A special plastic passivated organic solar cell hole transport structure and a preparation method and application thereof

Abstract

The application provides a special plastic passivated organic solar cell hole transport structure and a preparation method and application thereof, and the special plastic passivated organic solar cell hole transport structure comprises a metal oxide layer and a special plastic passivation layer covering the surface of the metal oxide layer; the special plastic passivation layer is made of special plastic, and the special plastic is selected from any one of polyether sulfone, a functionalized polyether sulfone derivative and a blend of polyether sulfone and other polymers; and the metal oxide layer comprises any one of a molybdenum oxide layer, a nickel oxide layer, a tungsten oxide layer and a vanadium oxide layer. According to the application, the surface defects of the metal oxide layer are effectively passivated by the special plastic, charge recombination centers are reduced, interface energy level matching is optimized, defects of the hole transport layer are effectively reduced, hole transport efficiency is improved, charge recombination is inhibited, carrier transport efficiency is improved, and the energy conversion efficiency and stability of the organic solar cell are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of thin-film solar cell technology, and in particular to a hole transport structure for a special plastic passivated organic solar cell, its preparation method, and its application. Background Technology

[0002] Organic solar cells have become a highly promising new energy technology due to their outstanding advantages such as low cost, solution-processability, light weight, and large-area fabrication. In the structural system of organic solar cells, the hole transport layer is one of the core components determining the cell's performance, and it is crucial for controlling the interface energy level, extracting photogenerated carriers, and improving device stability.

[0003] Currently, hole transport layers in organic solar cells are mainly classified into two categories: polymer-based and metal oxide-based. Among polymer materials, polyvinyl dioxythiophene-polystyrene sulfonate (PEDOT:PSS) has become the most widely used hole transport medium due to its excellent light transmittance, suitable conductivity, convenient solution processability, and tunable work function. However, this material has significant limitations: on the one hand, commercially available PEDOT:PSS aqueous solutions are difficult to achieve uniform spin-coating deposition on the hydrophobic organic active layer surface, easily leading to poor interfacial contact; on the other hand, its strong acidity (pH value of approximately 1-2) corrodes indium tin oxide (ITO) electrodes, and its hygroscopicity accelerates the harmful degradation of the active layer. These factors together lead to a significant decrease in the long-term operational stability of the device, limiting its further development in practical applications and making it difficult to meet industrialization requirements.

[0004] To address the acidity and hygroscopicity issues of PEDOT:PSS, metal oxide hole transport materials, such as molybdenum oxide, nickel oxide, and tungsten oxide, have attracted widespread attention due to their excellent chemical inertness and stability. Unlike PEDOT:PSS, metal oxides are less prone to adverse interfacial reactions with organic active layers, and their excellent hydrophobic properties effectively prevent external moisture and oxygen from penetrating the device, thereby delaying the photoelectric aging process of the active layer. Furthermore, metal oxides can be prepared using various low-cost solution methods, such as sol-gel, hydrothermal, and spray pyrolysis, and are compatible with the low-temperature processing requirements of flexible substrates such as polyethylene terephthalate (PET) and polyimide (PI). More importantly, metal oxide films exhibit stable film quality and small batch-to-batch performance variations (relative standard deviation <5%), demonstrating excellent process repeatability. This makes them ideal for roll-to-roll mass production, laying a solid foundation for the industrial application of organic solar cells.

[0005] However, solution-prepared metal oxide thin films still face significant challenges in practical applications. First, low-temperature solution processes or non-stoichiometric growth easily lead to numerous defects on the film surface and in the bulk phase, such as oxygen vacancies, dangling bonds, and hydroxyl groups (-OH). These defects form deep-level traps in the band gap of the metal oxide, capturing holes during transport, resulting in a significant decrease in carrier mobility and an increased probability of nonradiative charge recombination, thereby reducing the device's fill factor (FF) and short-circuit current density (Jsc). Second, the work function of pure metal oxides often does not perfectly match the highest occupied molecular orbital (HOMO) level of adjacent organic active layers. This increases the hole injection barrier at the interface, leading to a significant decrease in the device's open-circuit voltage (Voc) (sometimes below 0.7 V), severely restricting the widespread application of metal oxides as high-performance hole transport layers.

