Organic photovoltaic cell and preparation method thereof

Abstract

The present invention discloses an organic photovoltaic cell and a preparation method thereof. The preparation method comprises the following steps: S11, forming a transparent front electrode on a transparent substrate; S12, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode; S13, patterning the transition layer to form at least one isolation frame, each isolation frame defining a photovoltaic area; wherein, each frame edge of the isolation frame is set to be wide at the top and narrow at the bottom in the height direction; S14, forming an organic photovoltaic layer and a back electrode on the transparent substrate in sequence; S15, etching away the isolation frame; S16, forming an insulating layer on the transparent substrate and patterning it to expose a local transparent front electrode and a local back electrode. The preparation method of the present invention realizes mass production of organic photovoltaic cells, and does not require laser etching, but only uses chemical etching, which not only realizes that the gap between the obtained nodes is less than 5μm, which is much lower than the node gap of laser etching, but also has high etching efficiency and little effect on the organic photovoltaic layer.

Description

Technical Field

[0001] The invention relates to the technical field of organic photovoltaic cells, and in particular to an organic photovoltaic cell and a preparation method thereof. Background Art

[0002] In recent years, a new type of thin-film solar cell has attracted widespread attention, namely, organic solar cells. Compared with traditional solar cells, the main advantages of organic solar cells are simple process, low production cost and high conversion rate. At present, the organic solar cells that can be mass-produced are mainly single-cell organic solar cells. In the process of mass production of multi-cell organic solar cells, it is difficult to carry out patterning because the organic photovoltaic layer uses methods such as scraping and cannot use methods such as exposure. However, when mass-producing multi-cell organic solar cells, it is necessary to determine the area size and strictly control the position of the electrodes and the position of the nodes, etc. The commonly used method in the industry is to etch out the pattern through laser, but laser etching is not only inefficient, but also easily causes large gaps between nodes, wasting space, and the laser contains energy. During the etching process, this energy will damage the organic photovoltaic layer and thus affect the conversion efficiency and service life.

[0003] Furthermore, the stability of organic solar cells is the main reason that affects the long-term use of the cells. It is necessary to encapsulate the organic photovoltaic cells around them to protect the organic photovoltaic layer and prevent water vapor from invading. Among them, the existing conventional encapsulation materials are mostly polyolefins (POE) or ethylene vinyl acetate copolymers (EVA), but the permeability of the encapsulation materials to substances such as water vapor and oxygen is relatively high, which will penetrate more water vapor and oxygen and other substances, seriously affecting the power generation performance of organic photovoltaic cells and even causing the battery components to fail. Glass is also used for sealing, but this will further increase the thickness of the organic photovoltaic cells. Summary of the invention

[0004] In order to solve the technical problem described in the background technology, the present invention provides an organic photovoltaic cell and a preparation method thereof.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A method for preparing an organic photovoltaic cell comprises the following steps:

[0007] S11, forming a transparent electrode layer on a transparent substrate and patterning it to obtain a transparent front electrode;

[0008] S12, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode;

[0009] S13, patterning the transition layer to form at least one isolation frame, each isolation frame defining a photovoltaic region; wherein each frame edge of the isolation frame is configured to be wider at the top and narrower at the bottom in the height direction;

[0010] S14, sequentially forming an organic photovoltaic layer and a back electrode on the entire surface of the transparent substrate;

[0011] S15, etching away the isolation frame and the film layer formed on the isolation frame;

[0012] S16, forming an insulating layer on the transparent substrate to fill the vacancies exposed after etching the isolation frame, that is, to cover the entire surface on the transparent front electrode, the organic photovoltaic layer and the back electrode, and patterning the insulating layer to expose a partial transparent front electrode and a partial back electrode.

[0013] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the preparation method also includes the following steps: S17, forming an auxiliary metal layer on the insulating layer, and in the same photovoltaic region, the auxiliary metal layer connected to the local transparent front electrode and the auxiliary metal layer connected to the local back electrode are separated from each other; the local transparent front electrode and the local back electrode on adjacent photovoltaic regions are connected through the auxiliary metal layer to form a battery connected in series.

[0014] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, in step S16, the insulating layer is provided with a slope angle at the corner where the partial transparent front electrode is exposed, and the slope angle is less than 90°.

[0015] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the transition layer is an organic resin layer or an AZO layer.

[0016] A method for preparing an organic photovoltaic cell comprises the following steps:

[0017] S21, forming a transparent electrode layer on a transparent substrate and patterning it to obtain a transparent front electrode;

[0018] S22, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode;

[0019] S23, patterning the transition layer to expose a partial transparent front electrode and form at least one isolation frame, each isolation frame defining a photovoltaic region;

[0020] S24, forming an organic photovoltaic layer in the photovoltaic region by inkjet or silk screen printing;

[0021] S25, forming a back electrode in the photovoltaic region;

[0022] S26, forming an insulating layer on the transparent substrate and patterning it to expose a partial transparent front electrode and a partial back electrode.

[0023] A method for preparing an organic photovoltaic cell comprises the following steps:

[0024] S31, forming a transparent electrode layer on a transparent substrate and patterning it to obtain a transparent front electrode;

[0025] S32, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode;

[0026] S33, patterning the transition layer to expose a partial transparent front electrode and form at least one isolation frame, each isolation frame defining a photovoltaic region; wherein each frame edge of the isolation frame is configured to be wider at the top and narrower at the bottom in the height direction;

[0027] S34, forming an organic photovoltaic layer on the entire surface of the transparent substrate;

[0028] S35, forming a back electrode in the photovoltaic region;

[0029] S36, removing the organic photovoltaic layer in the non-photovoltaic area by using an organic layer etching solution;

[0030] S37, forming an insulating layer on the transparent substrate and patterning it to expose a partial transparent front electrode and a partial back electrode.

