Method for forming electrode interconnects in integrated multilayer thin film electronic devices - Patents.com

Abstract

A method of forming an electrode interconnection between at least two adjacent unit devices of an integrated multilayer thin film electronic device, comprising the steps of: providing an intermediary device comprising: a first electrode layer on a thin film substrate, the first electrode layer comprising a first patterned coating comprising at least two spaced apart first electrode sections of adjacent unit devices; a first functional layer comprising a substantially continuous coating on the first electrode layer; and a second functional layer comprising a second patterned coating on the first functional layer comprising at least two spaced apart functional sections, each functional section positioned on the first functional layer and overlapping a portion of a first electrode section to define a gap portion between adjacent functional sections comprising a portion of the first electrode section and the first functional layer; and and depositing a second electrode layer on the second functional layer as a third patterned coating comprising at least two spaced apart second electrode sections of an adjacent unit device, each second electrode section positioned to overlap a portion of an adjacent interstitial portion comprising at least one functional section of the second functional layer and at least a portion of a first electrode section of an adjacent unit device, the third patterned coating being formed using a solution comprising a conductive species and at least a first solvent, wherein the first functional layer is soluble in the first solvent and the second functional layer has low to zero solubility in the first solvent such that deposition of the second electrode layer on the interstitial portion forms at least one conductive pathway through the first functional layer between the first and second electrodes of the adjacent unit devices.

Description

[Technical field]

[0001] Priority Cross Reference This application claims priority to Australian Provisional Patent Application No. 2021900606, filed March 4, 2021, the contents of which are to be understood as incorporated herein by reference.

[0002] The present invention generally relates to a method for forming interconnects between electrodes of at least two adjacent unit devices in an integrated multilayer thin film electronic device. The invention is particularly applicable to solution processed thin film photovoltaic (PV) devices, and it will be convenient to disclose the invention below with reference to exemplary applications. However, it should be understood that the invention is applicable to forming electrical interconnects in several different types of thin film electronic devices, particularly solution processed electronic devices, such as organic transistors, OLEDs, organic memories, and printed sensors. [Background technology]

[0003] The following discussion of the background art is intended to facilitate an understanding of the present invention. It should be understood, however, that the discussion is not an admission or admission that any of the matter referred to was part of the published, publicly known, or common general knowledge as of the priority date of this application.

[0004] Solution-processed thin-film electronic devices, including photovoltaic cells (PV), are the promising next generation of electronics. Large numbers of thin-film electronics need to be interconnected to scale up a single device for real-world applications. For example, PV cells are typically used in the form of modules that contain groups of PV cells connected in series for the power output required for a particular application.

[0005] Conventionally, interconnections of unit devices are made through placing physical gaps between functional layers of the unit devices, allowing spaced apart electrodes to overlap and physically connect. To fabricate modules, such gaps are created by patterning the modules such that gaps are created. Patterning can be done by one of three approaches, illustrated in FIG.

[0006] First, 2D printing methods, including inkjet printing, screen printing, gravure printing, etc. (shown in Fig. 1(a)): printing methods offer freedom in 2D patterns. Any pattern and gap can be set for the module. However, such processes generate layers by clusters of dots, resulting in non-uniformity of the final coating at the micrometer scale. Furthermore, the methods have poor thickness control. Therefore, such methods have not been the preferred method for fabricating thickness-sensitive layers such as the photoactive layer of a PV device.

[0007] Second, coating a pattern of stripes by slot-die or reverse gravure method is shown in Fig. 1(b). This approach has been most commonly used in the fabrication of printed PV due to the practicality of the process. Although such coating method produces a much better uniform coating than 2D printing method, the thickness of the edge of each stripe is different from the center due to Marangoni flow during the drying process (commonly known as the coffee ring effect). Moreover, narrow gaps of 0.5 mm or less cannot be reliably produced in the manufacturing process, which means loss of device area.

[0008] Third, a non-patterned coating and scribing approach is illustrated in FIG. 1(c): this approach is most ideal for achieving uniformity and high cell area across the substrate (so-called geometric fill factor, GFF). Compared to traditional approaches, uniformity provides high cell area efficiency, and high GFF provides higher power output. However, this approach has not been widely used for large area modules due to the significant cost of in-line scribers for manufacturing. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US Patent Application Publication No. US20190393423 Summary of the Invention [Problem to be solved by the invention]

[0010] It would therefore be desirable to provide new and / or improved processes for forming electrode interconnects in integrated multilayer thin film electronic devices, and more particularly, solution processed thin film electronic devices. [Means for solving the problem]

[0011] The present invention relates to a method for forming electrode interconnects in integrated multi-layer thin film electronic devices.

[0012] The present invention provides in a first aspect a method for forming an electrode interconnect between at least two adjacent unit devices of an integrated multilayer thin-film electronic device, comprising the steps of: a first electrode layer on the thin film substrate, the first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; a first functional layer comprising a substantially continuous coating on the first electrode layer; and A second functional layer comprising a second patterned coating on the first functional layer comprising at least two spaced apart functional sections, each functional section positioned on the first functional layer and overlapping a portion of one of the first electrode sections to define a gap between adjacent functional sections comprising a portion of the first electrode section and the first functional layer. providing an intermediary device, depositing a second electrode layer on the second functional layer as a third patterned coating comprising at least two spaced apart second electrode sections of adjacent unit devices, each second electrode section being positioned to overlap a portion of an adjacent interstitial portion comprising at least one functional section of the second functional layer and at least a portion of a first electrode section of an adjacent unit device, the third patterned coating being formed using a solution comprising a conductive species and at least a first solvent. Including, the first functional layer is soluble in a first solvent and the second functional layer has low to zero solubility in the first solvent, such that attachment of the second electrode layer to the gap portion forms at least one conductive pathway through the first functional layer between the first and second electrodes of adjacent unit devices; A method is provided.

[0013] The present invention thus provides an alternative process for forming electrical connections between spaced apart electrodes through functional layers of integrated multilayer thin film electronic devices by exploiting the selective solubility of components of the multilayer coating in the solvent used to form the second electrode layer.

[0014] Without wishing to be bound by any theory, the inventors believe that the differential orthogonal solubility of alternating material layers is key to forming the electrical interconnection between the electrode layers, where multiple layers are formed with alternating polarities such that subsequent layers can be deposited without re-dissolving the underlying layer. The first solvent dissolves at least a portion of the first functional layer in the interstitial areas to form an electrical interconnection between the first and second electrode layers through the first functional layer. In contrast, the second functional layer is not affected by the first solvent and is not dissolved during deposition of the second electrode layer.

[0015] The second functional layer preferably has substantially low to zero solubility in the first solvent, which ensures that the second functional layer remains substantially intact (defect free) when the second electrode layer is applied.

[0016] The differential orthogonal solubility of alternating material layers can be achieved by depositing layers of alternating polarity. In a preferred embodiment, the first functional layer and the second functional layer have different polarities. In some embodiments, the first functional layer comprises a polar layer and the second functional layer comprises a non-polar layer. In other embodiments, the first functional layer comprises a non-polar layer and the second functional layer comprises a polar layer. In this alternating polarity lay-up, the first solvent preferably has the same polarity as the first functional layer.

[0017] Thus, the first functional layer is a polar layer and the first solvent is a polar solvent. When the first functional layer is a non-polar layer, the first solvent is a non-polar solvent. The second functional layer is of a different polarity (whether polar or non-polar) than the first functional layer and therefore has low to zero solubility in the first solvent. The process can be repeated and form multiple layers of alternating polarity, i.e. polar / non-polar / polar / non-polar materials.

[0018] The first solvent can include any suitable solvent for depositing the second electrode layer and dissolving portions of the first functional layer to form at least one conductive pathway between the first and second electrodes of adjacent unit devices through the first functional layer. In an embodiment, the first solvent is DMF, DMSO, γ-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or a combination thereof; isopropanol, n-butanol, isobutanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or combinations thereof; or benzene, toluene, xylene, trimethylbenzene (e.g., mesitylene), chlorobenzene, dichlorobenzene, chloroform, dichloromethane, anisole, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, or combinations thereof Contains one or more of the following.

[0019] It should be understood that the choice of the first solvent depends on the required polarity and the composition of the various layers. When the integrated multilayer thin film electronic device includes an optoelectronic device, particularly a photovoltaic device, the choice of the first solvent depends on the composition of the photovoltaic layer. For example, in a perovskite device, the first solvent is preferably selected from: DMF, DMSO, γ-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or a combination thereof; or isopropanol, n-butanol, iso-butanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or a combination thereof. In an organic PV device, the first solvent is preferably selected from benzene, toluene, xylene, trimethylbenzene (e.g., mesitylene), chlorobenzene, dichlorobenzene, chloroform, dichloromethane, anisole, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, or a combination thereof.

[0020] It should be understood that a thin film electronic device comprises at least two adjacent unit devices, more preferably a series of adjacent unit devices, on a thin film substrate. Each adjacent unit device may comprise an interconnect formed according to the first aspect of the invention. In some embodiments, a plurality of unit devices may be arranged in a module, and each adjacent unit device of the module may be interconnected according to the first aspect of the invention. An integrated multi-layer thin film electronic device may comprise several unit devices and / or several modules arranged on a thin film substrate in a design configuration. Adjacent modules may also be connected / interconnected using a process according to the first aspect of the invention.

[0021] It should also be understood that unitary devices include individual devices or units within a thin film electronic device that need to be interconnected in series or parallel to form a larger integrated electronic device. The examples embodied in detail herein are individual cells (unitary devices) within optoelectronic devices, particularly photovoltaic devices. However, it should be understood that the present invention is applicable to connecting unitary devices that make up the integrated structure of many other solution processed integrated multilayer thin film electronic devices, such as organic transistors, OLEDs, organic memories, and printed sensors.

[0022] The first solvent typically dissolves a portion of the first functional layer to form a conductive pathway between the first and second electrodes of adjacent unit devices through the first functional layer. In an embodiment, the dissolved portion forms one or more channels through the first functional layer. Thus, the electrical interconnect is typically one or more channels through the first functional layer. The amount of dissolved first functional layer is typically small, forming nano- to micro-sized channels in the first functional layer. In an embodiment, at least one conductive pathway between the first and second electrodes of adjacent unit devices includes one or more micro- or nano-sized pathways, preferably one or more micro- or nano-sized channels through the first functional layer. In some embodiments, at least one conductive pathway between the first and second electrodes of adjacent unit devices includes one or more micro- to nano-sized pathways or channels through the first functional layer. In an embodiment, the at least one conductive pathway includes many micro- to nano-sized pathways or channels, in some cases millions of micro- to nano-sized pathways or channels. More specifically, at least one conductive pathway between the first electrode layer and the second electrode layer preferably includes one or more defects in the first functional layer, preferably including one or more pinhole defects through the thickness of the first functional layer.