[0006] Therefore, how to effectively passivate surface defects and optimize the interfacial energy level arrangement of metal oxides while retaining their inherent stability and processability advantages, so as to improve the energy conversion efficiency and long-term stability of organic solar cells, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a special plastic passivated organic solar cell hole transport structure, its preparation method and application, to solve the problems of severe charge recombination, low hole extraction efficiency and poor device stability faced by existing metal oxide hole transport layers in practical applications.

[0008] To achieve the above and other related objectives, the present invention provides a special plastic passivated organic solar cell hole transport structure, comprising:

[0009] A metal oxide layer and a special plastic passivation layer covering the surface of the metal oxide layer;

[0010] The special plastic passivation layer is made of special plastic, which is selected from any one of polyethersulfone, functionalized polyethersulfone derivatives, and blends of polyethersulfone with other polymers.

[0011] The metal oxide layer includes any one of a molybdenum oxide layer, a nickel oxide layer, a tungsten oxide layer, and a vanadium oxide layer.

[0012] This application employs polymer materials to modify the surface of metal oxides. Polyethersulfone (PES), as a high-performance engineering plastic, possesses excellent thermal stability, chemical inertness, and film-forming properties; however, its application in passivating defects in the hole transport layer of metal oxides has not been reported. This invention selects any one of polyethersulfone, functionalized polyethersulfone derivatives, and blends of polyethersulfone with other polymers as the passivating agent for the metal oxide layer. This is because the polyethersulfone molecule contains aromatic rings, ether bonds, sulfone groups, and other functional groups. The sulfone groups (-SO2-) in the polyethersulfone molecule have a strong electron-withdrawing ability and can form coordination interactions with defect sites on the surface of metal oxides; the ether bonds (-O-) have a certain degree of flexibility, which helps to form a dense and uniform film; and the aromatic ring structure endows the material with good thermal stability and hydrophobicity. This application uses special plastics to passivate the hole transport layer, effectively reducing defects in the hole transport layer, suppressing charge recombination, and improving carrier transport efficiency.

[0013] Preferably, the other polymers are selected from one or more of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and polymethyl methacrylate (PMMA).

[0014] Preferably, the polyethersulfone has a molecular weight of 1000~5000 g / mol and a molecular weight distribution index ≤2.5.

[0015] Preferably, the thickness of the metal oxide layer is 10~20nm, and the thickness of the special plastic passivation layer is 4~6nm.

[0016] Preferably, the functionalized polyethersulfone derivative is prepared by chemical modification of polyethersulfone or copolymerization of monomers containing functional groups.

[0017] Preferably, the functional group is selected from any one of carboxyl (-COOH), sulfonic acid (-SO3H), amino (-NH2), and phosphate (-PO3H2).

[0018] Preferably, the hole transport structure of the special plastic passivated organic solar cell further includes a functional material layer, which covers the surface of the special plastic passivation layer. The material of the functional material layer is selected from any one of self-assembled monolayers (SAMs), graphene quantum dots, and polyoxometalate compounds.

[0019] More preferably, the self-assembled monolayer is (2-(9H-carbazole-9-yl)ethyl)phosphonic acid 2PACZ or (tetra(4-aminodicyanostyryl)benzene) 4PADCB.

[0020] More preferably, the polymetallic oxy-oxide compound is phosphomolybdic acid or phosphotungstic acid.

[0021] The polyoxometallic cluster compounds provided in this application, after forming a thin film on the surface of a special plastic passivation layer, can serve as an interface modification material to effectively improve the film density of the interface modification layer and reduce its surface roughness, thereby improving device performance. For example, when applied to electrode interface modification, they can also be used to adjust the surface work function of the electrode.

