A solar cell device and a method for fabricating the same
By designing a transparent front electrode lead-out electrode structure and an insulating microstructure in solar cell devices, the problem of efficiency degradation caused by the high resistivity of the transparent front electrode was solved, achieving high-efficiency photoelectric conversion of large-area devices and promoting the industrial application of organic and perovskite solar cells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TRULY SEMICON
- Filing Date
- 2026-03-20
- Publication Date
- 2026-07-10
AI Technical Summary
Existing organic and perovskite solar cells exhibit a sharp decline in efficiency as their area increases. The high resistivity of the transparent front electrode leads to significant resistance to carrier transport, hindering rapid carrier extraction. Furthermore, the photosensitive materials are environmentally sensitive, limiting their large-scale application.
A transparent front electrode lead-out electrode structure was designed. By setting vias that penetrate to the surface of the transparent front electrode on the second insulating layer, the metal back electrode, and the photoelectric conversion structure layer, the front electrode lead-out electrode extends into the vias and is electrically connected to the transparent front electrode, while being electrically isolated from the metal back electrode and the photoelectric conversion structure layer. An insulating columnar microstructure or porous structure is used to reduce the equivalent resistance of the transparent front electrode.
It effectively solves the problems of resistance dissipation and recombination failure when charge carriers are transported in a high resistivity transparent front electrode, improves the photoelectric conversion efficiency of large-area devices, and provides a technical path for the industrial production of organic solar cells and perovskite solar cells.
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Figure CN122373586A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solar cell technology, and in particular to a solar cell device and its fabrication method. Background Technology
[0002] Among various low-carbon power generation methods, solar energy is considered to have significant advantages due to its environmental performance. Currently, first-generation crystalline silicon and amorphous silicon solar cells are still the mainstream technologies, while third-generation solar cells, although promising, have not yet achieved large-scale industrial application.
[0003] In recent years, the power generation efficiency of organic photovoltaic (OPV) and perovskite solar cells (PSC) has been continuously improving in the laboratory. However, these technologies face a common key problem: when the area of a single device increases to more than one square centimeter, the efficiency drops sharply. The fundamental reason for this phenomenon is that the device structure of these two types of solar cells must use a transparent conductive oxide (TCO) with high resistivity as the transparent front electrode. When photogenerated carriers need to be transported in a large area of high-resistivity transparent electrode, a large transport resistance is generated, causing the carriers to be unable to be quickly discharged, resulting in recombination quenching failure within the device, thus significantly reducing the power generation efficiency.
[0004] While amorphous silicon solar cells can address this issue using traditional photolithography processes, the photosensitive materials in OPV and PSC are extremely sensitive to moisture and oxygen in the environment, and will rapidly degrade upon exposure to ordinary atmospheric conditions. Therefore, traditional photolithography processes cannot be simply adopted to solve the problem of rapid carrier collection.
[0005] Currently, there is a lack of structural designs that can effectively reduce the transmission resistance of the transparent front electrode and improve the efficiency of large-area devices while protecting sensitive photovoltaic materials. This technological bottleneck severely restricts the practical application and large-scale industrialization of OPV and PSC type solar cells. Summary of the Invention
[0006] This invention discloses a solar cell device and its fabrication method, aiming to solve the technical problems existing in the prior art.
[0007] The present invention adopts the following technical solution: On one hand, embodiments of the present invention provide a solar cell device, comprising a transparent substrate, a transparent front electrode, a first insulating layer, a photoelectric conversion structure layer, a metal back electrode, a second insulating layer, and a front electrode lead-out electrode arranged sequentially. The second insulating layer, the metal back electrode, and the photoelectric conversion structure layer are provided with vias that extend to the surface of the transparent front electrode. The front electrode lead-out electrode extends into the via, is electrically connected to the transparent front electrode, and is electrically isolated from the metal back electrode and the photoelectric conversion structure layer. The front electrode lead-out electrode is used to guide the charge carriers collected by the transparent front electrode to the outer layer of the device.
[0008] As a preferred technical solution, the first insulating layer is disposed on the surface of the transparent front electrode to define the effective power generation area of the transparent front electrode; An insulating columnar microstructure is provided in the effective power generation area of the transparent front electrode to form a via. The columnar microstructure includes an insulating material capable of absorbing the laser wavelength used to create the via.
[0009] As a preferred technical solution, the surface of the second insulating layer is lower than the top of the columnar microstructure; The second insulating layer is used to electrically isolate the front electrode lead-out electrode from the metal back electrode, and it includes inorganic materials or patternable materials that do not corrode the metal back electrode.
[0010] As a preferred technical solution, the transparent front electrode is configured with one of the following structures: A composite structure of ITO and AZO; The composite structure of FTO and AZO; The ITO base layer structure has AZO dot-like structures only on the ITO surface in the via location area; The FTO base layer structure has AZO dot-like structures only on the FTO surface in the via location area.
[0011] As a preferred technical solution, the photoelectric conversion structure layer has holes, which are located in the effective power generation area of the transparent front electrode and penetrate the photoelectric conversion structure layer to form vias.
[0012] As a preferred technical solution, the second insulating layer covers the metal back electrode and exposes the holes; The second insulating layer comprises inorganic materials or patternable materials that do not corrode the metal back electrode.
