Organic solar cell based on dihalogen benzene additive and preparation method thereof

Abstract

The invention discloses an organic solar cell based on a dihalogen benzene additive, and a forward device of the organic solar cell comprises a transparent conductive substrate ITO, a hole transport layer, an organic active layer, an electron transport layer and a metal electrode which are sequentially stacked from bottom to top, the organic active layer comprises a polymer donor PM6, a non-fullerene electron acceptor L8-BO and a dihalogenated benzene additive TCBB. According to the organic solar cell based on the double-halogen benzene additive and the preparation method of the organic solar cell, the double-halogen benzene is introduced into the active layer of the organic solar cell as the active layer additive, and the aggregation state structure of the active layer film is optimized, so that the phase separation degree of a donor-acceptor material is improved, and the charge separation and transmission efficiency is improved. According to the organic solar cell prepared by adopting the technical scheme, the photoelectric conversion efficiency can reach 20.11%, the photoelectric conversion efficiency is obviously superior to that of a control group device with a DIO additive, and the device has good stability.

Description

Technical Field

[0001] This invention relates to the field of organic electronic materials and devices, and in particular to an organic solar cell based on a dihalogenated benzene additive and its preparation method. Background Technology

[0002] Organic solar cells, with their outstanding advantages such as being lightweight, flexible, low-cost, and solution-processable, have shown broad application prospects in the new energy field and have become one of the hot research directions in photovoltaic technology. The active layer, as the core component of an organic solar cell, directly determines the charge separation, transport efficiency, and final photoelectric conversion performance of the device due to the phase separation morphology and aggregated structure of its donor-acceptor materials. However, existing organic solar cells generally suffer from problems such as uncontrollable phase separation of donor and acceptor materials, uneven phase size, and obstructed charge transport paths during the active layer preparation process. This makes it difficult to break through the bottleneck in photoelectric conversion efficiency, and the device stability also needs improvement. Although existing technologies have attempted to improve the active layer morphology using various additives, most additives suffer from drawbacks such as high preparation costs, poor compatibility with active layer materials, easy residue leading to decreased device stability, or limited improvement effects, making it difficult to meet the needs of large-scale applications of high-performance organic solar cells.

[0003] Therefore, developing a low-cost, highly compatible additive that can significantly optimize the active layer structure and improve device performance is of great significance for promoting the industrialization of organic solar cells. Summary of the Invention

[0004] In view of the aforementioned deficiencies in the prior art, the technical problem to be solved by this invention is the excessive aggregation or non-uniform morphology of DIO, a commonly used additive in existing organic solar cells, which hinders exciton dissociation and charge transport. This invention provides an organic solar cell based on a dihalogenated benzene additive and its preparation method. Dihalogenated benzene is introduced as an active layer additive into the active layer of the organic solar cell. By optimizing the aggregated state structure of the active layer film, the phase separation degree of the donor-acceptor materials is improved, thereby enhancing charge separation and transport efficiency. The organic solar cell prepared using the technical solution of this invention achieves a photoelectric conversion efficiency of 20.11%, significantly better than the control group device with DIO additive, and the device exhibits good stability. The additive preparation process of this invention is simple, cost-controllable, and highly compatible, suitable for large-scale preparation of high-performance organic solar cells, providing a new and effective way to improve the performance of organic photovoltaic devices, and has significant industrial application value.

[0005] To achieve the above objectives, the present invention provides an organic solar cell based on a dihalogenated benzene additive. The organic solar cell forward device includes, from bottom to top, a transparent conductive substrate ITO, a hole transport layer, an organic active layer, an electron transport layer, and a metal electrode, wherein the organic active layer comprises a polymer donor PM6, a non-fullerene electron acceptor L8-BO, and a dihalogenated benzene additive TCBB.

[0006] The chemical structural formula of the polymer donor PM6 is shown below:

[0007] ;

[0008] The chemical structure of the non-fullerene electron acceptor L8-BO is shown below:

[0009] ;

[0010] The chemical structural formula of the halogenated additive TCBB is shown below:

[0011] .

[0012] Furthermore, the organic solar cell forward device specifically includes, from bottom to top, an ITO glass, a 2PACz hole transport layer, an organic active layer, a PNDIT-F3N electron transport layer, and a metal Ag cathode.

