All-polymer organic solar cell device and method of preparing the same

Abstract

This application relates to the field of solar cell technology and provides a polymeric organic solar cell device. The polymeric organic solar cell device includes a substrate, a hole transport layer, an active layer, an electron transport layer, and an electrode layer stacked sequentially. The active layer is prepared using a high-boiling-point environmentally friendly solvent. The active layer includes a donor and an acceptor. The donor is dissolved in the high-boiling-point environmentally friendly solvent, and the acceptor cooperates with the donor to form the active layer. In the polymeric organic solar cell device provided by this application, the active layer uses a high-boiling-point environmentally friendly solvent, replacing chloroform, a solvent with a low boiling point, low vapor pressure, and a tendency to produce high toxicity. This enables the large-area fabrication of the polymeric organic solar cell device. Furthermore, the vertical morphology of the active layer is more easily controlled, and the photoelectric conversion efficiency of the polymeric organic solar cell device can be significantly improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a polymer organic solar cell device and its preparation method. Background Technology

[0002] Organic solar cells are solar cells whose core components are composed of organic materials. They primarily use photosensitive organic materials as semiconductors, generating voltage and forming current through the photovoltaic effect, thus achieving solar power generation.

[0003] Organic solar cells (OSCs) offer advantages such as low production cost, flexibility, tunable color, and semi-transparency. As a novel third-generation photovoltaic technology, OSCs hold great promise for future energy applications. The competitiveness of OSCs primarily depends on their cost, power generation per unit weight, and low-energy, environmentally friendly manufacturing process.

[0004] In recent years, due to in-depth research on high-efficiency photovoltaic materials, device optimization, and interface engineering, bulk heterojunction (BHJ) OSCs using polymer donors and non-fullerene small molecule acceptors (SMAs) have also developed rapidly. The active layer in solar cells is mainly fabricated by combining donors and acceptors. Bulk heterojunction (BHJ) organic solar cells, formed by combining polymer donors and small molecule acceptors, have repeatedly achieved photoelectric conversion efficiencies (PCEs) exceeding 18%. Although this type of solar cell has high PCE, it also has some drawbacks: poor mechanical properties and insufficient stability under photothermal conditions.

[0005] In contrast, all-polymer organic solar cells (All-OSCs), composed of polymer donors and polymer acceptors, inherit the advantages of their predecessors and also possess higher tensile and flexural toughness, as well as potentially higher light (or thermal) stability. These properties give them better prospects for large-scale production, making All-OSCs a rapidly emerging hot topic in this field. To date, the photoelectric conversion efficiency of all-polymer organic solar cells has reached approximately 16%, demonstrating the enormous potential of this type of solar cell.

[0006] Currently, chloroform is mostly used as the active layer solvent in the field of all-polymer organic solar cells. However, chloroform has a low boiling point and is prone to oxidation, which produces highly toxic substances and is not conducive to the large-area fabrication of organic solar cells. Summary of the Invention

[0007] To address or partially address the aforementioned problems, this application provides a polymeric organic solar cell device comprising a substrate, a hole transport layer, an active layer, an electron transport layer, and an electrode layer stacked sequentially. The active layer is prepared using a high-boiling-point environmentally friendly solvent. The active layer includes a donor and an acceptor. The donor is dissolved in the high-boiling-point environmentally friendly solvent, and the acceptor cooperates with the donor to form the active layer.

[0008] In the polymer organic solar cell device provided by the above solution, the solvent of the active layer is a high-boiling-point environmentally friendly solvent, which replaces chloroform solvent with low boiling point, low vapor pressure and easy to produce toxicity, making it possible to manufacture the polymer organic solar cell device on a large scale.

[0009] As a further aspect of this application: the donor comprises a wide-bandgap polymer material, and the acceptor comprises a narrow-bandgap polymer.

[0010] As a further aspect of this application: the donor includes PM6, and the acceptor includes PYF-To.

[0011] As a further aspect of this application: the high-boiling-point environmentally friendly solvent includes one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution.

[0012] As a further aspect of this application: the substrate comprises glass on which a conductive material has been deposited.

[0013] This application also provides a method for fabricating a polymer organic solar cell device, the method comprising:

[0014] Provide a substrate on which a hole transport layer is formed;

[0015] On the hole transport layer, a PM6 film is formed using a high-boiling-point environmentally friendly solvent, and a receptor PYF-To film is formed on the PM6 film to obtain an active layer;

[0016] An electron transport layer and an electrode layer are formed sequentially on the active layer.

