A method for improving the tensile property and electrical property of a photoactive layer, a solar cell and a preparation method
By adding acetonitrile as a process aid to the photoactive layer solution precursor and combining it with specific materials and process steps to prepare solar cells, the problems of insufficient tensile and electrical properties of the photoactive layer have been solved, resulting in improved performance, reduced costs, and expanded application areas.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-29
- Publication Date
- 2026-03-31
AI Technical Summary
The photoactive layer of existing organic solar cells has shortcomings in terms of tensile and electrical properties, which limits its application in fields such as flexible devices and semi-transparent buildings.
Acetonitrile, a process aid, is added to the photoactive layer solution precursor, and a photoactive layer is formed by standing and annealing. Solar cells are prepared by combining specific materials and process steps, including spin coating of the anode and cathode interface layers and vacuum evaporation of metal electrodes.
It significantly improves the tensile and electrical properties of the photoactive layer, simplifies the processing, reduces costs, and expands the application range of organic solar cells.
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Figure CN115915878B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solar cell technology, specifically to a method for improving the tensile and electrical properties of the photoactive layer, as well as a solar cell and its fabrication method. Background Technology
[0002] With the rapid development of novel DA-type conjugated polymers and non-fullerene acceptors, the power conversion efficiency (PCE) of organic solar cells has reached over 18%, so electrical performance is no longer a limitation for their applications. Organic solar cells, due to their low cost and semi-transparency, can also be used in next-generation semi-transparent building photovoltaic systems, such as power-generating exterior walls and light-blocking curtains. Furthermore, their stretchability offers broad application prospects in wearable devices, electronic skin, flexible robots, and building-integrated materials. Meeting these application requirements necessitates that the photoactive layer of organic solar cells possess even higher stretchability.
[0003] The key properties of solar cells include photoelectric performance and the mechanical properties of the photoactive layer. Tensile modulus and elongation at break are two important parameters characterizing mechanical properties. Photoelectric conversion efficiency, fill factor, open-circuit voltage, and short-circuit current characterize photoelectric performance. Currently, photoactive layers are generally based on wrinkled or spring-shaped prestressed photoactive layers, achieved by adding flexible battery auxiliary materials or fabricating the photoactive layer into wrinkled or spring-like shapes. This not only increases the complexity of the photoactive layer's processing but also affects the cell's photoelectric conversion efficiency, which limits the large-scale application and promotion of organic solar cells.
[0004] Therefore, there is a need for a method that can simultaneously improve the electrical and tensile properties of the photoactive layer to overcome the shortcomings of the existing technology. Summary of the Invention
[0005] The present invention aims to solve the technical problems in the prior art by providing a method and a solar cell and preparation method that can simultaneously improve the tensile properties and electrical properties of the photoactive layer.
[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:
[0007] This invention provides a method for improving the tensile and electrical properties of a photoactive layer, comprising the following steps:
[0008] S1: Electron donor powder and electron acceptor fiber are added to the main solvent to form a photoactive layer solution precursor;
[0009] S2: Add process aids to the photoactive layer solution precursor to form a photoactive layer solution;
[0010] S3: Let the photoactive layer solution stand;
[0011] S4: After the photoactive layer solution has been allowed to stand, it is spin-coated onto the anode interface layer to form a film, and then annealed to obtain the photoactive layer.
[0012] The process aid mentioned in step S2 is acetonitrile, with the chemical formula CH3CN.
[0013] As a preferred embodiment of the method for improving the tensile and electrical properties of the photoactive layer of the present invention, the electron donor powder in step S1 is J52-2F, the electron acceptor fiber is N2200, and the main solvent is chloroform with the chemical formula CHCl3.
[0014] As a preferred embodiment of the method for improving the tensile and electrical properties of the photoactive layer according to the present invention, the total concentration of electron donors and electron acceptors in the photoactive layer solution precursor in step S1 is 8-12 mg / mL, and the volume fraction of the process aids in step S2 is 0.5%-5%.
[0015] As a preferred embodiment of the method for improving the tensile and electrical properties of the photoactive layer of the present invention, the standing time in step S3 is 12 hours; the annealing temperature in step S4 is 75℃-140℃ and the time is 10-12 minutes.
[0016] The present invention also provides a positive polymer solar cell, comprising an anode conductive layer, an anode interface layer, a photoactive layer, a cathode interface layer and a metal electrode, wherein the photoactive layer is a photoactive layer prepared on the anode interface layer according to the method described above for improving the tensile properties and electrical properties of the photoactive layer.