[0013] As a preferred technical solution, it also includes a third insulating layer, which is disposed on the side wall of the hole and between the second insulating layer and the front electrode lead-out electrode; The third insulating layer may consist of inorganic materials or patternable materials that do not corrode the metal back electrode.
[0014] As a preferred technical solution, the transparent front electrode is configured with one of the following structures: ITO single-layer structure, FTO single-layer structure, AZO single-layer structure, ITO / Ag / ITO multilayer composite structure.
[0015] As a preferred technical solution, the photoelectric conversion structure layer includes a photosensitive layer, a hole transport layer, and an electron transport layer; The photosensitive layer is disposed between the hole transport layer and the electron transport layer, and the photosensitive layer includes organic photovoltaic materials or perovskite photovoltaic materials.
[0016] As a preferred technical solution, the photosensitive layer is made of perovskite photovoltaic material, and a nanoscale dense thin film structure is provided on the side of the photosensitive layer near the metal back electrode to protect the photosensitive layer.
[0017] As a preferred technical solution, the metal back electrode includes one or more materials selected from silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium.
[0018] As a preferred technical solution, the front electrode lead-out electrode includes one or more materials selected from silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium.
[0019] As a preferred technical solution, the first insulating layer comprises organic or inorganic materials.
[0020] On the other hand, for the aforementioned solar cell device, embodiments of the present invention provide a preparation method, comprising: A transparent front electrode is formed and patterned on a transparent substrate; A first insulating layer is formed and patterned on the surface of the transparent front electrode to expose the effective power generation area; Insulating columnar microstructures are formed within the effective power generation area; A photoelectric conversion structure layer, a metal back electrode, and a second insulating layer are sequentially formed on the transparent front electrode. Through laser processing, a through hole is formed at the position of the columnar microstructure, extending to the surface of the transparent front electrode; A front electrode lead-out electrode is formed on the surface of the second insulating layer, extending into the via and electrically connected to the transparent front electrode.
[0021] As a preferred technical solution, the step of forming an insulating columnar microstructure within the effective power generation area includes: Apply a patternable insulating material to the effective power generation area; The insulating material is patterned to form a columnar microstructure perpendicular to the transparent front electrode within the effective power generation area. The material of the columnar microstructure is capable of absorbing the laser wavelength used to create the via, and the shape and / or size of the columnar microstructure is configured to physically separate the metal back electrode deposited on its top and the metal back electrode on the surface of the photoelectric conversion structure layer into two non-communicating parts.
[0022] In view of the above-mentioned solar cell device, embodiments of the present invention also provide another preparation method, including: A transparent front electrode is formed and patterned on a transparent substrate; A first insulating layer is formed and patterned on the surface of the transparent front electrode to expose the effective power generation area; A photoelectric conversion structure layer, a metal back electrode, and a second insulating layer are sequentially formed on the transparent front electrode; A patterned second insulating protective layer is formed on the second insulating layer; The second insulating layer, the metal back electrode, and the photoelectric conversion structure layer are etched through the second insulating protective layer to form a via that extends to the surface of the transparent front electrode. A third insulating layer is formed on the sidewall of the via and the surface of the second insulating layer; Etching removes the third insulating layer at the bottom of the via, exposing the transparent front electrode; A front electrode lead-out electrode is formed on the surface of the third insulating layer, extending into the via and electrically connected to the transparent front electrode.
[0023] The technical solution adopted in this invention can achieve the following beneficial effects: This invention provides a solar cell device and its fabrication method, effectively solving the technical problem that the efficiency of existing organic solar cells and perovskite solar cells drops sharply when the area is increased.
[0024] Specifically, the solar cell device provided by this invention features a front electrode lead-out electrode structure. Through-holes extending to the surface of the transparent front electrode are formed in the second insulating layer, the metal back electrode, and the photoelectric conversion structure layer. The front electrode lead-out electrode extends into the through-holes and is electrically connected to the transparent front electrode, while simultaneously being electrically isolated from the metal back electrode and the photoelectric conversion structure layer. This structure allows photogenerated carriers collected by the transparent front electrode to be rapidly conducted out through the metal front electrode lead-out electrode, avoiding the resistance dissipation and recombination failure problems that occur when carriers travel long distances in the high-resistivity transparent front electrode.
[0025] For the fabrication of solar cell devices, this invention provides two implementation methods: one is to form vias by setting insulating columnar microstructures on the transparent front electrode and using laser processing; the other is to form vias by forming holes in the photoelectric conversion structure layer and then using an etching process. Both methods can effectively reduce the equivalent resistance of the transparent front electrode and significantly improve the photoelectric conversion efficiency of the device.
[0026] Compared with traditional solar cells, this invention breaks through the limitation of device area on efficiency, enabling organic solar cells and perovskite solar cells to maintain high efficiency even with increased area. It provides a feasible technical path for the industrial production of large-area flexible solar cells and is of great significance for promoting the widespread application of solar energy as an environmentally friendly energy source. Attached Figure Description
[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 This is a structural diagram of a solar cell device disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the structure of the transparent front electrode disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the photoelectric conversion structure layer disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 10 This is a schematic diagram of the columnar microstructure disclosed in a preferred embodiment of Embodiment 1 of the present invention; Figure 11 This is a structural diagram of a solar cell device disclosed in a preferred embodiment of Embodiment 3 of the present invention.