[0031] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the organic layer etching solution includes at least one of xylene, acetone, ethanol and water.

[0032] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the following step is also included between steps S36 and 37: a slope angle is set at the corner of the isolation frame where the partial transparent front electrode is exposed, and the slope angle is less than 90°.

[0033] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the preparation method also includes the following steps: forming an auxiliary metal layer on the insulating layer, and in the same photovoltaic region, the auxiliary metal layer connected to the local transparent front electrode and the auxiliary metal layer connected to the local back electrode are separated and arranged; connecting the local transparent front electrode and the local back electrode on adjacent photovoltaic regions through the auxiliary metal layer to form a battery connected in series.

[0034] As a preferred embodiment of the method for preparing the organic photovoltaic cell provided by the present invention, the preparation method further includes the following steps: the auxiliary metal layer is also covered with a metal oxide layer or an inert metal layer; and / or the auxiliary metal layer is also covered with a non-metallic protective layer.

[0035] An organic photovoltaic cell comprises a transparent substrate and at least one organic battery unit formed on the transparent substrate; each of the organic battery units comprises a transparent front electrode, an organic photovoltaic layer and a back electrode stacked in sequence; each of the organic battery units further comprises an encapsulation layer, the encapsulation layer comprises an insulating layer and an auxiliary metal layer; the insulating layer covers the organic photovoltaic layer, the back electrode and the transparent front electrode, and the insulating layer is patterned to expose a local transparent front electrode and a local back electrode; the auxiliary metal layer covers the insulating layer, and within the same organic battery unit, the auxiliary metal layer connected to the local transparent front electrode and the auxiliary metal layer connected to the local back electrode are separated; the local transparent front electrode and the local back electrode on adjacent organic battery units are connected via an auxiliary metal layer to form a battery connected in series.

[0036] As a preferred embodiment of the organic photovoltaic cell provided by the present invention, the auxiliary metal layer is further covered with a metal oxide layer or an inert metal layer; and / or the organic photovoltaic cell is further covered with a non-metallic protective layer, which covers all the organic battery units.

[0037] As a preferred embodiment of the organic photovoltaic cell provided by the present invention, the insulating layer is provided with a slope angle at the connection between the auxiliary metal layer and the local transparent front electrode, and the slope angle is less than 90°.

[0038] The present invention has the following beneficial effects:

[0039] In the preparation method of the organic photovoltaic cell of the present invention, before forming the organic photovoltaic layer, an insulating isolation frame is first formed, and its height is at least higher than the height of the back electrode to prevent the isolation frame from being covered or blocked, resulting in the isolation frame being unable to be exposed, and the problem that the isolation frame cannot be etched away in the subsequent process; at the same time, each frame side of the isolation frame is set to be wide at the top and narrow at the bottom in the height direction. If it is not a structure with wide at the top and narrow at the bottom, when the organic photovoltaic layer is formed on the entire surface through the coating process, it will cause the organic photovoltaic layer to cover the isolation frame that needs to be etched away in the subsequent process, and the effect of multiple organic battery units cannot be produced. Furthermore, the setting of wide at the top and narrow at the bottom The design can automatically separate the organic photovoltaic layer in the photovoltaic area and the non-photovoltaic area when the organic photovoltaic layer is formed on the entire surface. With this design, the organic photovoltaic layer can be formed on the entire surface, and then the isolation frame can be etched away, that is, the organic photovoltaic layer formed on the isolation frame is also etched away, and only the organic photovoltaic layer is retained in the photovoltaic area, thereby completing the patterning of the organic photovoltaic layer. This process does not require laser etching, but conventional chemical etching can be used. Not only can the gap between the obtained nodes be less than 5μm, which is much lower than the node gap of about 50μm or more by laser etching, but the etching efficiency is high and the effect on the organic photovoltaic layer is very small.

[0040] The encapsulation layer of the organic photovoltaic cell of the present invention is mainly matched with an insulating layer and an auxiliary metal layer, wherein the insulating layer as the first sealing layer not only plays a role in isolating water vapor, but also plays a role in isolating the auxiliary metal layer from the back electrode to prevent short circuit; the auxiliary metal layer can be used as both a functional layer and an insulating layer, i.e., a second sealing layer, which not only reduces the process steps (i.e., reduces the steps of making an additional functional layer), but also plays a role in further isolating water vapor. In the existing organic photovoltaic cells, in order to increase the transmittance of the transparent front electrode, its thickness is appropriately reduced, but its resistance is relatively large. The general practice is to make a large number of fine metal grids on the transparent front electrode to reduce the resistance, but the process precision is high and there is a risk of disconnection due to the smallness. The present invention uses the auxiliary metal layer as the second sealing layer as a functional layer, connected to the transparent front electrode, to reduce the resistance of the transparent front electrode without the need for a high-precision process, and also avoids the risk of disconnection, and at the same time helps to improve the conversion efficiency of the battery; furthermore, the auxiliary metal layer also plays a role in connecting adjacent organic battery cells in series, and further, the auxiliary metal layer can also be used as an electrode lead-out binding site. The encapsulation layer of the organic photovoltaic cell of the present invention mainly utilizes the combination of an insulating layer and an auxiliary metal layer, which solves the problem that the existing encapsulation layer has only a single functional encapsulation layer that isolates water and oxygen, and also avoids the problem that it is difficult to make thinner by using glass encapsulation, and also avoids the structural complexity and numerous steps of the existing multi-layer stacked encapsulation film layer technology. At the same time, the time interval between the completion of the organic photovoltaic cell substrate and the encapsulation is increased to prevent the organic photovoltaic cell from being stored for too long due to not being encapsulated in time, resulting in a decrease in efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a top view of the organic photovoltaic cell of the present invention;

[0042] Figure 2 for Figure 1 Sectional view at AA in the middle;

[0043] Figure 3 for Figure 1 Sectional view at the middle BB;