[0017] Compared with traditional solar cell fabrication methods, the above scheme mainly uses PM6 as a donor and PYF-To as an acceptor for the active layer, and is fabricated in two steps: forming a PM6 film on the substrate and forming an acceptor PYF-To film on the PM6 film. This makes the vertical morphology of the active layer easier to control and can greatly improve the photoelectric conversion efficiency of the polymer organic solar cell device.

[0018] At the same time, the use of high-boiling-point environmentally friendly solvents instead of chloroform solvents with low boiling point, low vapor pressure, and high toxicity makes it possible to fabricate this polymer organic solar cell device on a large scale.

[0019] As a further aspect of this application: the method of forming a PM6 film using a high-boiling-point environmentally friendly solvent includes:

[0020] The donor PM6 was dissolved in a high-boiling-point environmentally friendly solvent to obtain a PM6 solution, and the PM6 solution was stirred.

[0021] The PM6 solution is heated, and the cooled substrate is rotated while the PM6 solution is added dropwise to form a PM6 film on the substrate.

[0022] As a further aspect of this application: the formation of the receptor PYF-To membrane on the PM6 membrane includes:

[0023] The pre-prepared receptor PYF-To solution is dynamically spin-coated onto the PM6 membrane, making the receptor PYF-To solution miscible with the PM6 membrane, and simultaneously forming a receptor PYF-To membrane on the PM6 membrane.

[0024] As a further aspect of this application, the method also includes:

[0025] The receptor PYF-To is dissolved in a high-boiling-point environmentally friendly solvent to obtain an initial receptor PYF-To solution. An additive is added, and the initial receptor PYF-To solution is stirred to mix the additive with the receptor PYF-To solution to obtain a receptor PYF-To solution.

[0026] As a further aspect of this application: the high-boiling-point environmentally friendly solvent includes one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution.

[0027] This application provides a polymeric organic solar cell device, comprising a substrate, a hole transport layer, an active layer, an electron transport layer, and an electrode layer connected in sequence. The solvent of the active layer is a high-boiling-point environmentally friendly solvent, which replaces chloroform solvent, which has a low boiling point, low vapor pressure, and is prone to producing high toxicity. This makes it possible to fabricate the polymeric organic solar cell device over a large area.

[0028] Furthermore, compared to traditional solar cell fabrication methods, this application also provides a method for fabricating a polymeric organic solar cell device. This method primarily involves a two-step, layer-by-layer preparation of the active layer: the donor and acceptor solutions are prepared separately; a PM6 donor film is first prepared on a substrate, and then a PYF-To acceptor film is prepared on the PM6 film, thereby forming the active layer. This method of fabricating the active layer makes its vertical morphology easier to control and can significantly improve the photoelectric conversion efficiency of the polymeric organic solar cell device. Attached Figure Description

[0029] Figure 1This is a schematic diagram of the structure of the all-polymer organic solar cell device provided in the embodiments of this application.

[0030] Figure 2 This is a schematic diagram of the fabrication process of the all-polymer organic solar cell device provided in the embodiments of this application.

[0031] Figure 3 This is a schematic diagram of the fabrication process of the all-polymer organic solar cell device provided in the embodiments of this application.

[0032] Figure 4 This is a comparison chart of the current density curves and voltage curves of the all-polymer organic solar cell device provided in the embodiments of this application and existing solar cell devices.

[0033] Figure 5 This is a comparison chart of the short-circuit current density curve and light intensity curve of the all-polymer organic solar cell device provided in the embodiments of this application and existing solar cell devices.

[0034] Explanation of main components and symbols:

[0035] 100, Substrate; 200, Hole transport layer; 300, Active layer; 400, Electron transport layer; 500, Electrode layer.

[0036] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0038] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should be understood that, in order to clearly describe the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. For example, the first groove and the second groove are only used to distinguish different grooves and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0040] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0041] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0042] This application provides a polymeric organic solar cell device and its fabrication method. The device includes: providing a substrate; forming a hole transport layer on the substrate; forming a PM6 film on the hole transport layer using a high-boiling-point environmentally friendly solvent; and forming an acceptor PYF-To film on the PM6 film to obtain an active layer; and sequentially forming an electron transport layer and an electrode layer on the active layer to obtain the polymeric organic solar cell device. The solvent for the active layer is a high-boiling-point environmentally friendly solvent, replacing chloroform, a solvent with a low boiling point, low vapor pressure, and high toxicity, making large-area fabrication of the polymeric organic solar cell device possible. Furthermore, the active layer primarily uses PM6 as the donor and PYF-To as the acceptor, and is fabricated in two steps: forming a PM6 film on the substrate and forming an acceptor PYF-To film on the PM6 film. This makes the vertical morphology of the active layer easier to control, the electron and hole mobility easier to regulate, and significantly improves the photoelectric conversion efficiency of the polymeric organic solar cell device.