[0022] This invention also provides a method for preparing the hole transport structure of the above-mentioned special plastic passivated organic solar cell, comprising the following steps:

[0023] (1) Dissolve the special plastic in an organic solvent to obtain a special plastic coating liquid;

[0024] (2) The special plastic coating liquid is applied to the surface of the metal oxide layer; during the coating process, process parameters such as spin coating speed, spraying pressure, and immersion time are controlled to ensure that the special plastic coating liquid can uniformly cover the surface of the metal oxide layer.

[0025] (3) Annealing: A special plastic passivation layer is formed on the surface of the metal oxide layer to obtain a hole transport structure for a special plastic passivated organic solar cell. During the annealing process, the polyethersulfone molecular chain segments rearrange and form a stable interface bond with the metal oxide surface. At the same time, the residual solvent is removed, and the sulfone groups (-SO2-) in the polyethersulfone molecules coordinate with the oxygen vacancies or dangling bonds on the metal oxide surface to form a stable chemical bond. The polyethersulfone molecular chains cover the surface of the metal oxide, fill the surface defects, and reduce the defect state density. At the same time, the polyethersulfone thin layer can act as a protective layer to block external water and oxygen erosion and improve the interface stability.

[0026] Preferably, in step (1), the organic solvent is selected from one or a mixture of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) and dimethyl sulfoxide (DMSO).

[0027] Preferably, in step (1), the concentration of the special plastic in the special plastic coating liquid is 0.5~5 mg / mL.

[0028] Preferably, in step (2), the coating is applied by spin coating or blade coating.

[0029] Preferably, in step (2), the metal oxide layer can be prepared by wet methods such as spin coating, blade coating, inkjet printing, etc., or by dry methods.

[0030] Preferably, in step (3), the annealing temperature is 100~150℃ and the annealing time is 10~15min.

[0031] The present invention also provides an application of the above-mentioned special plastic passivated organic solar cell hole transport structure in the fabrication of organic solar cells.

[0032] The present invention also provides an organic solar cell, comprising, in order from bottom to top, a transparent substrate, a bottom electrode layer, the aforementioned special plastic passivated organic solar cell hole transport structure, an organic active layer, an electron transport layer, and a top electrode layer.

[0033] Under illumination, the organic active layer of an organic solar cell absorbs photons and generates excitons (electron-hole pairs). These excitons dissociate at the donor-acceptor interface to form free charge carriers. Holes migrate to the bottom electrode through the hole transport layer, while electrons migrate to the top electrode through the electron transport layer. Because the hole transport layer of the aforementioned organic solar cell is passivated with a special plastic, the defect state density on the metal oxide surface is significantly reduced, charge recombination is effectively suppressed, and holes can be transported to the electrodes more efficiently. This improves the cell's open-circuit voltage, short-circuit current, and fill factor, ultimately enhancing the cell's energy conversion efficiency. Simultaneously, the special plastic passivation layer possesses excellent hydrophobicity and chemical stability, enhancing the hole transport layer's resistance to water and oxygen corrosion and extending the cell's lifespan.

[0034] Preferably, the transparent substrate is glass or an organic film.

[0035] More preferably, the material of the organic film is thermoplastic polyurethane elastomer (TPU), polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN).

[0036] Preferably, the bottom electrode layer is selected from any one of indium tin oxide thin film, silver nanowire thin film and translucent silver thin film.

[0037] Preferably, the organic active layer is composed of a blend of donor and acceptor materials.

[0038] The donor material is selected from one or more of oligothiophene materials, triphenylamine materials, benzodithiophene materials, and pyrrolopyrroledione materials; the acceptor material is a non-fullerene fused ring electron acceptor material.

[0039] More preferably, the benzodithiophene polymer is PM6, and the non-fullerene fused ring electron acceptor material is Y6 or L8-BO.

[0040] Preferably, the material of the electron transport layer is a metal oxide or an organic compound.

[0041] Preferably, the metal oxide is tin oxide or zinc oxide.

