A solar cell and display device

Abstract

A solar cell and a display device, on a substrate of the solar cell, a laminated cell area is provided. The solar cell in the laminated cell area comprises a first photovoltaic device and a second photovoltaic device arranged in a stack; the first photovoltaic device is an amorphous silicon solar cell, and the second photovoltaic device is an organic or perovskite solar cell. Moreover, the transparent front electrode layers of the two photovoltaic devices are electrically connected through a hole structure to form a parallel connection; or the substrate is transparent, and a light-transmitting cell area is further provided thereon, the second photovoltaic device extends from the laminated cell area to the upper surface of the substrate to form a photovoltaic cell structure on the light-transmitting cell area. The solar cell of the present application has high photoelectric conversion efficiency and large output current, is suitable for display devices, and is particularly effective when applied to large-area photovoltaic devices and display devices thereof. In addition, it also helps to promote the industrialization of OPV technology and PSC technology, and promote the diversification of related products.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a solar cell and a display device. Background Technology

[0002] With the rapid development of electronic technology, people are using a wide variety of portable and wearable electronic products. To improve the user experience of these products, in addition to increasing the battery capacity to extend battery life, emergency power contingency plans must also be considered during product design. Currently, the best solution is to equip these electronic products with additional solar panels.

[0003] Currently, the solar cells used in smartphones are all amorphous silicon solar cells. However, these cells have low PCE (Photoelectric Conversion Efficiency). In an AM1.5 atmospheric environment and with an illuminance of 1 sun (the average intensity of sunlight reaching the Earth's surface under standard test conditions), the PCE is only about 7%, and it further decreases to about 3% under low indoor illuminance conditions. In addition, these solar cells also suffer from the insurmountable Staebler-Wronski (light-induced degradation) effect. After about 100 hours of strong light exposure, the PCE irreversibly drops to about 5%, which greatly limits the use of amorphous silicon solar cells, which are already not very effective.

[0004] Therefore, how to develop a solar cell that can effectively improve photoelectric conversion efficiency and is suitable for display devices has become an urgent problem to be solved in the industry. Summary of the Invention

[0005] In order to solve at least one problem existing in the prior art, the purpose of this application is to provide a solar cell and a display device that can effectively improve the photoelectric conversion efficiency of solar cells, are suitable for display devices, and have particularly significant effects when applied to large-area photovoltaic devices and their display devices.

[0006] To achieve the above objectives, this application provides a solar cell, wherein the substrate of the solar cell includes a stacked cell region;

[0007] In the stacked battery region, the solar cell includes:

[0008] A first photovoltaic device, stacked on the substrate, is an amorphous silicon solar cell; and,

[0009] The second photovoltaic device, stacked on the first photovoltaic device, is an organic solar cell or a perovskite solar cell;

[0010] in,

[0011] The first photovoltaic device includes a first transparent front electrode layer disposed on the substrate; the second photovoltaic device includes a second transparent front electrode layer disposed on the first photovoltaic device; and the second transparent front electrode layer is connected to the first transparent front electrode layer through a hole structure, serving as an auxiliary electrode for the front electrode of the first photovoltaic device.

[0012] This application also provides another type of solar cell, wherein the transparent substrate of the solar cell includes a stacked cell region and a light-transmitting cell region; wherein,

[0013] In the stacked battery region, the solar cell includes:

[0014] A first photovoltaic device, stacked on the substrate, is an amorphous silicon solar cell; and,

[0015] The second photovoltaic device, stacked on the first photovoltaic device, is an organic solar cell or a perovskite solar cell;

[0016] In the light-transmitting cell region, the second photovoltaic device extends from the stacked cell region to the upper surface of the transparent substrate, forming a photovoltaic structure on the light-transmitting cell region.

[0017] Optionally, the visible light transmittance of the light-transmitting cell region ranges from 40% to 90%.

[0018] Optionally, the first photovoltaic device includes a first transparent front electrode layer, a first photovoltaic layer, a first back electrode layer, and an insulating layer stacked sequentially from bottom to top; wherein the insulating layer is used to electrically insulate the first photovoltaic device from the second photovoltaic device;

[0019] The second photovoltaic device includes a second transparent front electrode layer, a second photovoltaic layer, a second back electrode layer, and an encapsulation layer stacked sequentially from bottom to top.

[0020] Alternatively, the second transparent front electrode layer is connected to the first transparent front electrode layer through a hole structure, serving as an auxiliary electrode for the front electrode of the first photovoltaic device.