[0044] Figure 4 It is a schematic diagram of the process at AA in the method for preparing an organic photovoltaic cell in Example 3 of the present invention;

[0045] Figure 5 It is a schematic diagram of the process at BB in the method for preparing an organic photovoltaic cell in Example 3 of the present invention;

[0046] Figure 6 It is a schematic diagram of the process at AA in the method for preparing an organic photovoltaic cell in Example 4 of the present invention;

[0047] Figure 7 It is a schematic diagram of the process at BB in the method for preparing an organic photovoltaic cell in Example 4 of the present invention;

[0048] Figure 8 This is a schematic diagram of the process at AA in the method for preparing an organic photovoltaic cell in Example 5 of the present invention;

[0049] Fig. 9 This is a schematic diagram of the process at BB in the method for preparing an organic photovoltaic cell according to Example 5 of the present invention. DETAILED DESCRIPTION

[0050] The present invention is described in detail below with reference to the examples. The examples are only preferred embodiments of the present invention and are not intended to limit the present invention.

[0051] Example 1

[0052] like Figure 1As shown, this embodiment provides an organic photovoltaic cell, which includes a transparent substrate 1 and at least one organic battery unit 2 formed on the transparent substrate 1. In this embodiment, the at least one organic battery unit 2 is a single organic battery unit 2. Each of the organic battery units 2 includes a transparent front electrode 21, an organic photovoltaic layer 22 and a back electrode 23 stacked in sequence, wherein the organic photovoltaic layer 22 includes at least a HTL, an ATL and an ETL stacked in sequence, the HTL is a hole transport layer, the ATL is an active layer, which is a donor-acceptor mixed solution obtained by mixing a donor and an acceptor material in a certain proportion, and the ETL is an electron transport layer; each of the organic battery units 2 also includes an encapsulation layer 24 to protect the organic photovoltaic layer 22 from being corroded by water vapor. In this embodiment, the encapsulation layer 24 includes an insulating layer 241 and an auxiliary metal layer 242; wherein, the insulating layer 241 covers the organic photovoltaic layer 22, the back electrode 23 and the transparent front electrode 21, and the insulating layer 241 is patterned to expose the local transparent front electrode 211 and the local back electrode 231; the insulating layer 241 is preferably but not limited to an organic resin layer, which, as a first sealing layer, not only plays a role in isolating water vapor, but also plays a role in isolating the auxiliary metal layer 242 and the back electrode 23 to prevent short circuit; the auxiliary metal layer 242 covers the insulating layer 241 and exposes the local back electrode 231 for leading out the negative electrode, and the auxiliary metal layer 242 is connected to the local transparent front electrode 211. In this embodiment, the auxiliary metal layer 242 as the second sealing layer is used as a functional layer and connected to the transparent front electrode 21, which not only reduces the resistance of the transparent front electrode 21, but also helps to improve the conversion efficiency of the battery without the need for high-precision process, but also avoids the hidden danger of disconnection and improves stability.

[0053] Furthermore, the auxiliary metal layer 242 is also covered with a metal oxide layer or an inert metal layer to protect the auxiliary metal layer 242. The auxiliary metal layer 242 is preferably, but not limited to, a metal layer such as Al, Mo, etc.

[0054] The transparent substrate may be glass, polyethylene terephthalate (PET) film, PON (polyethylene naphthoate) film, PP (polypropylene) film, PI (polyimide) film, PI (polyimide) film or triacetyl cellulose (TAC) film, but is not limited thereto.

[0055] Furthermore, the organic photovoltaic cell also includes a non-metallic protective layer 243, which covers all the organic battery cells 2. The non-metallic layer can be selected from non-metallic sealing layers such as SiNx and SiO2. The non-metallic protective layer 243 is used as a third sealing layer, and its main function is to prevent the auxiliary metal layer 242 from being corroded and to further isolate the entire organic photovoltaic cell from oxygen and water vapor, thereby improving the stability of the device. As other embodiments, the non-metallic layer can also be selected from an organic resin layer or a combination layer of multiple organic or inorganic non-metallic layers, or a conventional encapsulation film layer.

[0056] Furthermore, the insulating layer 241 is provided with a slope angle 2411 at the connection between the auxiliary metal layer 242 and the local transparent front electrode 211. The slope angle 2411 refers to an obtuse angle relationship formed between the surface of the insulating layer 241 in contact with the transparent front electrode 21 and the surface of the transparent front electrode 21, that is, the slope angle a is less than 90°. Such a design can prevent the auxiliary metal layer 242 from breaking at the corner during film formation, thereby avoiding the problem of poor connection caused by breaking.

[0057] It should be noted that Figure 1 The exposed position of the partial back electrode shown in the figure is not limited to that shown in the figure, but can be other positions, and the size of the exposed area also depends on the specific situation. Because the auxiliary metal layer is a little reflective, the color of the metal reflection can be seen from the transparent front electrode through the gap between the sections, so it is preferred to set the exposed position of the partial back electrode at the edge, that is, the corner, so that the influence of the reflection becomes very small.

[0058] Example 2

[0059] like Figure 1-3 As shown, this embodiment is based on the embodiment 1, and is different from the embodiment 1 in that: the at least one organic battery unit 2 includes more than two organic battery units 2, that is, the organic photovoltaic cell of this embodiment is composed of multiple organic battery units 2 connected. Further, the adjacent organic battery units 2 are connected in series through the auxiliary metal layer 242. It can be understood that the auxiliary metal layer 242 is covered on the insulating layer 241. In the same organic battery unit 2, the auxiliary metal layer 242 connected to the local transparent front electrode 211 and the auxiliary metal layer 242 connected to the local back electrode 231 are separated, that is, the two are insulated; the local transparent front electrode 211 and the local back electrode 231 on the adjacent organic battery units 2 are connected through the same auxiliary metal layer 242 to form a battery connected in series.