[0042] Preferably, the organic compound is selected from poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)) dibromide (PFN-Br) and poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)). Any one of (PFN), 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthrone[2,1,9-DEF:6,5,10-D'E'F']diisoquinoline (PDINN), and N,N'-bis[3-(dimethylamino)propyl]perylene-3,4,9,10-tetracarboxylic acid diimide (PDIN).

[0043] Preferably, the material of the top electrode layer is a metal, a conductive nanomaterial, or a multilayer electrode material.

[0044] More preferably, the metal is selected from any one of Ag, Al, Cu and Au.

[0045] More preferably, the conductive nanomaterial is a metal nanowire or nanoparticle.

[0046] More preferably, the multilayer electrode material is selected from any two or more of ITO, Ag, Al, Cu and Au.

[0047] The present invention also provides an organic solar cell module including the above-described organic solar cells.

[0048] As described above, the present invention has the following beneficial effects:

[0049] (1) By effectively passivating the surface defects of the metal oxide layer with special plastics, the charge recombination centers are reduced, the interface energy level matching is optimized, the defects of the hole transport layer are effectively reduced, the hole transport efficiency is improved, the charge recombination is suppressed, the carrier transport efficiency is improved, and thus the energy conversion efficiency and stability of organic solar cells are significantly improved.

[0050] (2) The polyethersulfone molecule contains aromatic rings, ether bonds, sulfone groups and other functional groups. The sulfone group (-SO2-) in the polyethersulfone molecule has a strong electron-withdrawing ability and can form coordination with the defect sites on the surface of metal oxides; the ether bond (-O-) has a certain degree of flexibility, which helps to form a dense and uniform film; the aromatic ring structure gives the material good thermal stability and hydrophobicity.

[0051] (3) The hole transport layer of the organic solar cell is passivated with special plastics. The defect state density on the surface of the metal oxide is significantly reduced, the charge recombination is effectively suppressed, and the holes can be transported to the electrode more efficiently, thereby improving the open circuit voltage, short circuit current and fill factor of the cell, and ultimately improving the energy conversion efficiency of the cell. Attached Figure Description

[0052] Figure 1 The diagram shows the structure of an organic solar cell.

[0053] Figure 2 The results of stability tests for the organic solar cells prepared in Example 1 and Comparative Example 1 are shown.

[0054] Explanation of reference numerals: 1. Transparent substrate; 2. Bottom electrode layer; 3. Metal oxide layer; 4. Special plastic passivation layer; 5. Organic active layer; 6. Electron transport layer; 7. Top electrode layer. Detailed Implementation

[0055] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0056] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0057] Furthermore, it should be understood that the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, does not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise stated. It should also be understood that the combined connection relationship between one or more devices / apparatus mentioned in this invention does not preclude the existence of other devices / apparatus before or after the combined devices / apparatus, or the insertion of other devices / apparatus between these explicitly mentioned devices / apparatus, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or limiting the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0058] Example 1

[0059] This application provides a method for fabricating a hole transport structure for a special plastic passivated organic solar cell, including:

[0060] (1) Wet preparation of nickel oxide thin films:

[0061] Ink preparation: Nickel acetate tetrahydrate was dissolved in ethylene glycol monomethyl ether at a concentration of 10 mg / mL, and aged overnight with stirring at room temperature. Then, acetylacetone at a volume ratio of 10% was added and stirred for 30 min. The ink was filtered through a 0.45 μm PES aqueous filter before coating.

[0062] Preparation of nickel oxide thin film: The ink was coated onto the substrate material by common methods such as spin coating and blade coating. After drying and annealing, a nickel oxide thin film was formed with a thickness of 15 nm. The spin coating process was carried out under the following conditions: 3000 rpm for 30 s; heating at 120℃ for 5 min, then heating at 320℃ for 1 h, cooling to 120℃ and then transferring to a glove box to cool to room temperature.

[0063] (2) Fabrication of hole transport structure for passivated organic solar cells using special plastics:

[0064] Polyethersulfone was dissolved in N,N-dimethylformamide (DMF) and stirred at room temperature for 1 hour to prepare a special plastic coating solution with a concentration of 1 mg / mL.