[0023] It should be understood that the at least one conductive pathway can include any number of pathways or channels through the first functional layer between the first and second electrodes of adjacent unitary devices. Typically, the process forms a large number of nano- to micro-pathways or channels. In most cases, the at least one conductive pathway includes millions of nano- to micro-channels through the first functional layer. For example, the entire area of ​​a 2 mm x 100 mm line that includes a multilayer thin-film electronic device can be a conductive pathway depending on the configuration of the layers. In some cases, the entire layer (the first functional layer that is not covered by the second functional layer under the second electrode) can be uniformly conductive. In these embodiments, substantially all or all of the interstitial portions (portions of the first functional layer that are not covered by the second functional layer under the second electrode) provide a conductive pathway between the first and second electrodes. Each of the nano- to micro-pathways or channels is distributed through, along, and near the first functional layer to form a conductive pathway between the first and second electrodes.

[0024] Without wishing to be limited by any theory, in these embodiments, the inventors exploit a failure mechanism well known in integrated multilayer thin film electronic devices, where solvent from one or more subsequently deposited layers can damage the structure of the layer on which it is deposited. For example, when an organic solvent-based conductive paste is deposited on top of an organic thin film layer, the thin film will be damaged and lose function, forming a conductive channel through the layer. The solvent can create physical defects in the layer, such as the potential for short circuit formation through pinholes in the organic thin film layer.

[0025] It should be understood that the conductive pathways typically include nano- to micro-channels through the first functional layer, although the present invention can create other morphologies. For example, in some embodiments, the conductive pathways may be formed on a larger scale, such as micro- to mm-sized channels or pathways. Additionally, other configurations other than pathways or channels can be used, such as apertures or openings through the first functional layer.

[0026] The gap between adjacent functional sections is preferably configured to position at least one conductive path through the first functional layer between the first and second electrodes of adjacent unit devices, and thus the gap between adjacent functional sections preferably includes only the first electrode layer and the first functional layer.

[0027] The integrated multilayer thin-film electronic device can have any number of functional layers. The nature and number of functional layers depends on the function and required configuration of the integrated multilayer thin-film electronic device. In some embodiments, the intermediary device comprises at least one additional functional layer between the first electrode layer and the second electrode layer, preferably between the first electrode layer and the second functional layer. In some embodiments, the intermediary device comprises at least one of: at least one additional functional layer between the first functional layer and the second functional layer, or at least one additional functional layer between the first electrode layer and the first functional layer.

[0028] The at least one further functional layer can be two or more layers. It should also be understood that in some embodiments further coatings / layers are possible between the first electrode layer and the substrate. In these embodiments, each of the further functional layers preferably comprises a patterned coating comprising at least two spaced apart second sections having a complementary configuration to the functional sections of the second functional layer. It should be understood that "complementary configuration" refers to a complementary pattern and / or shape of the functional sections of the second functional layer to the functional sections of the second functional layer. In this sense, the at least one further functional layer, the second functional layer, is attached to the second functional layer in a complementary and / or corresponding pattern so as to also define gap portions similar and substantially corresponding to the gap portions of the second functional layer between adjacent functional sections in the further functional layer. This also ensures that there are adequate gaps in the further functional layer or layers for forming electrical connections between the spaced apart electrodes available as already discussed.

[0029] In an embodiment, the further functional layer comprises a further charge selective layer. The further charge selective layer may comprise at least one of: at least one electrode screening layer; at least one hole blocking layer; at least one electron blocking layer; at least one hole transport layer; or at least one electron transport layer. In an embodiment, the further functional layer comprises a complementary charge selective layer to the second functional layer, preferably located between the first electrode layer and the second functional layer.

[0030] In some embodiments, the intermediary device includes at least one additional functional layer between the substrate and the first functional layer, for example, the substrate may include an additional coating layer on its surface.

[0031] The intermediary device may also be formed through sequential deposition of various layers. In embodiments, the method further comprises: depositing a first electrode layer on a thin film substrate, the first electrode layer comprising a first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; depositing a first functional layer comprising a substantially continuous coating on the first electrode layer; and applying a second functional layer including the second patterned coating to a first functional layer including at least two spaced apart functional sections, each functional section positioned on the first functional layer to overlap a portion of a first electrode section to define a gap between adjacent functional sections that includes a portion of the first electrode section and the first functional layer; The method may include forming an intermediary device by

[0032] The various layers can be deposited to form integrated multilayer thin film electronic devices and / or intermediary devices using a variety of deposition techniques. In some embodiments, at least one of the first electrode layer, the first functional layer, the second functional layer, or the second electrode layer is deposited on the substrate using at least one of: casting, doctor blading, printing, screen printing, inkjet printing, pad printing, knife coating, meniscus coating, slot die coating, gravure coating, reverse gravure coating, kiss coating, microroll coating, curtain coating, slide coating, spray coating, flexographic printing, offset printing, rotary screen printing, or dip coating.

[0033] In some embodiments, the process of the present invention further comprises drying each deposited layer of the integrated multilayer thin film electronic device. The drying step can comprise any number of drying processes, including one or a combination of air drying, convection drying, atmospheric drying, heat treating, annealing, quenching, or the like. In some embodiments, the drying step comprises heat treating the deposited coating of each layer at a temperature of at least 60° C., preferably at least 70° C., more preferably at least 100° C., and even more preferably at least 120° C.

[0034] In some embodiments, each deposited coating / layer is air dried. In other embodiments, convection or forced drying techniques are used. In some embodiments, heat can be applied to encourage evaporation of the respective solvents. In some embodiments, a gas quenching technique is used to rapidly dry each coating / layer. Gas quenching should be understood to include rapid cooling and drying of the deposited layers through application of a drying gas such as nitrogen, argon, or other inert gas. In a preferred embodiment, high pressure nitrogen at room temperature is used for the gas quenching process.

[0035] The first and second patterned layers include a patterned coating of discrete spaced apart sections, each functional section of the second functional layer positioned to overlap a portion of the total area of ​​one electrode section of the first electrode layer and defining a plurality of spaced apart interstitial portions between adjacent functional sections in the second functional layer, each interstitial portion including the first electrode layer and the first functional layer. It should be understood that the overlapping step includes overlapping layered sections of each layer in the multi-layer structure.

[0036] The first and second patterned coatings can have any suitable configuration. In an embodiment, the first patterned coating comprises a plurality of spaced apart individual first electrode sections, each electrode section comprising a geometric shape arranged in a regular pattern on the thin film substrate. Each electrode section preferably has the same shape. In some embodiments, the first patterned coating comprises a mosaic-like pattern. In other embodiments, the first patterned coating is formed in a grid pattern. The second patterned coating preferably comprises a complementary pattern to the first patterned coating. Nevertheless, it should be understood that in other embodiments, the electrode sections can have any shape and do not need to match in shape across the individual layers.

[0037] In certain embodiments, the first patterned coating and the second patterned coating include a plurality of spaced apart rectangular sections having a first longitudinal axis attached to a flexible strip having a second longitudinal axis aligned along the strip length, the rectangular sections being arranged on the flexible strip with the first longitudinal axis aligned perpendicular to the second longitudinal axis.

[0038] The third patterned coating preferably comprises a pattern complementary to the second patterned coating, and preferably the first patterned coating. In an embodiment, the third patterned coating comprises a lattice, preferably a lattice formed from a regular repeating geometric shape. The lattice can be formed from a series of spaced apart elements, preferably a plurality of spaced apart lines.

[0039] Variations in the configuration of the lattice of the third patterned coating can be used to highlight sections of the lattice. For example, the thickness of selected portions of the lattice can be configured to be greater compared to other portions of the lattice to form highlighted portions or sections of the lattice. Those highlighted portions can be designed to form a pattern within the lattice, which, when designed to have a contrasting shade and / or color relative to the underlying layers, can produce a visual and / or visible pattern that is not discernible to a viewer of the integrated multilayer thin film electronic device. The visual and / or visible pattern can include a pattern, a picture, an indicia, or the like. In an embodiment, the thickness of selected portions of elements within the lattice is thicker relative to the thickness of adjacent elements within the lattice to produce a configuration of selected indicia within the thicker elements of the lattice. In an embodiment where the lattice is formed from a series of spaced apart lines, the width of selected portions of the lines within the lattice can be greater relative to the width of adjacent elements within the lattice to produce a configuration of selected indicia within the wider lines of the lattice. Examples of selected indicia include one or more of a logo, a letter, a number, a symbol, a pattern, a rendered image, a word, a sign, a mark, an emblem, a tag, a seal, a stamp, and the like. In certain embodiments, the thickness or width of a selected portion of an element in the lattice is at least 1.5 times, and preferably 2 times, the thickness or width of an adjacent element in the lattice, however, it should be understood that any suitable thickness or width difference may be used that provides a distinguishable rendering of the selected indicia.

[0040] To aid in representing selected indicia within the grid, the color of the second electrode layer is preferably selected to contrast with the first and second functional layers, the color preferably being selected to produce lines of high contrast relative to the colors of the first and second functional layers.

[0041] The thin film substrate may comprise any suitable thin film on whose surface multiple layers of an integrated multi-layer thin film electronic device can be deposited. In an embodiment, the thin film substrate comprises a flexible substrate. It should be understood that the substrate may comprise at least one of a polymer, a metal, a ceramic, or a glass, preferably a polymer coating. In an embodiment, the thin film substrate comprises an indium tin oxide (ITO); a polyethylene terephthalate (PET); or an ITO-PET substrate, preferably a PET substrate patterned with ITO. For example, the substrate may comprise a PET substrate with an ITO pattern 10 mm wide with 1 mm wide gaps. However, it should be understood that any suitable ITO pattern may be used.

[0042] The method of the present invention can be used with any solution-processed electronic device, such as organic transistors, OLEDs, organic memory, and printed sensors. It is also applicable to some inorganic metal-based devices, but layers made with metal oxide particles are not redissolvable, thus limiting its application. The present invention finds particular application in photovoltaic and optoelectronic solar devices. Examples include organic solar unit devices, OPV, perovskite solar unit devices, and roll-to-roll.

[0043] As mentioned above, an integrated multi-layer thin-film electronic device can have any number of functional layers. In an embodiment, the substrate comprises: At least one coating of a transparent conductor layer; At least one hole transport layer comprising an organic or inorganic semiconductor; or At least one electron transport layer comprising an organic or inorganic conductor. The coating may include one or more layers or coatings selected from at least one of:

[0044] The transparent conductor layer can be selected from a transparent conductive oxide (TCO); a multilayer hybrid coating; or a polymer-based conductor. For example, the transparent conductive oxide (TCO) can include tin-doped indium oxide (ITO), fluoride-doped tin oxide (FTO), doped zinc oxide, such as aluminum-doped zinc oxide (AZO), or indium-doped cadmium oxide; the multilayer hybrid coating can include TCO-metal-TCO; the polymer-based conductor includes a mixture of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate) with and without a metal lattice (PEDOT:PSS).

[0045] A further aspect of the invention provides an optoelectronic device formed using a process according to the first aspect of the invention.

[0046] A second aspect of the present invention comprises: a first electrode layer on the thin film substrate, the first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; a first functional layer comprising a substantially continuous coating on the first electrode layer; and a second functional layer comprising a second patterned coating on the first functional layer comprising at least two spaced apart functional sections, each functional section positioned on the first functional layer and overlapping a portion of one of the first electrode sections to define a gap between adjacent functional sections that includes a portion of the first electrode section and the first functional layer; and a second electrode layer on the second functional layer, the second electrode layer including a third patterned coating including at least two spaced apart second electrode sections of adjacent unit devices, each of the second electrode sections positioned to overlap a portion of an adjacent gap including at least one functional section of the second functional layer and at least one portion of a first electrode section of an adjacent unit device; Including, Each gap portion includes at least one conductive path through the first functional layer between the first electrode and the second electrode of adjacent unit devices; An integrated multi-layer thin film electronic device is provided.