[0013] Furthermore, the mass ratio of PM6:L8-BO in the organic active layer is 0.4 to 1:1.2; the concentration of TCBB is 8 mg / ml to 12 mg / ml.

[0014] Furthermore, the short-circuit current density of the organic solar cell reached 28.45 ± 0.19 mA cm⁻¹. -2 The fill factor reached 80.94±0.32%, and the energy conversion efficiency reached 20.11±0.12%.

[0015] Furthermore, the organic active layer is the active layer.

[0016] In a preferred embodiment of the present invention, a method for preparing an organic solar cell based on a dihalogenated benzene additive is provided, comprising the following steps:

[0017] S1. The ITO glass slide is ultrasonically treated with detergent, deionized water, acetone and isopropanol in sequence, and then treated with ultraviolet ozone cleaning machine.

[0018] S2. 2PACz is deposited on an ITO glass slide using a static spin coating method, and then heated and annealed to form a hole transport layer;

[0019] S3. Dissolve PM6 and L8-BO together in chloroform solution at a mass ratio of (0.4~1):1.2, then add TCBB at a concentration of 8mg / ml-12mg / ml, then transfer the sample to a glove box under nitrogen atmosphere, heat and stir, and then spin coat it onto hole transport layer 2PACz to form an active layer.

[0020] S4. Dissolve PNDIT-F3N in a mixed solvent of methanol and acetic acid, and use a static spin-coating method to form a PNDIT-F3N solution onto the active layer to form an electron transport layer;

[0021] S5. Deposit the metal Ag electrode onto the PNDIT-F3N electron transport layer by vapor deposition.

[0022] Furthermore, in step S2, the static spin coating speed is 3000 rpm, the annealing temperature is 100℃, and the annealing time is 10 min.

[0023] Furthermore, in step S3, the material concentration of the active layer is 16 mg / mL.

[0024] Furthermore, in step 3, the spin coating speed is 2000–5000 rpm, the annealing temperature is 90–120°C, and the annealing time is 10 min.

[0025] Furthermore, in step S4, the concentration of methanol solvent is 1 mg / mL, the concentration of acetic acid solvent is 19 mg / mL, the spin coating speed is 3000 rpm, and the spin coating time is 30 s.

[0026] Technical effect

[0027] This invention provides an organic solar cell based on a dihalogenated benzene additive and its fabrication method. Dihalogenated benzene is introduced as an active layer additive into the active layer of the organic solar cell. By optimizing the aggregated state structure of the active layer film, the phase separation of the donor and acceptor materials is improved, thereby enhancing charge separation and transport efficiency. The organic solar cell fabricated using this invention achieves a photoelectric conversion efficiency of 20.11%, significantly better than the control group device using DIO additive, and the device exhibits good stability. The additive preparation process described in this invention is simple, cost-controllable, and highly compatible, making it suitable for large-scale fabrication of high-performance organic solar cells. This provides a new and effective approach to improving the performance of organic photovoltaic devices and has significant industrial application value.

[0028] The specific technical effects are as follows:

[0029] This invention precisely controls the phase separation morphology: halogen atoms in TCBB molecules can regulate the aggregation behavior of donor-acceptor materials through halogen bond interactions, enabling the active layer to form a uniform micro / nano phase separation structure, thus avoiding charge recombination caused by excessively large phase regions and charge transport obstruction caused by excessively small phase regions.

[0030] This invention improves charge separation and transport efficiency: the electronegativity of halogen atoms in TCBB can optimize energy level matching within the active layer, reduce the charge separation energy barrier, and promote the orderly stacking of donor / acceptor molecules, thereby increasing carrier mobility and reducing charge loss during transport.

[0031] This invention improves the compatibility of active layer materials and the uniformity of thin films: TCBB can reduce the phase separation tendency of donor and acceptor materials in solution, improve their compatibility, and make the active layer film prepared by spin coating more uniform in thickness and lower in surface roughness, thereby reducing device performance fluctuations caused by film defects.

[0032] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0033] Figure 1 These are structural diagrams of the organic solar cell forward device of the present invention and device efficiency diagrams of Example 2 and Comparative Example 1;

[0034] Figure 2 These are AFM images of the active layer thin films of Example 2 and Comparative Example 1, respectively, prepared in the organic solar cells of this invention.