[0060] It is worth noting that the connection between the adjacent organic battery cells 2 can be completed when the auxiliary metal layer 242 is formed, that is, when the auxiliary metal layer 242 is formed, the auxiliary metal layer 242 of the previous organic battery cell 2 is connected to the transparent front electrode 21, and this auxiliary metal layer 242 is then connected to the exposed back electrode 23 of the next organic battery cell 2, thereby realizing the mutual connection between the positive electrode of the previous section and the negative electrode of the next section.

[0061] The auxiliary metal layer 242 of this embodiment not only serves as a second sealing layer to further effectively isolate water vapor, but also serves as a functional layer, connected to the transparent front electrode 21 to reduce the resistance of the transparent front electrode 21, which helps to improve the conversion efficiency of the battery without the need for high-precision process and avoids the risk of disconnection; at the same time, the auxiliary metal layer 242 also serves as a series connection between adjacent organic battery cells 2, and further, the auxiliary metal layer 242 can also serve as an electrode lead-out binding site. In this way, this embodiment cleverly combines the auxiliary metal layer 242 with the insulating layer 241 to form a sealing layer to effectively isolate water vapor, and at the same time uses the auxiliary metal layer 242 as a functional layer, so that when making the transparent front electrode 21, it is not necessary to use a high-precision process to obtain a fine metal grid, reducing process requirements and improving yield.

[0062] Example 3

[0063] like Figure 4 , 5 As shown, this embodiment provides a method for preparing an organic photovoltaic cell, which comprises the following steps:

[0064] S11, forming a transparent electrode layer on the transparent substrate 1 and patterning it to obtain a transparent front electrode 21, such as Figure 4 a, as shown in 5a.

[0065] The transparent front electrode 21 can be made of ITO, FTO, AZO, or transparent high-conductivity materials such as conductive polymers or graphene. The transparent electrode layer can be formed by PVD vacuum sputtering and other equipment; then the transparent electrode layer is patterned by yellow light etching to obtain the transparent front electrode 21 pattern.

[0066] S12, forming a transition layer on the transparent substrate 1, the top of which is at least higher than the top of the back electrode 23;

[0067] S13, patterning the transition layer to form a plurality of isolation frames 25, each of which defines a photovoltaic region 3; wherein each frame edge of the isolation frame 25 is configured to be wide at the top and narrow at the bottom in the height direction, such as Figure 4 b, as shown in 5b.

[0068] In this embodiment, the transition layer is an organic resin layer, such as photoresist, or other insulating materials that can be etched; the transition layer can also be other metal oxides such as AZO, and the subsequent process can be etched away by acid etching liquids such as lactic acid without simultaneously etching the transparent front electrode 21. Specifically, an organic resin layer can be formed on the transparent front electrode 21 by equipment such as scraping, spin coating or silk screen printing, and then patterned to form a plurality of isolation frames, each of which defines a photovoltaic region 3; wherein the top of the isolation frame is at least higher than the top of the back electrode 23, so as to prevent the isolation frame from being covered or blocked, resulting in the isolation frame being unable to be exposed, and the problem that the subsequent process cannot be etched away.

[0069] Each frame side of the isolation frame is set to be wide at the top and narrow at the bottom in the height direction. It can be understood that the longitudinal section of the isolation frame in the width direction is a structure that is wide at the top and narrow at the bottom, such as an inverted trapezoid or an umbrella shape. If it is not a structure that is wide at the top and narrow at the bottom, when the organic photovoltaic layer 22 or the back electrode 23 is formed on the entire surface by the coating process, the organic photovoltaic layer 22 will cover the isolation frame that needs to be etched away in the subsequent process, and the effect of multiple organic battery cells 2 cannot be achieved. The design of wide at the top and narrow at the bottom can automatically separate the organic photovoltaic layer in the photovoltaic area 3 from the non-photovoltaic area when the organic photovoltaic layer is formed on the entire surface.

[0070] It should be noted that part of the non-photovoltaic area can be covered by the transition layer. In order to facilitate intuitive display of the schematic diagram, not all non-photovoltaic areas are shown in the schematic diagram.

[0071] S14 , forming an organic photovoltaic layer 22 on the entire surface of the transparent substrate 1 and forming a back electrode 23 on the organic photovoltaic layer 22 at least in the photovoltaic region 3 .

[0072] like Figure 4 As shown in Fig. 5c, the HTL layer, the ATL layer and the ETL layer are sequentially scraped on the entire surface of the transparent substrate 1. It should be noted that in addition to scraping, spraying, screen printing, inkjet printing and other methods can also be used. Since the organic photovoltaic layer 22 cannot be exposed, it is difficult to make a pattern. It is understandable that due to the process of scraping the entire surface, the photovoltaic area 3 and the non-photovoltaic area including the isolation frame have an organic photovoltaic layer 22.

[0073] like Figure 4 As shown in d and 5d, after the organic photovoltaic layer 22 is made, the back electrode 23 is plated by evaporation or sputtering. If evaporation is used, the pattern is made directly by using a mask plate so that the back electrode 23 is only formed in the photovoltaic area 3; if sputtering is used, after the electrode layer is formed, it is necessary to use yellow light exposure to develop the pattern, and then further acid etching is performed to obtain the back electrode 23 only in the photovoltaic area 3. The back electrode can also be formed on the entire surface, and then the back electrode on the isolation frame is removed synchronously when etching the isolation frame.

[0074] It is worth noting that after the organic photovoltaic layer 22 and the back electrode 23 are manufactured, the isolation frame can be exposed so as to be subsequently etched away by an etching solution.

[0075] S15, etching away the isolation frame 25 and the film layer formed on the isolation frame 25, such as Figure 4 e, as shown in 5e.