[0065] A special plastic coating liquid was applied to a nickel oxide film by spin coating. After annealing at 100°C for 10 minutes, a special plastic passivation layer with a thickness of 5 nm was formed on the surface of the nickel oxide film. The spin coating speed was 4000 rpm and the time was 30 seconds, thus obtaining the nickel oxide / polyethersulfone hole transport layer, which is the hole transport structure of the special plastic passivated organic solar cell.

[0066] like Figure 1 As shown, this embodiment also provides an organic solar cell, including a transparent substrate 1, a bottom electrode layer 2, a metal oxide layer 3, a special plastic passivation layer 4, an organic active layer 5, an electron transport layer 6, and a top electrode layer 7, which are stacked sequentially from bottom to top.

[0067] The transparent substrate is made of glass, the bottom electrode layer is made of ITO cathode, the metal oxide layer is made of the aforementioned nickel oxide thin film, the special plastic passivation layer is made of the aforementioned polyethersulfone layer, the organic active layer is made of PM6:L8-BO active layer, the electron transport layer is made of ZnO nanoparticles, and the top electrode layer is made of Ag anode.

[0068] This embodiment also provides a method for preparing the above-mentioned organic solar cell, including the following steps:

[0069] Preparation of the organic active layer: PM6 (donor material) and L8-BO (acceptor material) were weighed at a mass ratio of 1:1.2, and o-xylene solvent was added at a total concentration of 24 mg / mL. The mixture was heated and stirred at 80°C for 6 hours. The ink was then coated onto the substrate material using common methods such as spin coating and blade coating. After drying and annealing, the organic active layer was formed. The spin coating process was performed at 3000 rpm for 30 seconds and annealed at 100°C for 10 minutes.

[0070] Preparation of the electron transport layer: Zinc oxide nanoparticles were dissolved in methanol at a concentration of 10 mg / ml. The ink was coated onto the active layer by common methods such as spin coating and blade coating. The electron transport layer was obtained by annealing at 80℃ for 5 min. The spin coating process was carried out at 3000 rpm for 30 s.

[0071] Transfer the scraped sheet into the vapor deposition chamber. When the vacuum level inside the vapor deposition chamber is less than 1×10⁻⁶, -5 After reaching mbar, vacuum evaporation of the metal can begin. The total silver electrode thickness to be deposited is approximately 100 nm, resulting in an effective area of ​​0.11815 cm² based on the evaporation template. -2 OSCs batteries.

[0072] Example 2

[0073] The difference between Example 2 and Example 1 lies in the material of the special plastic passivation layer in the hole transport structure of the special plastic passivated organic solar cell. Specifically, sulfonated polyethersulfone is used, and the process includes the following steps:

[0074] Sulfonated polyethersulfone was dissolved in N,N-dimethylformamide (DMF) and stirred at room temperature for 1 hour to prepare a special plastic coating solution with a concentration of 2 mg / mL.

[0075] The ink was coated onto a nickel oxide film using a spin coating process. After annealing at 100°C for 10 minutes, a special plastic passivation layer with a thickness of 15 nm was formed on the surface of the nickel oxide film. The spin coating speed was 6000 rpm and the time was 30 seconds. This process yielded a nickel oxide / sulfonated polyethersulfone hole transport layer, which is the hole transport structure of the special plastic passivated organic solar cell.

[0076] The organic solar cell in this embodiment differs from that in Embodiment 1 in that the hole transport structure of the special plastic passivated organic solar cell is different. It uses the above-mentioned nickel oxide / sulfonated polyethersulfone hole transport layer, while the other components and their preparation methods are exactly the same as in Embodiment 1.

[0077] Example 3

[0078] The difference between Example 3 and Example 1 is that the preparation method of the nickel oxide film is different. Specifically, it is prepared by dry method through PVD process, and the thickness of the nickel oxide film is 15nm. The rest of the structure and preparation method are exactly the same as those in Example 1.