[0035] Figure 3 These are absorption diagrams of the active layer thin films prepared in Example 2 and Comparative Example 1 of the organic solar cell of the present invention;

[0036] Figure 4 This refers to the device short-circuit current (J) of the organic solar cells in Comparative Example 1 and Examples 1 to 3 of the present invention. SC - Open circuit voltage (V) OC (Line graph)

[0037] Figure 5 These are the device EQE curves of the solar cells in Comparative Example 1 and Examples 1 to 3 of this invention;

[0038] Figure 6 These are SCLC diagrams of the organic solar energy devices fabricated in Embodiment 2 and Comparative Example 1 of the present invention;

[0039] Figure 7 These are light intensity dependence diagrams of the organic solar energy devices fabricated in Embodiment 2 and Comparative Example 1 of the present invention;

[0040] Figure 8 This is a dark current diagram of the organic solar energy device prepared in Example 2 and Comparative Example 1 of the present invention. Detailed Implementation

[0041] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0042] In the following description, specific details, such as particular internal procedures and techniques, are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will appreciate that the invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of the invention with unnecessary detail.

[0043] The polymer donor PM6, acceptor L8-BO, hole transport layer 2PACz, and DIO used in the embodiments of this invention were purchased from Solon Organic Optoelectronics Technology (Beijing) Co., Ltd., respectively. The hole transport layer 2PACz was purchased from TCI (Shanghai) Chemical Industry Development ...

[0044] Preliminary preparations: Dissolve 2PACz in ethanol to prepare a 10 mg / mL solution for later use; dissolve PNDIT-F3N in a mixed solution of methanol and acetic acid to prepare a 1 mg / mL solution for later use.

[0045] The donor PM6 and acceptor L8-BO were weighed at a mass ratio of PM6:L8-BO of 1:1.2. The dihalogenated benzene additive TCBB was added at concentrations of 8 mg / ml, 10 mg / ml, and 12 mg / ml, respectively. Chloroform solvent was then added, and the mixture was heated and stirred at 50°C for 1 hour to prepare a device with a bulk heterostructure.

[0046] This invention provides an organic solar cell based on a dihalogenated benzene additive. The organic solar cell forward device includes, from bottom to top, a transparent conductive substrate ITO, a hole transport layer, an organic active layer, an electron transport layer, and a metal electrode, wherein the organic active layer comprises a polymer donor PM6, a non-fullerene electron acceptor L8-BO, and a dihalogenated benzene additive TCBB.

[0047] The chemical structural formula of the polymer donor PM6 is shown below:

[0048] ;

[0049] The chemical structure of the non-fullerene electron acceptor L8-BO is shown below:

[0050] ;

[0051] The chemical structural formula of the halogenated additive TCBB is shown below:

[0052] .

[0053] Example 1:

[0054] This invention provides a method for preparing an organic solar cell using dihalogenated benzene as an active layer additive, comprising the following steps:

[0055] S1. The ITO conductive glass with a sheet resistance of 15Ω and dimensions of 1.69mm×16.9mm is subjected to the following cleaning operations in sequence: First, it is ultrasonically treated with a 0.5% (w / w) detergent solution for 20 minutes to remove surface oil stains; then, it is ultrasonically cleaned with deionized water for 20 minutes to remove residual detergent; subsequently, it is ultrasonically treated with acetone for 20 minutes and isopropanol for 20 minutes to remove organic residues; finally, the cleaned ITO glass is placed in a plasma cleaner for 2 minutes. The purpose is to solve the problems of numerous surface defects and poor contact with the hole transport layer in the existing technology of ITO.

[0056] S2. In a nitrogen-filled vacuum glove box with a water and oxygen content of <0.1 ppm, a 0.3 mg / mL ethanol solution of 2PACz was applied to the ITO glass surface using a static spin-coating method. After adding the solution, wait 15 seconds before spin-coating. The spin-coating speed was 3000 rpm for 30 seconds. After spin-coating, the sample was transferred to an annealing station and annealed at 100°C for 10 minutes to form a monolayer hole transport layer. After annealing, the sample was washed with ethanol at 5000 rpm for 30 seconds. 2PACz is a high-mobility hole transport material. This step promotes the ordered stacking of 2PACz molecules through annealing, thereby improving the hole transport efficiency from the active layer to ITO.