[0047] At least one conductive pathway between the first and second electrodes of adjacent unitary devices preferably comprises one or more micro- or nano-sized pathways, preferably one or more micro- or nano-sized channels through the first functional layer, preferably one or more micro- or nano-sized pathways or channels. In embodiments, the at least one conductive pathway comprises a large number of micro- or nano-sized pathways or channels, and in some cases millions of micro- to nano-sized pathways or channels. In some embodiments, substantially all or all of the interstitial portions provide a conductive pathway between the first and second electrodes.

[0048] Thus, a second aspect of the invention provides an integrated multilayer thin film electronic device in which the electrical connection between two spaced apart electrodes through the multilayer structure comprises at least one micro- or nano-sized conductive pathway, which typically comprises a defect, such as a pinhole defect, through the associated functional layer or layers.

[0049] It should be understood that the device of the second aspect of the invention is preferably formed from a method according to the first aspect of the invention, and therefore features discussed in relation to the first aspect of the invention should be understood to relate equally to analogous features of this second aspect of the invention.

[0050] Again, the first and second functional layers preferably have different polarities. In an embodiment, the first functional layer comprises a polar layer and the second functional layer comprises a non-polar layer. In another embodiment, the first functional layer comprises a non-polar layer and the second functional layer comprises a polar layer.

[0051] At least one conductive pathway between a first electrode and a second electrode of adjacent unit devices preferably comprises one or more channels, and more preferably one or more defects, in the first functional layer, which in embodiments may comprise one or more pinhole defects through the thickness of the first functional layer.

[0052] The gaps between adjacent functional sections preferably contain only the first electrode layer and the first functional layer.

[0053] The first and second patterned coatings can have any suitable configuration. The first patterned coating preferably includes a plurality of spaced apart individual first electrode sections, each electrode section including a geometric shape arranged in a regular pattern on the thin film substrate. Each electrode section preferably has the same shape. In an embodiment, the first patterned coating includes a mosaic-like pattern. The second patterned coating preferably includes a complementary pattern to the first patterned coating. However, it should be understood that in other embodiments, the electrode sections can have any shape and do not need to match their shapes across the individual layers.

[0054] In an embodiment, the first patterned coating and the second patterned coating include a plurality of spaced apart rectangular sections having a first longitudinal axis applied to the flexible strip with the second longitudinal axis aligned along the length of the strip, the rectangular sections being arranged on the flexible strip with the first longitudinal axis aligned perpendicular to the second longitudinal axis.

[0055] The third patterned coating typically comprises a complementary pattern to the second patterned coating, preferably the first patterned coating. In an embodiment, the third patterned coating comprises a lattice, preferably a lattice formed from a regular repeating geometric shape. The lattice is preferably formed from a series of spaced apart elements, preferably a plurality of spaced apart lines. The thickness of selected portions of the elements in the lattice can be configured to be thicker relative to the thickness of adjacent elements in the lattice to generate selected indicative configurations in thicker elements of the lattice. In an embodiment where the lattice is formed from a series of spaced apart lines, the width of selected portions of the lines in the lattice can be greater relative to the width of adjacent elements in the lattice to generate selected indicative configurations in wider lines of the lattice. In an embodiment, the thickness or width of selected portions of the elements in the lattice is at least 1.5 times, preferably 2 times, the thickness or width of adjacent elements in the lattice.

[0056] As already explained, the colour of the second electrode layer is selected to contrast with the first and second functional layers, preferably to create a line of high contrast with the colour of the first and second functional layers.

[0057] The thin film substrate may comprise any suitable thin film onto which multiple layers of an integrated multi-layer thin film electronic device may be deposited. In an embodiment, the thin film substrate comprises a flexible substrate. It should be understood that the substrate may comprise at least one of a polymer, a metal, a ceramic, or a glass, preferably a polymer coating.

[0058] Integrated multilayer thin-film electronic devices can be used for any solution-processed electronic device, such as organic transistors, OLEDs, organic memory, and printed sensors. Some inorganic material-based devices are also applicable, but layers fabricated with metal oxide particles are not redissolvable, so applications are limited.

[0059] The present invention finds particular application in photovoltaic and optoelectronic solar devices. Examples include organic solar cells, OPV, perovskite solar cells, roll-to-roll. In some embodiments, thin film electronic devices include solution processed electronic devices such as organic transistors, OLEDs, organic memory, and printed sensors.

[0060] The thin film electronic device of the first or second aspect of the present invention preferably comprises an optoelectronic device, more preferably a solution processed photovoltaic device or a photoactive sensor. Optoelectronic devices can include a wide range of photoactive devices, such as photoelectric, photovoltaic, and similar devices, including but not limited to photovoltaic cells, photoactive sensors including photodetectors, and the like.

[0061] Thus, an optoelectronic device according to the present invention may comprise a photoactive device such as a photovoltaic cell, a photoactive sensor, or a light emitting device. In some embodiments, the optoelectronic device may be selected from a photodiode, a phototransistor, a photoamplifier, a photoresistor, a photodetector, a photosensitive detector, a solid-state triode, a battery electrode, a light emitting device, a light emitting diode, a transistor, a solar cell, a laser, and a diode emitting laser.

[0062] When the integrated multilayer thin-film electronic device comprises an optoelectronic device, the first functional layer preferably comprises a photoactive layer. The photoactive layer may comprise at least one of an organic photovoltaic compound or a perovskite photoactive compound. In an embodiment, the photoactive layer may comprise at least one of one or more organic photovoltaic compounds or one or more perovskite photoactive compounds. Furthermore, the second functional layer preferably comprises a charge selective layer. The charge selective layer may comprise at least one of: at least one electrode screening layer; at least one hole blocking layer; at least one electron blocking layer; at least one hole transport layer; or at least one electron transport layer. In an embodiment, the second functional layer comprises at least one hole transport layer.

[0063] The first electrode layer preferably comprises a transparent electrode layer. The second electrode layer preferably comprises a metal electrode, more preferably a silver electrode, formed using a solution comprising a metal or an ionic form of a metal and at least a first solvent.

[0064] The present invention uses organic PV as an example, however the invention can be used in other electronic devices and with different orders of polarity, e.g. perovskite photoactive layer / non-polar layer / polar conductive ink.

[0065] The term "thickness" as used herein refers to the average thickness of a component of an optoelectronic device. The thickness of the various layers is generally tailored to the desired process and properties of the integrated multilayer thin-film electronic device. In an embodiment, at least one of the first electrode layer, the first functional layer, the second functional layer, or the second electrode layer has a dry layer thickness of less than 1 μm, preferably 100 nm to 600 nm, more preferably 200 to 400 nm, more preferably 300 to 400 nm, and even more preferably about 300 nm.

[0066] An integrated multilayer thin-film electronic device may include various layers depending on the configuration of the device. In an embodiment, the intermediary device includes at least one further functional layer between the first electrode layer and the second electrode layer, preferably between the first electrode layer and the second functional layer. In some embodiments, the integrated multilayer thin-film electronic device further includes at least one of: at least one further functional layer between the first and second functional layers, or at least one further functional layer between the first electrode layer and the first functional layer. Each of the further functional layers preferably includes a patterned coating including at least two spaced apart second sections having a complementary configuration to the functional sections of the second functional layer. It should be understood that "complementary configuration" relates to a complementary shape and / or pattern to the functional sections of the second functional layer. In this sense, the at least one further functional layer, the second functional layer, is applied with a complementary and / or corresponding pattern to the second functional layer so as to also define gap portions similar and substantially corresponding to the gap portions of the second functional layer between adjacent functional sections in the further functional layer. This also ensures that there is adequate gap in the layers for making electrical connections between further functional layers or spaced apart electrodes, which can be utilised as previously discussed in relation to the first aspect of the invention.

[0067] In an embodiment, the further functional layer comprises a further charge selective layer. The further charge selective layer may comprise at least one of: at least one electrode screening layer; at least one hole blocking layer; at least one electron blocking layer; at least one hole transport layer; or at least one electron transport layer. In an embodiment, the further functional layer comprises a complementary charge selective layer to the second functional layer. For example, when the second functional layer comprises at least one hole transport layer, the further functional layer comprises an electron transport layer. Similarly, when the second functional layer comprises an electron transport layer, the further functional layer comprises at least one hole layer. When the further functional layer comprises a further charge selective layer, the further charge selective layer is typically positioned between the first electrode and the first functional layer. In such an embodiment, the first electrode layer is preferably a transparent electrode layer, and the first functional layer is preferably a photoactive layer.

[0068] In some embodiments, the substrate comprises: At least one coating of a transparent conductor layer; At least one hole transport layer comprising an organic or inorganic semiconductor; or At least one electron transport layer comprising an organic or inorganic conductor. The coating may include one or more layers or coatings selected from at least one of:

[0069] Again, the transparent conductor layer can be selected from transparent conductive oxides (TCOs); multilayer hybrid coatings; or polymer-based conductors. For example, transparent conductive oxides (TCOs) can include tin-doped indium oxide (ITO), fluoride-doped tin oxide (FTO), doped zinc oxide, such as aluminum-doped zinc oxide (AZO), or indium-doped cadmium oxide; multilayer hybrid coatings can include TCO-metal-TCOs; polymer-based conductors include mixtures of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate) with and without metal lattices (PEDOT:PSS).

[0070] In some embodiments, the substrate may include one or more layers or coatings onto which the deposited layer is deposited. These coatings are preferably: At least one coating of a transparent conductor layer; at least one electrode screening layer; at least one hole blocking layer; at least one electron blocking layer; at least one hole transport layer, or At least one electron transport layer At least one of the following is selected:

[0071] For example, the substrate may be coated with: at least one coating of a transparent conductor layer, and at least one hole transport layer attached to the transparent conductor layer; or At least one coating of a transparent conductor layer and at least one electron transport layer attached to the transparent conductor layer. may include.

[0072] In another embodiment, the substrate is provided with a coating of: at least one coating of a transparent conductor layer, and at least one hole transport layer attached to the transparent conductor layer; or At least one coating of a transparent conductor layer and at least one electrode screening layer attached to the transparent conductor layer. may include.

[0073] The electrode screening material may be coated to a thickness between 10 and 25 nm. The electrode screening layer preferably comprises at least one hole blocking layer; or at least one electron blocking layer.

[0074] In some embodiments, at least one hole transport layer comprises an organic or inorganic semiconductor, hi some embodiments, at least one electron transport layer comprises an organic or inorganic conductor.

[0075] The coating applied to the substrate typically depends on the configuration of the photoactive device of which the applied photoactive layer forms a part. In a conventional structure of a photoactive device layer, the substrate includes at least one coating of a transparent conductor layer and at least one hole transport layer applied to the transparent conductor layer. In an inverted structure of a photoactive device layer, the substrate includes at least one coating of a transparent conductor layer and at least one electron transport layer applied to the transparent conductor layer. Of course, various other layers are possible depending on the desired structure of the photoactive device, as will be apparent to one skilled in the art.