[0043] The following details the polymer organic solar cell device and its fabrication method.

[0044] The inventors of this application have discovered that currently, the vast majority of high-efficiency organic solar cells on the market use chloroform as the solvent for the active layer during manufacturing. The disadvantages of this solvent include its low boiling point, low vapor pressure, and susceptibility to toxic substances, which could lead to poisoning of operators and is also detrimental to the large-scale fabrication of organic solar cells.

[0045] To facilitate understanding, let's first give a brief introduction to chloroform. Chloroform, generally referring to trichloromethane, has the molecular formula CHCl3. It is a colorless, transparent liquid with a characteristic odor, is non-flammable, heavy, and volatile. It is sensitive to light; when exposed to light, it reacts with oxygen in the air, gradually decomposing to produce highly toxic phosgene (carbonyl chloride) and hydrogen chloride. Therefore, it is quite dangerous.

[0046] Therefore, if a high-boiling-point, low-toxicity, environmentally friendly solvent can be used to replace chloroform, it will be more suitable for the industrialization of organic solar cells.

[0047] In view of this, the present application provides a polymeric organic solar cell device, see [link to relevant documentation]. Figure 1 As shown, Figure 1This is a schematic diagram of the structure of the all-polymer organic solar cell device provided in an embodiment of this application. The device includes:

[0048] 100 for the substrate;

[0049] Hole transport layer 200, one side of which can be connected to one side of substrate 100;

[0050] The high-temperature resistant active layer 300 has one side that can be connected to the side of the hole transport layer 200 away from the substrate 100. The active layer 300 includes a donor and an acceptor. The donor is dissolved in a high-boiling-point environmentally friendly solvent, and the acceptor and the donor cooperate to form the active layer 300.

[0051] One side of the electron transport layer 400 can be connected to the side of the active layer 300 away from the hole transport layer 200;

[0052] One side of the electrode layer 500 can be connected to the side of the electron transport layer 400 away from the active layer 300.

[0053] By using high-boiling-point, environmentally friendly solvents, chloroform, a solvent with low boiling point, low vapor pressure, and potential for producing toxic substances, can be replaced. Compared to chloroform, high-boiling-point, environmentally friendly solvents offer better safety performance, and their high boiling point and environmentally friendly properties make them more suitable for fabricating solar cell devices.

[0054] High-boiling-point environmentally friendly solvents can include one of the following: toluene solution, o-xylene solution, tetrahydrofuran solution, trimethylbenzene solution, etc.

[0055] The inventors of this application have discovered that the substrate 100 may include a transparent conductive material deposited thereon, allowing operators to clearly see the location of the conductive material, which facilitates the fabrication of the positive electrode.

[0056] A conductive film is provided on the surface of the hole transport layer 200. The conductive film may include PEDOT:PSS, and the conductive film may contact the transparent conductive material indium tin oxide glass to form a positive electrode.

[0057] Furthermore, the transparent conductive material is preferably indium tin oxide glass. The donor in the active layer 300 includes a wide bandgap polymer material, such as PM6, and the acceptor includes a narrow bandgap polymer, such as PYF-To.

[0058] The electron transport layer 400 has a conductive film on its surface, and the conductive film is in contact with the transparent conductive material indium tin oxide glass to form a positive electrode.

[0059] A silver film is deposited on the electrode layer 500 to form a silver electrode, which is the negative electrode. The thickness of the silver film can be 90-110 nm, which can ensure that the prepared solar cell device is relatively lightweight.

[0060] Furthermore, the thickness of the silver film is preferably 100nm, which can ensure product performance while reducing the amount of silver electrode used and saving costs.

[0061] This application also provides a method for fabricating a fully polymeric organic solar cell device, see [link to relevant documentation]. Figure 2 , Figure 3 As shown, Figure 2 This is a schematic diagram of the fabrication process of the all-polymer organic solar cell device provided in the embodiments of this application.

[0062] Figure 3 This is a schematic diagram of the fabrication process of the polymer organic solar cell device provided in the embodiments of this application; the method includes the following steps:

[0063] S1. Provide a substrate 100 and form a hole transport layer 200 on the substrate 100;

[0064] In the embodiments of this application, the high-boiling-point environmentally friendly solvent may include one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution, but is not limited to the above solvents.