[0057] S3. Weigh the donor material PM6 and acceptor material L8-BO at a mass ratio of 1:1.2, and dissolve them together in chloroform to prepare a mixed solution with a total PM6 and L8-BO concentration of 16 mg / mL. Stir magnetically for 1 hour until completely dissolved. Apply the active layer solution to the hole transport layer surface using a static spin-coating method at 3000 rpm for 30 seconds. After spin-coating, place the sample on a heating stage and anneal at 100°C for 10 minutes to form an organic active layer with a thickness of 120 nm. The dihalogen groups of TCBB can promote the orderly stacking of donor / acceptor molecules, solving the problem of difficulty in controlling molecular orientation with existing additives. During annealing, TCBB can act as a "phase separation regulator," enabling the active layer to form an "interpenetrating network structure" and improving carrier separation efficiency.

[0058] S4. Take PNDIT-F3N powder and prepare a methanol solution of 1 mg / mL. Add 52.6 μL of acetic acid to each 1 mL of the solution. Use static spin coating to coat the solution onto the surface of the active layer. Spin coating speed is 3000 rpm and time is 30 s to form an electron transport layer with a thickness of 5 nm.

[0059] S5. Transfer the sample to the vacuum evaporation chamber, with a vacuum level <1×10⁻⁶. -3 Under the condition of Pa, Ag electrodes were deposited at a rate of 0.3 nm / s to a thickness of 100 nm.

[0060] Example 2:

[0061] This invention provides a method for preparing an organic solar cell using dihalogenated benzene (TCBB) as an active layer additive. A control device was prepared according to the method in Example 1, except that the concentration of the active additive TCBB in the device was 10 mg / ml. This example is used to explore the optimal concentration range of TCBB.

[0062] Example 3:

[0063] This invention provides a method for preparing an organic solar cell using dihalogenated benzene (TCBB) as an active layer additive. A control device was prepared according to the method in Example 1, except that the concentration of the active additive TCBB in the device was 12 mg / ml. This example is used to explore the optimal concentration range of TCBB.

[0064] Comparative Example 1:

[0065] This invention provides a method for preparing an organic solar cell using dihalogenated benzene as an active layer additive. A control device was prepared according to the method in Example 1, except that the active additive in the device was DIO at a concentration of 5% wt. This comparative example is used to compare the performance differences between TCBB and traditional additives.

[0066] This embodiment and the comparative example characterize the light absorption properties of the organic photovoltaic devices and corresponding thin films and materials. The following description is in conjunction with the appendix. Figure 1-3 Detailed explanation:

[0067] Figure 1 The structure diagram of the organic solar cell forward device of the present invention and the device efficiency diagram of Example 2 and Comparative Example 1 are shown. Specifically, the structure of the organic photovoltaic device and the current density-voltage characteristic curve are shown.

[0068] Figure 1 The left side shows a schematic diagram of the layered structure of an organic photovoltaic device. The device structure consists of: a transparent electrode (ITO), a hole transport layer (2PACz), an active layer (BHJ), an interface modification layer (PNDIT-F3N), and a metal electrode (Ag) stacked sequentially on a substrate; the active layer contains an active layer additive (TCBB, whose molecular structure is shown below). Figure 1 The chemical structural formula of the active layer region is shown in the figure.

[0069] Figure 1 The right side shows the current density-voltage (JV) characteristic curves of this device with different additives (DIO, TCBB):

[0070] In the curves, the blue curve corresponds to the device with added DIO, and the red curve corresponds to the device with added TCBB;

[0071] The horizontal axis represents the applied voltage (unit: V), and the vertical axis represents the current density (unit: mA·cm⁻²).

[0072] The inset graph shows a comparison of the power conversion efficiency (PCE) of the devices: the PCE of the device with added TCBB is significantly higher than that of the device with added DIO, indicating that TCBB as an additive can effectively improve the photoelectric conversion performance of the device.