[0028] Explanation of reference numerals in the attached figures: Transparent substrate 10, transparent front electrode 20, photoelectric conversion structure layer 30, electron transport layer 31, photosensitive layer 32, hole transport layer 33, metal back electrode 40, first insulating layer 51, second insulating layer 52, third insulating layer 53, front electrode lead-out electrode 60, via 70, columnar microstructure 71. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.
[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.
[0031] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0032] Example 1 refer to Figure 1 To address the problems existing in the prior art, this invention provides a solar cell device comprising a transparent substrate 10, a transparent front electrode 20, a first insulating layer 51, a photoelectric conversion structure layer 30, a metal back electrode 40, and a second insulating layer 52 arranged sequentially. Preferably, the second insulating layer 52, the metal back electrode 40, and the photoelectric conversion structure layer 30 are provided with vias 70 extending to the surface of the transparent front electrode 20, and the outer surface of the second insulating layer 52 is also provided with a front electrode lead-out electrode 60. Preferably, the front electrode lead-out electrode 60 extends into the via 70, is electrically connected to the transparent front electrode 20, and is electrically isolated from the metal back electrode 40 and the photoelectric conversion structure layer 30. The front electrode lead-out electrode 60 is used to guide the charge carriers collected by the transparent front electrode 20 to the outer layer of the device.
[0033] like Figure 2 In a preferred embodiment, the transparent front electrode 20 includes at least an AZO layer disposed on the transparent substrate 10. Preferably, the sheet resistance of the transparent front electrode 20 is ≤30Ω / □, and the thickness of the AZO layer is in the range of 0.1~5μm, preferably 0.6μm~1.5μm.
[0034] In a preferred embodiment, the transparent front electrode 20 is configured as a composite structure of ITO and AZO, which is disposed on the transparent substrate 10 and includes an ITO-based base layer and an AZO layer disposed on the ITO base layer. Optionally, the ITO base layer may be first disposed on the transparent substrate 10, and the AZO layer may be further disposed on the ITO base layer, such as... Figure 3Alternatively, the AZO layer is first deposited on the transparent substrate 10, and then the ITO layer is further deposited on the AZO layer, such as... Figure 4 Alternatively, an ITO layer may be sandwiched between two AZO layers, and this sandwich structure may then be disposed on the transparent substrate 10, such as... Figure 5 Alternatively, the transparent substrate 10 is sandwiched between two ITO layers, and then an AZO layer is further disposed on the sandwich structure, such as... Figure 6 .
[0035] In another preferred embodiment, the transparent front electrode 20 is configured as a composite structure of FTO and AZO, comprising a base layer based on FTO material and an AZO layer disposed on the FTO base layer. Optionally, the FTO base layer may be first disposed on the transparent substrate 10, and the AZO layer may be further disposed on the FTO base layer, such as... Figure 3 Alternatively, the AZO layer is first deposited on the transparent substrate 10, and then the FTO layer is further deposited on the AZO layer, such as... Figure 4 Alternatively, an FTO layer may be sandwiched between two AZO layers, and this sandwich structure may then be disposed on the transparent substrate 10, as shown below. Figure 5 Alternatively, the transparent substrate 10 is sandwiched between two FTO layers, and then an AZO layer is further disposed on the sandwich structure, such as... Figure 6 .
[0036] In another preferred embodiment, the transparent front electrode 20 is configured as an ITO substrate structure, and AZO dot-like structures are formed only on the ITO surface in the region of the via 70, such as... Figure 7 Alternatively, AZO dot structures may be set only inside the ITO in the area of via 70, such as Figure 8 .
[0037] In another preferred embodiment, the transparent front electrode 20 is configured as an FTO substrate structure, and AZO dot-like structures are provided only on the FTO surface in the region of the via 70, such as... Figure 7 Alternatively, AZO dot structures may be set only inside the FTO in the area of via 70, such as Figure 8 .
[0038] like Figure 9 In a preferred embodiment, the photoelectric conversion structure layer 30 includes a photosensitive layer 32, a hole transport layer 33, and an electron transport layer 31. The photosensitive layer 32 is disposed between the hole transport layer 33 and the electron transport layer 31. The positions of the hole transport layer 33 and the electron transport layer 31 can be interchanged, and are not specifically limited in this embodiment.
[0039] Specifically, the photosensitive layer 32 is the core active layer of the solar cell, responsible for absorbing sunlight and converting light energy into electrical energy, generating electron-hole pairs (excitons). The electron transport layer 31 is mainly used to selectively transport and collect electrons generated by the photosensitive layer 32, while blocking the transport of holes and reducing carrier recombination. The hole transport layer 33 is mainly used to selectively transport and collect holes generated by the photosensitive layer 32, while blocking the transport of electrons and reducing carrier recombination. The positions of the hole transport layer 33 and the electron transport layer 31 can be interchanged because the solar cell can be designed as a conventional structure (nip structure) or an inverted structure (pin structure). In the conventional structure, the electron transport layer 31 is close to the transparent front electrode 20, and the hole transport layer 33 is close to the metal back electrode 40; while in the inverted structure, the hole transport layer 33 is close to the transparent front electrode 20, and the electron transport layer 31 is close to the metal back electrode 40. Both structures can achieve the function of a solar cell, only the current flow direction is opposite, and the choice can be made flexibly according to the specific material properties and application requirements.