[0017] In a preferred embodiment of the present invention, the thickness of the anode interface layer is 20-30 nm; the material of the anode interface layer is PEDOT:PSS.
[0018] In a preferred embodiment of the present invention, the cathode interface layer has a thickness of 5-15 nm and the material of the cathode interface layer is PFN-Br.
[0019] In a preferred embodiment of the present invention, the metal electrode is Ag and the thickness of the metal electrode is 100 nm.
[0020] This invention also provides a method for preparing a positive-mounted polymer solar cell, comprising the following steps:
[0021] Step 1: Spin-coat a dispersion of the anode interface layer material onto the surface of the anode ITO substrate to form the anode interface layer;
[0022] Step 2: According to the method of the present invention for improving the tensile and electrical properties of the photoactive layer, a photoactive layer solution is spin-coated onto the surface of the anode interface layer away from the anode ITO substrate to form a photoactive layer;
[0023] Step 3: Spin-coat a dispersion of cathode interface layer material onto the surface of the photoactive layer away from the anode interface layer to form a cathode interface layer;
[0024] Step 4: Under vacuum conditions, Ag is vapor-deposited on the surface of the cathode interface layer away from the photoactive layer to form a metal electrode.
[0025] In a preferred embodiment of the method for preparing the positive polymer solar cell of the present invention, step 1 involves pretreatment of the anode ITO substrate, which includes cleaning, drying, and UVO treatment.
[0026] The beneficial effects of this invention are:
[0027] This invention successfully improves both the tensile and electrical properties of the photoactive layer of a solar cell by directly adding process aids to the active layer formulation. Furthermore, the process aids used in this invention are inexpensive and readily available; the desired effect is achieved after only 12 hours of settling following the addition of the aids, thus reducing processing difficulty. Therefore, this invention is characterized by its low cost and ease of operation, overcoming the shortcomings of existing technologies and filling a gap in the field. Attached Figure Description
[0028] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0029] Figure 1 The diagram shows the structure of the solar cell device of the present invention. From top to bottom, the components are Ag electrode, PFN-Br cathode transport layer, photoactive layer, PEDOT:PSS anode transport layer, and ITO anode.
[0030] Figure 2 The chemical structural formulas of the electron donor J52-2F and the electron acceptor N2200 used are given. Detailed Implementation
[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific implementation methods of this application will be described in detail below with reference to the accompanying drawings and embodiments.
[0032] The described embodiments are some, but not all, of the embodiments of the present invention.
[0033] Secondly, many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0034] Furthermore, this application is described in detail with reference to the schematic diagrams. When describing the embodiments of this application in detail, for ease of explanation, the three-dimensional schematic diagrams showing the device structure will be partially enlarged without following the general scale. Moreover, the schematic diagrams are only examples and do not represent the three-dimensional dimensions of the materials involved in the actual manufacturing process. They should not limit the scope of protection of this application.
[0035] Example 1
[0036] This application provides a standard polymer solar cell, the structural diagram of which can be found in the embodiment. Figure 1 It is prepared by the following steps:
[0037] S1: Add 6 mg of electron donor J52-2F and 3 mg of electron acceptor N2200 to 0.9 mL of the main solvent chloroform to form a photoactive layer solution precursor with a total concentration of 10 mg / mL;
[0038] S2: Add 0.0045 mL of acetonitrile to the photoactive layer solution precursor, with a volume fraction of 0.5% of the photoactive layer solution precursor, to form the photoactive layer solution;
[0039] S3: Let the photoactive layer solution stand for 12 hours;
[0040] S4: The glass substrate with the ITO conductive layer is ultrasonically treated with alkaline optical glass cleaning solution, deionized water, acetone, isopropanol and deionized water for 24 minutes each, then the residual moisture is dried with nitrogen gas of 99.9% purity, and then ultraviolet-ozone plasma surface treatment is performed for 25 minutes.
[0041] S5: Spin-coat the PEDOT:PSS solution onto the surface of the treated ITO conductive layer at a spin speed of 5000 rpm for 30 s, and then anneal it in an oven at 140°C for 20 min to form an anode interface layer with a thickness of 26 nm.
[0042] S6: Spin-coat the photoactive layer solution obtained in step S3 onto the surface of the anode interface layer at 2000 rpm, and anneal at 130°C for 10 minutes to obtain the photoactive layer.