[0073] Figure 2 AFM height morphology of active layer films with different additives (DIO, TCBB):

[0074] Figure 2 (a) The surface roughness (RMS) of the film with added DIO is 1.38 nm and the height fluctuation range is -6.1 nm to 6.2 nm;

[0075] Figure 2 (b) The corresponding thin film with added TCBB has a surface roughness (RMS) of 0.89 nm and a height fluctuation range of -3.8 nm to 4.0 nm;

[0076] Depend on Figure 1 , Figure 2The comparison shows that the surface of the film with added TCBB is smoother, indicating that TCBB can improve the film quality of the active layer, reduce film defects, and facilitate the transport and collection of charge carriers.

[0077] Figure 3 Normalized light absorption spectra of donor material PM6 and acceptor material L8-BO with different additives (DIO, TCBB):

[0078] In the curves, yellow (PM6+DIO) and green (PM6+TCBB) represent the absorption of the donor material, while blue (L8-BO+DIO) and red (L8-BO+TCBB) represent the absorption of the acceptor material.

[0079] The horizontal axis represents the incident light wavelength (unit: nm), and the vertical axis represents the normalized absorption intensity (unit: au).

[0080] The results showed that the light absorption intensity of both PM6 and L8-BO was improved after the addition of TCBB, and the absorption peaks were red-shifted, indicating that TCBB can enhance the light-capturing ability of the active layer material, cover a wider solar spectrum range, and thus improve the photogenerated carrier density of the device.

[0081] Photovoltaic performance testing of the device:

[0082] The light source is AM1.5G, and the sunlight intensity is 100mW / cm². 2 Simulated sunlight was used, and the intensity of the light source was tested and calibrated using a standard silicon cell. The testing instrument was a Keithley 2420 tester. The J values ​​of the devices in Comparative Example 1 and Examples 1 to 3 were obtained through testing. SC - Voltage (V) OC ) curve, such as Figure 4 As shown.

[0083] The external quantum efficiency (EQE) curves of the solar cell devices prepared in Comparative Example 1 and Examples 1 to 3 were measured using a solar cell testing system (7-STAR7-SCSpec). The results are as follows: Figure 5 As shown.

[0084] Figure 6 The measured curves of hole mobility (μh) and electron mobility (μe) as a function of voltage are as follows:

[0085] In the diagram, the blue curve corresponds to the device with added DIO, and the red curve corresponds to the device with added TCBB;

[0086] The above figure shows the hole mobility curve: hole mobility μ of the DIO group. h =1.367×10 −4 cm 2 V−1 s −1 μ of TCBB group h =2.613×10−4cm 2 V −1 s −1 ;

[0087] The figure below shows the electron mobility curves: electron mobility μ of the DIO group. e =1.079×10 −4 cm 2 V −1 s −1 μ of TCBB group e =2.220×10 −4 cm 2 V −1 s −1 ;

[0088] The results show that the addition of TCBB improves both hole and electron mobility of the device. This is because TCBB promotes the orderly stacking of active layer molecules, reduces the potential barrier for carrier transport, and solves the problem of limited mobility improvement by traditional additives.

[0089] Figure 7 J of the device under different light intensities sc With V oc Response curve:

[0090] The image above is J. sc - Light intensity curve: α is the fitting index (ideal value is 1), α=0.897 for DIO group, α=0.946 for TCBB group;

[0091] The image below is V oc - Light intensity curve: n is the ideal factor (ideal value is 1), DIO group n=1.460kT / q, TCBB group n=1.113kT / q;

[0092] The results show that α is closer to 1 and n is closer to the ideal value in the TCBB group, reflecting that TCBB effectively suppresses carrier recombination in the active layer and makes the device performance more stable under different light intensities.

[0093] Figure 8 The current density of the device in the dark state is a function of voltage:

[0094] The blue curve corresponds to the DIO group, and the red curve corresponds to the TCBB group. When the voltage is in the range of -2V to 2V, the dark state current density of the TCBB group is significantly lower than that of the DIO group.

[0095] The results show that the dark-state current represents the leakage current level of the device. The TCBB group has a lower leakage current, indicating that TCBB optimizes the interface morphology of the active layer, reduces leakage channels caused by interlayer defects, and improves the stability and energy conversion efficiency of the device.

[0096] The performance of the devices prepared in Examples 1-3 and the control device in Comparative Example 1, obtained through testing, is shown in the table below: including open-circuit voltage (V). OC ), short-circuit current (J) SC ), fill factor (FF) and power conversion efficiency (PCE), where: PCE = V OC *J SC *FF.