[0079] Example 4

[0080] The difference between Example 4 and Example 2 is that the preparation method of the nickel oxide film is different. Specifically, it is prepared by dry method through PVD process, and the thickness of the nickel oxide film is 15nm. The rest of the structure and preparation method are exactly the same as those in Example 2.

[0081] Example 5

[0082] The difference between Example 5 and Example 1 is that the material of the metal oxide layer in the hole transport structure of the special plastic passivated organic solar cell is different. Specifically, a molybdenum oxide thin film is used, and the molybdenum oxide thin film with a thickness of 18 nm is prepared by PVD process. The other components and their preparation methods are exactly the same as in Example 1.

[0083] Example 6

[0084] The difference between Example 6 and Example 5 is that the preparation method of the molybdenum oxide film is different, specifically prepared by a wet process. The other components and their preparation methods are exactly the same as in Example 1.

[0085] Methods for wet preparation of molybdenum oxide thin films:

[0086] (1) Preparation of ink: Ammonium tetramolybdate dihydrate ((NH4)2Mo4O 13 Dissolve ·2H2O) in deionized water to obtain a precursor solution with a concentration of 3.5 mg / mL; stir overnight at 90°C with a magnetic stirrer at 500 rpm to ensure uniform heat distribution, and then filter through a 0.45 μm syringe filter to obtain an ammonium molybdate precursor solution;

[0087] (2) Preparation of wet molybdenum oxide film: The ink was coated onto the substrate material by spin coating, followed by annealing and other post-treatments to form a molybdenum oxide film with a thickness of 18 nm. The spin coating process conditions were: 3000 rpm, 30 s, 280 °C for 10 min, and then cooled to 150 °C before being transferred to a glove box to cool to room temperature.

[0088] The organic solar cell device provided in this embodiment includes an ITO cathode, a molybdenum oxide layer, a polyethersulfone layer, a PM6:L8-BO active layer, a ZnO electron transport layer, and an Ag anode.

[0089] Example 7

[0090] The difference between Example 7 and Example 3 lies in the material of the special plastic passivation layer in the hole transport structure of the special plastic passivated organic solar cell. Specifically, it uses a blend of polyethersulfone and polymethyl methacrylate (PMMA) for passivation, including the following steps:

[0091] Polyethersulfone and polymethyl methacrylate were dissolved in DMF at a mass ratio of 9:1 and stirred at room temperature for 1 hour to obtain a special plastic coating solution with a concentration of 2 mg / mL.

[0092] Preparation of polyethersulfone and polymethyl methacrylate film: The ink was coated onto a nickel oxide film by spin coating, and then annealed at 100°C for 10 min to form a polyethersulfone and polymethyl methacrylate film. The spin coating process was performed at a speed of 6000 rpm for 30 s.

[0093] The organic solar cell device provided in this embodiment includes an ITO cathode, a nickel oxide layer, a polyethersulfone and polymethyl methacrylate layer, a PM6:L8-BO active layer, a ZnO electron transport layer, and an Ag anode.

[0094] Example 8

[0095] The difference between Example 8 and Example 3 is that the hole transport structure of the special plastic passivated organic solar cell is different. Specifically, it also includes a functional material layer covering the surface of the special plastic passivation layer polyethersulfone layer. The material of the functional material layer is (2-(9H-carbazole-9-yl)ethyl)phosphonic acid 2PACZ. The rest of the structure and preparation method are exactly the same.

[0096] Example 9

[0097] The difference between Example 9 and Example 3 is that the hole transport structure of the special plastic passivated organic solar cell is different. Specifically, it also includes a functional material layer covering the surface of the special plastic passivation layer polyethersulfone layer. The material of the functional material layer is (tetra(4-aminodicyanostyryl)benzene)4PADCB. The rest of the structure and preparation method are exactly the same.