[0076] It should be understood that not all photoactive device structures will use a TCO as a transparent conductor layer. For example, a perovskite cell can be prepared on a silicon solar cell to produce a tandem solar cell. Furthermore, a printed conductive layer can be used in place of a TCO. In some embodiments, a photoactive device including a photoactive layer made according to the present invention can be made directly on a TCO. The present invention is intended to encompass all of these embodiments.

[0077] The various layers may include any suitable components currently known in the art, such as: Suitable transparent conductor layers can be selected from: transparent conductive oxides (TCOs) including tin-doped indium oxide (ITO), fluoride-doped tin oxide (FTO), doped zinc oxide, e.g. aluminum-doped zinc oxide (AZO), or indium-doped cadmium oxide; multilayer hybrid coatings can include TCO-metal-TCO; polymer-based conductors include mixtures of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate) with and without metal lattice (PEDOT:PSS); Suitable hole transport layers include poly(3,4-ethylenedioxythiophene) (PEDOT), a mixture of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate (PEDOT:PSS), poly(4,4-dioctylcyclopentadithiophene); poly(3-hexylthiophene-2,5-diyl) (P3HT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly[N-9″-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT). , poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT), poly(N-alkyldiketopyrrolopyrroledithienylthieno[3,2-b]thiophene) (DPP-DTT), 2,2(,7,7(-tetrakis-(N,N-di-p-methoxyphenylamine)9,9(-spirobifluorene) (spiro-OMeTAD), MoO3 or the like (with or without a suitable dopant); Suitable electron transport layers include zinc oxide, titanium dioxide, tungsten trioxide, ethoxylated polyethyleneimine (PEIE) or the like; Suitable conductor layers include Au, Ag, C (e.g., graphite / carbon black, CNT, vapor grown carbon fibers graphene or the like), Al, Mg, Cu, or suitable alloys thereof or the like.

[0078] In one particular embodiment, the integrated multilayer thin film electronic device comprises a photovoltaic device including the following layers: flexible ITO (transparent electrode) / PEIE (electron selective layer) / PI-4 (photoactive layer - commercial photoactive ink) / S315 (hole selective layer - commercial PEDOT:PSS ink) / PV-416 (black electrode - commercial silver paste).

[0079] It should be understood that each of the layers may be applied to an integrated multilayer thin film electronic device according to the method of the first aspect of the invention as a solution, mixture, admixture, paste or the like in, with or in conjunction with a suitable carrier solvent, the solvent being selected to have an appropriate polarity to match the differential orthogonal solubility of the alternating layers of materials corresponding to the preferably alternating polarity of the layers. Suitable solvents include: DMF, DMSO, gamma-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or combinations thereof; isopropanol, n-butanol, isobutanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or combinations thereof; or benzene, toluene, xylene, trimethylbenzene (e.g., mesitylene), chlorobenzene, dichlorobenzene, chloroform, dichloromethane, anisole, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, or combinations thereof One or more of the following are included:

[0080] The present invention will now be described with reference to the accompanying drawing figures which show particularly preferred embodiments of the invention. [Brief description of the drawings]

[0081] [Figure 1(a)] 1A-1D are schematic diagrams illustrating a comparison of three prior art approaches to forming electrode interconnects in integrated multilayer thin-film electronic devices. [Figure 1(b)] 1A-1D are schematic diagrams illustrating a comparison of three prior art approaches to forming electrode interconnects in integrated multilayer thin-film electronic devices. [Figure 1(c)] 1A-1D are schematic diagrams illustrating a comparison of three prior art approaches to forming electrode interconnects in integrated multilayer thin-film electronic devices. [Diagram 2]1A-1C show layers including a solar cell constructed according to the present invention in (a) a conventional solar cell structure; (b) an inverted solar cell structure; and (b) a tandem solar cell structure. [Diagram 3] FIG. 1 is a schematic diagram of series-connected photovoltaic (PV) modules showing: (a) a conventional module via patterned photoactive layers; (b) a module design developed in this invention, where unpatterned photoactive layers are used and interconnections are formed via self-generated electrical pathways. [Figure 4] 1A-1C show exemplary designs of PV modules processed by roll-to-roll production that can be produced using the methods of the present invention, including (a) an infinity PV module, (b) CSIRO's smart module, and (c) CSIRO's vertical module design. [Diagram 5] FIG. 1 provides further examples of PV module designs that can be produced using the methods of the present invention, including (a) a vertical module, and (b) a conventional parallel module, and (c) an unconventional module design fabricated by using laser scribing (Belectric, Germany). [Figure 6(a)] FIG. 1 shows various rear electrode patterns for devices of the invention: (i) examples of mask designs used for printing electrodes with solid lines; (ii) examples of mask designs used for printing electrodes with a grid pattern. [Figure 6(b)] FIG. 10 illustrates various rear electrode patterns for the device of the present invention, showing a printed electrode with a grid pattern that incorporates variations in line thickness to provide a visual pattern. [Figure 6(c)] FIG. 1 illustrates various rear electrode patterns for devices of the present invention, showing a printed electrode with a grid pattern that incorporates variations in line thickness to provide a visual pattern. [Figure 7]Exemplary current density (per cell area instead of total module area for comparison)-voltage characteristics are provided for a single PV cell and a vertical module with 19 cells connected in series with the device configuration: flexible ITO (transparent electrode) / PEIE (electron selective layer) / PI-4 (commercial photoactive ink) / S315 (hole selective layer—commercial PEDOT:PSS ink) / PV-416 (back electrode—commercial silver paste). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0082] The present invention describes a new method for forming an electrical interconnect between two spaced apart electrodes in an integrated multilayer thin-film electronic device without the need to include physical gaps in the patterning of the individual layers of the device.

[0083] Multilayer thin-film electronic devices The present invention relates to integrated multilayer thin film electronic devices and can be used with any solution processed electronic device, such as organic transistors, OLEDs, organic memory, and printed sensors. The present invention finds particular application with photovoltaic and optoelectronic solar devices, such as organic solar cells, OPVs, perovskite solar cells, roll-to-roll, and therefore will be described in the context of those types of devices. However, it should be understood that the present invention may also relate to other solution processed electronic devices, such as photoactive sensors, organic transistors, light emitting devices such as OLEDs, organic memory, and printed sensors.

[0084] Photovoltaic cells, particularly thin film and flexible solar cells, are formed as multilayer coatings on a substrate. Figures 2(a) and 2(b) illustrate examples of layer structures of multilayer organic solar cells constructed according to embodiments of the present invention. As shown in Figures 2(a) and 2(b), this multilayer coating structure can be arranged on a substrate in at least two different configurations, referred to in the art as (A) a conventional structure 50 or (B) an inverted structure 60 (Figure 2(b)). The nature and order of the transport layers - as well as the nature of the metal electrodes - depend on whether the cell follows a regular or inverted device mechanism.

[0085] FIG. 2(a) depicts a conventional structure 50 formed on a substrate having the following layers layered sequentially on its surface: a transparent conductor (such as a transparent conducting oxide (TCO), a conducting polymer, or a thin metal) with or without a conductive lattice, followed by a hole transport layer; followed by a photoactive layer; followed by an electron transport layer, and then a conductor layer (typically a metal).

[0086] FIG. 2(b) depicts an inverted structure 60 formed on a substrate having the following layers layered sequentially on its surface: a transparent conductor (such as a transparent conducting oxide (TCO), a conducting polymer, or a thin metal) with or without a conductive lattice, followed by an electron transport layer; followed by a photoactive layer; followed by a hole transport layer, followed by a photoactive layer; followed by a hole transport layer, followed by a conductor layer (typically a metal).

[0087] In an inverted structure 60, the positive and negative electrodes are reversed so that charge leaves the device in the opposite direction to that in a normal device. Inverted cells can utilize cathodes from among more suitable materials; inverted OPVs enjoy longer lifetimes than regularly structured OPVs and typically exhibit higher efficiencies compared to their conventional counterparts.

[0088] It should be understood that the hole transport layer or electron transport layer may be omitted in some embodiments of the conventional 50 and inverted 60 structures described above, and therefore these layers may be optional in certain embodiments.

[0089] The solar cell may include a tandem or multijunction solar cell 70. As shown in FIG. 2(c), the tandem structure is formed on a substrate using two stacked solar cell structures, i.e., a top cell and a bottom cell of conventional or inverted structure. The stacked structure includes two different solar cells of the same or different configuration. The example provided includes the following layers layered in sequence on its surface: a transparent conductor layer (TCO, conductive polymer or thin metal) with or without a current collector grid; followed by a top cell - either type A (FIG. 1A) or type B (FIG. 2B) of solar cells; followed by a transparent conductor layer (TCO, conductive polymer or thin metal) with or without a conductive grid; followed by a bottom cell (either type A (FIG. 2A) or type B (FIG. 2B) of solar cells); followed by a metal (or conductor) layer. It should be understood that substrates such as glass, plastic, metal, or ceramic can also be used, but are optional.

[0090] Each layer can be formed by one of several coating techniques known in the art, including casting, doctor blading, screen printing, inkjet printing, pad printing, knife coating, meniscus coating, slot die coating, gravure coating, reverse gravure coating, kiss coating, microroll coating, curtain coating, slide coating, spray coating, flexographic printing, offset printing, rotary screen printing, or dip coating. It should be understood that a person skilled in the art may be able to adopt a suitable technique for depositing each layer based on techniques known in the art.

[0091] The various layers can include any suitable components currently known in the art. Examples include: A suitable photoactive layer may be selected from one or more organic photovoltaic compounds, or one or more perovskite photoactive compounds. Suitable transparent conductor layers may be selected from transparent conductive oxides (TCOs) including tin-doped indium oxide (ITO), fluoride-doped tin oxide (FTO), doped zinc oxide such as aluminum-doped zinc oxide (AZO), or indium-doped cadmium oxide; multilayer hybrid coatings (e.g. TCO-metal-TCO); polymer-based conductors including mixtures of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate) with and without metal lattices (PEDOT:PSS); Suitable hole transport layers include transparent conductive polymers such as at least one of poly(3,4-ethylenedioxythiophene) (PEDOT), a mixture of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate (PEDOT:PSS), poly(4,4-dioctylcyclopentadithiophene); doped P3HT (poly(3-hexylthiophene-2,5-diyl)) or the like; Suitable electron transport layers include zinc oxide, titanium dioxide, tungsten trioxide, ethoxylated polyethyleneimine (PEIE) or the like; Suitable conductive layers include aluminum, silver, magnesium, copper, gold, or suitable alloys thereof, or the like; and Suitable substrates include metals, polymers, ceramics, or glass.

[0092] It should be understood that typically an electron transport layer is also a hole blocking layer, or vice versa. Similarly, typically an electron blocking layer is also a hole transport layer, or vice versa. Vacuum-based OLEDs tend to use additional layers (ejection layers, blocking layers) to further boost efficiency. Solution-processed devices typically do not use such additional layers.