[0097]

[0098] As shown in the table above, when the halogenated additive TCBB is added to the PM6:L8-BO binary system, the open-circuit voltage first increases and then decreases, while the fill factor and short-circuit current density first increase and then decrease as the TCBB content gradually increases. When the TCBB concentration is 10 mg / ml, the short-circuit current density of the organic solar cell reaches 28.45 ± 0.19 mA cm⁻¹. -2 The fill factor reached 80.94±0.32%, and the energy conversion efficiency reached 20.11±0.12%, indicating that the addition of the halogenated additive TCBB successfully improved the device performance.

[0099] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An organic solar cell based on a dihalogenated benzene additive, characterized in that, The organic solar cell forward device includes, from bottom to top, a transparent conductive substrate ITO, a hole transport layer, an organic active layer, an electron transport layer and a metal electrode, wherein the organic active layer contains a polymer donor PM6, a non-fullerene electron acceptor L8-BO and a dihalobenzene additive TCBB. The chemical structural formula of the polymer donor PM6 is shown below: ； The chemical structure of the non-fullerene electron acceptor L8-BO is shown below: ； The chemical structural formula of the halogenated additive TCBB is shown below: 。 2. The organic solar cell based on a dihalogenated benzene additive as described in claim 1, characterized in that, The organic solar cell forward device specifically includes, from bottom to top, an ITO glass layer, a 2PACz hole transport layer, an organic active layer, a PNDIT-F3N electron transport layer, and a metal Ag cathode.

3. An organic solar cell based on a dihalogenated benzene additive as described in claim 1, characterized in that, The mass ratio of PM6:L8-BO in the organic active layer is 0.4 to 1:1.2; the concentration of TCBB is 8 mg / ml to 12 mg / ml.

4. An organic solar cell based on a dihalogenated benzene additive as described in claim 1, characterized in that, The short-circuit current density of the organic solar cell reaches 28.45 ± 0.19 mA cm⁻¹. -2 The fill factor reached 80.94±0.32%, and the energy conversion efficiency reached 20.11±0.12%.

5. An organic solar cell based on a dihalogenated benzene additive as described in claim 1, characterized in that, The organic active layer is an active layer.

6. A method for preparing an organic solar cell based on a dihalogenated benzene additive, characterized in that, Includes the following steps: S1. The ITO glass slide is ultrasonically treated with detergent, deionized water, acetone and isopropanol in sequence, and then treated with ultraviolet ozone cleaning machine. S2. 2PACz is deposited on an ITO glass slide using a static spin coating method, and then heated and annealed to form a hole transport layer; S3. Dissolve PM6 and L8-BO together in chloroform solution at a mass ratio of (0.4~1):1.2, then add TCBB at a concentration of 8mg / ml-12mg / ml, then transfer the sample prepared in S2 into a glove box under nitrogen atmosphere, heat and stir, and then spin coat it onto hole transport layer 2PACz to form an active layer. S4. Dissolve PNDIT-F3N in a mixed solvent of methanol and acetic acid, and use a static spin-coating method to form a PNDIT-F3N solution onto the active layer to form an electron transport layer; S5. Deposit the metal Ag electrode onto the PNDIT-F3N electron transport layer by vapor deposition.

7. The method for preparing an organic solar cell based on a dihalogenated benzene additive as described in claim 6, characterized in that, In step S2, the static spin coating speed is 3000 rpm, the annealing temperature is 100℃, and the annealing time is 10 min.

8. The method for preparing an organic solar cell based on a dihalogenated benzene additive as described in claim 6, characterized in that, In step S3, the total concentration of PM6 and L8-BO added is 16 mg / mL.

9. The method for preparing an organic solar cell based on a dihalogenated benzene additive as described in claim 6, characterized in that, In step S3, the spin coating speed is 2000–5000 rpm, the annealing temperature is 90–120°C, and the annealing time is 10 min.

10. The method for preparing an organic solar cell based on a dihalogenated benzene additive as described in claim 6, characterized in that, In step S4, the concentration of methanol solvent is 1 mg / mL, the concentration of acetic acid solvent is 19 mg / mL, the spin coating speed is 3000 rpm, and the spin coating time is 30 s.

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