[0040] In a preferred embodiment, the photosensitive layer 32 can be made of organic photovoltaic material or perovskite photovoltaic material. When it is a perovskite photovoltaic material, a nanoscale dense thin film structure is preferably formed on the side of the photosensitive layer 32 near the metal back electrode 40 to protect the perovskite photovoltaic material and prevent water vapor and oxygen from corroding the perovskite material and causing device failure.
[0041] In a preferred embodiment, the metal back electrode 40 is made of one or more of the following metals with low resistivity: silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium.
[0042] In a preferred embodiment, a first insulating layer 51 is disposed on the surface of the transparent front electrode 20 to define the effective power generation area of the solar cell and to provide insulation for subsequent structures. A second insulating layer 52 is disposed between the metal back electrode 40 and the front electrode lead-out electrode 60 to electrically isolate the front electrode lead-out electrode 60 from the metal back electrode 40.
[0043] Preferably, the first insulating layer 51 comprises an organic or inorganic material. When the first insulating layer 51 is in direct contact with the ITO layer of the transparent front electrode 20, silicon dioxide is preferably used as the insulating material; when the transparent front electrode 20 adopts a composite structure, a silicon nitride layer or a silicon oxynitride layer can be further covered on the surface of the silicon dioxide layer to form a multilayer insulating structure. The aforementioned inorganic insulating material can be prepared by chemical vapor deposition (CVD) or physical vapor deposition (PVD).
[0044] Preferably, the second insulating layer 52 is made of at least one layer of inorganic material such as silicon dioxide, silicon nitride, or silicon oxynitride by CVD, or is made of a patternable material that does not corrode the metal back electrode 40 material.
[0045] Preferably, the front electrode lead-out electrode 60 is made of one or more of the following metals with low resistivity: silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium.
[0046] Specifically, the front electrode lead-out electrode 60 is electrically connected to the transparent front electrode 20 through the aforementioned via 70. Its function is to guide the charge carriers collected by the transparent front electrode 20 around the via 70 to the outer layer of the device structure through the via 70. Due to the use of a metal material with low resistivity, the front electrode lead-out electrode 60 can utilize the low resistivity of the metal to quickly collect and conduct photogenerated charge carriers. In terms of device structure, the front electrode lead-out electrode 60 is electrically connected to the output terminal (PAD) of the transparent front electrode 20 of the same cell. This connection method can avoid the problems of transmission resistance dissipation and recombination failure when photogenerated charge carriers are transported in the high-resistivity transparent front electrode 20 without using this device structure. Thus, the overall photoelectric conversion efficiency of the device can be greatly improved without being limited by the area of a single cell.
[0047] like Figure 10 In a preferred embodiment, an insulating columnar microstructure 71 is provided in the effective power generation area of the transparent front electrode 20 for forming a via 70. The columnar microstructure 71 includes an insulating material capable of absorbing the laser wavelength used to form the via 70, and the shape and / or size of the columnar microstructure 71 is configured to physically divide the metal back electrode 40 deposited on its top and the metal back electrode 40 on the surface of the photoelectric conversion structure 30 layer into two non-communicating parts.
[0048] Preferably, the columnar microstructure 71 has a rectangular, trapezoidal, or inverted trapezoidal cross-section in the plane perpendicular to the transparent front electrode 20.
[0049] Preferably, the columnar microstructure 71 can be an insulator directly made of photoresist material, or it can be an insulator made with the aid of photoresist material. Optionally, the columnar microstructure 71 is configured to be colorless or yellow to dark yellow to absorb the laser processing energy during the via fabrication process of the via 70, preventing the laser energy from breaking down the transparent front electrode 20. Its color is based on the laser wavelength that can fully absorb the laser used to process the via 70. In this embodiment, the laser wavelength is preferably in the ultraviolet band, so a material that can absorb ultraviolet lasers is selected to fabricate this columnar structure accordingly.
[0050] Preferably, the outer diameter of the columnar microstructure 71 is between 5 and 500 μm, more preferably 15 to 50 μm, the height of the columnar microstructure 71 is preferably 1 to 10 μm, more preferably 3 to 6 μm, and its top end preferably protrudes 0.1 to 3 μm from the surface of the second insulating layer 52.
[0051] Specifically, the top of the columnar microstructure 71 protrudes from the surface of the second insulating layer 52 to ensure accurate positioning of the via 70 during laser processing, while effectively absorbing laser energy and preventing the laser energy from directly acting on the transparent front electrode 20. This improves the accuracy and controllability of the via 70 formation and avoids unnecessary damage to the transparent front electrode 20.
[0052] Preferably, the distance between two adjacent columnar microstructures 71 is between 50 and 5000 μm. The arrangement of the columnar microstructures 71 can be random or regular, and the number is determined based on the ratio of the total cross-sectional area of the columnar microstructures 71 to the total area of the effective photovoltaic region.
[0053] The design principle of the columnar microstructure 71 is to minimize its area proportion while ensuring the processing quality of the via 70. Therefore, preferably, the total cross-sectional area of the columnar microstructure 71 accounts for less than 10% of the total effective photovoltaic area to maximize the photoelectric conversion efficiency of the solar cell. Since the columnar microstructure 71 itself is not an effective power generation area, the smaller its area, the greater its contribution to the total output power of the device. The specific contribution depends on the structure of the device and is not specifically limited in this embodiment.