[0043] S7: Dissolve PFN-Br in methanol to obtain a cathode interface layer solution of 0.5 mg / mL. Spin-coat the cathode interface layer solution onto the surface of the photoactive layer at 3000 rpm to obtain a cathode interface layer with a thickness of 8 nm.
[0044] S8: Using vacuum evaporation, a layer of silver with a thickness of 100nm and an evaporation area of 0.08 square centimeters is deposited on the PFN-Br surface to obtain the finished polymer solar cell.
[0045] The molecular structural formulas of J52-2F and N2200 are as follows: Figure 2 As shown.
[0046] The chemical formula of the process aid acetonitrile is CH3CN.
[0047] Examples 2-5
[0048] The difference between Examples 2-5 and Example 1 lies in the volume fraction of acetonitrile, the added process aid, in the photoactive layer solution precursor, as follows:
[0049] Example 2
[0050] This application provides a standard polymer solar cell, which is prepared by the following steps:
[0051] S1: Add 6 mg of electron donor J52-2F and 3 mg of electron acceptor N2200 to 0.9 mL of the main solvent chloroform to form a photoactive layer solution precursor with a total concentration of 10 mg / mL;
[0052] S2: Add 0.009 mL of acetonitrile to the photoactive layer solution precursor, with a volume fraction of 1.0% of the photoactive layer solution precursor, to form the photoactive layer solution;
[0053] S3: Let the photoactive layer solution stand for 12 hours;
[0054] S4: The glass substrate with the ITO conductive layer is ultrasonically treated with alkaline optical glass cleaning solution, deionized water, acetone, isopropanol and deionized water for 24 minutes each, then the residual moisture is dried with nitrogen gas of 99.9% purity, and then ultraviolet-ozone plasma surface treatment is performed for 25 minutes.
[0055] S5: Spin-coat the PEDOT:PSS solution onto the surface of the treated ITO conductive layer at a spin speed of 5000 rpm for 30 s, and then anneal it in an oven at 140°C for 20 min to form an anode interface layer with a thickness of 26 nm.
[0056] S6: Spin-coat the photoactive layer solution obtained in step S3 onto the surface of the anode interface layer at 2000 rpm, and anneal at 130°C for 10 minutes to obtain the photoactive layer.
[0057] S7: Dissolve PFN-Br in methanol to obtain a cathode interface layer solution of 0.5 mg / mL. Spin-coat the cathode interface layer solution onto the surface of the photoactive layer at 3000 rpm to obtain a cathode interface layer with a thickness of 8 nm.
[0058] S8: Using vacuum evaporation, a layer of silver with a thickness of 100nm and an evaporation area of 0.08 square centimeters is deposited on the PFN-Br surface to obtain the finished polymer solar cell.
[0059] Example 3
[0060] This application provides a standard polymer solar cell, which is prepared by the following steps:
[0061] S1: Add 6 mg of electron donor J52-2F and 3 mg of electron acceptor N2200 to 0.9 mL of the main solvent chloroform to form a photoactive layer solution precursor with a total concentration of 10 mg / mL;
[0062] S2: Add 0.0135 mL of acetonitrile to the photoactive layer solution precursor, with a volume fraction of 1.5% of the photoactive layer solution precursor, to form the photoactive layer solution;
[0063] S3: Let the photoactive layer solution stand for 12 hours;
[0064] S4: The glass substrate with the ITO conductive layer is ultrasonically treated with alkaline optical glass cleaning solution, deionized water, acetone, isopropanol and deionized water for 24 minutes each, then the residual moisture is dried with nitrogen gas of 99.9% purity, and then ultraviolet-ozone plasma surface treatment is performed for 25 minutes.
[0065] S5: Spin-coat the PEDOT:PSS solution onto the surface of the treated ITO conductive layer at a spin speed of 5000 rpm for 30 s, and then anneal it in an oven at 140°C for 20 min to form an anode interface layer with a thickness of 26 nm.
[0066] S6: Spin-coat the photoactive layer solution obtained in step S3 onto the surface of the anode interface layer at 2000 rpm, and anneal at 130°C for 10 minutes to obtain the photoactive layer.
[0067] S7: Dissolve PFN-Br in methanol to obtain a cathode interface layer solution of 0.5 mg / mL. Spin-coat the cathode interface layer solution onto the surface of the photoactive layer at 3000 rpm to obtain a cathode interface layer with a thickness of 8 nm.
