into thin film device 100. In FIG. 6D, the laser power used forms a via hole with a raised gutter-like curl-up 127 in the back contact layer 120 around the exposed portion 117 of the substrate. The curl up 127 can include a curl up variation of the curl up and back 127 or curl up only 127 'shown in FIG. 6C. The underlying substrate 110 is also visible as a result of partial ablation of the back contact layer 120. FIG. 6D also illustrates a CIGS type wall 155 'covering a portion of the front contact layer 150. Also, in FIG. 6D, inside the laser power increase distance portion 405, the inner surface 135 of the CIGS type wall 134 that is narrower than the rest around the via hole is visible. The fact that the portion of the via hole is typically smaller than the average width of the via hole, except for the end length 406 leading to the distal end 106, is within the laser power increase distance portion 405 following the end corresponding to the start 105 of drilling. . The profile of the obtuse joint 159 indicates the outer limit of the line segment via hole. In other respects, FIG. 6D corresponds to the description provided for FIGS. 1A and 4A.

  [0065] FIG. 6E shows an image of a thin film device 200 with line segment via holes 165, 165 'obtained with a microscope equipped with a camera. A portion of the second line segment via hole is also visible to the left of the image. Both line segment via holes are therefore part of the series of line segment via holes 210 shown in FIG. FIG. 6E illustrates the location of the starting end 105 of the drilling, the end 106 of the drilling, the location of at least one of the raised portions 155 ′ of the CIGS type alloy, and the gutter curls 127, 127 of the back contact layer component 128. 'Have been highlighted. The scribing direction is therefore from left to right. Those skilled in the art will recognize that the features of the line segment via holes 165 'on the left side of the scribing direction 101, highlighted by the ellipse 8001, are finer than those on the right side of the scribing direction, highlighted by the ellipse 8002. You will notice. The line segment via hole 165 ′ thus exhibits an asymmetry with respect to the scribing direction 101. The profile of the obtuse joint 159 indicates the outer limit of the line segment via hole.

  [0066] One skilled in the art may want to measure the characteristics of the line segment via holes 165, 165 '. For example, at least one of measuring the width of the lip 1355 of the raised portion 155 'of the conductive CIGS type alloy and measuring the width of the curl-up 1275 of the back contact layers 120, 124, 126, 128, 129 may include: An indication that the line segment via hole is correctly formed can be provided. Said measurement is achieved, for example, by a conductive alloy in which a satisfactory monolithic interconnection from the back contact layer to the front contact layer results from a permanent change in the chemical composition of the semiconductor optoelectronic active layer in which the line segment via holes are drilled. Can be provided. The width 1355 of the conductive CIGS type alloy lip ranges from about 3 μm to about 15 μm, preferably from about 5 μm to about 20 μm, more preferably from about 8 μm to about 12 μm. The width of the back contact layer curl-up 1275 ranges from about 2 μm to about 15 μm, preferably from about 4 μm to about 10 μm, more preferably from about 6 μm to about 8 μm.

  [0067] Another relevant criterion for assessing how well the line segment via holes 165, 165 'are formed relates to, for example, the distance separating opposing features with respect to the center line of the line segment via hole according to the direction of scribing. There is. Opposing features may be, for example, the width of the gutter curls 127, 127 ', the inner surface 135 of the CIGS type wall, the obtuse joint 159 of the front contact layer, or the exposed portion of the substrate 110 of the considered line segment via hole. . For example, one skilled in the art can evaluate scribing quality by measuring the radius of curvature at the start 105 and end 106 of the drilled end based on the visible contour formed by the features. For example, the radius of curvature based on the profile of the obtuse joint 159 ranges from about 7 μm to about 40 μm, preferably about 12 μm to about 25 μm, and more preferably about 15 μm to about 20 μm at the starting end 105 of the drilling. At the end 106 of the drilling, the radius of curvature based on the profile of the obtuse joint 159 ranges from about 10 μm to about 50 μm, preferably about 20 μm to about 35 μm, more preferably about 23 μm to about 30 μm.

Claims (20)