[0021] Optionally, at least one of the second transparent front electrode layer and the first back electrode layer,

[0022] The transmittance of a single element in the 600nm-800nm ​​wavelength range is greater than 30%, and / or the transmittance of a single element in the 400nm-600nm wavelength range is greater than 70%.

[0023] Optionally, at least one of the second transparent front electrode layer and the first back electrode layer has a sheet resistance of less than 100 Ω / cm.2 ; and / or,

[0024] The sheet resistance of the second back electrode layer is less than 50 Ω / cm 2 .

[0025] Optionally, the second photovoltaic layer includes a stacked electron transport layer, a photovoltaic active layer, and a hole transport layer; wherein the photovoltaic active layer satisfies at least one of the following conditions: the thickness of the photovoltaic active layer is less than or equal to 60 nm; the single-cell transmittance in the 400 nm-600 nm band is greater than 50%; and the normalized absorbance in the 600 nm-1000 nm band is greater than 0.5.

[0026] Optionally, the aperture area of ​​the via structure is greater than 10 μm. 2 .

[0027] This application also provides a display device, which includes a display panel and the aforementioned solar cell, wherein the solar cell is disposed on the display side of the display panel.

[0028] This application discloses a solar cell and a display device. The solar cell has high photoelectric conversion efficiency and large output current, making it suitable for display devices, especially when applied to large-area photovoltaic devices and their display devices. Furthermore, it helps to promote the industrialization of OPV and PSC technologies and facilitates the diversification of related products.

[0029] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a bottom view of the stacked structure of the solar cells according to Embodiment 1 of this application;

[0032] Figure 2 for Figure 1 A-A' cross-sectional view of the solar cell in the middle;

[0033] Figure 3 for Figure 1 B-B' cross-sectional view of a solar cell in China;

[0034] Figure 4 for Figure 1 C-C' cross-sectional view of a solar cell in China;

[0035] Figure 5 for Figure 1 A schematic diagram of the structure of the first transparent front electrode layer of a solar cell;

[0036] Figure 6 for Figure 1 A schematic diagram of the structure of the first photovoltaic layer of a solar cell;

[0037] Figure 7 for Figure 1 A schematic diagram of the structure of the first back electrode layer of a solar cell;

[0038] Figure 8 for Figure 1 A schematic diagram of the insulating layer structure of a solar cell;

[0039] Figure 9 for Figure 1 A schematic diagram of the structure of the second transparent front electrode layer in a solar cell;

[0040] Figure 10 for Figure 1 A schematic diagram of the structure of the second photovoltaic layer in a solar cell;

[0041] Figure 11 for Figure 1 A schematic diagram of the structure of the second back electrode layer in a solar cell;

[0042] Figure 12 for Figure 1 A schematic diagram of the encapsulation layer of a solar cell;

[0043] Figure 13 This is a cross-sectional view of a stacked structure of a solar cell according to Embodiment 2 of this application;

[0044] Figure 14 This is a cross-sectional view of the stacked structure of another solar cell according to Embodiment 2 of this application.

[0045] Specifically, the following reference numerals are included:

[0046] Solar cell - 100; Substrate - 10; First photovoltaic device - 20; Second photovoltaic device - 30; Via structure - 40; Lead-out terminal overlap block - 50;

[0047] First transparent front electrode layer - 21; Transparent front electrode lead-out terminal - 211; Auxiliary metal layer - 212; First photovoltaic layer - 22; First back electrode layer - 23; First back electrode lead-out terminal - 231; Insulating layer - 24;

[0048] Second transparent front electrode layer - 31; Second photovoltaic layer - 32; Second back electrode layer - 33; Second back electrode lead-out terminal - 331; Encapsulation layer - 34. Detailed Implementation

[0049] Embodiments of this application will now be described in detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0050] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0051] First, it should be noted that the rapidly emerging third-generation solar cells in recent years include OPV (Organic Photovoltaics) and PSC (Perovskite Solar Cells). They have already achieved high efficiencies in small-area devices in the laboratory. The NREL (National Renewable Energy Laboratory) has recorded an efficiency of over 19.2% for OPV single-junction devices and 26.1% for PSC single-junction devices, which has surpassed crystalline silicon solar cells and is the preferred choice for external (or embedded) solar cells in wearable and portable electronic products.

[0052] However, in the development of OPV and PSC, there are still insurmountable technical challenges—the efficiency of these solar cells drops rapidly as the area of ​​a single device increases, especially for PSC-type devices. Numerous academic institutions, research institutes, and manufacturing companies have invested heavily in research to address this issue, but so far, they have not been able to solve it, directly impacting the industrialization of OPV and PSC technologies and the widespread application of related products.