[0065] Furthermore, the inventors of this application have discovered that xylene solutions, tetrahydrofuran solutions, and trimethylbenzene solutions have a lower ability to dissolve the donor PM6 and the acceptor PYF-To compared to toluene solutions. Therefore, toluene solutions are preferred as the high-boiling-point environmentally friendly solvent.

[0066] Next, using toluene solution as an example, we will explain each step in detail.

[0067] Step S1 may further include: spin coating of substrate 100, thermal annealing and cooling to form hole transport layer 200.

[0068] The spin coating operation may include steps S11-S13:

[0069] S11. Coat the substrate 100 with PEDOT:PSS solution;

[0070] S12. Place the substrate 100 on the suction cup of the spin coater, set the parameters of the spin coater, and start the spin coater to spin coat the substrate 100.

[0071] S13. Remove the coated substrate 100 and place it on a heating table for heat annealing.

[0072] Specifically, a PEDOT:PSS solution can be pre-prepared, and then an appropriate amount of the PEDOT:PSS solution can be drawn using a syringe. The solution is then filtered through a hydrophobic filter head, which can hold a volume of 0.45 μl. The filtered PEDOT:PSS solution is then coated onto a substrate 100.

[0073] Understandably, a PEDOT:PSS solution is an aqueous solution of a high-molecular-weight polymer with high conductivity. It is primarily composed of two substances: PEDOT and PSS. Depending on the ratio of these two substances, aqueous solutions with different conductivity can be obtained. PEDOT is a polymer of EDOT (i.e., 3,4-ethylenedioxythiophene monomer), and PSS is polystyrene sulfonate.

[0074] Place the substrate 100 on the suction cup of the spin coater and set the spin coater speed, for example, the speed can be set to 4000-6000 rpm, preferably 5000 rpm.

[0075] After setting the rotation speed, start the spin coater to spin coat the substrate 100. The spin coating time can be 20-40 seconds, preferably 30 seconds.

[0076] Remove the coated substrate 100 and place it on a heating stage at 100-140°C for 5-15 minutes of heat annealing, preferably on a heating stage at 120°C for 10 minutes of heat annealing.

[0077] Understandably, hot annealing is a metal heat treatment process to change the morphology of the active layer. It refers to slowly heating the metal to a certain temperature, holding it for a sufficient time, and then cooling it at an appropriate rate, so that the molecules in the organic layer move under the action of thermodynamics, and the morphology changes.

[0078] Spin coating mainly refers to the process of first applying paint droplets (i.e., PEDOT:PSS solution) to a substrate 100, and then starting the spin coater. The spin coater rotates the substrate 100, and the centrifugal force and gravity generated by the rotation of the substrate 100 cause the paint droplets (i.e., PEDOT:PSS solution) falling on the substrate 100 to be evenly distributed on the surface of the substrate 100. Spin coating can make the paint droplets evenly distributed on the surface of the substrate 100.

[0079] The inventors of this application have also discovered that if glass with a transparent conductive material deposited on it is used as the substrate 100, it can be easily combined with the electron transport layer 400 to create a positive electrode.

[0080] Preferably, the transparent conductive material may include indium tin oxide (i.e., ITO). Considering the actual size of the solar cell device, the dimensions of the substrate 100 may be 15mm*15mm*1mm.

[0081] S2. Using a toluene solution, a PM6 membrane is formed on the hole transport layer 200, and a receptor PYF-To membrane is formed on the PM6 membrane to obtain an active layer 300.

[0082] Multiple experiments revealed that the polymer donor PM6 exhibits excellent experimental repeatability and stability, allowing for repeated use. The polymer acceptor PYF-To, derived through the derivation and polymerization of a symmetrical small-molecule acceptor, retains the advantages of small-molecule acceptors while enhancing the film-forming properties, mechanical properties, additional electron transport channels, and improved photothermal stability of the active layer 300. PYF-To itself has also undergone fluorination treatment on its original molecular structure, resulting in excellent solubility. Furthermore, the absorption spectrum undergoes a red shift after fluorination, which, from another perspective, increases the final device current.

[0083] Therefore, using a combination of donor PM6 and acceptor PYF-To can make the energy level transition of solar cell devices more natural, which is conducive to exciton separation; it also makes the light absorption ranges of the two materials, donor PM6 and acceptor PYF-To, complementary, which greatly improves the photoelectric conversion efficiency of solar cell devices.

[0084] Furthermore, step S2 specifically includes steps S21-S23:

[0085] S21. Dissolve the donor PM6 in toluene solution to obtain PM6 solution, and stir the PM6 solution.

