Annealing device and preparation method of organic solar cell

Abstract

The application discloses an annealing device and a preparation method of an organic solar cell. The annealing device comprises a sealed box, a humidity detector arranged in the sealed box and used for detecting the relative humidity in the sealed box, a humidifier arranged in the sealed box, a dehumidifier arranged in the sealed box, a heating table arranged in the sealed box, and a culture dish arranged on the heating table and used for containing a post-processing solvent and an organic active layer of the solar cell, so as to perform a solvent vapor annealing treatment on the organic active layer of the solar cell. The device can control the relative humidity in the sealed box, simulate an air environment, and perform the solvent vapor annealing treatment on the organic active layer of the solar cell. The solvent vapor forms a protective layer outside the organic active layer, so as to prevent the water vapor and oxygen in the sealed box from contacting the organic active layer of the solar cell, thereby improving the open-circuit voltage, the fill factor and the short-circuit current of the organic solar cell.

Description

Technical Field

[0001] This invention relates to the field of organic solar cell technology, and in particular to an annealing apparatus and a method for preparing organic solar cells. Background Technology

[0002] In related technologies, the core of organic solar cells is an organic active layer formed by blending donor and acceptor materials. Photogenerated excitons separate and charge is transported here. When the organic active layer and cathode interface modification layer are solution-treated in a relatively humid air environment, the carrier mobility and exciton diffusion length of the donor and acceptor materials in the organic active layer are low, resulting in the organic active layer's inability to effectively absorb sunlight. This leads to low photoelectric conversion efficiency of organic solar cells, which is detrimental to future large-scale, low-cost roll-to-roll production processes. Summary of the Invention

[0003] This application proposes an annealing apparatus and a method for fabricating organic solar cells to solve the technical problem that thermal annealing of the organic active layer of organic solar cells in an air environment with high relative humidity (RH) leads to poor morphology and low photoelectric conversion efficiency.

[0004] On one hand, this application provides an annealing apparatus for post-processing the organic active layer of a solar cell. The annealing apparatus includes: Sealed box; A humidity detector is installed inside the sealed box and used to detect the relative humidity inside the sealed box; A humidifier is installed inside the sealed box; A dehumidifier is installed inside the sealed box; A heating platform is installed inside the sealed box; A petri dish is placed on the heating stage and used to contain the post-treatment solvent and the organic active layer of the solar cell for solvent vapor annealing of the organic active layer of the solar cell.

[0005] Optionally, the annealing device further includes a control unit, which is communicatively connected to the humidity detector, the humidifier, the dehumidifier, and the heating platform, respectively. The control unit is used to control the working status of the humidifier, the dehumidifier, and the heating platform.

[0006] Optionally, the post-treatment solvent is chloroform.

[0007] Optionally, the relative humidity inside the sealed box is 30%~95%, and the heating temperature of the heating table is 60℃~120℃.

[0008] On the other hand, this application also provides a method for preparing an organic solar cell, comprising: A transparent substrate is provided, the transparent substrate comprising a substrate and an anode layer; An anode interface modification layer is prepared on the anode layer; An organic active layer is prepared on the anode interface modification layer; A transparent substrate with the organic active layer attached is placed in the culture dish of the annealing apparatus according to any one of claims 1-4 to perform solvent vapor annealing on the organic active layer. A cathode interface modification layer is prepared on the organic active layer after solvent vapor annealing. A metal electrode is fabricated on the cathode interface modification layer.

[0009] Optionally, before preparing the anode interface modification layer on the anode layer, the method further includes: Perform initial cleaning of the transparent substrate; For deep cleaning, place the transparent substrate in the cleaning solution and sonicate for 10 to 20 minutes. Dry the transparent substrate in an oven at 70℃~90℃; For transparent substrates, use ultraviolet or plasma ozone cleaning for 15 to 30 minutes.

[0010] Optionally, the preparation of the anode interface modification layer on the anode layer includes: PEDOT:PSS was spin-coated onto a transparent substrate using a spin coater at a speed of 3000 rpm to 5000 rpm for 25 to 30 seconds. The spin-coated PEDOT:PSS was then subjected to hot-table annealing at 100℃~150℃ for 10min~15min.

[0011] Optionally, the preparation of the organic active layer on the anode interface modification layer includes: PM6 and L8-BO were dissolved in the first solvent to form a donor-acceptor mixed solution, thus obtaining the original solution of the organic active layer. The original organic active layer solution was heated at 40℃~60℃ for 0.5h~1.5h to obtain the organic active layer solution. The organic active layer solution is coated onto the anode interface modification layer.

[0012] Optionally, the concentration of PM6 is 7 mg / mL to 8 mg / mL, the concentration of L8-BO is 8.4 mg / mL to 9.6 mg / mL, the mass ratio of PM6 to L8-BO is 1:1 to 1:1.2, and the first solvent is chloroform, chlorobenzene, toluene, or o-xylene.

[0013] Optionally, the preparation of the cathode interface modification layer on the organic active layer after solvent vapor annealing includes: PNDIT-F3N is dissolved in a second solvent to obtain a cathode interface modification layer solution, wherein the concentration of the cathode interface modification layer solution is 0.5 mg / mL to 1 mg / mL; The cathode interface modification layer solution was spin-coated onto the organic active layer and allowed to stand and dry for 10 to 20 minutes.

[0014] As can be seen from the above technical solutions, the annealing device provided in this application can control the relative humidity inside the sealed box to simulate an air environment. The annealing device can also perform solvent vapor annealing on the organic active layer of the solar cell. The solvent vapor can form a protective layer outside the organic active layer to prevent water vapor and oxygen inside the sealed box from contacting the organic active layer of the solar cell, thereby significantly improving its open-circuit voltage, fill factor and short-circuit current, and obtaining higher photoelectric conversion efficiency and collection advantages. Moreover, by adjusting the relative humidity and heating temperature inside the sealed box, the influence of different relative humidity and heating temperature on the organic active layer during solvent vapor annealing can be detected, thereby determining the optimal relative humidity and heating temperature. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the annealing apparatus of the present invention; Figure 2 This is a schematic diagram of an organic solar cell structure according to an embodiment of the present invention; Figure 3 The JV curves of the organic solar cells of Example 1 and Comparative Example 1 of the present invention under AM 1.5G standard simulated sunlight are shown. Figure 4 The JV curves of the organic solar cells of Example 2 and Comparative Example 1 of the present invention under AM 1.5G standard simulated sunlight are shown. Figure 5 The JV curves of the SVA post-processing of organic solar cells of Example 3 and Comparative Example 1 of the present invention under different humidity conditions and simulated sunlight under AM 1.5G standard are shown.