[0053] Based on this, this application provides a solar cell employing an amorphous silicon-OPV tandem solar cell or an amorphous silicon-PSC tandem solar cell with complementary absorption spectra. This effectively improves the photoelectric conversion efficiency of the solar cell and is suitable for display devices, with particularly significant effects when applied to large-area photovoltaic devices and their display applications. Furthermore, it fully leverages the advantages of the variety and tunable bandgap of perovskite and organic photovoltaic materials, contributing to the industrialization of OPV and PSC technologies and promoting the diversification of related products.

[0054] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0055] Example 1

[0056] This embodiment provides a solar cell. For example... Figure 1 - Figure 12 As shown, a stacked cell region is provided on the substrate 10 of the solar cell 100.

[0057] It should be noted that, in this embodiment, the substrate 10 of the solar cell 100 can be either a transparent substrate or a non-transparent substrate. No specific limitation is imposed in this regard.

[0058] The stacked battery region includes: a first photovoltaic device 20 and a second photovoltaic device 30 stacked sequentially.

[0059] The first photovoltaic device 20, layered on the substrate 10, is an amorphous silicon solar cell; the second photovoltaic device 30, layered on the first photovoltaic device 20, is an organic solar cell or a perovskite solar cell. Preferably, the absorption spectra of the first photovoltaic device 20 and the second photovoltaic device 30 are nearly complementary or complementary.

[0060] Specifically, based on amorphous silicon solar cells, and considering the absorption characteristics of the solar spectrum by amorphous silicon solar cells, an amorphous silicon-OPV tandem solar cell can be fabricated using OPV materials whose absorption spectrum complements that of amorphous silicon; alternatively, an amorphous silicon-PSC tandem solar cell can be fabricated using PSC photovoltaic materials whose absorption spectrum complements that of amorphous silicon. Because perovskite materials and organic photovoltaic materials have the advantages of variety and tunable band gaps, this application helps to promote the industrialization of OPV and PSC technologies and to diversify related products.

[0061] Furthermore, the first photovoltaic device 20 includes a first transparent front electrode layer 21 disposed on the substrate 10; the second photovoltaic device 30 includes a second transparent front electrode layer 31 disposed on the first photovoltaic device 20. The second transparent front electrode layer 31 not only transmits the charge carriers collected by the transparent front electrode of the second photovoltaic device 30, but also connects to the first transparent front electrode layer 21 through the via structure 40 to form a parallel structure, so that it can also be used as an auxiliary electrode of the front electrode of the first photovoltaic device 20.

[0062] According to embodiments of this application, the solar cell employs an amorphous silicon-OPV tandem solar cell or an amorphous silicon-PSC tandem solar cell with complementary absorption spectra, resulting in high photoelectric conversion efficiency. Furthermore, by using a second transparent front electrode layer as an auxiliary electrode for the front electrode of the first photovoltaic device, the output current of the solar cell can be effectively increased. This solar cell is suitable for display devices, and its effect is particularly significant when applied to large-area photovoltaic devices and their display devices. In addition, it helps to promote the industrialization of OPV and PSC technologies and facilitates the diversification of related products.

[0063] like Figure 1 - Figure 4 As shown, in one embodiment, the first photovoltaic device 20 includes a first transparent front electrode layer 21, a first photovoltaic layer 22, a first back electrode layer 23, and an insulating layer 24 stacked sequentially from bottom to top; wherein the insulating layer 24 is used to electrically insulate the first photovoltaic device 20 from the second photovoltaic device 30. The second photovoltaic device 30 includes a second transparent front electrode layer 31, a second photovoltaic layer 32, a second back electrode layer 33, and an encapsulation layer 34 stacked sequentially from bottom to top.

[0064] This application designs and fabricates a stacked structure for solar cells in a vertically stacked manner, as detailed in the following reference. Figure 5 - Figure 12 The diagram illustrates the layer design of a Tandem device structure. During fabrication, the complete structure of the first photovoltaic device 20 (i.e., a stacked structure of the first transparent front electrode layer 21, the first photovoltaic layer 22, the first back electrode layer 23, and the insulating layer 24) is first fabricated on one surface of the substrate 10. Then, based on this structure, a front electrode auxiliary electrode of the first photovoltaic device 20 is fabricated; this auxiliary electrode is the second transparent front electrode layer 31 of the second photovoltaic device 30. This allows the second transparent front electrode layer 31 of the second photovoltaic device 30 to form a parallel connection with the first transparent front electrode layer 21 of the first photovoltaic device 20 through a via structure 40. Subsequently, the second photovoltaic layer 32, the second back electrode layer 33, and the encapsulation layer 34 of the second photovoltaic device 30 are fabricated sequentially.