[0086] Heat the PM6 solution, and use a spin coater to rotate the cooled substrate 100 while simultaneously adding PM6 solution dropwise to form a PM6 film on the substrate 100.

[0087] Specifically, in step S21, the toluene solution is measured into a solvent bottle A, and then the donor PM6 is placed in solvent bottle A to obtain a PM6 solution. The concentration of the PM6 solution can be 5 mg / ml to 12 mg / ml, preferably 8 mg / ml.

[0088] In addition, to accelerate the dissolution of PM6, the solvent bottle (e.g., a beaker, flask, etc.) can be placed on a heating platform and heated. The temperature of the heating platform is set to 50-70°C, preferably 60°C.

[0089] Furthermore, while heating the PM6 solution, a stirring device can be used to stir the PM6 solution in solvent bottle A at a temperature of 50-70℃ for 1.5-2.5 hours, preferably 2 hours. When spin-coating the PM6 solution, the spin coater speed and time can be set to 1500rpm-2500rpm and 25s-50s, respectively, preferably 2000rpm and 35s.

[0090] The mixing and heating equipment can be purchased directly from the market, so we will not go into too much detail about it here.

[0091] S22, A receptor PYF-To membrane is formed on the PM6 membrane.

[0092] Step S22 may further include: dynamically spin-coating the receptor PYF-To solution onto the PM6 membrane, with the spin coater speed and time being 1500rpm-2500rpm and 25s-50s, preferably 2000rpm and 35s, respectively. This forms a receptor PYF-To membrane on the PM6 membrane, at which point the two layers form an interpenetrating network structure.

[0093] Specifically, step S22 may also include preparing a receptor PYF-To solution.

[0094] First, the freshly extracted toluene solution can be placed into solvent bottle B. Then, the receptor material PYF-To is dissolved in solvent bottle B to obtain the initial receptor PYF-To solution. The concentration of the initial receptor PYF-To solution can be 8 mg / ml to 18 mg / ml, preferably 12 mg / ml.

[0095] Similarly, to accelerate the dissolution of the acceptor material PYF-To, a heating stage can be used to heat the initial acceptor PYF-To solution in solvent bottle B. The heating temperature of the heating stage can be between 50-70°C, preferably 60°C. While heating the initial acceptor PYF-To solution, a stirring device can be used to stir the initial acceptor PYF-To solution in solvent bottle B. The stirring time can be 1-2.5 hours, preferably 1.5 hours.

[0096] After the stirring operation is completed, wait for the initial acceptor PYF-To solution to cool down. Then, add an additive with a volume volume of 2% to the cooled initial acceptor PYF-To solution. The additive can be 1-chloronaphthalene (CN).

[0097] After adding the additive, stir at room temperature for 0.3-1 h to fully mix the additive with the initial receptor PYF-To solution, preferably for 0.5 h, to finally obtain the receptor PYF-To solution.

[0098] S23. Using a spin coater, the receptor PYF-To solution, which is fully mixed with the additive, is dynamically spin-coated onto the PM6 membrane.

[0099] The receptor PYF-To solution, after being thoroughly mixed with the additives, can rapidly swell the lower layer, i.e., become miscible with the PM6 membrane. At the same time, it can also rapidly form a receptor PYF-To membrane on the surface of the PM6 membrane, resulting in an active layer 300.

[0100] S3. An electron transport layer 400 and an electrode layer 500 are sequentially formed on the active layer 300.

[0101] The step of forming the electron transport layer 400 may include:

[0102] A certain weight of methanol solution can be weighed and placed in solvent bottle C. Acetic acid with a volume ratio of 0.3-1% (preferably 0.5%) is added to solvent bottle C. The methanol solution and acetic acid are stirred together until they are evenly mixed.

[0103] Weigh a certain amount of electron transport layer 400 material, preferably PNDIT-F3N. Add PNDIT-F3N to solvent bottle C at a rate of 0.5 mg / ml. During the addition of PNDIT-F3N, stir the methanol solution and acetic acid at room temperature for 8-12 minutes, preferably 10 minutes, ensuring that PNDIT-F3N is completely dissolved to obtain an electron transport solution.

[0104] Using a spin coater, the electron transport solution is dynamically spin-coated onto the acceptor PYF-To film to obtain the electron transport layer 400. After the dynamic spin coating is completed, an existing scraper (e.g., a scraper blade) can be used to scrape open any side of the electron transport layer 400, allowing the hole transport layer 200 to come into contact with the bottom transparent conductive material, indium tin oxide glass, to form a positive electrode.