A method of forming at least one thin film CIGS device (100, 200), comprising forming a line segment via hole (163, 165, 165 ', 167) in a region of the thin film CIGS device,
The device comprises:
Front contact layers (150, 152, 154, 156, 158);
A semiconductor optoelectronic active layer (130);
A back contact layer (120, 124, 126, 128, 129);
A substrate (110);
Consisting of
And the line segment via hole is
Formed during drilling of the line segment via hole, by continuous wave laser drilling to the line segment via hole, the laser power gradually increasing from a first power level to a second power level;
Penetrating at least a part of the front contact layer and the semiconductor optoelectronic active layer,
And by drilling with the laser,
Forming a CIGS-type wall (134, 134 ', 132, 136, 138) of a conductive, permanently metallized, copper-rich CIGS-type alloy covering the inner surface (135) of said line segment via hole; The type alloy results from a permanent change in the chemical composition of the CIGS semiconductor optoelectronic active layer in which the line segment via holes are drilled;
Forming a conductive path between at least a part of the front contact layer and at least a part of the back contact layer,
Forming a bump-shaped raised portion (155) of a front contact on the surface of the front contact layer along an end of the inner surface (135) of the line segment via hole;
Forming raised portions (125, 127, 127 ') of the back contact layer that are raised toward the front contact layer;
Providing a method.   The method of claim 1, wherein forming the via hole removes a portion of the back contact layer in the via hole, thereby exposing a portion of a substrate. By forming the via hole, a portion of the back contact layer in the via hole is removed, thereby exposing a portion of the substrate, and the height of the back contact layer rising toward the front contact layer 3. The method of claim 1 or 2, wherein forming the bent portion comprises forming a gutter curl-up . The method of claim 3, wherein the gutter curl-up comprises a portion of a back contact layer curling over a portion of the CIGS-type wall.   The method according to any of the preceding claims, wherein the step of forming the via hole is by at least one laser forming a laser spot with an asymmetric laser spot diagram on the thin film CIGS device.   4. The laser power increase during drilling of the via hole includes the gradual increase of laser power during movement of a laser spot from the laser toward the via hole (415). 6. The method according to any one of items 5 to 5.   The drilling of the via hole is performed by microscopy viewed from the light-exposed side of the device, such that the drilling of the line segment via hole is less than at a second end corresponding to the drilling end (106) of the line segment via hole. 7. The inner surface of the CIGS type alloy having an elliptical pattern having a smaller radius of curvature at a first end corresponding to the start of the drilling (105). 7. The method according to claim 1.   Drilling the via hole with the laser including moving a laser spot from the laser such that the laser energy supplied to at least a portion of the via hole is between 1 J / m and 8 J / m. The method according to any one of claims 1 to 7, characterized in that: The drilling of the via hole by the laser comprises a time interval when the laser supply fluence is in a range of 5 × 10 ⁸ J / m ^{2 to} 41 × 10 ⁸ J / m ^2. The method according to any one of claims 8 to 13. The drilling of the via hole by the laser comprises a time interval when the laser supply steady state fluence is in the range of 7.5 × 10 ⁸ J / m ^{2 to} 11 × 10 ⁸ J / m ^2. The method according to claim 9.   The method according to any one of claims 1 to 10, wherein the drilling of the via hole is performed simultaneously with laser scribing of an ablating line adjacent to the front contact layer.   The step of forming the thin film CIGS device (100, 200) includes forming a dashed line (210) comprising a plurality of the line segment via holes (163, 165, 165 ', 167) in the region of the thin film CIGS device. A method according to any one of the preceding claims, characterized in that: A method of forming at least one thin film CIGS device (100, 200), comprising forming a line segment via hole (163, 165, 165 ', 167) in a region of the thin film CIGS device,
The device comprises:
A substrate (110);
A front contact layer (150, 152, 154, 156, 158) disposed on the substrate;
A back contact layer (120, 124, 126, 128, 129) disposed on the substrate;
A semiconductor optoelectronic active layer (130) disposed between the front contact layer and the back contact layer;
Consisting of
And the line segment via hole is
Formed by drilling using the power of a laser,
Penetrating at least a part of the front contact layer and the semiconductor optoelectronic active layer,
And by laser drilling,
Forming a CIGS-type wall (134, 134 ', 132, 136, 138) of a conductive, permanently metallized, copper-rich CIGS-type alloy covering the inner surface (135) of said line segment via hole; A type wall along the line segment via hole, forming a conductive path between a portion of the front contact layer and a portion of the back contact layer;
Forming raised portions (125, 127, 127 ') of the back contact layer that are raised toward the front contact layer to form a gutter-shaped curl-up ;
Providing a method. 14. The method of claim 13, wherein the gutter curl-up is formed by a change in power applied by a laser during drilling of the line segment via hole. The gutter-shaped curl-up is formed by a progressive increase in laser power applied to the line segment via hole from a first power level to a second power level during drilling of the line segment via hole. 14. The method according to claim 13, wherein: The gutter-like curl-up is progressive in laser power applied to the line segment via hole from a first power level to a second power level during movement of a laser spot from the laser directed to the via hole. 14. The method according to claim 13, wherein said method is formed by augmentation. 14. The method of claim 13, wherein the gutter curl up includes a portion of the back contact layer that curls over a portion of the CIGS type wall.   The method of claim 13, wherein the CIGS-type wall includes a portion extending above the front contact layer. The CIGS-type wall includes a portion extending above the front contact layer;
14. The method of claim 13, wherein a portion of the front contact layer is disposed between a portion of the semiconductor photoactive layer and the CIGS type wall extending over the front contact layer. 19. The method of claim 18, wherein the gutter curl-up includes a portion of a back contact layer curling over a portion of the CIGS-type wall.

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