[0065] Combination Figure 3 - Figure 5 as well as Figure 7 and Figure 11 As shown, the first back electrode layer 23 can be independently led out to the periphery of the device through the first back electrode lead-out terminal 231, and the second back electrode layer 33 can be independently led out to the periphery of the device through the second back electrode lead-out terminal 331. Both are electrically connected to the lead-out terminal overlap block 50 disposed around the effective power generation area, serving as one output electrode of the device. At the same time, the second transparent front electrode layer 31 is responsible for collecting charge carriers, which are conducted through the hole structure 40 to the first transparent front electrode layer 21 of the first photovoltaic device 20. Together with the charge carriers collected by the front electrode of the first photovoltaic device 20, they are combined and output to the transparent front electrode lead-out terminal 211 disposed around the entire stacked photovoltaic device, serving as the other output electrode of the device.

[0066] In one embodiment, the sheet resistance of the first transparent front electrode layer 21 is preferably less than 30 Ω / cm. 2 .

[0067] It is understood that the material of the first transparent front electrode layer 21 includes, but is not limited to, TCO (Transparent Conducting Oxide) materials, silver nanoparticles, graphene, carbon nanotubes, ultrathin metals, or conductive polymers with high electrical conductivity. This application does not impose specific limitations in this regard.

[0068] Specifically, the ultrathin metal mentioned above can be a metallic element or alloy with a thickness of less than 30 nm. The high-conductivity conductive polymer mentioned above can be polyacetylene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), or polybenzodifurandione (PBFDO) with a conductivity greater than 1000 S / cm. The TCO mentioned above can be AZO (Aluminum Doped Zinc Oxide), ITO (Indium Tin Oxide), or FTO (Fluorine-doped Tin Oxide).

[0069] In a specific example, when TCO material is used as the first transparent front electrode layer 21, the TCO layer can also be texturized so that the amorphous silicon layer can fully absorb the incident light.

[0070] In one embodiment, the amorphous silicon photovoltaic layer can be made of hydrogenated amorphous silicon (a-Si:H) produced by CVD (Chemical Vapor Deposition). The amorphous silicon solar cell can be a single-layer structure or a multilayer structure; this application does not impose specific limitations on this.

[0071] Specifically, the amorphous silicon photovoltaic layer has a PIN or NIP structure, where the P layer is a hole transport layer, the I layer is a photosensitive layer, and the N layer is an electron transport layer. Further, the amorphous silicon photovoltaic layer includes at least one set of P layers, I layers, and N layers stacked sequentially. The P layers can be stacked structures with energy level gradients (including P1, P2, ..., Pn); the N layers can also be stacked structures with energy level gradients (including N1, N2, ..., Nn).

[0072] In one embodiment, the sheet resistance of the first back electrode layer 23 is preferably less than 100 Ω / cm. 2 .

[0073] In a specific example, the material of the first back electrode layer 23 includes, but is not limited to, one or more of the following materials: TCO, nano-silver, graphene, carbon nanotubes, ultrathin metals, or conductive polymers with high electrical conductivity.

[0074] Among them, the ultrathin metal is preferably a single substance or alloy with a thickness of less than 30 nm, and is composed of one or more of Ag, Al, Cr, Cu, Au, Pt, Mo, Ti, Sn, and Mg metals; the conductive polymer with high electrical conductivity can be polyacetylene, PEDOT:PSS, or PBFDO with an electrical conductivity greater than 1000 S / cm.

[0075] As one embodiment, the first back electrode layer 23 has a single-cell transmittance greater than 30% in the 600nm-800nm ​​wavelength band. As another embodiment, the first back electrode layer 23 has a single-cell transmittance greater than 70% in the 400nm-600nm wavelength band. As yet another embodiment, the first back electrode layer 23 has a single-cell transmittance greater than 30% in the 600nm-800nm ​​wavelength band and a single-cell transmittance greater than 70% in the 400nm-600nm wavelength band.

[0076] In one embodiment, the insulating layer 24 may be made of a transparent photoresist material, such as polyimide resin, acrylic resin, phenolic resin, siloxane resin, etc.; or it may be a transparent inorganic thin film material, such as one or more of alumina, zirconium oxide, titanium oxide, silicon oxide, silicon nitride, or silicon oxynitride.