[0105] The dynamic spin coating parameters of the spin coater can be 1500rpm-2500rpm, preferably 2000rpm, and the dynamic spin coating time can be 30s-40s, preferably 35s.

[0106] It is important to emphasize that dynamic spin coating is not the same as spin coating operation. The following example, using a substrate C with a film A and a film B to be formed on film A, will explain dynamic spin coating:

[0107] During the spin coating process, while the substrate C is rotating, a solution is simultaneously added dropwise onto membrane A. This process ensures the solution on membrane A is evenly distributed, facilitating the formation of a new membrane B on membrane A. Dynamic spin coating accelerates the dissolution of the solution with membrane A, while simultaneously forming a new membrane B on membrane A.

[0108] Furthermore, the detailed steps for fabricating the electrode layer 500 may include the following steps:

[0109] S34. Using a thermal evaporation coating apparatus, silver is deposited on the side of the electron transport layer 400 away from the active layer 300 to obtain the electrode layer 500.

[0110] To facilitate understanding of the specific steps involved in fabricating electrode layer 500, a detailed explanation will be provided below:

[0111] S341. Turn on the main power of the thermal evaporation coating instrument, turn on the cooling water circulation machine, and open the vent valve to break the vacuum to normal pressure; breaking the vacuum means breaking the vacuum state.

[0112] The prepared substrate 100, hole transport layer 200, active layer 300, and electron transport layer 400 are placed in a mask. Then, the substrate 100, hole transport layer 200, active layer 300, electron transport layer 400, and mask are placed together in a thermal evaporation coating apparatus; wherein, the mask may have a specific pattern, which means a pattern that can be selected manually.

[0113] S342. After placing silver particles into the evaporation boat of the thermal evaporation coating machine, close the evaporation chamber door and start the thermal evaporation coating machine to deposit silver electrodes on the surface of the electron transport layer 400. The silver electrodes are the electrode layer 500.

[0114] The silver electrode thickness can be 90nm-110nm, preferably 100nm. A thickness of 90-110nm ensures that the fabricated solar cell device is relatively lightweight. A thickness of 100nm is preferred, as it ensures product performance while reducing the amount of silver electrode used, thus saving costs.

[0115] It should be noted that the thermal evaporation coating machine is existing equipment and can be purchased directly on the market. The connection relationships between the circulating water machine, vent valve, and other structures disclosed above are also existing technologies, so the connection relationships of each structure will not be described in detail here.

[0116] To facilitate understanding of how silver plating is performed, the specific steps for silver plating using a thermal evaporation coating machine are explained below:

[0117] 1) First, close the vent valve, then open the mechanical pump and pre-extraction valve in sequence to extract the chamber pressure of the thermal evaporation coating instrument to 0.1 Pa, and then close the pre-extraction valve.

[0118] 2) Next, sequentially open the fore-stage valve, molecular pump, and main valve to obtain a high vacuum. Ensure the chamber vacuum reaches at least 10⁻⁴ Pa.

[0119] 3) Then, current is applied to the evaporation boat. As the current increases, the temperature of the tungsten boat in the evaporation boat rises. The temperature of the tungsten boat is controlled by controlling the current, so that the evaporation rate of silver is controlled. The evaporation rate is controlled at 0.5 / s-1 / s. When the thickness of the silver electrode finally reaches 100nm, the current is turned off.

[0120] 4) Next, close the main valve, molecular pump and fore-stage valve in sequence. When the speed of the molecular pump drops to 0, turn off the mechanical pump and open the vent valve to break the vacuum.

[0121] 5) Finally, the sample consisting of the substrate 100, hole transport layer 200, active layer 300, electron transport layer 400 and electrode layer 500 stacked in sequence is taken out to obtain the polymer organic solar cell device.

[0122] Traditional solar cell fabrication methods utilize chloroform solvents, which have low boiling points, low vapor pressures, and are prone to producing highly toxic substances, posing significant risks and hindering large-area fabrication and roll-to-roll printing production of organic solar cells. In contrast, the polymeric organic solar cell device fabricated in this application uses environmentally friendly solvents with high boiling points, offering high safety and ease of fabrication. Furthermore, the active layer 300 primarily employs PM6 as the donor and PYF-To as the acceptor, fabricated through a two-step process: forming a PM6 film on the substrate 100 and then forming a PYF-To acceptor film on the PM6 film. This allows for greater control over the vertical morphology of the active layer 300 and significantly improves the photoelectric conversion efficiency of the polymeric organic solar cell device.