[0017] Explanation of reference numerals in the attached figures: 10. Annealing apparatus; 11. Sealed box; 111. Sealed cover; 12. Humidity detector; 13. Humidifier; 14. Dehumidifier; 15. Heating platform; 16. Petri dish; 20. Organic solar cell; 21. Transparent substrate; 211. Substrate; 212. Anode layer; 22. Anode interface modification layer; 23. Organic active layer; 24. Cathode interface modification layer; 25. Metal electrode; 26. Positive electrode. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should also 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.

[0020] 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.

[0021] like Figure 1 As shown, this application provides an annealing apparatus 10 for post-processing the organic active layer 23 of a solar cell, achieving high-performance morphology optimization of the organic solar cell 20, ensuring stable performance of the organic solar cell 20 under extremely high humidity conditions, and improving the photoelectric conversion efficiency of the organic solar cell 20. The annealing apparatus 10 includes a sealed box 11, a humidity detector 12, a humidifier 13, a dehumidifier 14, a heating stage 15, and a petri dish 16.

[0022] For example, such as Figure 1As shown, the sealed enclosure 11 is used to create a sealed environment, isolating it from external temperature and humidity fluctuations and airflow interference. The material of the sealed enclosure 11 is selected from at least one of quartz glass, polytetrafluoroethylene (PTFE), or stainless steel. For example, quartz glass has thermal stability and light transmittance, ensuring the sealed enclosure 11 remains stable under high-temperature annealing conditions, while also facilitating observation of the real-time status of the petri dish 16 samples within the sealed enclosure 11 by those skilled in the art. PTFE is corrosion-resistant, preventing the corrosion and adhesion of organic solvents and avoiding solvent erosion of the inner wall of the sealed enclosure 11. Stainless steel combines high strength and rigidity, ensuring that the sealed enclosure 11 does not rust or deform during long-term use in high-humidity environments.

[0023] Optionally, the sealed box 11 is equipped with a sample stage to place a humidity detector 12, a humidifier 13, a dehumidifier 14, a heating stage 15, and a petri dish 16. The sealed box 11 is provided with uniformly distributed gas guide holes to ensure the uniform spatial distribution of temperature and humidity inside the sealed box 11 and to avoid local condensation or dry dead corners when the air humidity in the sealed box 11 is high.

[0024] Optionally, the sealed box 11 is generally rectangular in shape, with a sealing cover 111 connected to the top. The sealing cover 111 is movably mounted on the sealed box 11 to cover or expose the humidity detector 12, humidifier 13, dehumidifier 14, heating stage 15, and petri dish 16. When the sealing cover 111 is covering, it provides a sealed and stable reaction environment, preventing external air from affecting the solvent vapor annealing (SVA) process. When the sealing cover 111 is exposed, those skilled in the art can remove the humidity detector 12, humidifier 13, dehumidifier 14, heating stage 15, and petri dish 16 from the sealed box 11. The sealing cover 111 also serves to hold experimental consumables, facilitating sample transfer after annealing.

[0025] Optionally, one side of the sealing cover 111 is rotatably mounted to the sealing box 11 by means of a hinge or pin, and the other opposite side of the sealing cover 111 is detachably connected to the sealing box 11 by means of magnetic attraction or snap-fit, so that when the sealing cover 111 is covered, the sealing cover 111 can be stably mounted to the sealing box 11.

[0026] Furthermore, a humidity detector 12 is installed inside the sealed box 11 and is used to detect the relative humidity inside the sealed box 11. The humidity detector 12 can collect humidity data in real time and provide timely feedback. The annealing device 10 regulates the humidity environment by controlling the working status of the humidifier 13 and the dehumidifier 14.

[0027] Optionally, the humidity detector 12 includes a humidity sensor, which can be either resistive or capacitive. For example, when the humidity sensor is resistive, water vapor in the air is adsorbed onto the resistive humidity detector 12, and the resistivity and resistance value of the humidity sensor change, thus measuring the relative humidity inside the sealed box 11.

[0028] Optionally, multiple humidity sensors can be used, distributed across the environment to collect real-time data on dry-bulb temperature and relative humidity within the microenvironment. The location and number of humidity sensors can be selected based on specific requirements.

[0029] Furthermore, the humidifier 13 is disposed inside the sealed box 11 and is used to replenish water vapor into the sealed box 11. When the relative humidity of the humidity detector 12 is lower than a preset threshold, the humidifier 13 replenishes water vapor into the sealed box 11. In order to avoid large droplets directly settling on the surface of the organic active layer 23 and damaging its morphology, the water aerosol output by the humidifier 13 needs to be softened and diffused by a built-in microporous buffer baffle.

[0030] Furthermore, a dehumidifier 14 is disposed within the sealed chamber 11 and is used to remove water vapor from the sealed chamber 11. When the relative humidity detected by the humidity detector 12 is higher than a preset threshold, the dehumidifier 14 removes the replenished water vapor from the sealed chamber 11. In addition, before performing SVA treatment, the dehumidifier 14 can reduce the relative humidity within the sealed chamber 11 through at least one of a semiconductor refrigeration condenser plate or a dry gas purging and replacement system to achieve a smooth and uniform dehumidification effect.

[0031] Furthermore, the heating stage 15 is housed within the sealed enclosure 11 and is used to heat the samples in the petri dish 16 to achieve temperature control. The heating stage 15 also features a residual heat warning function to ensure operational safety. The heating stage 15 includes a heating element, a temperature control device, a temperature sensor, and a wireless communication module. The temperature sensor and the wireless communication module are electrically connected to the temperature control device. The wireless communication module receives or transmits wireless communication signals, and the temperature sensor senses changes in the temperature of the heating element and provides feedback to the temperature control device.

[0032] Furthermore, the petri dish 16 is placed on the heating stage 15 and is used to contain the post-treatment solvent and the organic active layer 23 of the solar cell for SVA treatment of the organic active layer 23 of the solar cell. Understandably, the petri dish 16 is made of a light-transmitting material to improve heating efficiency and reduce heat loss, while allowing for observation of the organic active layer 23 at any time.