[0076] The isolation frame 25 is etched away to etch away the isolation frame 25 and at least the organic photovoltaic layer 22 thereon, thereby exposing the partial transparent front electrode 211 and simultaneously etching away the organic photovoltaic layer 22 in the non-photovoltaic region. Specifically, a demolding liquid is used to remove the photoresist isolation frame and the organic photovoltaic layer 22 thereon.

[0077] S16, forming an insulating layer 241 on the transparent substrate 1 to fill the vacant space after etching the isolation frame 25, that is, the entire surface covers the transparent front electrode, the organic photovoltaic layer and the back electrode; and patterning the insulating layer 241 to expose the partial transparent front electrode 211 and the partial back electrode 231, such as Figure 4 f, as shown in 5f.

[0078] The insulating layer 241 is preferably, but not limited to, an organic resin layer. After the organic resin layer is coated, it is patterned to expose a partial transparent front electrode 211 and a partial back electrode 231 .

[0079] The isolation frame is etched away, and then an organic resin layer is formed. The shape and position of the organic resin layer actually replaces the isolation frame. It can be understood that the organic resin layer is also a structure that is wide at the top and narrow at the bottom, such as an inverted trapezoid. When the auxiliary metal layer 242 is formed, it is easy to break at the corner where it contacts the transparent front electrode 21, resulting in poor connection. In order to solve this problem, the inventors set the insulating layer 241 with a slope angle 2411 at the corner where the partial transparent front electrode 211 is exposed, such as Figure 4 As shown in 5f, the slope angle 2411 refers to the obtuse angle relationship formed between the surface of the insulating layer 241 in contact with the transparent front electrode 21 and the surface of the transparent front electrode 21, such as Figure 4 f, that is, the slope angle a is less than 90°. It can be understood that the inverted trapezoidal structure is supplemented with a side less than 90°. Such a design can prevent the auxiliary metal layer 242 from breaking at the corner during film formation, thereby avoiding the problem of poor connection caused by breaking, and preventing short circuits of the positive and negative electrodes.

[0080] S17, forming an auxiliary metal layer 242 on the insulating layer 241, wherein in the same organic battery unit 2, the auxiliary metal layer 242 connected to the local transparent front electrode 211 and the auxiliary metal layer 242 connected to the local back electrode 231 are separated and arranged; the local transparent front electrode 211 and the local back electrode 231 on the adjacent organic battery units 2 are connected through the auxiliary metal layer to form batteries connected in series, such as Figure 4 g, as shown in 5g.

[0081] The auxiliary metal layer 242 is preferably but not limited to a metal material such as Al, Mo, etc. Specifically, the auxiliary metal layer 242 is deposited on the insulating layer 241 by vacuum sputtering.

[0082] Furthermore, the adjacent organic battery cells 2 are connected in series through the auxiliary metal layer 242. It is worth noting that the connection between the adjacent organic battery cells 2 can be completed when the auxiliary metal layer 242 is formed, that is, when the auxiliary metal layer 242 is formed, the auxiliary metal layer 242 of the previous organic battery cell 2 is connected to the transparent front electrode 21, and this auxiliary metal layer 242 is then connected to the exposed back electrode 23 of the next organic battery cell 2, so that the positive electrode of the previous section and the negative electrode of the next section are connected to each other, such as Figure 4 Therefore, the auxiliary metal layer 242 not only connects the positive electrode of one battery to the negative electrode of another battery to connect the batteries of different sections, but also plays an insulating and protective role to further prevent water vapor, oxygen, etc. from affecting the organic photovoltaic layer 22.

[0083] The auxiliary metal layer 242 of the present embodiment not only serves as a second sealing layer to further effectively isolate water vapor, but also serves as a functional layer, connected to the transparent front electrode 21 to reduce the resistance of the transparent front electrode 21, which helps to improve the conversion efficiency of the battery without the need for high-precision process and avoids the risk of disconnection. At the same time, the auxiliary metal layer 242 also serves as a series connection between adjacent organic battery cells 2. Furthermore, the auxiliary metal layer 242 can also serve as a lead-out binding site for the electrode.

[0084] The method for preparing the organic photovoltaic cell further includes the following steps: a metal oxide layer or an inert metal layer is formed on the auxiliary metal layer 242 to protect the auxiliary metal layer 242 from corrosion.

[0085] The method for preparing the organic photovoltaic cell further comprises the following steps: Figure 4As shown in Figures 5h and 5h, a non-metallic protective layer 243 is formed on the auxiliary metal layer 242. The material of the non-metallic protective layer 243 can be non-metallic films such as SiNx and SiO2, or a conventional packaging film layer. As the third sealing layer, it can protect the entire organic photovoltaic cell and further enhance the water- and oxygen-isolating effect, while also preventing the auxiliary metal layer 242 from being corroded.

[0086] Example 4

[0087] like Figure 6 , 7 As shown, this embodiment provides a method for preparing an organic photovoltaic cell, which comprises the following steps:

[0088] S21, forming a transparent electrode layer on the transparent substrate 1 and patterning it to obtain a transparent front electrode 21, such as Figure 6 a, as shown in 7a.

[0089] The transparent front electrode 21 can be made of ITO, FTO, AZO, or transparent high-conductivity materials such as conductive polymers or graphene. The transparent electrode layer can be formed by PVD vacuum sputtering and other equipment; then the transparent electrode layer is patterned by yellow light etching to obtain the transparent front electrode 21 pattern.

[0090] S22, forming a transition layer on the transparent substrate 1, the top of which is at least higher than the top of the back electrode 23;

[0091] S23, patterning the transition layer to expose the partially transparent front electrode 211 and form a plurality of isolation frames 25, each of which defines a photovoltaic region 3, such as Figure 6 b, as shown in 7b.