[0093] The photoactive layer may, in some embodiments, include one or more organic photoactive compounds. Preferably, the organic photoactive compound is in the form of an ink. The organic photoactive layer generally includes a combination of an electron donor material and an electron acceptor material. In some embodiments, the organic photoactive compound includes an organic photoactive layer composite ink, which includes at least one electron donor material, at least one electron acceptor material, and an organic solvent. Other components may also be present to enhance the functionality of the photoactive layer, as taught, for example, in U.S. Patent Application No. US20190393423A1, which teaches an organic photoactive layer including an electron donor material, an electron acceptor material, an organic solvent, and an organic amine compound, the contents of which should be understood to be incorporated herein by reference.

[0094] Electron donor material refers to a semiconductor material whose molecules can donate electrons to an organic solar cell photoactive layer under conditions of photoexcitation to achieve charge separation. In some embodiments, the electron donor material comprises a conjugated polymer electron donor material and / or a conjugated small organic molecule electron donor material.

[0095] In embodiments, conjugated polymeric electron donor materials include, but are not limited to, any one or more of P3HT (poly(3-hexylthiophene)), PTB7, PTB7-Th, PffBT4T-2OD, and structural variations thereof. Conjugated small organic molecule electron donor materials preferably include polymers based on benzothiophene (BDT) as a core, and polymers based on oligothiophene as a core. For example, conjugated small organic molecule electron donor materials include DR3TSBDT, DRCN7T, and structural variations thereof.

[0096] Electron acceptor material refers to a semiconductor material whose molecules can accept electrons in an organic solar cell photoactive layer under photoexcitation conditions to achieve charge separation. In some embodiments, the electron accepting pair material includes any one or combination of two or more of, but not limited to, fullerene electron acceptor materials, fullerene derivative electron acceptor materials, and non-fullerene electron acceptor materials.

[0097] In embodiments, the fullerene electron acceptor material and the fullerene derivative electron acceptor material include any one or a combination of two or more of, but not limited to, PCBM, such as [6,6]-phenyl-C61-methylbutyrate (PC61BM) or PC71BM, bis-PC61BM, and IC61BA. The non-fullerene electron acceptor material preferably includes an organic conjugated electron acceptor material. More preferably, the organic conjugated electron acceptor material includes any one or a combination of two or more of, but not limited to, perylene diimide (PDI) derivatives, naphthodimide (NDI) derivatives, indacene derivatives, fluorene derivatives, benzothiadiazole (BT) derivatives, and subphthalocyanine (SubPc) derivatives.

[0098] The organic solvent preferably includes, but is not limited to, o-dichlorobenzene, chlorobenzene, chloroform, toluene, xylene, trimethylbenzene, and the like.

[0099] Examples of suitable organic photoactive compounds include P3HT:PCBM or PI-4 (commercial active layer ink from infinityPV, Jyllinge, Denmark), PBF-QxF:Y6 D18:Y6, or D18:Y6:PCBM.

[0100] In other embodiments, the photoactive layer can include one or more perovskite photoactive compounds. The term "perovskite" as used herein refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a material layer having a structure related to that of CaTiO3. The structure of CaTiO3 can be represented by the formula AMX3, where A and M are cations of different sizes and X is an anion. M is selected from Pb, Sn, Ge, Ca, Sr, Cd, Cu, Ni, Mn, Co, Zn, Fe, Mg, Ba, Si, Ti, Bi, or In, and X is selected from at least one of F, Cl, Br, or I. In many embodiments, M is a metal cation, and more preferably a divalent metal cation, such as Ca 2+ , Sr2+ , Cd 2+ , Cu 2+ , Ni 2+ , Mn 2+ , Fe 2+ , Co 2+ , Pd 2+ , Ge 2+ , Sn 2+ , Pb 2+ , Sn 2+ , Yb 2+ , and Eu 2+ In some embodiments, the second cation comprises Sn 2+ , Pb 2+ , and Cu 2+ In a preferred embodiment, M is selected from Pb, Sn, Ge, Si, Ti, Bi, or In.

[0101] In the unit cell, the A cations are at (0,0,0), the M cations are at (1 / 2, 1 / 2, 1 / 2), and the X anions are at (1 / 2, 1 / 2, 0). The A cations are usually larger than the M cations. Those skilled in the art will appreciate that when A, M, and X vary, the different ion sizes can cause the structure of the perovskite material to be distorted away from the structure adopted by CaTiO3 to a structure distorted to a lower symmetry. The symmetry is also lower when the material includes a layer having a structure related to that of CaTiO3. Materials including layers of perovskite materials are well known. For example, the structure of a material adopting a K2 iF4 type structure includes a layer of perovskite material.

[0102] The perovskite semiconductor used in the present invention is typically capable of (i) absorbing light and thereby generating free charge carriers; and / or (ii) emitting light by accepting both electron and hole charges, which then recombine and emit light. Thus, the perovskite used is typically a light absorbing and / or emitting perovskite. Thus, the perovskite semiconductor used in the present invention may be a perovskite that acts as an n-type, electron transporting semiconductor when photodoped. Alternatively, it may be a perovskite that acts as a p-type, hole transporting semiconductor when photodoped. Thus, the perovskite may be an n-type, p-type, or intrinsic semiconductor. In a preferred embodiment, the perovskite used is one that acts as an n-type, electron transporting semiconductor when photodoped.

[0103] In some embodiments, A in AMX3 is of the formula (R1R2R3R4N), where: R1 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R2 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R3 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; and R4 includes an organic cation having a substituent that is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl.

[0104] In some embodiments, R1 in the organic cation is hydrogen, methyl, or ethyl, R2 is hydrogen, methyl, or ethyl, R3 is hydrogen, methyl, or ethyl, and R4 is hydrogen, methyl, or ethyl. For example, R1 can be hydrogen or methyl, R2 can be hydrogen or methyl, R3 can be hydrogen or methyl, and R4 can be hydrogen or methyl. In some embodiments, F can be a substituent of an alkyl chain attached to N or a sub-alkyl chain from N.

[0105] In some embodiments, A in AMX3 is of the formula (R5R6N=CH-NR7R8), where: R5 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R6 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R7 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R8 includes an organic cation having a substituent that is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl.

[0106] Alternatively, the organic cation has the formula (RNH) + (wherein R5 is hydrogen, or unsubstituted or substituted C1-C20 alkyl). For example, R5 may be methyl or ethyl. Typically, R5 is methyl.

[0107] In some embodiments, the organic cation has the formula R5R6N=CH-NR7R8, where R5 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R6 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R7 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl; R8 is hydrogen, unsubstituted or substituted C1-C20 alkyl, or unsubstituted or substituted aryl. Typically, R5 in the cation is hydrogen, methyl, or ethyl, R6 is hydrogen, methyl, or ethyl, R7 is hydrogen, methyl, or ethyl, and R8 is hydrogen, methyl, or ethyl. For example, R5 may be hydrogen or methyl, R6 may be hydrogen or methyl, R7 may be hydrogen or methyl, and R8 may be hydrogen or methyl. The organic cation can have the formula, for example (H2N=CH-NH2) + has.

[0108] As used herein, an alkyl group can be a substituted or unsubstituted linear or branched saturated radical, often a substituted or unsubstituted linear saturated radical, and more frequently an unsaturated linear saturated radical. A C1-C20 alkyl group is an unsubstituted or substituted linear or branched saturated hydrocarbon radical. Typically, it is a C1-C10 alkyl, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl, or a C1-C6 alkyl, such as methyl, ethyl, propyl, butyl, pentyl, or hexyl, or a C1-C4 alkyl, such as methyl, ethyl, i-propyl, n-propyl, t-butyl, s-butyl, or n-butyl.

[0109] If an alkyl group is substituted, it typically bears one or more substituents selected from substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted aryl (as defined herein), cyano, amino, C1-C10 alkylamino, di(C1-C10) alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, hydroxy, oxo, halo, carboxy, ester, acyl, acyloxy, C1-C20 alkoxy, aryloxy, haloalkyl, sulfonic acid, sulfhydryl (i.e., thiol-SH), d-C10 alkylthio, arylthio, sulfonyl, phosphate, phosphate ester, phosphonic acid, and phosphonate ester. Examples of substituted alkyl groups include haloalkyl, hydroxyalkyl, aminoalkyl, alkoxyalkyl, and alkaryl groups. The term alkaryl, as used herein, refers to a C1-C20 alkyl group in which at least one hydrogen atom is replaced by an aryl group. Examples of such groups include, but are not limited to, benzyl (phenylmethyl, PhCH2-), benzhydryl (Ph2CH-), trityl (triphenylmethyl, Ph3C-), phenylethyl (phenylethyl, Ph-CH2CH2-), styryl (Ph-CH=CH-), cinnamyl (Ph-CH=CH-CH2-).Typically, a substituted alkyl group bears one, two or three substituents, e.g., one or two.

[0110] An aryl group is a substituted or unsubstituted monocyclic or bicyclic aromatic group typically containing 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms, in the ring portion. Examples include phenyl, naphthyl, indenyl, and indanyl groups. An aryl group may be unsubstituted or substituted. When an aryl group as defined above is substituted, it typically bears one or more substituents selected from unsubstituted C1-C6 alkyl (to form an aralkyl group), unsubstituted aryl, cyano, amino, C1-C10 alkylamino, di(C1-C10) alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, hydroxy, halo, carboxy, ester, acyl, acyloxy, C1-C20 alkoxy, aryloxy, haloalkyl, sulfhydryl (i.e., thiol, -SH), C1-10 alkylthio, arylthio, sulfonic acid, phosphoric acid, phosphate ester, phosphonic acid, and phosphonic acid ester, and sulfonyl. Typically, it carries 0, 1, 2, or 3 substituents. Substituted aryl groups may be substituted at two positions with a single C1-C6 alkylene group or with a bidentate group represented by the formula -X-(C1-C6) alkylene group or -X-(C1-C6) alkylene-X-, where X is selected from O, S, and R, and R is H, aryl, or C1-C6 alkyl. Thus, a substituted aryl group may be an aryl group fused with a cycloalkyl group or with a heterocyclyl group. The ring atoms of the aryl group may contain one or more heteroatoms (as in a heteroaryl group). Such aryl groups (heteroaryl groups) are substituted or unsubstituted monocyclic- or bicyclic heteroaromatic groups, typically containing 6 to 10 atoms in the ring portion including one or more heteroatoms. Generally, it is a 5- or 6-membered ring containing at least one heteroatom selected from O, S, N, P, Se, and Si. For example, it may contain 1, 2, or 3 heteroatoms.Examples of heteroaryl groups include pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thienyl, pyrazolidinyl, pyrrolyl, oxazolyl, oxadiazolyl, isoxazolyl, thiadiazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, quinolyl, and isoquinolyl. Heteroaryl groups can be unsubstituted or substituted, for example as specified above for aryl. Typically, they bear 0, 1, 2, or 3 substituents.

[0111] The perovskite semiconductor layer of the present invention typically comprises at least one anion X selected from a halide anion and a chalcogenide anion. The term "halide" refers to an anion of a group 7 element, i.e., a halogen. Typically, a halide refers to a fluoride anion, a chloride anion, a bromide anion, an iodide anion, or an astatine anion. The term "chalcogenide anion" as used herein refers to an anion of a group 6 element, i.e., a chalcogen. Typically, a chalcogenide refers to an oxide anion, a sulfide anion, a selenide anion, or a telluride anion. In a preferred embodiment, the anion X is selected from at least one of F, Cl, Br, or I.