[0077] In one embodiment, the second transparent front electrode layer 31 is electrically connected to the first transparent front electrode layer 21 through a via structure 40 disposed on the first photovoltaic layer 22, the first back electrode layer 23, and the insulating layer 24, or through the outer edge of the insulating layer 24. Preferably, the minimum area of ​​the inner diameter of the via structure 40 is 10 μm. 2 .

[0078] In a specific example, the sheet resistance of the second transparent front electrode layer 31 is preferably less than 100 Ω / cm. 2 .

[0079] As one embodiment, the second transparent front electrode layer 31 has a single-cell transmittance greater than 30% in the 600nm-800nm ​​wavelength range. As another embodiment, the second transparent front electrode layer 31 has a single-cell transmittance greater than 70% in the 400nm-600nm wavelength range. As yet another embodiment, the second transparent front electrode layer 31 has a single-cell transmittance greater than 30% in the 600nm-800nm ​​wavelength range and a single-cell transmittance greater than 70% in the 400nm-600nm wavelength range.

[0080] It is understood that the material of the second transparent front electrode layer 31 includes, but is not limited to, one or more of the following materials: TCO, nano-silver, graphene, carbon nanotubes, ultrathin metals, or conductive polymers with high electrical conductivity.

[0081] Among them, the ultrathin metal is preferably a single substance or alloy with a thickness of less than 30 nm, and is composed of one or more of Ag, Al, Cr, Cu, Au, Pt, Mo, Ti, Sn, and Mg metals; the conductive polymer with high electrical conductivity can be polyacetylene, PEDOT:PSS, or PBFDO with an electrical conductivity greater than 1000 S / cm.

[0082] In one embodiment, the second photovoltaic layer 32 is specifically of the OPV or PSC type. This OPV or PSC type photovoltaic layer comprises a three-layer basic structure: an electron transport layer, a photovoltaic active layer, and a hole transport layer. In a specific example, the optical bandgap of the photovoltaic active layer material is preferably between 1.0 eV and 1.5 eV, exhibiting strong absorption of light waves in the 600 nm to 1000 nm range.

[0083] In specific examples, the OPV photovoltaic active layer material can be composed of polymer donors or small molecule donors and small molecule acceptors.

[0084] As an example, the OPV photovoltaic active layer material is composed of one or more of the polymer donor PTB7-Th and the small molecule acceptor IEIC or its derivatives (such as IEICO-4F). PTB7-Th is poly([2,6′-4,8-di(5-ethylhexylthiophene)benzo[1,2-b; 3,3-b]dithiophene]{3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}); IEIC is a non-fullerene electron acceptor molecule in the field of organic solar cells; and IEICO-4F is a non-fullerene small molecule acceptor based on IEIC but chemically modified with the introduction of fluorine atoms.

[0085] As another example, a combination of the small molecule donor "aluminum chlorophthalocyanine" and the receptor "fullerene and its derivatives" is used.

[0086] As another example, a combination of a material containing a "triphenylamine group" as a donor and "fullerene and its derivatives" as an acceptor is used.

[0087] In one embodiment, the sheet resistance of the second back electrode layer 33 is less than 5 Ω / cm. 2 .

[0088] In a specific example, the material of the second back electrode layer 33 is a metallic element or alloy, which may be composed of one or more of the following metals: Ag, Al, Cr, Cu, Au, Pt, Mo, Ti, Sn, and Mg.

[0089] In one embodiment, the encapsulation layer 34 can be prepared by ALD (Atomic Layer Deposition) or TFE (Thin Film Encapsulation), or a rigid or flexible solid material can be used as the encapsulation of the back cover device. A resin or adhesive with the function of blocking water vapor and absorbing water and oxygen can also be provided between the back cover and the back electrode.

[0090] It should be noted that the first photovoltaic device 20 and the second photovoltaic device 30 can be PIN type or NIP type; they can be series or parallel. Furthermore, at least one of the stacked photovoltaic devices can be a single-layer series multi-section design or a single-layer single-section design. This application does not impose specific limitations in these respects.