[0123] To verify the performance of the polymeric organic solar cell device fabricated using this method, the performance of the polymeric organic solar cell device prepared by this method and that prepared by conventional methods were compared and tested under the same conditions. The test results are shown below. Figure 4 , Figure 5 As shown, Figure 4 This is a comparison chart of the current density curves and voltage curves of the all-polymer organic solar cell device provided in the embodiments of this application and existing solar cell devices. Figure 5 The short-circuit current density curves and light intensity curves of the all-polymer organic solar cell device provided in the embodiments of this application and existing solar cell devices are shown. Figure 4 , Figure 5 In the text, "BC-PM6:PYF-To" represents the traditional one-step preparation method, while "SqP-PM6 / PYF-To" represents the preparation method of this application.

[0124] exist Figure 4 In this context, open-circuit voltage (VOC) mainly refers to the voltage obtained when the positive and negative electrodes of an organic solar cell are open-circuited under illumination (i.e.,...). Figure 4 The open-circuit voltage (voltage at zero current density) is typically expressed in volts (V). It is primarily related to the energy difference between the LUMO level of the acceptor and the HOMO level of the donor, providing the driving force for charge separation in the device. Simultaneously, the open-circuit voltage is also related to factors such as the morphology of the active layer 300, electrode materials, and surface modification layers. It can be seen that the open-circuit voltage of the polymeric organic solar cell device in this application is approximately 0.905V.

[0125] Short-circuit current density (JSC) is defined as the current per unit area obtained when the positive and negative electrodes of an organic solar cell are short-circuited under illumination, i.e., the maximum output current density, with units of mA / cm². 2 The effect is mainly influenced by factors such as the absorption spectrum range and intensity of the donor-acceptor materials in the active layer 300, exciton extraction and recombination, carrier mobility, and the morphology of the active layer 300. In other words, see [link to relevant documentation]. Figure 4 As shown, when the voltage is zero, the circuit is short-circuited, and the short-circuit current is obtained. Dividing the short-circuit current by the corresponding device area gives the short-circuit current density (JSC). Therefore, the short-circuit current density of the all-polymer organic solar cell device fabricated by this method can be calculated to be 25.16 mA / cm².

[0126] The fill factor (FF) is defined as the ratio of a device's maximum output power to the product of its open-circuit voltage and short-circuit current. Specifically, it is the ratio of the product of the maximum operating current (Jmax) and the maximum operating voltage (Vmax) to the product of the short-circuit current density (JSC) and the open-circuit voltage (VOC), and is a dimensionless quantity. Factors affecting the FF include the morphology of the active layer 300, carrier mobility, and the device's series resistance. The fill factor can be calculated and has a value of 0.695.

[0127] Power conversion efficiency (PCE) is defined as the ratio of maximum output power (Pmax) to incident light intensity (Plight), and is directly proportional to open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor (FF). The PCE value can be calculated using relevant formulas and is 15.82%.

[0128] The formulas for calculating the fill factor and photoelectric conversion efficiency are already available, so they will not be explained here.

[0129] Using the same method, the open-circuit voltage of the solar cell device prepared by the existing method is 0.898V, the short-circuit current density is 23.51mA / cm2, the fill factor is 0.673, and the photoelectric conversion efficiency is 14.21%. Comparison of the above data shows that the polymeric organic solar cell device prepared in this application has a better donor-acceptor match and significantly improved performance.

[0130] In addition, see Figure 5 As shown, compared with solar cell devices prepared by traditional methods, the polymer organic solar cell devices prepared by this method have less carrier recombination and can perform better photoelectric conversion.

[0131] Charge carriers refer to freely moving charged particles, such as electrons and ions. In semiconductor physics, vacancies (holes) left in covalent bonds due to electron loss are considered charge carriers. In metals, charge carriers are electrons; in semiconductors, there are two types: electrons and holes. Charged particles are charged particles that can move in a directed manner under the influence of an electric field. Examples include free electrons and holes in semiconductors, free electrons in conductors, positive and negative ions in electrolytes, and ions in discharge gases.

[0132] In some embodiments, the substrate 100 may be pre-processed before step S1. The pre-processing step may include:

[0133] First, ultrasonic treatment is performed. This mainly involves using commercially available ultrasonic equipment to sequentially ultrasonicate the substrate 100 in soapy water, deionized water, acetone solvent, and isopropanol solvent for 3-10 minutes, with the preferred ultrasonic time being 5 minutes.