[0033] Compared with related technologies, the annealing apparatus 10 provided in this application can control the relative humidity inside the sealed box 11 to simulate an air environment. The annealing apparatus 10 can also perform SVA treatment on the organic active layer 23 of the solar cell. Solvent vapor can form a protective layer on the outside of the organic active layer 23 to prevent water vapor and oxygen inside the sealed box 11 from contacting the organic active layer 23 of the solar cell, thereby significantly improving its open-circuit voltage, fill factor and short-circuit current, and obtaining higher photoelectric conversion efficiency and power collection advantages. Moreover, by adjusting the relative humidity and heating temperature inside the sealed box 11, the influence of different relative humidity and heating temperature on the organic active layer 23 during SVA treatment can be detected, thereby determining the optimal relative humidity and heating temperature.

[0034] In some embodiments, the annealing apparatus 10 further includes a control unit, which is communicatively connected to the humidity detector 12, the humidifier 13, the dehumidifier 14 and the heating table 15, respectively, and is used to control the working status of the humidifier 13, the dehumidifier 14 and the heating table 15.

[0035] Specifically, the control unit communicates wirelessly with the humidity detector 12, humidifier 13, dehumidifier 14, and heating platform 15. When the relative humidity value in the annealing device 10 exceeds a preset threshold, the control unit controls the dehumidifier 14 to reduce the relative humidity to bring it within the set range. When the heating temperature value in the annealing device 10 exceeds a preset threshold, the control unit adjusts the heating temperature of the heating platform 15 to bring it within the set range. The preset threshold is either the relative humidity threshold of the humidifier 13 or the dehumidifier 14, or the heating temperature threshold of the heating platform 15.

[0036] Furthermore, when the humidity inside the sealed chamber 11 is lower than a preset threshold, the humidity sensor detects that the humidity inside the sealed chamber 11 is too low and transmits this information to the control unit. After receiving this information, the control unit can control the humidifier 13 to replenish water vapor inside the sealed chamber 11. When the humidity inside the sealed chamber 11 is higher than the preset threshold, the humidity sensor detects that the humidity inside the sealed chamber 11 is too high and transmits this information to the control unit. After receiving this information, the control unit can control the dehumidifier 14 to remove water vapor from inside the sealed chamber 11. Next, if the temperature of the sealed chamber 11 is lower than the preset threshold, the heating platform 15 is activated to heat the culture dish 16. If the temperature of the sealed chamber 11 is higher than the preset threshold, the heating temperature of the heating platform 15 is reduced.

[0037] In some embodiments, the post-treatment solvent is chloroform, and a low-boiling-point solvent is selected. The post-treatment solvent can adjust the morphology of the non-equilibrium organic active layer 23 to a morphology more favorable to photovoltaic performance, and suppress the damage of water and oxygen molecules to the morphology of the organic active layer 23, thereby controlling the morphology of the organic active layer 23. In some specific embodiments, the post-treatment solvent may also be dichloromethane, carbon disulfide, or tetrahydrofuran.

[0038] For example, chloroform has a high vapor pressure and a moderate boiling point, and can form a stable saturated vapor environment at room temperature or under heating conditions. This vapor slowly penetrates into the organic active layer 23 film, promoting the orderly crystallization of the donor and acceptor materials and π... π stacking optimizes the phase separation scale of the organic active layer 23. Simultaneously, the high vapor pressure repels the intrusion of external moisture and oxygen, maintaining the integrity of the active layer morphology and preventing the intensification of charge recombination caused by water and oxygen doping.

[0039] In some embodiments, the relative humidity inside the sealed chamber 11 is 30% to 95%, and the heating temperature of the heating platform 15 is 60°C to 120°C. For example, the relative humidity inside the sealed chamber 11 includes values ​​such as 30%, 45%, 55%, 65%, 75%, 85%, and 95%. When the relative humidity inside the sealed chamber 11 is higher than 95%, the excessively high humidity environment will cause a large number of water molecules to be adsorbed or penetrate into the interior of the organic active layer 23, disrupting the molecular arrangement of the donor and acceptor materials and reducing the photoelectric conversion efficiency of the organic solar cell 20.

[0040] For example, the heating temperature of the heating stage 15 includes values ​​such as 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, and 120°C. When the heating temperature of the heating stage 15 is below 60°C, the heat energy is insufficient to form a saturated steam environment, resulting in low carrier mobility of the donor and acceptor materials in the organic active layer 23. When the heating temperature of the heating stage 15 is above 120°C, it may cause thermal degradation of the donor or acceptor materials in the organic active layer 23, destroying their chemical structure and accelerating the diffusion and penetration of water and oxygen molecules, leading to a significant decrease in the performance of the organic solar cell 20.

[0041] This application also provides a method for preparing an organic solar cell 20, comprising: A transparent substrate 21 is provided, the transparent substrate 21 including a substrate 211 and an anode layer 212; An anode interface modification layer 22 is prepared on the anode layer 212; An organic active layer 23 is prepared on the anode interface modification layer 22; The transparent substrate 21 with the organic active layer 23 attached is placed in the petri dish 16 of the annealing apparatus 10 to perform SVA treatment on the organic active layer 23. A cathode interface modification layer 24 is prepared on the organic active layer 23 after SVA treatment; A metal electrode 25 is fabricated on the cathode interface modification layer 24.

[0042] As can be seen from the above, the method for fabricating an organic solar cell 20 proposed in this application involves placing the organic active layer 23 in an annealing apparatus 10 for SVA treatment. By isolating it from external moisture and oxygen intrusion, the method compensates for the performance gap between inert and environmental treatment conditions in the organic solar cell 20. Under high humidity, SVA treatment of the organic active layer 23 facilitates exciton extraction and dissociation, providing a stronger molecular driving force for the acceptor material, thereby improving the morphology of the organic active layer 23. Simultaneously, higher photoelectric conversion efficiency is achieved in an air environment, providing a feasible solution for the industrial production of organic solar cells 20.

[0043] In some embodiments, the substrate 211 has a thickness of 1.0 mm to 1.2 mm, the anode layer 212 has a thickness of 180 nm to 220 nm, the anode interface modification layer 22 has a thickness of 5 nm to 50 nm, the organic active layer 23 has a thickness of 30 nm to 500 nm, the cathode interface modification layer 24 has a thickness of 5 nm to 30 nm, and the metal electrode 25 has a thickness of 20 nm to 200 nm.

[0044] In some embodiments, before preparing the anode interface modification layer 22 on the anode layer 212, the following steps are further included: Perform preliminary cleaning on the transparent substrate 21; The transparent substrate 21 was placed in the cleaning solution and ultrasonically cleaned for 10 to 20 minutes. The transparent substrate 21 was dried in an oven at 70℃~90℃; The transparent substrate 21 is cleaned with ultraviolet light or plasma ozone for 15 to 30 minutes.