[0098] Comparative Examples 1-7 (using unpassivated solar cells)

[0099] Comparative Examples 1 to 7 correspond to Examples 1 to 7, respectively. The difference between each group is that it does not include the special plastic passivation layer. Specifically, it consists of: ITO cathode, oxide layer, PM6:L8-BO active layer, ZnO electron transport layer, and Ag anode.

[0100] Comparative Examples 8-9

[0101] Comparative Examples 8 and 9 correspond to Examples 8 and 9, respectively. The difference between them and Examples 8 and 9 is that they do not include the special plastic passivation layer and the functional material layer. Specifically, they are: ITO cathode, oxide layer, PM6:L8-BO active layer, ZnO electron transport layer, and Ag anode.

[0102] The performance of the organic solar cells prepared in Examples 1-8 and Comparative Examples 1-8 was tested under standard test conditions (AM 1.5G, 100 mW / cm²). 2 The S100 digital source table was used for testing. The test results are shown in Table 1:

[0103] Table 1. Performance test results of organic solar cells prepared in Examples 1-8 and Comparative Examples 1-8

[0104]

[0105] In Table 1, Voc is the open-circuit voltage, Jsc is the short-circuit current density, FF is the fill factor, and PCE is the power conversion efficiency.

[0106] As shown in Table 1, the organic solar cell employing the special plastic passivation hole transport structure of this application exhibits significantly better performance than the organic solar cell without the special plastic passivation hole transport structure. The energy conversion efficiency of the organic solar cell prepared in Example 3 is more than 15% higher than that of Comparative Example 3. The energy conversion efficiency of the organic solar cell in Comparative Example 3, using an unpassivated nickel oxide hole transport layer, is only 14.21%, while the energy conversion efficiency of the organic solar cell in Example 3, using a nickel oxide / polyethersulfone hole transport structure obtained after polyethersulfone passivation treatment, can be increased to 16.73%. Similarly, the energy conversion efficiency of the organic solar cell in Comparative Example 6, using an unpassivated molybdenum oxide hole transport layer, is 16.71%, while the energy conversion efficiency of the organic solar cell in Example 6, using a molybdenum oxide / polyethersulfone hole transport structure obtained after polyethersulfone passivation treatment, is increased to 17.74%.

[0107] Table 1 also shows that the performance of organic solar cells with hole transport structures passivated by special plastics with added functional material layers is improved compared to the standard. In Example 8, the energy conversion efficiency of the organic solar cell with a nickel oxide / polyethersulfone / 2PACZ hole transport structure after polyethersulfone passivation and 2PACZ treatment is increased to 16.47%; in Example 9, the energy conversion efficiency of the organic solar cell with a nickel oxide / polyethersulfone / 4PACZ hole transport structure after polyethersulfone passivation and 4PACZ treatment is increased to 17.66%, even higher than the 16.73% energy conversion efficiency of the organic solar cell with a nickel oxide / polyethersulfone hole transport structure obtained only after polyethersulfone passivation in Example 3. The above data comparison shows that passivating the hole transport layer with special plastics significantly improves the fill factor and short-circuit current density of organic solar cell devices, effectively reduces defects in the hole transport layer, suppresses charge recombination, and improves carrier transport efficiency. A comparison of the data from Examples 3 and 4 shows that using hole transport layers passivated with different types of special plastics can produce an unexpected technical effect of simultaneously increasing both open-circuit voltage and short-circuit current density.

[0108] The stability of the organic solar cells prepared in Example 1 and Comparative Example 1 was tested. An aging test was conducted for 500 hours under ambient humidity of 85% and temperature of 85°C. The test results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the organic solar cell prepared by this invention can still maintain an initial energy conversion efficiency of over 90%, while the energy conversion efficiency of the unpassivated cell drops to below 48% of the initial value. This indicates that the special plastic passivation treatment significantly improves the stability of the organic solar cell.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A hole transport structure for a special plastic passivated organic solar cell, characterized in that, include: A metal oxide layer and a special plastic passivation layer covering the surface of the metal oxide layer; The special plastic passivation layer is made of special plastic, which is selected from any one of polyethersulfone and functionalized polyethersulfone derivatives; the metal oxide layer includes any one of molybdenum oxide layer, nickel oxide layer, tungsten oxide layer and vanadium oxide layer; the thickness of the special plastic passivation layer is 4~6 nm.