[0054] Specifically, the aforementioned effective power generation area and effective photovoltaic area refer to the same area, namely the functional area in the solar cell device that can perform photoelectric conversion. In this area, although the columnar microstructures 71 set on the transparent front electrode 20 occupy a part of the area, these columnar microstructures 71 themselves do not participate in the photoelectric conversion process. Therefore, the actual effective photovoltaic area should be the total effective power generation area minus the total cross-sectional area of the columnar microstructures 71.
[0055] In a preferred embodiment, the solar cell device further includes a back cover disposed outside the front electrode lead-out electrode 60, which may be a solid type or a thin film type.
[0056] Preferably, when the encapsulation back cover is of the thin film type, it is disposed on the surface of the front electrode lead-out electrode 60. A water-oxygen barrier layer is preferably disposed on the side of the encapsulation back cover adjacent to the front electrode lead-out electrode 60, and the water-oxygen barrier layer covers the front electrode lead-out electrode 60. More preferably, the water-oxygen barrier layer is composed of an organic material film layer or an inorganic material film layer, or the water-oxygen barrier layer is formed by overlapping organic and inorganic material film layers, or the water-oxygen barrier layer is formed by mixing organic and inorganic materials in a predetermined ratio.
[0057] Preferably, when the encapsulation back cover is solid, a desiccant with water and oxygen adsorption capacity is preferably provided between the encapsulation back cover and the front electrode lead-out electrode 60. The edge of the solid encapsulation back cover is sealed to the transparent substrate 10 with an adhesive to form a closed structural space, which can effectively prevent external water and oxygen from penetrating into the device and improve the stability and service life of the device.
[0058] In a preferred embodiment, this embodiment also provides a display device that integrates the aforementioned solar cell device.
[0059] Preferably, the display device includes a display panel and a solar cell device, with the solar cell device disposed in a non-display area of the display panel. Preferably, the solar cell device can be arranged in the frame, back panel, or non-display area of the display device. Because the solar cell device has columnar microstructures 71 and through-holes 70 formed on the transparent front electrode 20, it can achieve efficient photoelectric conversion, enabling it to collect ambient light energy and convert it into electrical energy, thereby providing auxiliary power or serving as backup power for the display device. This is particularly suitable for portable display devices, outdoor displays, or low-power display terminals, effectively improving the energy efficiency and battery life of the display device.
[0060] Example 2 This invention provides a method for fabricating a solar cell device. This method is used to fabricate the solar cell device described in Example 1 above. The technical features already included in the above examples are naturally inherited in this example and will not be repeated.
[0061] In a preferred embodiment, the preparation method comprises the following steps: First, a transparent front electrode 20 is formed and patterned on a transparent substrate 10. A first insulating layer 51 of organic or inorganic material is fabricated on its surface and patterned to expose the effective power generation area and the electrode output terminal. Then, a patternable insulating material is coated on the effective power generation area and patterned to form a columnar microstructure 71 perpendicular to the transparent front electrode 20 in the effective power generation area.
[0062] Further, a photoelectric conversion structure layer 30, a metal back electrode 40, and a second insulating layer 52 are formed sequentially, and the second insulating layer 52 is patterned. Then, through laser processing, a via 70 is formed at the position of the columnar microstructure 71. The via 70 extends from the second insulating layer 52 to the surface of the transparent front electrode 20.
[0063] After fabricating the via 70 of the columnar microstructure 71, the transparent substrate 10 is further locally masked using an evaporation vapor deposition mask (EVP MASK). A metal thin film with a thickness exceeding 100 nm is deposited on the surface of the second insulating layer 52. Since the columnar microstructure 71 protrudes from the surface of the second insulating layer 52, the metal film deposited on the inner wall of the via 70 will not contact the surrounding electron transport layer 31, hole transport layer 33, photosensitive layer 32, and metal back electrode 40, forming a mutually insulating state with these layers. Only the metal deposited to the bottom of the via 70 can form an ohmic contact with the transparent front electrode 20, and together with the metal on the inner wall of the via 70 and the metal on the surface of the second insulating layer 52, form the front electrode lead-out electrode 60. The metal deposited on the surface of the second insulating layer 52 forms a large-area continuous conductive film, which rapidly conducts the photogenerated carriers collected on one side of the transparent front electrode 20 through the metal in the via 70 with extremely low resistance, and then transmits them through the large-area metal film with extremely low impedance to the electrode terminals formed by the transparent front electrode 20 material, which have the opposite polarity to the electrode terminals formed by the metal back electrode 40.
[0064] Preferably, after forming the electrode lead-out electrode 60, a packaging back cover can be further provided. The packaging back cover can be a solid type or a thin film type. For the specific structure, please refer to the above embodiment 1, which will not be repeated here.
[0065] In this embodiment, by precisely controlling the fabrication of the columnar microstructure 71 and the formation of the via 70, a highly efficient electrical connection between the front electrode lead-out electrode 60 and the transparent front electrode 20 is achieved, while ensuring insulation isolation from other functional layers. The large-area conductive film formed by the metal thin film on the surface of the second insulating layer 52 significantly reduces resistance, accelerates the collection and transport of photogenerated carriers, and solves the energy loss problem caused by the high resistance of traditional transparent electrodes. The overall process is compatible with existing manufacturing processes, easy to implement in large-scale production, and has industrial application value.