[0112] In some embodiments, the perovskite layer comprises an organometal halide perovskite. In these embodiments, the first cation A is an organic cation, more preferably an ammonium group or other nitrogen-containing organic cation. This organic cation (A) in this type of perovskite can include a number of organic cations, including protonated alkylamines, cycloalkylamines (e.g., pyrrolidine or cyclohexylamine), arylamines, and aromatic heterocycles (such as pyridine). In some embodiments, A is of the general formula RCH2NH3 + , RC(NH2)2 + , R a R b CH1NH3 + , R a R b R c CNH3+ , R a R b NH2 + , or R a R b R c NH + wherein R, R a , R b , R c contains H or a substituted or unsubstituted alkyl group(s), preferably a C1 to C6 substituted or unsubstituted alkyl or aryl group(s). Although several organometal halide perovskites are possible, the preferred A of the perovskite compound is CH3NH3 + or HC(NH2)2 + Includes at least one of the following.

[0113] The resulting perovskite layer preferably comprises an organometal halide perovskite. For example, in some embodiments, the perovskite layer comprises at least one of CH3NH3MX3 or HC(NH2)2MX3, where M is selected from Pb, Sn, Tl, Bi, or In; and X is selected from at least one of F, Cl, Br, or I. In other embodiments, the perovskite comprises an organo-lead halide perovskite, preferably at least one of CH3NH3PbX3 or HC(NH2)2PbX3, where X is selected from at least one of F, Cl, Br, or I.

[0114] In some embodiments, in the optoelectronic device of the present invention, the perovskite is a perovskite compound selected from CH3NH3PbI3, CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbF3, CH3NH3PbBrI2, CH3NH3PbBrCl2, CH3NH3PbIBr2, CH3NH3PbICl2, CH3NH3PbClBr2, CH3NH3PbI2Cl, CH3NH3SnBrI2, CH3NH3SnBrCl2, CH3NH3SnF2Br, CH3NH3SnIBr2, CH3NH3SnICl2, CH3NH3SnF2I, CH3NH3SnClBr2, CH3NH3SnI2Cl, or CH3NH3SnF2Cl.

[0115] Of course, X does not necessarily have to be a single halide. The resulting perovskite layer may comprise a mixed halide perovskite, where X in CH3NH3MX3 or HC(NH2)2MX3 comprises two or more of F, Cl, Br, or I. Thus, CH3NH3MX3 may be CH3NH3MCl x I 3-x , CH3NH3MI 3-x CI x or similar. x I 3-x , CH3NH3MI 3-x CI x It should be understood that the perovskite layer may include non-stoichiometric materials, where M is selected from at least one of Pb, Sn, Ge, Si, Ti, Bi, or In, preferably M is Pb. In an exemplary embodiment, the perovskite layer is CH3NH3PbCl x I 3-x It is one of a family. In a preferred embodiment, x is close to zero (i.e., very low chloride content). In another embodiment, x=0, providing a triiodide perovskite material layer.

[0116] Processes for forming integrated multilayer thin film electronic devices. The integrated multilayer thin film electronic devices of the present invention are comprised of multiple layers of functional materials, including conductors and semiconductors. As previously discussed, one of the important factors in forming multilayer electronic devices is to consider the orthogonal solubility of the alternating materials in each layer. For example, a water / alcohol based ink (polar material) can be deposited onto a layer made from an organic solvent based ink (non-polar material) without re-dissolving the underlying layer. The process can be repeated to form multiple layers with alternating polarities, i.e. polar / non-polar / polar / non-polar materials.

[0117] If an organic solvent-based conductive paste is deposited on top of an organic thin film layer, the thin film will be damaged and lose functionality, resulting in the formation of conductive channels through the layer, a phenomenon that has been the primary failure mechanism for printed PV when the intermediate layer (polar material) has physical defects (i.e., short circuit formation through pinholes in the water-soluble charge selective layer).

[0118] The present invention strategically uses the orthogonal solubility differences of different layers in a multi-layer structure of a thin-film electronic device to exploit the solubility of at least one layer of the structure to create at least one conductive path through a functional layer located between a first electrode and a second electrode of adjacent cells (unit cells). Without being limited to any theory, the inventors exploited the problematic short circuit formation through organic layers to create a conductive path for electrode interconnection. This alternating interconnect configuration replaces the patterning of layers with at least one of the functional layers allowing at least one non-patterned organic layer to be used for module fabrication.

[0119] The present invention can therefore take advantage of the non-patterning coating and scribing approach shown in FIG. 1(c) (described in the Background of the Invention section) without the need for expensive scribing systems.

[0120] In photovoltaic or optoelectronic devices, non-patterned coatings are the preferred photoactive layer. Removal of the patterning requirement for the photoactive layer solves many of the challenges associated with the manufacture of printed PV and provides design freedom that creates more market opportunities.

[0121] FIG. 3 illustrates the difference in construction between a photoactive device 100 formed using one of the prior art methods as shown in FIG. 1-(a); and a photoactive device 200 formed using a method according to the present invention. The prior art photoactive device shown in FIG. 3(a) includes a patterned photoactive layer formed on a substrate 130 using printing, patterning, or scribing as previously described. The electrical inter-unit device connections 102 between the back electrode 105 of the first cell (unit device) 103 and the transparent electrode 110 between the second cell (unit device) 104 are made through patterned gaps formed in the photoactive layer 115 and the charge selection layer 120. In comparison, the photoactive device 200 constructed according to the present invention (as shown in FIG. 3(b)) includes a non-patterned photoactive layer 215. An electrical inter-unit device connection 202 between the back electrode 205 of the first unit device 203 and the transparent electrode 210 of the second unit device 204 is formed through patterned gaps formed in the charge selection layer 220 and at least one micro- or nano-sized conductive pathway through the non-patterned photoactive layer 215.

[0122] The patterned charge selection layer 220 is used in conjunction with the differential orthogonal solubilities of the charge selection layer 220 and the photoactive layer 215 to control the selective formation of one micro- or nano-sized conductive pathway through the non-patterned photoactive layer 215 when depositing the different layers of the multilayered photoactive device 200.

[0123] This electrode interconnection, i.e. the process of forming an electrical inter-cell connection 202 between the back electrode 205 of the first cell 203 and the transparent electrode 210 of the second cell 204, is achieved using the following general steps: 1. depositing a transparent electrode layer 210 onto a thin film substrate 230 as a first patterned coating including at least two spaced apart first electrode sections 210A and 210B of adjacent cells 203 and 204 formed as a rectangle in FIG. 3; 2. depositing a photoactive layer 215 as a substantially continuous coating onto the transparent electrode layer 210; and 3. Depositing the charge selection layer 220 as a patterned coating on the photoactive layer 215. The pattern generally includes at least two spaced apart functional sections 220A and 220B (formed as rectangles in FIG. 3), each functional section 220A and 220B patterned to be positioned on the photoactive layer 215 to overlap a portion of one of the first electrode sections 210A and 210B to define a gap portion 235 between adjacent functional sections 220A and 220B that includes a portion of that first electrode section 210 and the transparent electrode layer 210.

[0124] These steps produce intermediary devices that include a patterned transparent electrode layer 210, a substantially continuous photoactive layer 215, and a patterned charge selection layer 220. These photoactive devices 200 are completed by depositing a back electrode 205 as a patterned coating in the following steps: 4. The back electrode 205 is deposited on the charge selective layer 220 as a third patterned coating comprising at least two spaced apart second electrode sections 205A and 205B, each second electrode section 205A, 205B positioned to overlap at least one functional section 220A and 220B of the charge selective layer 220 and a portion of an adjacent gap portion 235 comprising at least a portion of the first electrode sections 210A and 210B of adjacent cells 203 and 204. The back electrode 205 is formed using a solution comprising a conductive species and at least a first solvent. In this setup, the gap portion 235 between adjacent functional sections preferably comprises only the transparent electrode layer 210 and the photoactive layer 215.

[0125] The layers and solvents are selected to have differential orthogonal solubilities of the alternating layers of material, such that photoactive layer 215 is soluble in a first solvent and charge selection layer 220 has low to zero solubility in the first solvent. Photoactive layer 215 and charge selection layer 220 are formulated to have different polarities, with the first solvent having the same polarity as photoactive layer 215. Thus, if photoactive layer 215 is a polar layer, the first solvent is a polar solvent. If photoactive layer 215 is a non-polar layer, the first solvent is a non-polar solvent. Charge selection layer 220 is of a different polarity relative to photoactive layer 215.

[0126] In an embodiment, the first solvent comprises: A. DMF, DMSO, gamma-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or combinations thereof; B. isopropanol, n-butanol, isobutanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or combinations thereof; or C. benzene, toluene, xylene, trimethylbenzene (e.g., mesitylene), chlorobenzene, dichlorobenzene, chloroform, dichloromethane, anisole, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, or combinations thereof.

[0127] Again, it should be understood that the choice of the first solvent depends on the required polarity and the composition of the various layers. Integrated multilayer thin-film electronic devices include optoelectronic devices, particularly photovoltaic devices, and the choice of the first solvent depends on the composition of the photovoltaic layer. In perovskite devices, the first solvent is preferably selected from either A or B above, depending on the polarity of that layer. In organic PV devices, the first solvent is preferably selected from C above.

[0128] The first solvent from the deposited composition of the back-electrode layer 205 dissolves at least a portion of the photoactive layer 215 in the interstitial portion 235 to form an electrical interconnection between the transparent electrode layer 210 and the back-electrode 205 through the photoactive layer 215. In contrast, the charge selective layer 220 is unaffected by the first solvent, does not dissolve during deposition of the back-electrode 205, and remains substantially intact (defect-free) when the back-electrode 205 is deposited. Thus, deposition of the back-electrode 205 in the interstitial portion 235 forms one or more (typically many) micro- to nano-sized conductive pathways between the back-electrode 205 of the first cell 203 and the transparent electrode 210 of the second cell 204 through the photoactive layer 215.

[0129] The present invention therefore provides an alternative process for forming electrical connections between spaced apart electrodes through the functional layers of an integrated multilayer thin-film electronic device by using solvents to form the back-electrode 205 and taking advantage of the selective solubility of the components of the multilayer coating.

[0130] Although only two adjacent cells (unit devices) are shown in Figure 3, it should be understood that the photoactive device 200 of Figure 3 typically includes a series of adjacent cells on a thin film substrate and may be arranged in a module, and each adjacent cell may include an interconnect formed in accordance with the present invention.

[0131] Although not illustrated, the electrical inter-cell connections 202 are typically formed from several nano- to micro-sized channels in the photoactive layer 215. As explained above, these typically include one or more defects in the photoactive layer 215, such as pinhole defects through the thickness of the photoactive layer 215. Typically, the process forms a large number of nano- to micro-pathways or channels. In most cases, this conductive path includes millions of nano- to micro-channels through the photoactive layer 215. For example, the entire area of ​​a 2 mm by 100 mm line can be a conductive path, depending on the active layer and the conductive paste. In some cases, the entire layer (the photoactive layer 215 not covered by the charge selection layer 220) can be uniformly conductive. The nano- to micro-pathways or channels are distributed through, along, and near the photoactive layer 215.