[0045] Optionally, the cleaning solution can be one or more of deionized water, ethanol, and isopropanol. The ultrasonic time is 10 min to 20 min, for example, the ultrasonic time can include values ​​such as 10 min, 12 min, 14 min, 16 min, 18 min, and 20 min, so as to clean away tiny impurities and attached dust on the transparent substrate 21.

[0046] Optionally, the drying temperature inside the oven is 70℃~90℃, including values ​​such as 70℃, 75℃, 80℃, 85℃, and 90℃. When the drying temperature is below 70℃, the drying is incomplete, resulting in the transparent substrate 21 containing moisture; when the drying temperature is above 90℃, it will cause the transparent substrate 21 to undergo thermal deformation.

[0047] Optionally, the transparent substrate 21 can be cleaned using ultraviolet light or plasma ozone for a time ranging from 15 to 30 minutes, such as 15, 18, 20, 25, and 30 minutes. If the cleaning time is less than 15 minutes, the cleaning is incomplete, and impurities will remain on the surface of the transparent substrate 21. If the cleaning time is greater than 30 minutes, excessive oxidation will lead to an increase in surface oxygen vacancies, resulting in surface carbonization or micropore formation.

[0048] In some embodiments, preparing an anode interface modification layer 22 on the anode layer 212 includes: PEDOT:PSS was spin-coated onto a transparent substrate 21 using a spin coater at a speed of 3000 rpm to 5000 rpm for 25 to 30 seconds. The spin-coated PEDOT:PSS was then subjected to hot-table annealing at 100℃~150℃ for 10min~15min.

[0049] Optionally, the spin coating speed of the spin coater is 3000rpm~5000rpm, for example, the speed can include values ​​such as 3000rpm, 3500rpm, 4000rpm, 4500rpm and 5000rpm, so that PEDOT:PSS can be uniformly and evenly spin coated on the transparent substrate 21, reducing the occurrence of agglomeration.

[0050] For example, when the spin coating speed of the spin coater is less than 3000 rpm, the spin coating is insufficient, resulting in micropores or cracks inside the film and a decrease in light transmittance; when the spin coating speed of the spin coater is greater than 5000 rpm, the high speed will cause the solution to splash, which will reduce the interface uniformity of the anode interface modification layer 22 and increase the surface resistance.

[0051] Optionally, the spin coating time of the spin coater is 25s to 30s, including values ​​such as 25s, 26s, 27s, 28s, 29s and 30s, so as to achieve a uniform distribution of PEDOT:PSS.

[0052] Optionally, the spin-coated PEDOT:PSS is subjected to hot-stage annealing at 100℃~150℃ for 10min~15min. PEDOT:PSS has the function of extracting and transporting holes, and can extract holes from the active layer 4 and transport them to the anode layer 212 to form a driving current, thereby reducing the loss of holes and electrons. Annealing treatment can promote the adhesion between the anode interface modification layer 22 and the transparent substrate 21, reduce the risk of interlayer delamination during the operation of the organic solar cell 20, increase stability, and at the same time play a role in preventing moisture or providing a barrier.

[0053] Optionally, the hot-stage annealing temperature is 100℃~150℃, for example, values ​​such as 100℃, 110℃, 120℃, 130℃, 140℃, and 150℃, thereby promoting the optimization of the morphology of the anode interface modification layer 22. For example, when the hot-stage annealing temperature is greater than 150℃, the anode interface modification layer 22 undergoes chemical decomposition, resulting in decreased conductivity and light transmittance; when the hot-stage annealing temperature is less than 100℃, residual solution or solvent disrupts exciton dissociation.

[0054] Optionally, the annealing time on the hot stage is 10 min to 15 min, for example, values ​​such as 10 min, 11 min, 12 min, 13 min, 14 min and 15 min, so that PEDOT:PSS can be bonded to the transparent substrate 21.

[0055] For example, when the annealing time on the hot table is greater than 15 minutes, the anode interface modification layer 22 becomes over-dried, which accelerates the shrinkage of the anode interface modification layer 22 and easily generates microcracks; when the annealing time on the hot table is less than 10 minutes, the anode interface modification layer 22 that is not sufficiently annealed has weak bonding force with the transparent substrate 21, resulting in a decrease in conductivity.

[0056] In some embodiments, the preparation of the organic active layer 23 on the anode interface modification layer 22 includes: PM6 and L8-BO were dissolved in the first solvent to form a donor-acceptor mixed solution, resulting in organic active layer 23 solution. The organic active layer 23 solution was heated at 40℃~60℃ for 0.5h~1.5h to obtain the organic active layer 23 solution. The organic active layer 23 solution is coated onto the anode interface modification layer 22.

[0057] This can improve the morphology or molecular arrangement of the organic active layer 23, enhance light absorption and carrier collection, and improve charge transport efficiency.

[0058] Optionally, the organic active layer 23 solution is heated to a temperature of 40℃~60℃, such as 40℃, 45℃, 50℃, 55℃ and 60℃, so that PM6 and L8-BO can be uniformly dissolved and dispersed.

[0059] For example, when the heating temperature is greater than 60°C, PM6 and L8-BO over-crystallize or decompose; when the heating temperature is less than 40°C, PM6 and L8-BO do not dissolve sufficiently, resulting in a grainy texture.

[0060] Optionally, the heating time of the organic active layer 23 solution is 0.5h to 1.5h, including values ​​such as 0.5h, 0.7h, 0.9h, 1.1h, 1.3h and 1.5h, so that PM6 and L8-BO can be fully integrated and uniformly dispersed.

[0061] For example, when the heating time is less than 0.5 h, the incomplete dissolution of PM6 and L8-BO and the residue of the first solvent reduce the charge transport efficiency; when the heating time is greater than 1.5 h, thermal degradation and excessive evaporation of the first solvent will occur, further affecting the open circuit voltage and short circuit current density.

[0062] In some embodiments, the concentration of PM6 is 7 mg / mL to 8 mg / mL, the concentration of L8-BO is 8.4 mg / mL to 9.6 mg / mL, the mass ratio of PM6 to L8-BO is 1:1 to 1:1.2, and the first solvent is chloroform, chlorobenzene, toluene, or o-xylene.