[0066] Example 3 refer to Figure 11 To address the problems existing in the prior art, this invention provides a solar cell device comprising a transparent substrate 10, a transparent front electrode 20, a first insulating layer 51, a photoelectric conversion structure layer 30, a metal back electrode 40, and a second insulating layer 52 arranged sequentially. Preferably, the second insulating layer 52, the metal back electrode 40, and the photoelectric conversion structure layer 30 are provided with vias 70 extending to the surface of the transparent front electrode 20, and the outer surface of the insulating layer is also provided with a front electrode lead-out electrode 60. Preferably, the front electrode lead-out electrode 60 extends into the via 70, is electrically connected to the transparent front electrode 20, and is electrically isolated from the metal back electrode 40 and the photoelectric conversion structure layer 30. The front electrode lead-out electrode 60 is used to guide the charge carriers collected by the transparent front electrode 20 to the outer layer of the device.
[0067] In a preferred embodiment, the transparent front electrode 20 can be an ITO single-layer structure, an FTO single-layer structure, or an AZO single-layer structure disposed on the transparent substrate 10; in another preferred embodiment, the transparent front electrode 20 can also directly adopt an ITO / Ag / ITO multilayer composite structure, in which case the thickness of the Ag film in the ITO / Ag / ITO multilayer composite structure is preferably less than 25nm, and the sheet resistance of the transparent front electrode 20 is ≤30Ω / □.
[0068] In a preferred embodiment, the photoelectric conversion structure layer 30 includes a photosensitive layer 32, a hole transport layer 33, and an electron transport layer 31. The photosensitive layer 32 is disposed between the hole transport layer 33 and the electron transport layer 31. The positions of the hole transport layer 33 and the electron transport layer 31 can be interchanged, and are not specifically limited in this embodiment.
[0069] In a preferred embodiment, the photosensitive layer 32 can be selected from organic photovoltaic materials or perovskite photovoltaic materials. When it is a perovskite photovoltaic material, it is preferable to form a nanoscale dense thin film structure on the side of the photosensitive layer 32 near the metal back electrode 40 to protect the perovskite photovoltaic material and prevent water vapor and oxygen from corroding the perovskite material and causing device failure.
[0070] In a preferred embodiment, the metal back electrode 40 is made of one or more of the following metals with low resistivity: silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium.
[0071] In a preferred embodiment, in addition to the first insulating layer 51 and the second insulating layer 52, a third insulating layer 53 is also included, wherein the first insulating layer 51 is disposed on the surface of the transparent front electrode 20 to define the effective power generation area of the solar cell; the second insulating layer 52 covers the metal back electrode 40 and exposes the sidewalls of the hole; and the third insulating layer 53 is disposed on the sidewalls of the hole and between the second insulating layer 52 and the front electrode lead-out electrode 60.
[0072] Preferably, the first insulating layer 51 comprises organic or inorganic materials, and may be configured in the same way as in Embodiment 1 above.
[0073] Preferably, the second insulating layer 52 is made of at least one layer of inorganic material such as silicon dioxide, silicon nitride, or silicon oxynitride by CVD, or is made of a patternable material that does not corrode the metal back electrode 40 material.
[0074] In a preferred embodiment, when an inorganic material is used as the second insulating layer 52, a photoresist material, i.e., the second insulating protective layer, is further coated onto the entire surface of the inorganic thin film using a photolithography process. A via pattern 70 is then formed using photolithography, and the second insulating layer 52 and photosensitive layer 32 at the bottom of the via 70 are removed using a chemical dry etching method. After etching the second insulating layer 52 and photosensitive layer 32, the second insulating protective layer can be retained or removed using plasma ashing, but it cannot be removed using traditional wet stripping methods to avoid corrosion of the back electrode and photosensitive layer 32 by the stripping solution.
[0075] Preferably, the third insulating layer 53 is made of at least one layer of inorganic material such as silicon dioxide, silicon nitride, or silicon oxynitride by CVD, or is made of a patternable material that does not corrode the metal back electrode 40 material.
[0076] In a preferred embodiment, when an inorganic material is used as the third insulating layer 53, a photoresist material, i.e., a third insulating protective layer, is further coated onto the entire surface of the third insulating layer 53 using a photolithography process. A via pattern 70 is then formed using photolithography, and the third insulating layer 53 at the bottom of the via 70 is removed using a chemical dry etching method. After etching the third insulating layer 53, the third insulating protective layer can be retained or removed.
[0077] Preferably, the front electrode lead-out electrode 60 is made of one or more of the following metals with low resistivity: silver, aluminum, gold, copper, platinum, titanium, molybdenum, and chromium. Specifically, it can adopt the same configuration as in Embodiment 1 above.
[0078] In a preferred embodiment, the photoelectric conversion structure layer 30 is provided with a hole, which is disposed in the effective power generation area of the transparent front electrode 20, and the hole penetrates the photoelectric conversion structure layer 30 to form a via 70.
[0079] Specifically, when the electron transport layer 31 or hole transport layer 33 disposed on the surface of the transparent front electrode 20 is made of inorganic materials (such as ZnO, NiO, TiO2, WO3, etc.), it is necessary to first form holes in the effective power generation area to expose the transparent front electrode 20 below for its electrical connection with the front electrode lead-out electrode 60, and then fabricate the photosensitive layer 32 by coating or deposition. Preferably, the diameter of the holes is 5~500μm, more preferably 15~50μm.