[0132] The compositions of the various layers depend on the configuration of the photoactive device 200. As discussed above, the photoactive layer 215 may include at least one of one or more organic photovoltaic compounds or one or more perovskite photoactive compounds, the possible compositions of which are also discussed above. Additionally, the charge selection layer 220 may include at least one of: at least one electrode screening layer; at least one hole blocking layer; at least one electron blocking layer; at least one hole transport layer; or at least one electron transport layer, the possible compositions of which are also discussed above. In some embodiments, the charge selection layer 220 comprises a hole transport layer, such as a mixture of poly(3,4-ethylenedioxythiophene and polystyrenesulfonate (PEDOT:PSS). The transparent electrode layer 210 can comprise any suitably configurable conductive species, such as tin-doped indium oxide (ITO), fluoride-doped tin oxide (FTO), doped zinc oxide, such as aluminum-doped zinc oxide (AZO), or indium-doped cadmium oxide. And finally, the back-electrode 205 preferably comprises a metallic electrode, and more preferably a silver electrode formed using a solution comprising a metal or an ionic form of a metal and a first solvent (as discussed above). It should be understood that the above compositions should not be limiting of the invention, and other suitable compositions are possible as discussed throughout this specification.

[0133] It should be understood that additional layers can be included in the multi-layer structure of device 200 in addition to the layers shown in device 200 illustrated in Fig. 3. For example, an additional charge selective layer (one of a hole transport layer or an electron transport layer, depending on the configuration of the photoactive device, as illustrated and described with respect to devices 50, 60, and 70 illustrated in Fig. 2) can be included between transparent electrode layer 210 and photoactive layer 215, for example, as shown in devices 50 and 60 illustrated in Fig. 2(a) and Fig. 2(b). This additional charge selective layer can be deposited as a fourth patterned coating having a complementary and corresponding pattern to the second patterned coating of charge selective layer 220 deposited on photoactive layer 215, which also defines complementary and corresponding interstitial portions 235 to provide the required overlap of back electrode 205 of first cell 203 and transparent electrode 210 of second cell 204 to facilitate a conductive path through photoactive layer 215 between these two electrodes.

[0134] It should be understood that each of the above-mentioned layers for devices 50, 60, and 70 illustrated and described with respect to Figures 2(a), 2(b), and 2(c), and device 200 of Figure 3, can be applied to an integrated multilayer thin-film electronic device as a solution, mixture, admixture, paste, or the like, with or in combination with a suitable carrier solvent to form the device (see below). The solvent is selected to have an appropriate polarity to match the differential orthogonal solubility of the alternating layers of materials, corresponding to the preferably alternating polarity of the layers. Suitable solvents include: DMF, DMSO, gamma-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or combinations thereof; or Isopropanol, n-butanol, isobutanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or combinations thereof Includes:

[0135] As previously discussed, various deposition techniques can be used to deposit the various layers to form the integrated multilayer thin-film electronic device 200. In some embodiments, at least one of the transparent electrode layer 210, the photoactive layer 215, the charge selection layer 220, or the back-electrode 205 is deposited on the substrate using at least one of: casting, doctor blading, printing, screen printing, inkjet printing, pad printing, knife coating, meniscus coating, slot-die coating, gravure coating, reverse gravure coating, kiss coating, microroll coating, curtain coating, slide coating, spray coating, flexography, offset printing, rotary screen printing, or dip coating.

[0136] Each deposited layer of the integrated multilayer thin-film electrode device 200 may also be subjected to a drying process / step to aid in drying the layer. The drying step may include any number of drying processes including one or a combination of air drying, convection drying, atmospheric drying, heat treatment, annealing, quenching, or the like. In some embodiments, drying the deposited layer includes heat treatment of the deposited layer at a temperature of at least 60° C., preferably at least 70° C., more preferably at least 100° C., and even more preferably at least 120° C.

[0137] Design freedom for high performance and aesthetics A major advantage of solution-processed thin-film electrode devices is their potential fabrication by low-cost roll-to-roll printing. Roll-to-roll production of printed organic PV has already been demonstrated by several groups, including the applicants.

[0138] Figures 4(a) and 4(b) show examples of printed PV produced roll-to-roll, with the film moving direction moving from left to right in the figure as indicated by arrow 302. Design 300 shown in Figure 4(a) shows a series connected module design developed by InfinityPV. This design allows for "cut-to-size" of the required output voltage. Design 320 shown in Figure 4(b) offers the flexibility to set the output voltage and current. The devices shown in Figures 4(a) and 4(b) can be produced using the method of the present invention.

[0139] Although the modules offer flexibility and advantages over traditional rigid solar cells, the cells are made "parallel" to the production direction due to limitations of the production method. Such designs require inter-module linkers / gaps for large area attachment, resulting in GFF losses due to inactive areas.

[0140] The interconnects produced using the method of the present invention allow for greater flexibility in the design of devices, such as device 330 in FIG. 4(c). The device shown in FIG. 4(c) is patterned with cells 332 configured as laterally spaced rectangles positioned lengthwise perpendicular to the longitudinal axis LL of the longitudinal length of the substrate film on which the cells 332 are printed, producing a vertical cell design module. The series connections between adjacent cells 332 can be made to infinity throughout the film using the interconnect process of the present invention without area loss of inter-module connections. Any part of the film can be cut in terms of the required deposition area or output voltage. If all modules have the same cell area efficiency, it is believed that the vertical design module will have a higher power output compared to the conventional layout (e.g., as shown in FIG. 4(a) and FIG. 4(b)) simply due to the larger proportion of cell area.

[0141] The process and device configuration of the present invention not only provide higher performance at lower cost, but also provide design freedom. An example of one device 400 including a module with a vertical cell design configuration is shown in FIG. 5(a). These devices 400 can have a more flat appearance from the front (substrate side). However, depending on the thickness or material, the device 400 can be completely opaque without any pattern or translucency as shown in FIG. 4. However, as will be explained in more detail below, an image such as the CSIRO logo (shown in FIG. 5(a)) can be added to the module. A conventional module 410 is shown in FIG. 5(b) for comparison. A vertically aligned stripe pattern (with respect to the vertical axis of the coating) can be aesthetic in certain designs / applications, and this vertical stripe pattern may limit commercial applications of printed PV.

[0142] A non-conventional module design 420 reported by Belectric OVP GmbH (now OPVIUS) is also shown in Figure 5(c). Module design 420 was fabricated by Belectric OPV GmbH using laser scribing such that physical gaps were created. It should be understood that this module design can also be fabricated using embodiments of the process of the present invention.

[0143] Printed indicators The first patterned coating on the transparent electrode layer 210 and the second patterned coating on the charge selection layer 220 can have any suitable configuration. In Figures 3, 4(c), 5(a), and 6(a), 6(b), 6(c), the first patterned coating comprises a plurality of spaced apart individual rectangular first electrode sections 210A, 210B arranged in a regular pattern on the thin film substrate 230. Each electrode section 210A, 210B has the same shape. The second patterned coating comprises a rectangular grid pattern complementary to the first patterned coating.

[0144] In the embodiment shown in Figures 6(a), 6(b), and 6(c), the first patterned coating and the second patterned coating include a plurality of spaced apart rectangular sections having a first longitudinal axis YY applied to the substrate 230 such that the length of the rectangular sections runs widthwise on the substrate 230 and such that the rectangular sections are spaced apart and aligned lengthwise along a second longitudinal axis LL that follows the length of the substrate 230.

[0145] The back-electrode 205 can be designed by screen printing thin solid lines of the back-electrode composition onto the dried charge selection layer 220, for example, as shown in Figure 4(c) and Figure 6(a)(i). Further details of possible printing patterns are illustrated in Figure 6(a). In each of these embodiments, the back-electrode 205 is printed to include interstices, for example as a grid or spaced apart lines. As shown in Figure 6(a)(i), the lines of the back-electrode 205 in each cell 505 can be arranged as a set of homogenous lines. However, further design freedom can be realized by using different line thicknesses and thus varying the transparency of the overall device. Furthermore, further design freedom of the pattern can be realized by printing the back-electrode 205 coating (third patterned coating) as a lattice 515, 525, 535 formed from regularly repeating geometric shapes, such as hexagons shown in devices 510, 520, 530 of Figures 6(a)(ii), 6(b), and 6(c).

[0146] The grid 525, 535 can then be given an accentuated pattern, such as the CSIRO brand (FIGS. 5(a) and 6(b)), by accentuating sections of the grid 525, 535 by using thicker / wider lines in those portions of the grid 525, 535 compared to other portions of the grid 525, 535. Those accentuated portions can be designed to form a pattern within the grid 525, 535, which, when designed to have contrasting shades and / or colors to the underlying layers, can produce a visual and / or visible pattern that is nullified to a viewer of the integrated multilayer thin-film electronic device. The visual and / or visible pattern can include a pattern, picture, indicia, such as a logo, letter, number, symbol, pattern, rendered image, one or more words, a sign, mark, emblem, tag, seal, stamp, etc. In certain embodiments, the thickness / width of a selected portion of an element of the grid 525, 535 is at least 1.5 times, and preferably twice, the thickness of an adjacent element of the grid 525, 535. However, it should be understood that any suitable thickness / width difference may be used that provides a distinguishable rendering of the selected indicia.

[0147] As shown in Figure 6(b), a logo such as the CSIRO logo can be provided by varying the thickness of the lines of grid 525 to produce a darker pattern giving the letters that make up CSIRO. Gradient images can also be achieved by varying the thickness / width of the lines of grid 535 so that different shadows are produced, as shown in Figure 6(c).

[0148] The color of the second electrode layer is preferably selected to contrast with the first and second functional layers to assist in imparting a selected index to the gratings 525, 535. The color is preferably selected to produce lines of high contrast to the colors of the first and second functional layers.

[0149] It should be understood that images and indicia can be produced on any regular repeating grid of linear third patterned coatings, for example using the more conventional stripe design shown in Figure 6(a)(i). However, it is possible that these patterns may introduce high contrast lines that may detract from the image or indicia being attempted to impart. EXAMPLES

[0150] Example 1 Organic Photovoltaic Modules A roll-to-roll (R2R) processed organic photovoltaic (OPV) module containing a number of series-connected strip cells in an "inverted" configuration was fabricated on an ITO-based PET coating (8 Ω / sq, OPV8, Solutia) to obtain a device consisting of PET|ITO|PEIE|Pi-4|PEDOT:PSS|Ag. An indium tin oxide-polyethylene terephthalate (ITO-PET) substrate was used with a vertical module design 10 mm wide ITO pattern with 1 mm wide gaps. The device configuration was therefore: flexible ITO / PEIE (electron selective layer) / PI-4 (commercial photoactive ink) / S315 (commercial PEDOT:PSS ink, hole selective layer) / PV-416 (commercial silver paste).