[0092] The transition layer in this embodiment is an organic resin layer, such as photoresist, or other insulating materials; specifically, an organic resin layer can be formed on the transparent front electrode 21 by means of equipment such as scraping, spin coating or silk screen printing, and then patterned to expose the local transparent front electrode and form a plurality of isolation frames, each of which defines a photovoltaic region 3; wherein the top of the isolation frame is at least higher than the top of the back electrode 23, so as to prevent the problem that the organic photovoltaic layer and the back electrode are higher than the isolation frame and exposed during production.

[0093] Preferably, the longitudinal section of the isolation frame in the width direction can be set to a bowl shape, and the slope angle 2411 on both sides of the isolation frame is greater than 90 degrees. Such a design can prevent the auxiliary metal layer 242 from breaking at the corner (slope angle 2411) during film formation, thereby avoiding the problem of poor connection caused by breaking, and preventing short circuit between the positive and negative poles.

[0094] S24, forming an organic photovoltaic layer 22 in the photovoltaic region 3 by inkjet or silk screen printing, such as Figure 6 c, as shown in 7c;

[0095] Specifically, HTL, ATL and ETL are accurately formed in sequence in the photovoltaic region 3 by inkjet printing or silk screen printing. The inkjet printing or silk screen printing method can better control the amount of each layer of solution to make an organic photovoltaic layer 22 with uniform thickness; and the step of etching the isolation frame used in Example 3 can be omitted, and the chemical reagents such as the demolding liquid used for etching the isolation frame can be avoided. React with the activity of the organic photovoltaic layer 22 in the photovoltaic region 3, thereby affecting the ability to give or absorb electrons and the photoelectric conversion efficiency.

[0096] S25, forming a back electrode 23 in the photovoltaic region 3, such as Figure 6 d, as shown in 7d.

[0097] After the organic photovoltaic layer 22 is formed, the back electrode 23 is plated by evaporation or sputtering. If evaporation is used, a mask is directly used to make a pattern so that the back electrode 23 is only formed in the photovoltaic area 3; if sputtering is used, after the electrode layer is formed, it is necessary to use yellow light exposure to develop the pattern, and then further acid etching is performed to obtain the back electrode 23 only in the photovoltaic area 3.

[0098] S26, forming an insulating layer 241 on the transparent substrate 1 and patterning the insulating layer 241 to expose a partial transparent front electrode 211 and a partial back electrode 231, as shown in FIG. Figure 6 e, as shown in 7e.

[0099] It is understandable that the insulating layer 241 includes but is not limited to an organic resin layer. The isolation frame 25 and the insulating layer 241 constitute a first sealing layer. In this step, the insulating layer 24 can be formed on the entire surface and then patterned to cover the back electrode in the photovoltaic area 3 and expose the local transparent front electrode and the local back electrode; it can also be formed in a specific area, that is, the insulating layer is formed only in the photovoltaic area 3, and then patterned to expose the local back electrode. In specific implementation, the method of forming the insulating layer can be selected according to actual conditions.

[0100] S27, forming an auxiliary metal layer 242 on the insulating layer 241, wherein in the same organic battery unit 2, the auxiliary metal layer 242 connected to the local transparent front electrode 211 and the auxiliary metal layer 242 connected to the local back electrode 231 are separated and arranged; the local transparent front electrode 211 and the local back electrode 231 on the adjacent organic battery units 2 are connected through the auxiliary metal layer to form batteries connected in series, such as Figure 6 f, as shown in 7f.

[0101] The auxiliary metal layer 242 is preferably but not limited to a metal material such as Al, Mo, etc. Specifically, the auxiliary metal layer 242 is deposited on the insulating layer 241 by vacuum sputtering.

[0102] Furthermore, the adjacent organic battery cells 2 are connected in series through the auxiliary metal layer 242. It is worth noting that the connection between the adjacent organic battery cells 2 can be completed when the auxiliary metal layer 242 is formed, that is, when the auxiliary metal layer 242 is formed, the auxiliary metal layer 242 of the previous organic battery cell 2 is connected to the transparent front electrode 21, and this auxiliary metal layer 242 is then connected to the exposed back electrode 23 of the next organic battery cell 2, so that the positive electrode of the previous section and the negative electrode of the next section are connected to each other, such as Figure 6 Therefore, the auxiliary metal layer 242 not only connects the positive electrode of one battery to the negative electrode of another battery to connect the batteries of different sections, but also plays an insulating and protective role to further prevent the influence of water vapor, oxygen, etc. on the organic photovoltaic layer 22.

[0103] The auxiliary metal layer 242 of the present embodiment not only serves as a second sealing layer to further effectively isolate water vapor, but also serves as a functional layer, connected to the transparent front electrode 21 to reduce the resistance of the transparent front electrode 21, which helps to improve the conversion efficiency of the battery without the need for high-precision process and avoids the risk of disconnection. At the same time, the auxiliary metal layer 242 also serves as a series connection between adjacent organic battery cells 2. Furthermore, the auxiliary metal layer 242 can also serve as a lead-out binding site for the electrode.

[0104] The method for preparing the organic photovoltaic cell further includes the following steps: a metal oxide layer or an inert metal layer is formed on the auxiliary metal layer 242 to protect the auxiliary metal layer 242 from corrosion.

[0105] The method for preparing the organic photovoltaic cell further comprises the following steps: Figure 6 As shown in g and 7g, a non-metallic protective layer 243 is formed on the auxiliary metal layer 242. The material of the non-metallic protective layer 243 can be non-metallic films such as SiNx and SiO2, or a conventional packaging film layer. As the third sealing layer, it can protect the entire organic photovoltaic cell and further enhance the water- and oxygen-isolating effect, while also preventing the auxiliary metal layer 242 from being corroded.

[0106] Example 5

[0107] like Figure 8 , 9 As shown, this embodiment provides a method for preparing an organic photovoltaic cell, which comprises the following steps:

[0108] S31, forming a transparent electrode layer on the transparent substrate 1 and patterning it to obtain a transparent front electrode 21, such as Figure 8 a, as shown in 9a.