[0091] According to the solar cell 100 in Embodiment 1 of this application, as Figure 1 - Figure 12As shown, the second transparent front electrode layer 31 is electrically connected to the first transparent front electrode layer 21 of the first photovoltaic device 20 via a via structure 40, serving as both the front electrode of the first photovoltaic device 20 and the transparent front electrode of the second photovoltaic device 30, thus enabling the first photovoltaic device 20 and the second photovoltaic device 30 to form a parallel connection. During photovoltaic conversion in the second photovoltaic layer 32, the second transparent front electrode layer 31 collects charge carriers, which, along with the charge carriers collected by the front electrode of the first photovoltaic device 20, are combined through the via structure 40 and output to the transparent front electrode lead-out terminals 211 located around the entire stacked photovoltaic device. Meanwhile, the first back electrode layer 23 of the first photovoltaic device 20 and the second back electrode layer 33 of the second photovoltaic device 30 each have terminals leading out from the periphery of the device, connected to the lead-out terminal overlap block 50, also forming an electrical connection. Ultimately, the transparent front electrode lead-out terminals 211 and the lead-out terminal overlap block 50 serve as the positive and negative electrodes of the stacked device, respectively. The solar cells designed in this way have high photoelectric conversion efficiency and large output current, making them suitable for display devices, and their effects are particularly significant when applied to large-area photovoltaic devices and their display applications. Furthermore, it helps to promote the industrialization of OPV and PSC technologies, and facilitates the diversification of related products.

[0092] Example 2

[0093] This embodiment provides another type of solar cell. For example... Figure 13 As shown, the solar cell 100 uses a transparent substrate 10, which includes a stacked cell region and a light-transmitting cell region.

[0094] In the tandem battery region, the solar cell 100 includes a first photovoltaic device 20 and a second photovoltaic device 30 stacked together. The first photovoltaic device 20, stacked on a transparent substrate 10, is an amorphous silicon solar cell; the second photovoltaic device 30, stacked on the first photovoltaic device 20, is an organic solar cell or a perovskite solar cell. Preferably, the second photovoltaic device 30 is arranged to have an absorption spectrum complementary or nearly complementary to that of the first photovoltaic device 20.

[0095] In the light-transmitting cell region, the second photovoltaic device 30 extends from the stacked cell region to the upper surface of the transparent substrate 10, forming a photovoltaic structure on the light-transmitting cell region.

[0096] In other words, within the light-transmitting cell region of the solar cell 100, the structure is as follows: a second photovoltaic device 30 is disposed on the transparent substrate 10. That is, a second transparent front electrode layer 31, a second photovoltaic layer 32, a second back electrode layer 33, and an encapsulation layer 34 are stacked sequentially from bottom to top. Furthermore, within the stacked cell region of the solar cell 100, the structure is as follows: a first photovoltaic device 20 and a second photovoltaic device 30 are stacked sequentially from bottom to top on the transparent substrate 10. That is, a first transparent front electrode layer 21, a first photovoltaic layer 22, a first back electrode layer 23, an insulating layer 24, a second transparent front electrode layer 31, a second photovoltaic layer 32, a second back electrode layer 33, and an encapsulation layer 34 are stacked sequentially from bottom to top.

[0097] As a further preferred embodiment, such as Figure 14 As shown, the cell structure of the solar cell 100 in Embodiment 2 in the tandem cell region is the same as that in Embodiment 1. That is, in this preferred example, in the tandem cell region, the second transparent front electrode layer 31 of the second photovoltaic device 30 and the first transparent front electrode layer 21 of the first photovoltaic device 20 are electrically connected through the hole structure 40, so that the second transparent front electrode layer 31 can also be used as the auxiliary electrode of the front electrode of the first photovoltaic device 20, realizing the parallel connection of the two photovoltaic devices.

[0098] It should be noted that, in this preferred example, the characteristics and explanations of the tandem cell region of the solar cell described in Embodiment 1 above also apply to the tandem cell region of the solar cell in this type of preferred example, and will not be repeated here.

[0099] In one embodiment, such as Figure 13 As shown, in order to reduce the surface resistance of the first transparent front electrode layer 21, an auxiliary metal layer 212 may also be provided on its surface, below it, or inside it.

[0100] It is understood that the auxiliary metal layer 212 can be disposed in the effective power generation area of ​​the solar cell 100, in the peripheral area of ​​the solar cell 100, or in both the effective power generation area and the peripheral area of ​​the solar cell 100. This application does not impose specific limitations in this regard.

[0101] In a specific example, the auxiliary metal layer 212 can be made of one or more of the following metals: Ag, Al, Cr, Cu, Au, Mo, Ti, Sn, and Mg.

[0102] In one embodiment, the second transparent front electrode layer 31 has a transmittance of more than 30% in the visible light range (380nm-760nm), and the transmitted wavelength is determined according to the type of the first photovoltaic device 20 and the design requirements of the device's light-transmitting area.