[0080] Preferably, the distance between two adjacent holes is between 50 and 5000 μm. The arrangement of the holes can be random or regular, and their number is determined based on the ratio of the cross-sectional area of the holes to the total area of the effective photovoltaic region. Preferably, the total cross-sectional area of all holes accounts for less than 10% of the total area of the effective photovoltaic region.
[0081] In a preferred embodiment, the solar cell device further includes a back cover disposed outside the front electrode lead-out electrode 60, which may be a solid type or a thin film type.
[0082] Preferably, when the encapsulation back cover is of the thin film type, it is disposed on the surface of the front electrode lead-out electrode 60. A water-oxygen barrier layer is preferably disposed on the side of the encapsulation back cover adjacent to the front electrode lead-out electrode 60, and the water-oxygen barrier layer covers the front electrode lead-out electrode 60. More preferably, the water-oxygen barrier layer is composed of an organic material film layer or an inorganic material film layer, or the water-oxygen barrier layer is formed by overlapping organic and inorganic material film layers, or the water-oxygen barrier layer is formed by mixing organic and inorganic materials in a predetermined ratio.
[0083] Preferably, when the encapsulation back cover is solid, a desiccant with water and oxygen adsorption capacity is preferably provided between the encapsulation back cover and the front electrode lead-out electrode 60. The edge of the solid encapsulation back cover is sealed to the transparent substrate 10 with an adhesive to form a closed structural space, which can effectively prevent external water and oxygen from penetrating into the device and improve the stability and service life of the device.
[0084] In a preferred embodiment, this embodiment also provides a display device that integrates the aforementioned solar cell device. Preferably, the display device includes a display panel and a solar cell device, with the solar cell device disposed in a non-display area of the display panel. The solar cell device enables highly efficient photoelectric conversion, allowing it to collect ambient light energy and convert it into electrical energy, thereby providing auxiliary power or serving as backup power for the display device, thus improving the energy efficiency and battery life of the display device.
[0085] Example 4 This invention provides a method for fabricating a solar cell device. This method is used to fabricate the solar cell device described in Example 3 above. The technical features already included in the above examples are naturally inherited in this example and will not be repeated.
[0086] In a preferred embodiment, the preparation method comprises the following steps: First, a transparent front electrode 20 is formed and patterned on a transparent substrate 10. A first insulating layer 51 of organic or inorganic material is fabricated and patterned on its surface to expose the effective power generation area and electrode output terminal. Then, a photoelectric conversion structure layer 30, a metal back electrode 40 and a second insulating layer 52 are sequentially formed on the transparent front electrode 20. The second insulating layer 52 is patterned and coated with a second insulating protective layer.
[0087] Furthermore, chemical dry etching is used to dry etch the opening positions of the second insulating protective layer, etching several holes, namely vias 70, into the exposed second insulating layer 52. The metal back electrode 40 and the photoelectric conversion structure layer 30 below the second insulating layer 52 are then etched, and the vias 70 are etched all the way to the surface of the transparent front electrode 20.
[0088] Then, a third insulating layer 53 is formed on the sidewall of the via 70 and the surface of the second insulating layer 52, and photoresist is coated on the surface of the third insulating layer 53 to form several open-hole structures exposed on the surface of the third insulating layer 53. The opening size of the third insulating layer 53 is smaller than the opening size of the second insulating layer 52. Therefore, during the dry etching process of the third insulating layer 53, the insulating film located on the sidewall of the via 70 is also protected by the third insulating photoresist, and only the part of the bottom of the via 70 that contacts the surface of the transparent front electrode 20 is exposed. The dry etching process can only remove the third insulating layer 53 on the surface of the transparent front electrode 20 at the bottom of the via 70.
[0089] After the via 70 is fabricated, the transparent substrate 10 is further locally masked using a mask. Preferably, a metal thin film with a thickness of more than 100 nm is deposited on the surface of the third insulating layer 53. Since the third insulating layer 53 has isolated the metal back electrode 40 and the photoelectric conversion structure layer 30 on the inner wall of the via 70, the metal film layer deposited on the inner wall of the via 70 will not come into contact with the electron transport layer 31, hole transport layer 33, photosensitive layer 32 and metal back electrode 40 around it, forming a mutually insulating state with these layers. Only the metal deposited at the bottom of the via 70 can form an ohmic contact with the transparent front electrode 20, and together with the metal on the inner wall of the via 70 and the metal on the surface of the third insulating layer 53, form the front electrode lead-out electrode 60. The metal deposited on the surface of the third insulating layer 53 forms a large-area continuous conductive film. With extremely low resistance, the photogenerated carriers collected on one side of the transparent front electrode 20 are quickly conducted out through the metal in the via 70 and then transported through the large-area metal film with extremely low impedance to the electrode terminals formed by the transparent front electrode 20 material, which have opposite polarities to the electrode terminals formed by the metal back electrode 40.