[0063] Optionally, the concentration of PM6 includes values ​​of 7 mg / mL, 7.2 mg / mL, 7.4 mg / mL, 7.6 mg / mL, 7.8 mg / mL, and 8 mg / mL. The concentration of L8-BO can include values ​​of 8.4 mg / mL, 8.6 mg / mL, 8.8 mg / mL, 9.0 mg / mL, 9.2 mg / mL, 9.4 mg / mL, and 9.6 mg / mL. Specifically, the mass ratio of PM6 to L8-BO is 1:1 to 1:1.2, for example, ratios include 1:1, 1:1.05, 1:1.1, 1:1.15, and 1:1.2, as well as values ​​within a range between any two of the aforementioned specific values. By controlling the ratio of PM6 to L8-BO, the acceptor molecules are arranged more tightly and orderly in the organic active layer 23, improving charge transport and reducing charge recombination, thereby significantly increasing the short-circuit current density and fill factor of the organic solar cell 20, and thus achieving higher photoelectric conversion efficiency.

[0064] Optionally, the first solvent is chloroform, chlorobenzene, toluene, or o-xylene. The first solvent is used to dissolve the donor and acceptor materials to prepare the organic active layer 23 solution. These types of solvents can dissolve the conjugated polymer donor and the non-fullerene small molecule acceptor, which is beneficial for forming a homogeneous and stable mixed solution.

[0065] For example, chloroform has high volatility, which can promote the dissolution of donor and acceptor materials, and prevent pinholes and craters during spin coating. For example, when chlorobenzene is used as the first solvent, its high boiling point and slow evaporation rate result in more uniform swelling and dispersion of the donor and acceptor. For example, when toluene or o-xylene is used as the solvent, its good solubility for non-fullerene acceptors and moderate surface tension can improve the spreadability of the organic active layer 23 on the anode interface modification layer 22.

[0066] In some embodiments, the preparation of the cathode interface modification layer 24 on the organic active layer 23 after solvent vapor annealing includes: PNDIT-F3N was dissolved in a second solvent to obtain a cathode interface modification layer solution with a concentration of 0.5 mg / mL to 1 mg / mL. The cathode interface modification layer solution was spin-coated onto the organic active layer 23 and allowed to stand and dry for 10 to 20 minutes.

[0067] Specifically, PNDIT-F3N exhibits better compatibility compared to traditional inorganic materials and can be processed at room temperature without the need for high-temperature annealing. Compared to other small-molecule interface materials and novel zwitterionic materials, PNDIT-F3N demonstrates better electrical conductivity and chemical stability.

[0068] Optionally, the second solvent can be a mixed solution of methanol and acetic acid, with a volume ratio of methanol to acetic acid of 1000:5~10. The complementary polarities of methanol and acetic acid can effectively dissolve highly crystalline polymers such as PNDIT-F3N, inhibit molecular aggregation, and optimize carrier transport efficiency.

[0069] For example, when the volume ratio of methanol to acetic acid is less than 1000:5, excess methanol can easily cause viscosity and corrosion problems, affecting the stability of the cathode interface modification layer 24; when the volume ratio of methanol to acetic acid is greater than 1000:10, excess methanol will reduce the solubility and film quality of the cathode interface modification layer 24.

[0070] Optionally, the concentration of the cathode interface modification layer solution is 0.5 mg / mL to 1 mg / mL, for example, concentrations of 0.5 mg / mL, 0.6 mg / mL, 0.8 mg / mL, and 1 mg / mL. When the concentration of the cathode interface modification layer solution is greater than 1 mg / mL, an excessively thick film is easily formed during spin coating, increasing the series resistance. At the same time, excessive molecular aggregation will disrupt the interfacial energy level matching and hinder electron transport. When the concentration of the cathode interface modification layer solution is less than 0.5 mg / mL, the surface of the cathode interface modification layer 24 cannot be continuously covered, resulting in discontinuous charge transport paths.

[0071] Optionally, the cathode interface modification layer solution is spin-coated onto the organic active layer 23, and the drying time is 10 min to 20 min, for example, values ​​such as 10 min, 12 min, 14 min, 16 min, 18 min, and 20 min. When the drying time is less than 10 min, the second solvent does not evaporate sufficiently, resulting in some residue of the second solvent; when the drying time is greater than 20 min, contaminants or impurities are mixed into the cathode interface modification layer solution.

[0072] In some embodiments, while depositing metal on the cathode interface modification layer 24 to obtain the metal electrode 25, a positive electrode 26 electrically connected to the anode layer 212 is also formed. The positive electrode 26 is spaced apart from the anode interface modification layer 22, the organic active layer 23, the cathode interface modification layer 24 and the metal electrode 25, and is used to electrically connect to an external circuit.

[0073] It should be noted that, if necessary, the positive electrode 26 can be used as a substitute material for the anode layer 212. The positive electrode 26 does not directly contact the organic active layer 23, the cathode interface modification layer 24, and the metal electrode 25 to avoid short circuits. When the organic solar cell 20 is connected to an external circuit, the positive electrode 26 can also serve as the positive terminal of the external circuit, collecting holes and forming a current loop through the external circuit, thus forming a complete electrical path together with the metal electrode 25.

[0074] The specific composition of the annealing apparatus 10 of this application, as well as the structure and preparation method of the organic solar cell 20, are described below with reference to specific embodiments.

[0075] Example 1 This embodiment 1 provides an annealing apparatus 10 for post-processing the organic active layer of a solar cell, such as... Figure 1 As shown, it includes a sealed box 11, a humidity detector 12, a humidifier 13, a dehumidifier 14, a heating platform 15, and a petri dish 16. This embodiment 1 also provides an organic solar cell 20, such as... Figure 2 As shown, it includes a transparent substrate 21, an anode interface modification layer 22, an organic active layer 23, a cathode interface modification layer 24, and a metal electrode 25.

[0076] The transparent substrate 21 has a transparent glass substrate 211, an ITO anode layer 212, and a total thickness of 1.2 mm. The anode interface modification layer 22 is made of PEDOT:PSS and has a thickness of 5 nm. The organic active layer 23 is made of PM6:L8-BO and has a thickness of 100 nm. The cathode interface modification layer 24 is made of PNDIT-F3N and has a thickness of 10 nm. The metal electrode 25 is a silver electrode and has a thickness of 100 nm.

[0077] The preparation method is as follows: Step 1: Provide a transparent substrate 21. Specifically, wipe the surface of the transparent substrate 21 with a lint-free paper moistened with ethanol, then place it in deionized water and isopropanol for ultrasonic treatment for 15 minutes each, then place it in a constant temperature oven for drying, and finally treat it with an ultraviolet ozone generator for 15 minutes to make the surface of the transparent substrate 21 clean and free of impurities.