[0103] In one embodiment, the second photovoltaic layer 32 includes a stacked electron transport layer, a photovoltaic active layer, and a hole transport layer. In a specific example, the thickness of the photovoltaic active layer is less than or equal to 60 nm, and the single-cell transmittance in the 400 nm-600 nm wavelength band is greater than 50%, to ensure that when applied to a display device, the light from the display screen can pass through the transmittance cell area, presenting a good display effect to the user.

[0104] As a further preferred option, the thickness of the photovoltaic active layer of the second photovoltaic layer 32 is in the range of 35nm-60nm, so as to balance better photovoltaic characteristics and transparency.

[0105] In one embodiment, the optical bandgap of the photovoltaic active layer material of the second photovoltaic layer 32 is between 1.0 eV and 1.5 eV, exhibiting strong absorption in the 600 nm-1000 nm wavelength band, with a normalized absorbance greater than 0.5 in this band. The normalized absorbance is a normalized representation of the photovoltaic active layer's ability to absorb light of different wavelengths within this band. Higher absorbance indicates that the photovoltaic active layer absorbs more light of that wavelength.

[0106] In specific examples, the OPV photovoltaic active layer material can be composed of polymer donors and small molecule acceptors, specifically one or more of P3HT and SF(DPPB)4, PTB7-Th and IEIC and IEIC derivatives (such as IEICO-4F).

[0107] Among them, P3HT is poly(3-hexylthiophene); SF(DPPB)4 has a cross-shaped spatial configuration with spirofluorene as the core, pyrrolopyrroledione as the arm, and phenyl as the end.

[0108] According to the solar cell 100 of Embodiment 2 of this application, by adding a light-transmitting cell structure in a specific area of ​​the substrate 10 (such as the display area of ​​the corresponding display panel), the output current of the photovoltaic device can be effectively increased based on the solar cell 100 in Embodiment 1, and the application effect of adapting to large-area display devices can be further optimized.

[0109] Example 3

[0110] This embodiment uses the following method to prepare the solar cell structure as described in Embodiment 1 or Embodiment 2 above.

[0111] The specific steps are as follows: forming a first transparent front electrode layer on the substrate → forming a first photovoltaic layer → forming a first back electrode layer → creating a pattern for the first back electrode layer → creating a pattern for the first photovoltaic layer → creating a pattern for the first transparent front electrode layer → forming an insulating layer and creating its pattern → forming a second transparent front electrode layer and creating its pattern → forming a second photovoltaic layer and creating its pattern → forming a second back electrode layer and creating its pattern → creating an encapsulation layer.

[0112] Example 4

[0113] This embodiment provides a display device (not shown in the figure) that includes a display panel and a solar cell as described in the above embodiment, wherein the solar cell is disposed on the display side of the display panel. That is, the display panel is stacked below the solar cell.

[0114] As one embodiment, the display device employs the solar cell described in Embodiment 1. The stacked cell area of ​​this solar cell can be offset from the VA area (display area) of the display panel.

[0115] In another embodiment, the display device employs the solar cell described in Embodiment 2. This solar cell comprises an opaque stacked cell region and a light-transmitting cell region, with the light-transmitting cell region overlapping or nearly overlapping the display area (VA area) of the display panel. In this embodiment, because the VA area of ​​the display panel is equipped with a transparent photovoltaic cell, the effective absorption and power generation area of ​​the photovoltaic is increased, thereby enabling the output of higher current.

[0116] In a specific example, the visible light transmittance of the transparent cell area of ​​the solar cell is between 40% and 90% to ensure better display effect and improve user experience.

[0117] In one embodiment, the display device located below the solar cell can be bonded to the encapsulation back cover of the solar cell using a transparent OCR (Optically Clear Resin) or OCA (Optically Clear Adhesive).

[0118] In one embodiment, the display panel structure includes an upper substrate and a lower substrate, wherein the upper substrate is disposed on the side closer to the photovoltaic layer of the solar cell, and the lower substrate is disposed on the side farther away from the photovoltaic layer of the solar cell, so that the display image is presented to the observer from the side of the upper substrate.

[0119] Preferably, the entire display panel can be used as the encapsulation back cover for its solar cells, which can effectively reduce the overall thickness and weight of the display device, improve the product's lightweight design, and further enhance the user experience.

[0120] It should be noted that the explanation of the solar cells in the above embodiments also applies to the display devices in the above embodiments, and will not be repeated here.