[0090] In this embodiment, by precisely controlling the patterning and etching processes of the second insulating layer 52 and the third insulating layer 53, a highly efficient electrical connection between the front electrode lead-out electrode 60 and the transparent front electrode 20 is achieved, while effectively avoiding the risk of short circuits with the metal back electrode 40 and the photoelectric conversion structure layer 30. In particular, the design of the opening size of the third insulating layer 53 being smaller than the opening size of the second insulating layer 52 ensures the insulation integrity of the via 70 sidewalls, providing reliable electrical isolation for subsequent metal deposition. The use of chemical dry etching instead of traditional wet stripping effectively prevents corrosion damage to the back electrode and photosensitive layer 32 by the stripping solution. The resulting large-area conductive metal film significantly reduces resistance, improves carrier collection and transport efficiency, and solves the energy loss problem caused by the high resistance of the transparent electrode, thereby significantly improving the overall performance and reliability of the solar cell device.
[0091] Preferably, after forming the electrode lead-out electrode 60, a packaging back cover can be further provided. The packaging back cover can be a solid type or a thin film type. For the specific structure, please refer to the above embodiment 3, which will not be repeated here.
[0092] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.
Claims
1. A solar cell device, characterized in that, It includes a transparent substrate, a transparent front electrode, a first insulating layer, a photoelectric conversion structure layer, a metal back electrode, a second insulating layer, and a front electrode lead-out electrode arranged sequentially. The second insulating layer, the metal back electrode, and the photoelectric conversion structure layer are provided with vias that extend to the surface of the transparent front electrode. The front electrode lead-out electrode extends into the vias, is electrically connected to the transparent front electrode, and is electrically isolated from the metal back electrode and the photoelectric conversion structure layer. The front electrode lead-out electrode is used to guide the charge carriers collected by the transparent front electrode to the outer layer of the device.
2. The solar cell device according to claim 1, characterized in that, The first insulating layer is disposed on the surface of the transparent front electrode to define the effective power generation area of the transparent front electrode; The effective power generation area of the transparent front electrode is provided with an insulating columnar microstructure for forming the via; the columnar microstructure includes an insulating material capable of absorbing the laser wavelength used to create the via.
3. The solar cell device according to claim 2, characterized in that, The surface of the second insulating layer is lower than the top of the columnar microstructure; The second insulating layer is used to electrically isolate the front electrode lead-out electrode from the metal back electrode, and it comprises an inorganic material or a patternable material that does not corrode the metal back electrode.
4. The solar cell device according to claim 2, characterized in that, The transparent front electrode is configured as one of the following structures: A composite structure of ITO and AZO; The composite structure of FTO and AZO; The ITO base layer structure has AZO dot-like structures only on the ITO surface in the via location area. The FTO base layer structure has AZO dot-like structures only on the FTO surface in the area of the via.
5. The solar cell device according to claim 1, characterized in that, The photoelectric conversion structure layer has holes, which are located within the effective power generation area of the transparent front electrode. The holes penetrate the photoelectric conversion structure layer to form the vias.
6. The solar cell device according to claim 5, characterized in that, The second insulating layer covers the metal back electrode and exposes the hole; The second insulating layer comprises an inorganic material or a patternable material that does not corrode the metal back electrode.
7. The solar cell device according to claim 6, characterized in that, It also includes a third insulating layer, which is disposed on the sidewall of the hole and between the second insulating layer and the front electrode lead-out electrode; The third insulating layer comprises an inorganic material or a patternable material that does not corrode the metal back electrode.
8. The solar cell device according to claim 5, characterized in that, The transparent front electrode is configured as one of the following structures: ITO single-layer structure, FTO single-layer structure, AZO single-layer structure, ITO / Ag / ITO multilayer composite structure.
9. A method for fabricating a solar cell device as described in claim 1, characterized in that, include: A transparent front electrode is formed and patterned on a transparent substrate; A first insulating layer is formed and patterned on the surface of the transparent front electrode to expose the effective power generation area; Insulating columnar microstructures are formed within the effective power generation area; A photoelectric conversion structure layer, a metal back electrode, and a second insulating layer are sequentially formed on the transparent front electrode. Through laser processing, a through hole is formed at the position of the columnar microstructure, extending to the surface of the transparent front electrode; A front electrode lead-out electrode is formed on the surface of the second insulating layer, extending into the via and electrically connected to the transparent front electrode.
10. The preparation method according to claim 9, characterized in that, The step of forming an insulating columnar microstructure within the effective power generation area includes: Apply a patternable insulating material to the effective power generation area; The insulating material is patterned to form a columnar microstructure perpendicular to the transparent front electrode within the effective power generation area. The material of the columnar microstructure is capable of absorbing the laser wavelength used to create the via, and the shape and / or size of the columnar microstructure is configured to physically separate the metal back electrode deposited on its top and the metal back electrode on the surface of the photoelectric conversion structure layer into two non-communicating parts.
11. A method for fabricating a solar cell device as described in claim 1, characterized in that, include: A transparent front electrode is formed and patterned on a transparent substrate; A first insulating layer is formed and patterned on the surface of the transparent front electrode to expose the effective power generation area; A photoelectric conversion structure layer, a metal back electrode, and a second insulating layer are sequentially formed on the transparent front electrode; A patterned second insulating protective layer is formed on the second insulating layer; The second insulating layer, the metal back electrode, and the photoelectric conversion structure layer are etched through the second insulating protective layer to form a via that extends to the surface of the transparent front electrode. A third insulating layer is formed on the sidewall of the via and the surface of the second insulating layer; Etching removes the third insulating layer at the bottom of the via, exposing the transparent front electrode; A front electrode lead-out electrode is formed on the surface of the third insulating layer, extending into the via and electrically connected to the transparent front electrode.