[0134] Understandably, the ultrasonic treatment times for substrate 100 in soapy water, deionized water, acetone, and isopropanol can be the same or different. For example, substrate 100 can be ultrasonicated in soapy water for 3 minutes, in deionized water for 4 minutes, in acetone for 5 minutes, and in isopropanol for 6 minutes; or it can be ultrasonicated in soapy water, deionized water, acetone, and isopropanol for 5 minutes each. After ultrasonic treatment, substrate 100 can be removed and dried.

[0135] The inventors of this application have also discovered that solar cells prepared using a clean and dust-free substrate 100 exhibit better conductivity. Therefore, in the step of drying the substrate 100, a nitrogen gun can be used to dry the substrate 100, followed by sterilization treatment using ultraviolet light or ozone for 20-40 minutes, preferably 30 minutes.

[0136] After the substrate has been treated with ultraviolet or ozone for 100%, proceed with step S1.

[0137] It should be noted that the ultraviolet or ozone treatment methods can include: irradiating the substrate 100 with an ultraviolet lamp; or: pre-filling the box structure with ozone, and then placing the substrate 100 inside the box structure. Of course, the embodiments of this application are not limited to only these two treatment methods.

[0138] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A polymeric organic solar cell device, characterized in that, The device comprises a substrate, a hole transport layer, an active layer, an electron transport layer, and an electrode layer stacked sequentially. The active layer is prepared using a high-boiling-point environmentally friendly solvent. The active layer includes a donor and an acceptor. The donor is dissolved in the high-boiling-point environmentally friendly solvent, and the acceptor combines with the donor to form the active layer. The donor includes a wide-bandgap polymer material, and the acceptor includes a narrow-bandgap polymer. The donor includes PM6, and the acceptor includes PYF-To. The high-boiling-point environmentally friendly solvent includes one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution. The acceptor PYF-To solution is dynamically spin-coated onto a PM6 membrane at a spin coater speed of 2000 rpm and a spin coater time of 35 s, forming an acceptor PYF-To membrane on the PM6 membrane. At this point, the two layers form an interpenetrating network structure.

2. The polymeric organic solar cell device as described in claim 1, characterized in that, The substrate includes indium tin oxide glass deposited with a transparent conductive material.

3. A method for fabricating a polymeric organic solar cell device, characterized in that, The preparation method includes: Provide a substrate on which a hole transport layer is formed; On the hole transport layer, a PM6 film is formed using a high-boiling-point environmentally friendly solvent, and a receptor PYF-To film is formed on the PM6 film to obtain an active layer; An electron transport layer and an electrode layer are sequentially formed on the active layer; the donor includes a wide bandgap polymer material, and the acceptor includes a narrow bandgap polymer; the donor includes PM6, and the acceptor includes PYF-To; the high-boiling-point environmentally friendly solvent includes one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution; the acceptor PYF-To solution is dynamically spin-coated onto the PM6 membrane at a spin coater speed of 2000 rpm and a time of 35 s, so that the acceptor PYF-To solution forms an acceptor PYF-To membrane on the PM6 membrane, at which point the two layers form an interpenetrating network structure.

4. The method for preparing the all-polymer organic solar cell device as described in claim 3, characterized in that, The method of forming a PM6 film using a high-boiling-point environmentally friendly solvent includes: The donor PM6 was dissolved in a high-boiling-point environmentally friendly solvent to obtain a PM6 solution, and the PM6 solution was stirred. The PM6 solution is heated, and the cooled substrate is rotated while the PM6 solution is added dropwise to form a PM6 film on the substrate.

5. The method for preparing the polymeric organic solar cell device as described in claim 4, characterized in that, The formation of the receptor PYF-To membrane on the PM6 membrane includes: The pre-prepared receptor PYF-To solution is dynamically spin-coated onto the PM6 membrane, making the receptor PYF-To solution miscible with the PM6 membrane, and simultaneously forming a receptor PYF-To membrane on the PM6 membrane.

6. The method for preparing the polymeric organic solar cell device as described in claim 5, characterized in that, The method further includes: The receptor PYF-To is dissolved in a high-boiling-point environmentally friendly solvent to obtain an initial receptor PYF-To solution. An additive is added, and the initial receptor PYF-To solution is stirred to mix the additive with the receptor PYF-To solution to obtain a receptor PYF-To solution.

7. The method for preparing a polymeric organic solar cell device according to any one of claims 3-6, characterized in that, The high-boiling-point environmentally friendly solvent includes one of toluene solution, o-xylene solution, tetrahydrofuran solution, and trimethylbenzene solution.

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