[0151] The modules were coated as follows:

[0152] An aqueous solution of PEIE (Mw 70,000 g / mol, 35-40% w / w, Aldrich) was diluted with 2-methoxyethanol to a concentration of 0.15% w / w. This solution was coated onto the ITO-based PET coating by reverse gravure coating method using a Mino-Labo™ coater (Yasui Seiki Co., Ltd.) to form a PEIE coating with an estimated thickness of about 10 nm. Both the PEIE and active polymer light absorbing layer were deposited with a reverse gravure (RG) coater and coated onto the ITO-PET substrate using a 200R roll with a coating width of 10 cm. Coating was performed at a speed of 1.0 m / min and an RG roll speed of 4 rpm. The PEIE layer was dried with hot air at 110 °C for about 7 s and annealed on a curved hot plate at 140 °C for about 7 s.

[0153] A Pi-4 (pre-made active ink by InfinityPV) polymer absorber layer (about 100 nm thick) was coated at a web speed of 1.0 m / min and a roll speed of 5.5 rpm. During deposition of the active layer, the coating was dried using hot air at 90° C. for about 7 seconds and on a curved hot plate at 90° C. for about 7 seconds only.

[0154] Roll-to-roll (R2R) deposition of PEDOT:PSS strips and Ag grids was performed using screen printing method on an Orthotec-2 R2R screen printing system with a drying step using hot air at 100° C. and IR radiation (30% intensity) for about 20 seconds. PEDOT:PSS was screen printed twice to form a pinhole-free layer using a screen printable paste containing S315 (Agfa) and ORGACON screen printing ink (Agfa) PEDOT:PSS materials in a 1:9 ratio that was mixed for 10 minutes using a high shear mixer (ULTRA-TURRAX T25, IKA Labortechnik).

[0155] To enhance the charge collection of the module and to establish interconnections between the 20 cells in series, a screen-printed grid was deposited using a commercial Ag ink (DuPont, PV416, 2021). The Ag ink has a co-solvent consisting of two alkyl esters: pentanedionic acid dimethyl ester (dimethyl glutarate) and butanedionic acid dimethyl ester (dimethyl succinate). Based on GC-MS analysis, dimethyl glutarate is the main solvent in the Ag ink. Each deposited layer had an offset of 0.2 to 0.5 mm from the underlying layer to allow direct connections to be made. The screen-printed Ag grid was dried using hot air at 100 °C and IR radiation (30% intensity) for approximately 20 s. The active area of ​​each strip cell is 8.1 cm 2 (Width: 0.9cm and Length: 9cm) Approximately 162cm 2 yielding a total active module area of

[0156] The device characteristics of the module are shown in Figure 6, which shows the example current density (per cell area, not the total module area for comparison)-voltage characteristics of a single PV cell and a vertical module with 19 cells connected in series.

[0157] Only commercial solutions are used in the demonstration examples without modification, however, it should be understood that solutions such as conductive inks can be modified for enhanced channel formation properties by adding good solvents for the photoactive layer.

[0158] It should be understood that while the above disclosure and examples relate to opto-electrical devices, particularly photovoltaic devices, the present invention is applicable to many other solution-processed integrated multilayer thin film electronic devices, such as organic transistors, OLEDs, organic memories, and printed sensors, in which the differential orthogonal solubility of alternating material layers and selected layer patterning taught in the methods of the present invention can be utilized in a similar manner to form electrical interconnects between two spaced apart electrode layers within the multilayer structure.

[0159] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described, and it is understood that the invention includes all such variations and modifications that fall within the spirit and scope of the invention.

[0160] When the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims), they shall be interpreted as specifying the presence of a referenced feature, integer, step, or component, but not excluding the presence of one or more other features, integers, steps, components, or groups thereof. [Explanation of symbols]

[0161] 50 Conventional structure 60 Inverted structure 70 Multi-junction solar cells 100 Photoactive Devices 102 Electrical unit device connections 103 First Cell 104 Second Cell 105 Back electrode 110 Transparent electrode 115 Photoactive layer 120 Charge selective layer 130 Substrate 200 Photoactive Devices 202 Device connectivity 203 First Unit Device 204 Second Unit Device 205 Back electrode 205A Electrode Section 205B Electrode Section 210 Transparent electrode 210A Electrode Section 210B Electrode Section 215 Photoactive layer 220 Charge selective layer 220A Functionality Section 220B Functionality Section 230 Thin Film Substrate 235 Gap 300 designs 302 Arrow 320 design 322 Unit module or single cell 330 Devices 332 cells 400 devices 410 Module 420 Modular Design 505 Cell 510 Devices 515 Lattice 520 Devices 525 Lattice 530 devices 535 Lattice

Claims

1. 1. A method for forming electrode interconnections between at least two adjacent unit devices of an integrated multilayer thin-film electronic device, comprising the steps of: a first electrode layer on the thin film substrate, the first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; a first functional layer comprising a substantially continuous coating on the first electrode layer; and a second functional layer comprising a second patterned coating on the first functional layer comprising at least two spaced apart functional sections, each functional section positioned on the first functional layer and overlapping a portion of one of the first electrode sections to define a gap between adjacent functional sections comprising a portion of the first electrode section and the first functional layer. providing an intermediary device, depositing a second electrode layer on the second functional layer as a third patterned coating comprising at least two spaced apart second electrode sections of adjacent unit devices, each second electrode section positioned to overlap a portion of an adjacent interstitial portion comprising at least one functional section of the second functional layer and at least a portion of the first electrode section of an adjacent unit device, the third patterned coating being formed using a solution comprising a conductive species and at least a first solvent; Including, The method of claim 1, wherein the first functional layer is soluble in the first solvent and the second functional layer has low to zero solubility in the first solvent, such that attachment of the second electrode layer to the interstitial portion forms at least one conductive pathway through the first functional layer between the first electrode and the second electrode of adjacent unit devices.

2. The method of claim 1 , wherein the second functional layer has substantially low to zero solubility in the first solvent.

3. the first functional layer comprises a polar layer and the second functional layer comprises a non-polar layer; or The first functional layer comprises a non-polar layer and the second functional layer comprises a polar layer; The first solvent has the same polarity as the first functional layer. The method of claim 1.

4. The first solvent is DMF, DMSO, γ-butyrolactone, acetone, acetylacetone, ethyl acetoacetate, NMP, DMAC, THF, or combinations thereof; isopropanol, n-butanol, isobutanol, ethanol, methanol, acetic acid, ethylene glycol, propylene glycol, glycerol, allyl alcohol, propargyl alcohol, inositol, or combinations thereof; or benzene, toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, chloroform, dichloromethane, anisole, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, or combinations thereof The method of claim 1 , comprising:

5. 2. The method of claim 1, wherein the at least one conductive pathway between the first and second electrodes of adjacent unit devices comprises one or more micro- to nano-sized pathways, preferably one or more micro- to nano-sized channels through the first functional layer, and the at least one conductive pathway between the first and second electrode layers preferably comprises one or more defects in the first functional layer, preferably one or more pinhole defects through a thickness of the first functional layer, and preferably substantially all or all of the gap portions provide a conductive pathway between the first and second electrodes.

6. The intermediate device, at least one further functional layer between the first and second functional layers; or at least one further functional layer between the first electrode layer and the first functional layer; At least one of The method of claim 1 , wherein each of the further functional layers preferably comprises a patterned coating comprising at least two spaced apart second sections having a complementary configuration to the functional sections of the second functional layer.

7. The method of claim 1 , wherein the intermediary device includes at least one additional layer between the substrate and the first functional layer.

8. depositing a first electrode layer on a thin film substrate, the first electrode layer comprising a first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; depositing a first functional layer comprising a substantially continuous coating on the first electrode layer; applying a second functional layer including a second patterned coating to the first functional layer including at least two spaced apart functional sections, each functional section positioned on the first functional layer to overlap a portion of one of the first electrode sections to define a gap between adjacent functional sections that includes a portion of that first electrode section and the first functional layer; The method of claim 1 , further comprising forming the intermediary device by:

9. 2. The method of claim 1, wherein the first patterned coating comprises a plurality of spaced apart individual first electrode sections, each electrode section comprising a geometric shape arranged in a regular pattern on the thin film substrate, each electrode section preferably having the same shape.

10. The method of claim 1 , wherein the second patterned coating comprises a pattern that is complementary to the first patterned coating.

11. The method of claim 1 , wherein the interstitial portions between adjacent functional sections include only the first electrode layer and the first functional layer.

12. 2. The method of claim 1, wherein the first patterned coating and the second patterned coating comprise a plurality of spaced apart rectangular sections having a first longitudinal axis attached to a flexible strip having a second longitudinal axis aligned along a strip length, the rectangular sections being arranged on the flexible strip with the first longitudinal axis aligned perpendicular to the second longitudinal axis.

13. the third patterned coating comprising: a pattern complementary to said second patterned coating, and preferably said first patterned coating; or A grating, preferably formed from a regularly repeating geometric shape, said grating preferably formed from a series of spaced apart elements, preferably a plurality of spaced apart lines, the thickness of selected portions of elements within said grating preferably being thicker relative to the thickness of adjacent elements within said grating so as to generate selected indicia configurations within thicker elements of said grating. The method of claim 1 , comprising:

14. 14. The method of claim 13, wherein a color of the second electrode layer is selected to contrast with the colors of the first and second functional layers, preferably to produce high contrast lines relative to the colors of the first and second functional layers.

15. The method of claim 1 , wherein the thin film substrate comprises a flexible substrate or at least one of a polymer, a metal, a ceramic, or a glass, preferably a polymer coating.

16. 2. The method of claim 1, wherein the first functional layer comprises a photoactive layer, the photoactive layer preferably comprising at least one of one or more organic photovoltaic compounds, or one or more perovskite photoactive compounds.

17. 17. The method of any one of claims 16, wherein the second functional layer comprises a charge selective layer, the second electrode layer comprises a metallic electrode, preferably a silver electrode, formed using a solution comprising a metal or an ionic form of a metal and at least a first solvent, and the first electrode layer preferably comprises a transparent electrode layer.

18. The substrate is At least one coating of a transparent conductor layer; At least one hole transport layer comprising an organic or inorganic semiconductor; or At least one electron transport layer comprising an organic or inorganic conductor.

20. The method of claim 17, comprising one or more layers or coatings selected from at least one of:

19. a first electrode layer on the thin film substrate, the first patterned coating including at least two spaced apart first electrode sections of adjacent unit devices; a first functional layer comprising a substantially continuous coating on the first electrode layer; and a second functional layer comprising a second patterned coating on the first functional layer comprising at least two spaced apart functional sections, each functional section positioned on the first functional layer and overlapping a portion of one of the first electrode sections to define a gap portion between adjacent functional sections that includes a portion of the first electrode section and the first functional layer; and a second electrode layer on the second functional layer including a third patterned coating including at least two spaced apart second electrode sections of adjacent unit devices, each of the second electrode sections positioned such that at least one functional section of the second functional layer overlaps a portion of an adjacent gap portion including at least a portion of the first electrode section of an adjacent unit device; Each gap portion includes at least one conductive path through the first functional layer between the first electrode and the second electrode of adjacent unit devices. Integrated multilayer thin-film electronic devices.

20. 20. The device of claim 19, wherein the at least one conductive pathway between the first electrode and the second electrode comprises one or more micro- to nano-sized pathways, preferably one or more micro- to nano-sized channels through the first functional layer, and substantially all or all of the gap portions provide the conductive pathway between the first electrode and the second electrode.

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