[0078] Step 2: Prepare an anode interface modification layer 22 on the transparent substrate 21 to form a substrate. Specifically, spin coat the anode interface modification layer 22 onto the pretreated transparent substrate 21 using a spin coater at a speed of 3000 rpm for 25 s. Then, perform hot annealing on the anode interface modification layer 22 at a temperature of 150°C for 15 min to obtain the anode interface modification layer 22 spin-coated onto the transparent substrate 21.

[0079] Step 3: Heat the organic active layer 23 solution to 40℃~60℃ to obtain the organic active layer 23 solution. Coat the organic active layer 23 solution onto the anode interface modification layer 22 to obtain the organic active layer 23. Specifically, dissolve the polymer PM6:L8-BO in chloroform to form a donor-acceptor mixed solution, wherein the donor PM6 concentration is 7 mg / mL and the acceptor L8-BO concentration is 8.4 mg / mL to obtain the organic active layer 23 solution. Coat the organic active layer 23 solution onto the anode interface modification layer 22 to obtain the organic active layer 23.

[0080] Step 4: Use the annealing device 10 to achieve a controllable humidity environment, and study the performance of organic solar cells 20 under different humidity conditions and the effect of steam annealing regulation under different humidity conditions. Specifically, use a dehumidifier 14 to remove the humidity in the control device to achieve a controllable environment of 30%~50%RH; at the same time, use a humidifier 13 to increase the humidity in the control annealing device 10 to achieve a controllable environment of 50%~95%RH.

[0081] Step 5: The organic active layer 23 solution is placed in different humidity environments for SVA. Specifically, the prepared organic active layer 23 film is placed in different humidity environments for 5 minutes and at a temperature of 100°C to prepare organic solar cells 20 within a humidity range of 30%~95%RH. By utilizing the advantages of SVA, the intrusion of external moisture and oxygen can be isolated, so as to achieve the preparation of organic active layer 23 of organic solar cells 20 under high humidity air environment conditions.

[0082] Step 6: Prepare a cathode interface modification layer 24 on the organic active layer 23. Specifically, dissolve PNDIT-F3N in a mixed solution of methanol and acetic acid with a volume ratio of 1000:10 to form a cathode interface modification layer solution with a concentration of 1 mg / mL. Use a spin coater to spin coat the dissolved cathode interface modification layer solution onto the organic active layer 23.

[0083] Step 7: Fabricate a metal electrode 25 on the cathode interface modification layer 24. Specifically, a silver electrode with a thickness of 120 nm is deposited on the cathode interface modification layer 24 using a metal evaporation source device at a vacuum degree of 4 × 10⁻⁶. -5 Pa.

[0084] In Example 1, the steam annealing time and temperature of the organic active layer 23 were 5 min and 100℃, respectively. The organic solar cells 20 finally fabricated according to the steps of Example 1 were designated as Sample 1-1, Sample 1-2, Sample 1-3, Sample 1-4, Sample 1-5, Sample 1-6, and Sample 1-7, corresponding to humidity ranges of 30% to 95%. Samples 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, and 1-7 were tested under AM1.5G standard sunlight using a solar simulator. V OC , J SC And FF, without preprocessing, can be used to perform performance tests under AM1.5G standard sunlight using a solar simulator, and read the open-circuit voltage (i.e., FF) provided by the solar simulator. V OC ), Short-Circuit Current Density (SCD) J SC The test results of the fill factor (FF) are used to calculate the photovoltaic conversion efficiency (PCE). Where PCE = (V oc × J sc × FF) / P in × 100%; P in The incident light power is expressed in mW / cm² or W / m², typically 100mW / cm² under standard test conditions AM1.5G.

[0085] As shown in Table 1, the performance test results of the organic solar cell 20 sample prepared in Example 1 show that the post-processing method of using SVA to isolate humidity and oxygen in the air environment can achieve the preparation of high-performance organic solar cells 20 in the humidity range of 30%~95%RH. Figure 3 The JV curves of the organic solar cells of Embodiment 1 and Comparative Example 1 of the present invention under AM1.5G standard simulated sunlight are shown. Figure 3 It can be seen that PCE remains at a high level within the 30%~95%RH range.

[0086] Table 1

[0087] Example 2 This embodiment 2 provides an annealing apparatus 10 for post-processing the organic active layer of a solar cell, such as... Figure 1 As shown, it includes a sealed box 11, a humidity detector 12, a humidifier 13, a dehumidifier 14, a heating platform 15, and a petri dish 16. This embodiment 2 also provides an organic solar cell 20, such as... Figure 2 As shown, it includes a transparent substrate 21, an anode interface modification layer 22, an organic active layer 23, a cathode interface modification layer 24, and a metal electrode 25.

[0088] The transparent substrate 21 has a transparent glass substrate 211, an ITO anode layer 212, and a total thickness of 1.2 mm. The anode interface modification layer 22 is made of PEDOT:PSS and has a thickness of 5 nm. The organic active layer 23 is made of PM6:L8-BO and has a thickness of 100 nm. The cathode interface modification layer 24 is made of PNDIT-F3N and has a thickness of 10 nm. The metal electrode 25 is a silver electrode and has a thickness of 100 nm.

[0089] The preparation method is as follows: Steps 1, 2 and 3 are largely the same as in Example 1.

[0090] Step 4: Place the organic active layer 23 in an air environment for SVA. Specifically, place the prepared organic active layer 23 film in the SVA device 10, add chloroform as a vapor solvent in the device, process for 5 minutes, and set the temperature of the heating stage 15 to 60℃, 80℃, 100℃ and 120℃ respectively.

[0091] Step 5: Prepare a cathode interface modification layer 24 on the organic active layer 23. Specifically, dissolve PNDIT-F3N in a mixed solution of methanol and acetic acid with a volume ratio of 1000:10 to form a cathode interface modification layer solution with a concentration of 1 mg / mL. Use a spin coater to spin coat the dissolved cathode interface modification layer solution onto the organic active layer 23.

[0092] Step 6: Fabricate a metal electrode 25 on the cathode interface modification layer 24. Specifically, a silver electrode with a thickness of 120 nm is deposited on the cathode interface modification layer 24 using a metal evaporation source device at a vacuum degree of 4 × 10⁻⁶. -5 Pa.