[0109] The transparent front electrode 21 can be made of ITO, FTO, AZO, or transparent high-conductivity materials such as conductive polymers or graphene. The transparent electrode layer can be formed by PVD vacuum sputtering and other equipment; then the transparent electrode layer is patterned by yellow light etching to obtain the transparent front electrode 21 pattern.

[0110] S32, forming a transition layer on the transparent substrate 1, the top of which is at least higher than the top of the back electrode 23;

[0111] S33, patterning the transition layer to expose the partially transparent front electrode 211 and form a plurality of isolation frames 25, each of which defines a photovoltaic region 3, wherein each frame side of the isolation frame 25 is configured to be wide at the top and narrow at the bottom in the height direction, such as Figure 8 b, as shown in 9b.

[0112] In this embodiment, the transition layer is an organic resin layer, such as photoresist, or other insulating materials; specifically, an organic resin layer can be formed on the transparent front electrode 21 by equipment such as scraping, spin coating or silk screen printing, and then patterned to expose the local transparent front electrode and form a plurality of isolation frames 25, each of which defines a photovoltaic region 3. Each frame edge of the isolation frame 25 is set to be wide at the top and narrow at the bottom in the height direction. It can be understood that the longitudinal section of the isolation frame in the width direction is an inverted trapezoidal or umbrella-shaped structure that is wide at the top and narrow at the bottom. The top of the isolation frame is at least higher than the top of the back electrode 23, and the organic photovoltaic layer 22 can be formed on the entire surface through the design of wide at the top and narrow at the bottom to automatically separate the photovoltaic region 3 from the organic photovoltaic layer in the non-photovoltaic region.

[0113] S34, forming an organic photovoltaic layer 22 on the entire surface of the transparent substrate 1, such as Figure 8 c, as shown in 9c;

[0114] like Figure 8 As shown in Figs. c and 9c, the HTL layer, the ATL layer and the ETL layer are sequentially scraped on the entire surface of the transparent substrate 1. It should be noted that, in addition to scraping, other methods such as spin coating, spraying, screen printing, and inkjet printing can also be used. It can be understood that due to the process of scraping the entire surface, the organic photovoltaic layer 22 is present in the photovoltaic area 3 and on the non-photovoltaic area including the isolation frame.

[0115] S35, forming a back electrode in the photovoltaic region 3, such as Figure 8 d, as shown in 9d.

[0116] After the organic photovoltaic layer 22 is formed, the back electrode 23 is plated by evaporation or sputtering. If evaporation is used, a mask is directly used to make a pattern so that the back electrode 23 is only formed in the photovoltaic area 3; if sputtering is used, after the electrode layer is formed, it is necessary to use yellow light exposure to develop the pattern, and then further acid etching is performed to obtain the back electrode 23 only in the photovoltaic area 3.

[0117] S36, removing the organic photovoltaic layer in the non-photovoltaic area by using an organic layer etching solution, such as Figure 8 e, as shown in 9e.

[0118] The isolation frame 25 and the back electrode 23 have wrapped the effective organic photovoltaic layer (i.e., the organic photovoltaic layer in the photovoltaic region 3 is protected), and the organic photovoltaic layer in the unwrapped area (i.e., the non-photovoltaic region) can be removed by soaking or spraying with an organic layer etching liquid, such as at least one of but not limited to xylene, acetone, ethanol, and water (i.e., removing the HTL layer, the ATL layer, and the ETL layer), thereby achieving a patterned organic photovoltaic layer without affecting the organic photovoltaic layer in the photovoltaic region 3. In this way, the step of etching the isolation frame used in Example 3 can be omitted, and the chemical reagents such as the demoulding liquid used to etch the isolation frame can be avoided from reacting with the activity of the organic photovoltaic layer 22 in the photovoltaic region 3, thereby affecting the ability to give or absorb electrons and the photoelectric conversion efficiency.

[0119] In some embodiments, the ETL layer and the ATL layer can be removed by acetone, and then the HTL layer can be removed by water or ethanol; in other embodiments, the ETL layer and the ATL layer can be removed by acetone + xylene mixture, and then the HTL layer can be removed by water. It is worth noting that the removal method and etching solution of the organic photovoltaic layer are not limited to this.

[0120] S37, forming an insulating layer 241 on the transparent substrate 1 and patterning the insulating layer 241 to expose a partial transparent front electrode 211 and a partial back electrode 231, as shown in FIG. Figure 8 g, as shown in 9g.

[0121] It is understandable that the insulating layer 241 includes but is not limited to an organic resin layer. The isolation frame 25 and the insulating layer 241 constitute a first sealing layer. In this step, the insulating layer 24 can be formed on the entire surface and then patterned to cover the back electrode in the photovoltaic area 3 and expose the local transparent front electrode and the local back electrode; it can also be formed in a specific area, that is, the insulating layer is formed only in the photovoltaic area 3, and then patterned to expose the local back electrode. In specific implementation, the method of forming the insulating layer can be selected according to actual conditions.

[0122] Since the isolation frame 25 is a structure that is wide at the top and narrow at the bottom, when the auxiliary metal layer 242 is subsequently formed, it is easy to break at the corner where it contacts the transparent front electrode 21, resulting in poor connection. In order to solve this problem, the inventors set a slope angle 2411 at the corner of the isolation frame 25 that exposes the partial transparent front electrode 211, such as Figure 8 As shown in FIG. 9f, the slope angle 2411 refers to the obtuse angle relationship formed between the surface of the insulating layer 241 in contact with the transparent front electrode 21 and the surface of the transparent front electrode 21, such as Figure 8 f, that is, the slope angle a is less than 90°. It can be understood that the inverted trapezoidal structure is supplemented with a side less than 90°. Such a design can prevent the auxiliary metal layer 242 from breaking at the corner during film formation, thereby avoiding the problem of poor connection caused by breaking.