[0121] It is understood that the display device in this application can be a smartphone, a wearable device, an in-vehicle device, or other types of display device. This application does not impose any specific limitations on it.

[0122] It should be noted that the concepts of "first" and "second" mentioned in this application are only used to distinguish different devices, units or structures, and are not used to limit the order of the functions performed by these devices, units or structures, or their interdependence or relative importance.

[0123] It should be noted that the terms “one” and “multiple” used in this application are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as “one or more”; “multiple” should be understood as two or more.

[0124] In the description of this application, it should be noted that the relationship between structures should be interpreted broadly. For example, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", and "outer" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0125] Furthermore, it should be noted that, for clarity, the dimensions of layers, regions, and devices, as well as their relative dimensions, may be exaggerated in the accompanying drawings. Throughout, the same or similar reference numerals denote the same or similar devices or components with the same or similar functions.

[0126] It should be understood that when a structure or layer is referred to as being "on," "adjacent to," or "connected to" other components or layers, it may be directly on, adjacent to, or connected to other components or layers, or there may be intervening components or structures.

[0127] It should be noted that the specific values ​​mentioned above are only for illustrating the implementation of this application in detail, and should not be construed as limiting the application. In other implementation methods or embodiments, other values ​​may be selected according to this application, and no specific limitations are made here.

[0128] It will be understood by those skilled in the art that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A solar cell, characterized in that, The substrate of the solar cell includes a tandem cell region; In the stacked battery region, the solar cell includes: A first photovoltaic device, stacked on the substrate, is an amorphous silicon solar cell; and, The second photovoltaic device is stacked on top of the first photovoltaic device; The first photovoltaic device includes a first transparent front electrode layer disposed on the substrate; the second photovoltaic device includes a second transparent front electrode layer disposed on the first photovoltaic device; and the second transparent front electrode layer is connected to the first transparent front electrode layer through a hole structure, serving as an auxiliary electrode for the front electrode of the first photovoltaic device.

2. A solar cell, characterized in that, The transparent substrate of the solar cell includes a tandem cell region and a light-transmitting cell region; wherein, In the stacked battery region, the solar cell includes: A first photovoltaic device, stacked on the substrate, is an amorphous silicon solar cell; and, The second photovoltaic device is stacked on top of the first photovoltaic device; In the light-transmitting cell region, the second photovoltaic device extends from the stacked cell region to the upper surface of the transparent substrate, forming a photovoltaic structure on the light-transmitting cell region.

3. The solar cell according to claim 2, characterized in that, The visible light transmittance of the light-transmitting cell region ranges from 40% to 90%.

4. The solar cell according to claim 2, characterized in that, The first photovoltaic device includes a first transparent front electrode layer, a first photovoltaic layer, a first back electrode layer, and an insulating layer stacked sequentially from bottom to top; wherein the insulating layer is used to electrically insulate the first photovoltaic device from the second photovoltaic device. The second photovoltaic device includes a second transparent front electrode layer, a second photovoltaic layer, a second back electrode layer, and an encapsulation layer stacked sequentially from bottom to top.

5. The solar cell according to claim 4, characterized in that, The second transparent front electrode layer is connected to the first transparent front electrode layer through a hole structure, and serves as the auxiliary electrode of the front electrode of the first photovoltaic device.

6. The solar cell according to claim 4, characterized in that, At least one of the second transparent front electrode layer and the first back electrode layer, The transmittance of a single element in the 600nm-800nm ​​wavelength range is greater than 30%, and / or the transmittance of a single element in the 400nm-600nm wavelength range is greater than 70%.

7. The solar cell according to claim 4, characterized in that, At least one of the second transparent front electrode layer and the first back electrode layer has a sheet resistance of less than 100 Ω / cm. 2 ; and / or, The sheet resistance of the second back electrode layer is less than 50 Ω / cm 2 .

8. The solar cell according to claim 4, characterized in that, The second photovoltaic layer includes a stacked electron transport layer, a photovoltaic active layer, and a hole transport layer; wherein the photovoltaic active layer satisfies at least one of the following conditions: the thickness of the photovoltaic active layer is less than or equal to 60 nm; the single-cell transmittance in the 400 nm-600 nm band is greater than 50%; and the normalized absorbance in the 600 nm-1000 nm band is greater than 0.

5.

9. The solar cell according to claim 5, characterized in that, The aperture area of ​​the via structure is greater than 10 μm. 2 .

10. A display device, characterized in that, It includes a display panel and a solar cell as described in any one of claims 1-9, wherein the solar cell is disposed on the display side of the display panel.

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