[0093] In Example 2, the temperatures of the heating stage 15 of the SVA device 10 were 60°C, 80°C, 100°C, and 120°C, respectively. The organic solar cells 20 finally prepared according to the steps of Example 2 were labeled as Sample 2-1, Sample 2-2, Sample 2-3, and Sample 2-4, respectively, and the PCE was calculated. The testing method was the same as in Example 1.

[0094] As shown in Table 2, the performance of the organic solar cell samples in Example 2 was tested. After the organic active layer 23 was prepared, organic solar cells 20 were prepared by post-treatment in SVA devices at different temperatures for 5 minutes. As the output temperature increased, the PCE also increased. When the temperature reached 120°C, the PCE showed a slight decreasing trend. This may be because excessive heat can cause thermal degradation of the donor or acceptor polymers, destroying their chemical structure or morphology, reducing charge separation and transport capabilities, and thus affecting cell performance. Therefore, the temperature for steam annealing of the organic active layer 23 in this application should not exceed 100°C. As shown in Figure 4, Figure 4 The JV curves of organic solar cells 20 prepared under AM 1.5G standard simulated sunlight at different temperature conditions for 5 min, as shown in Example 2 of the present invention, are displayed. In the temperature range of 60~100℃, Voc and FF increase with the increase of SVA temperature, which in turn has a positive effect on the improvement of PCE. The PCE value of organic solar cell 20 is the largest when the SVA temperature is 100℃.

[0095] Table 2

[0096] Example 3 This embodiment 3 provides an annealing apparatus 10 for post-processing the organic active layer of a solar cell, such as... Figure 1 As shown, it includes a sealed box 11, a humidity detector 12, a humidifier 13, a dehumidifier 14, a heating platform 15, and a petri dish 16. This embodiment 3 also provides an organic solar cell 20, such as... Figure 2 As shown, it includes a transparent substrate 21, an anode interface modification layer 22, an organic active layer 23, a cathode interface modification layer 24, and a metal electrode 25.

[0097] The transparent substrate 21 is made of transparent glass, the anode layer 212 is made of ITO, and the total thickness of the transparent substrate 21 is 1.2 mm. The anode interface modification layer 22 is made of PEDOT:PSS and has a thickness of 5 nm. The organic active layer 23 is made of PM6:L8-BO and has a thickness of 100 nm. The cathode interface modification layer 24 is made of PNDIT-F3N and has a thickness of 10 nm. The metal electrode 25 is a silver electrode and has a thickness of 120 nm.

[0098] The preparation method is as follows: Steps 1, 2 and 3 are largely the same as in Example 1.

[0099] Step 4: Place the active layer solution in an air environment for SVA. Specifically, place the prepared organic active layer 23 film in an air environment for SVA. The temperature of the heating stage 15 is 100℃, and the annealing time is set to 5min, 10min, 15min, and 20min respectively.

[0100] Step 5: Prepare a cathode interface modification layer 24 on the organic active layer 23. Specifically, dissolve PNDIT-F3N in a mixed solution of methanol and acetic acid with a volume ratio of 1000:10 to form a cathode interface modification layer solution with a concentration of 1 mg / mL. Use a spin coater to spin coat the dissolved cathode interface modification layer solution onto the organic active layer 23.

[0101] Step 6: Fabricate a metal electrode 25 on the cathode interface modification layer 24. Specifically, a silver electrode with a thickness of 120 nm is deposited on the cathode interface modification layer 24 using a metal evaporation source device at a vacuum degree of 4 × 10⁻⁴. 5 Pa.

[0102] In Example 3, the SVA post-processing time was set to 5 min, 10 min, 15 min, and 20 min, respectively. The organic solar cells 20 finally prepared according to the steps of Example 3 were designated as Sample 3-1, Sample 3-2, Sample 3-3, and Sample 3-4, respectively. Using a solar simulator, Sample 3-1, Sample 3-2, Sample 3-3, and Sample 3-4 were tested under AM1.5G standard sunlight. V OC , J SC And FF, and then calculate PCE; wherein, the test method is the same as in Example 1. As shown in Table 3, the performance test of the organic solar cell sample in Example 3. Under the condition of SVA treatment temperature of 100℃ and treatment time of 5~20min, the PCE of the organic solar cell 20 obtained also decreased with the increase of SVA treatment time, and the PCE was the largest when the time was 5min. Figure 5 The JV curves of the organic solar cell 20 prepared under AM 1.5G standard simulated sunlight at different annealing times, as shown in Example 3 of the present invention, are illustrated. With increasing time, V OC As the FF decreases, the PCE of the resulting organic solar cell 20 also decreases, reaching its maximum value after 5 minutes of processing.

[0103] Table 3

[0104] Comparative Example 1 Comparative Example 1 provides an organic solar cell 20, the only difference from Examples 1 and 2 being that step 4, in which the organic active layer 23 solution is placed in a controlled humidity air environment for SVA, is replaced with annealing at 100°C on a heating stage 15. All other steps are the same as in Example 1. The organic solar cell 20 finally prepared according to the steps of Comparative Example 1 is designated as Sample 4-1. Sample 4-1 was tested under AM1.5G standard sunlight using a solar simulator. V OC , J SC And FF, and then calculate PCE; wherein, the test method is the same as in Example 1.

[0105] As shown in Tables 1 and 4, Example 1 of this application uses a humidity control device to regulate different humidity levels and performs SVA fabrication under different humidity conditions. Compared with Comparative Example 1, the organic solar cell 20 prepared in Example 1 of this application has a significantly higher PCE than the organic solar cell 20 prepared by the hot-stage annealing process; and it still retains an efficiency advantage in the 30%~95%RH range, especially in the PM6:L8-BO system at 95%RH, where it still maintains a PCE of 18.52%.

[0106] As shown in Tables 1-3, Examples 1-3 of this application employed the SVA processing technology in an air environment. Compared to Comparative Example 1, Examples 1-3 exhibited a higher PCE than the organic solar cell 20 annealed using a conventional hot-stage annealing method.

[0107] Table 4

[0108] In Examples 1-3, the SVA fabrication process was used for the first time in an air environment within a device based on air humidity control. Compared with Comparative Example 1, the PCE of the organic solar cell 20 fabricated in an air environment was higher than that of the organic solar cell 20 fabricated by the conventional hot-stage annealing process.

[0109] In summary, the organic solar cell 20 prepared by the SVA process of this invention has improved open-circuit voltage, short-circuit current and fill factor to varying degrees, and has higher microstructure characteristics, which is more conducive to carrier transport and exciton dissociation, thereby improving the photoelectric conversion efficiency of the organic solar cell 20.