[0123] S38, forming an auxiliary metal layer 242 on the insulating layer 241, wherein in the same organic battery unit 2, the auxiliary metal layer 242 connected to the local transparent front electrode 211 and the auxiliary metal layer 242 connected to the local back electrode 231 are separated and arranged; the local transparent front electrode 211 and the local back electrode 231 on the adjacent organic battery units 2 are connected through the auxiliary metal layer to form batteries connected in series, such as Figure 8 h, as shown in 9h.

[0124] The auxiliary metal layer 242 is preferably but not limited to a metal material such as Al, Mo, etc. Specifically, the auxiliary metal layer 242 is deposited on the insulating layer 241 by vacuum sputtering.

[0125] Furthermore, the adjacent organic battery cells 2 are connected in series through the auxiliary metal layer 242. It is worth noting that the connection between the adjacent organic battery cells 2 can be completed when the auxiliary metal layer 242 is formed, that is, when the auxiliary metal layer 242 is formed, the auxiliary metal layer 242 of the previous organic battery cell 2 is connected to the transparent front electrode 21, and this auxiliary metal layer 242 is then connected to the exposed back electrode 23 of the next organic battery cell 2, so that the positive electrode of the previous section and the negative electrode of the next section are connected to each other, such as Figure 8 Therefore, the auxiliary metal layer 242 not only connects the positive electrode of one battery to the negative electrode of another battery to connect the batteries of different sections, but also plays an insulating and protective role to further prevent the influence of water vapor, oxygen, etc. on the organic photovoltaic layer 22.

[0126] The auxiliary metal layer 242 of the present embodiment not only serves as a second sealing layer to further effectively isolate water vapor, but also serves as a functional layer, connected to the transparent front electrode 21 to reduce the resistance of the transparent front electrode 21, which helps to improve the conversion efficiency of the battery without the need for high-precision process and avoids the risk of disconnection. At the same time, the auxiliary metal layer 242 also serves as a series connection between adjacent organic battery cells 2. Furthermore, the auxiliary metal layer 242 can also serve as a lead-out binding site for the electrode.

[0127] The method for preparing the organic photovoltaic cell further includes the following steps: a metal oxide layer or an inert metal layer is formed on the auxiliary metal layer 242 to protect the auxiliary metal layer 242 from corrosion.

[0128] The method for preparing the organic photovoltaic cell further comprises the following steps: Figure 8 As shown in i and 9i, a non-metallic protective layer 243 is formed on the auxiliary metal layer 242. The material of the non-metallic protective layer 243 can be non-metallic films such as SiNx and SiO2, or a conventional packaging film layer. As the third sealing layer, it can protect the entire organic photovoltaic cell and further enhance the water- and oxygen-isolating effect, while also preventing the auxiliary metal layer 242 from being corroded.

[0129] The above-mentioned embodiments merely express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. Any technical solution obtained in the form of equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

Claims

1. A method for preparing an organic photovoltaic cell, characterized in that: It includes the following steps: S21, forming a transparent electrode layer on a transparent substrate and patterning it to obtain a transparent front electrode; S22, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode; S23, patterning the transition layer to expose a partial transparent front electrode and form at least one isolation frame, each isolation frame defining a photovoltaic region; S24, forming an organic photovoltaic layer in the photovoltaic region by inkjet or silk screen printing; S25, forming a back electrode in the photovoltaic region; S26, forming an insulating layer on the transparent substrate and patterning it to expose a partial transparent front electrode and a partial back electrode, wherein the isolation frame and the insulating layer form a first sealing layer; S27. An auxiliary metal layer is formed on the insulating layer. In the same photovoltaic region, the auxiliary metal layer connected to the local transparent front electrode and the auxiliary metal layer connected to the local back electrode are separated from each other; the local transparent front electrode and the local back electrode on adjacent photovoltaic regions are connected through the auxiliary metal layer to form batteries connected in series.

2. A method for preparing an organic photovoltaic cell, characterized in that: It includes the following steps: S31, forming a transparent electrode layer on a transparent substrate and patterning it to obtain a transparent front electrode; S32, forming a transition layer on the transparent substrate, the top of which is at least higher than the top of the back electrode; S33, patterning the transition layer to expose a partial transparent front electrode and form at least one isolation frame, each isolation frame defining a photovoltaic region; wherein each frame edge of the isolation frame is configured to be wider at the top and narrower at the bottom in the height direction; S34, forming an organic photovoltaic layer on the entire surface of the transparent substrate; S35, forming a back electrode in the photovoltaic region; S36, removing the organic photovoltaic layer in the non-photovoltaic area by using an organic layer etching solution, wherein the organic layer etching solution includes at least one of xylene, acetone, ethanol and water; S37, setting a slope angle at the corner of the isolation frame exposing the partial transparent front electrode, the slope angle is less than 90°, forming an insulating layer on the transparent substrate and patterning it to expose the partial transparent front electrode and the partial back electrode, the isolation frame and the insulating layer constitute a first sealing layer; S38. An auxiliary metal layer is formed on the insulating layer. In the same photovoltaic region, the auxiliary metal layer connected to the local transparent front electrode and the auxiliary metal layer connected to the local back electrode are separated from each other; the local transparent front electrode and the local back electrode on adjacent photovoltaic regions are connected through the auxiliary metal layer to form batteries connected in series.

3. The method for preparing an organic photovoltaic cell according to claim 1 or 2, characterized in that: The preparation method further comprises the following steps: the auxiliary metal layer is also covered with a metal oxide layer or an inert metal layer; or the auxiliary metal layer is also covered with a non-metallic protective layer.

4. An organic photovoltaic cell, characterized in that: Prepared by any method of claims 1 to 3.

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