2. The hole transport structure of the special plastic passivated organic solar cell according to claim 1, characterized in that: The polyethersulfone has a molecular weight of 1000~5000 g / mol and a molecular weight distribution index ≤2.5; the thickness of the metal oxide layer is 10~20 nm; the functionalized polyethersulfone derivative is prepared by chemical modification of polyethersulfone or copolymerization of monomers containing functional groups; the functional group is selected from any one of carboxyl, sulfonic acid, amino, and phosphate groups.

3. The hole transport structure of the special plastic passivated organic solar cell according to claim 1, characterized in that: The hole transport structure of the special plastic passivated organic solar cell also includes a functional material layer, which covers the surface of the special plastic passivation layer. The material of the functional material layer is selected from any one of self-assembled monolayers, graphene quantum dots, and polyoxometalate compounds.

4. A method for preparing a hole transport structure for a special plastic passivated organic solar cell as described in any one of claims 1 to 3, characterized in that: Includes the following steps: (1) Dissolve the special plastic in an organic solvent to obtain a special plastic coating liquid; (2) The special plastic coating liquid is applied to the surface of the metal oxide layer; (3) Annealing is performed to form a special plastic passivation layer on the surface of the metal oxide layer, thereby obtaining a hole transport structure for a special plastic passivated organic solar cell.

5. The preparation method according to claim 4, characterized in that: In step (1), the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and dimethyl sulfoxide; the concentration of the special plastic in the special plastic coating liquid is 0.5~5 mg / mL; in step (2), the coating is applied by spin coating or blade coating; in step (3), the annealing temperature is 100~150℃ and the annealing time is 10~15 min.

6. The application of a special plastic passivated organic solar cell hole transport structure as described in any one of claims 1 to 3 in the fabrication of organic solar cells.

7. An organic solar cell, characterized in that: It includes a transparent substrate, a bottom electrode layer, a hole transport structure of a special plastic passivated organic solar cell as described in any one of claims 1 to 3, an organic active layer, an electron transport layer, and a top electrode layer, which are stacked sequentially from bottom to top.

8. The organic solar cell according to claim 7, characterized in that: The transparent substrate is glass or an organic film; the bottom electrode layer is selected from any one of indium tin oxide thin films, silver nanowire thin films, and translucent silver thin films; the organic active layer is composed of a blend of donor and acceptor materials; the donor material is selected from one or more of oligothiophene materials, triphenylamine materials, benzodithiophene materials, and pyrrolopyrroledione materials; the acceptor material is a non-fullerene fused ring electron acceptor material; the electron transport layer is made of metal oxides or organic compounds; the top electrode layer is made of metal, conductive nanomaterials, or multilayer electrode materials.

9. The organic solar cell according to claim 8, characterized in that: The organic membrane is made of thermoplastic polyurethane elastomer, polyimide, polyethylene terephthalate, or polyethylene naphthalate; the benzodithiophene polymer is PM6; the non-fullerene fused-ring electron acceptor material is Y6 or L8-BO; the metal oxide is tin oxide or zinc oxide; the organic compound is selected from poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)) dibromide, poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl-2,7-fluorene)-alt-2,7 The metal is selected from any one of (9,9-dioctylfluorene), 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthrone[2,1,9-DEF:6,5,10-D'E'F']diisoquinoline and N,N'-bis[3-(dimethylamino)propyl]perylene-3,4,9,10-tetracarboxylic acid diimide; the metal is selected from any one of Ag, Al, Cu and Au; the conductive nanomaterial is a metal nanowire or nanoparticle; the multilayer structure electrode material is selected from any two or more of ITO, Ag, Al, Cu and Au.

10. An organic solar cell module, characterized in that: Including the organic solar cell described in any one of claims 7 to 9.

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