[0110] Furthermore, by implementing a humidity control device, this application achieves air humidity control within a high humidity range of 30%RH to 95%RH, and can precisely control the humidity to a specific value. Simultaneously, the SVA process effectively isolates the intrusion of external moisture and oxygen in the air environment. Under different humidity conditions, especially at a high humidity of 95%RH, the PM6:L8-BO system still maintains a high PCE of 18.52%, highlighting the feasibility of using the SVA process to fabricate high-performance organic solar cells 20 in an air environment.

[0111] Understandably, the use of SVA fabrication technology in an air environment provides a framework for the industrial application of organic solar cells 20. Morphology control of the organic active layer 23 is one of the core methods for achieving high PCE in organic solar cells 20. Thermal annealing in a controlled inert atmosphere (such as a glove box) has proven to be an effective post-processing method. By providing thermal energy to overcome the molecular motion barrier, thermal annealing effectively promotes the ordered crystallization and π-phase of the donor and acceptor materials. π-stacking effectively enhances the charge transport performance of the device. However, the limitations of thermal annealing become prominent when the processing environment shifts to air conditions. According to Fick's diffusion law, the high-temperature environment accompanying thermal annealing significantly increases the free volume inside the organic active layer 23 film. According to the Arrhenius equation, the diffusion coefficient D increases exponentially with increasing temperature. This means that during thermal annealing in air, thermal energy actually acts as a "catalyst" for environmental impurities, accelerating the penetration of H2O and O2 into the bulk phase of the film, thereby generating deep-level traps and leading to severe charge recombination.

[0112] In summary, solution treatment of the active and electronic layers of organic solar cells in high-RH air leads to deteriorated morphology and a significant decrease in PCE. In contrast, SVA exhibits unique advantages: First, solvent plasticization achieves morphology optimization similar to or even superior to thermal annealing, inducing an ideal interpenetrating nanofiber network. More importantly, the saturated solvent vapor generated in the confined space of SVA forms a barrier. This outward vapor flux physically repels and isolates the intrusion of external moisture and oxygen. Therefore, the SVA process achieves high-performance morphology while ensuring environmental robustness of the device in extremely high humidity (up to 95% RH) environments. Notably, devices fabricated using the SVA method show significant improvements in photovoltaic performance and operational stability compared to devices processed using traditional TA. Specifically, SVA successfully bridged the performance gap between inert and environmental handling conditions, achieving the fabrication of high-performance organic solar cell 20 devices in a high humidity range of 30%-95%RH under controlled humidity conditions. It also achieved a PCE of up to 18.82% for small-area devices at 95%RH, thus providing a highly competitive technical path for the large-scale production of organic solar cells 20.

[0113] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An annealing apparatus for post-processing the organic active layer of a solar cell, characterized in that, The annealing apparatus includes: Sealed box; A humidity detector is installed inside the sealed box and used to detect the relative humidity inside the sealed box; A humidifier is installed inside the sealed box; A dehumidifier is installed inside the sealed box; A heating platform is installed inside the sealed box; A petri dish is placed on the heating stage and used to contain the post-treatment solvent and the organic active layer of the solar cell for solvent vapor annealing of the organic active layer of the solar cell.

2. The annealing apparatus according to claim 1, characterized in that, The annealing device also includes a control unit, which is communicatively connected to the humidity detector, the humidifier, the dehumidifier and the heating platform, respectively. The control unit is used to control the working status of the humidifier, the dehumidifier and the heating platform.

3. The annealing apparatus according to claim 1, characterized in that, The post-treatment solvent is chloroform.

4. The annealing apparatus according to claim 1, characterized in that, The relative humidity inside the sealed box is 30%~95%, and the heating temperature of the heating table is 60℃~120℃.

5. A method for preparing an organic solar cell, characterized in that, include: A transparent substrate is provided, the transparent substrate comprising a substrate and an anode layer; An anode interface modification layer is prepared on the anode layer; An organic active layer is prepared on the anode interface modification layer; A transparent substrate with the organic active layer attached is placed in the culture dish of the annealing apparatus according to any one of claims 1-4 to perform solvent vapor annealing on the organic active layer. A cathode interface modification layer is prepared on the organic active layer after solvent vapor annealing. A metal electrode is fabricated on the cathode interface modification layer.

6. The method for preparing an organic solar cell according to claim 5, characterized in that, Before preparing the anode interface modification layer on the anode layer, the method further includes: Perform initial cleaning of the transparent substrate; For deep cleaning, place the transparent substrate in the cleaning solution and sonicate for 10 to 20 minutes. Dry the transparent substrate in an oven at 70℃~90℃; For transparent substrates, use ultraviolet or plasma ozone cleaning for 15 to 30 minutes.

7. The method for preparing an organic solar cell according to claim 5, characterized in that, The step of preparing the anode interface modification layer on the anode layer includes: PEDOT:PSS was spin-coated onto a transparent substrate using a spin coater at a speed of 3000 rpm to 5000 rpm for 25 to 30 seconds. The spin-coated PEDOT:PSS was then subjected to hot-table annealing at 100℃~150℃ for 10min~15min.

8. The method for preparing an organic solar cell according to claim 5, characterized in that, The step of preparing the organic active layer on the anode interface modification layer includes: PM6 and L8-BO were dissolved in the first solvent to form a donor-acceptor mixed solution, thus obtaining the original solution of the organic active layer. The original organic active layer solution was heated at 40℃~60℃ for 0.5h~1.5h to obtain the organic active layer solution. The organic active layer solution is coated onto the anode interface modification layer.

9. The method for preparing an organic solar cell according to claim 8, characterized in that, The concentration of PM6 is 7 mg / mL to 8 mg / mL, the concentration of L8-BO is 8.4 mg / mL to 9.6 mg / mL, the mass ratio of PM6 to L8-BO is 1:1 to 1:1.2, and the first solvent is chloroform, chlorobenzene, toluene, or o-xylene.

10. The method for preparing an organic solar cell according to claim 5, characterized in that, The preparation of the cathode interface modification layer on the organic active layer after solvent vapor annealing includes: PNDIT-F3N is dissolved in a second solvent to obtain a cathode interface modification layer solution, wherein the concentration of the cathode interface modification layer solution is 0.5 mg / mL to 1 mg / mL; The cathode interface modification layer solution was spin-coated onto the organic active layer and allowed to stand and dry for 10 to 20 minutes.

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