[0068] S8: Using vacuum evaporation, a layer of silver with a thickness of 100nm and an evaporation area of 0.08 square centimeters is deposited on the PFN-Br surface to obtain the finished polymer solar cell.
[0069] Example 4
[0070] This application provides a standard polymer solar cell, which is prepared by the following steps:
[0071] S1: Add 6 mg of electron donor J52-2F and 3 mg of electron acceptor N2200 to 0.9 mL of the main solvent chloroform to form a photoactive layer solution precursor with a total concentration of 10 mg / mL;
[0072] S2: Add 0.018 mL of acetonitrile to the photoactive layer solution precursor, with a volume fraction of 2.0% of the photoactive layer solution precursor, to form the photoactive layer solution;
[0073] S3: Let the photoactive layer solution stand for 12 hours;
[0074] S4: The glass substrate with the ITO conductive layer is ultrasonically treated with alkaline optical glass cleaning solution, deionized water, acetone, isopropanol and deionized water for 24 minutes each, then the residual moisture is dried with nitrogen gas of 99.9% purity, and then ultraviolet-ozone plasma surface treatment is performed for 25 minutes.
[0075] S5: Spin-coat the PEDOT:PSS solution onto the surface of the treated ITO conductive layer at a spin speed of 5000 rpm for 30 s, and then anneal it in an oven at 140°C for 20 min to form an anode interface layer with a thickness of 26 nm.
[0076] S6: Spin-coat the photoactive layer solution obtained in step S3 onto the surface of the anode interface layer at 2000 rpm, and anneal at 130°C for 10 minutes to obtain the photoactive layer.
[0077] S7: Dissolve PFN-Br in methanol to obtain a cathode interface layer solution of 0.5 mg / mL. Spin-coat the cathode interface layer solution onto the surface of the photoactive layer at 3000 rpm to obtain a cathode interface layer with a thickness of 8 nm.
[0078] S8: Using vacuum evaporation, a layer of silver with a thickness of 100nm and an evaporation area of 0.08 square centimeters is deposited on the PFN-Br surface to obtain the finished polymer solar cell.
[0079] Example 5
[0080] This application provides a standard polymer solar cell, which is prepared by the following steps:
[0081] S1: Add 6 mg of electron donor J52-2F and 3 mg of electron acceptor N2200 to 0.9 mL of the main solvent chloroform to form a photoactive layer solution precursor with a total concentration of 10 mg / mL;
[0082] S2: Add 0.027 mL of acetonitrile to the photoactive layer solution precursor, with a volume fraction of 3.0% of the photoactive layer solution precursor, to form the photoactive layer solution;
[0083] S3: Let the photoactive layer solution stand for 12 hours;
[0084] S4: The glass substrate with the ITO conductive layer is ultrasonically treated with alkaline optical glass cleaning solution, deionized water, acetone, isopropanol and deionized water for 24 minutes each, then the residual moisture is dried with nitrogen gas of 99.9% purity, and then ultraviolet-ozone plasma surface treatment is performed for 25 minutes.
[0085] S5: Spin-coat the PEDOT:PSS solution onto the surface of the treated ITO conductive layer at a spin speed of 5000 rpm for 30 s, and then anneal it in an oven at 140°C for 20 min to form an anode interface layer with a thickness of 26 nm.
[0086] S6: Spin-coat the photoactive layer solution obtained in step S3 onto the surface of the anode interface layer at 2000 rpm, and anneal at 130°C for 10 minutes to obtain the photoactive layer.
[0087] S7: Dissolve PFN-Br in methanol to obtain a cathode interface layer solution of 0.5 mg / mL. Spin-coat the cathode interface layer solution onto the surface of the photoactive layer at 3000 rpm to obtain a cathode interface layer with a thickness of 8 nm.
[0088] S8: Using vacuum evaporation, a layer of silver with a thickness of 100nm and an evaporation area of 0.08 square centimeters is deposited on the PFN-Br surface to obtain the finished polymer solar cell.
[0089] Comparative Example 1
[0090] Comparative Example 1 provides a positive polymer solar cell. The difference between Comparative Example 1 and Examples 1 to 5 is that Comparative Example 1 does not contain the process aid acetonitrile.
[0091] Battery performance parameter testing
[0092] The device was placed at 100mW / cm 2 Electrical performance tests were conducted using a computer-controlled Keithley 2400 source meter under a standard AM 1.5G solar simulator. The electrical performance of the standard solar cells from Examples 1 to 5 and Comparative Example 1 was tested, and the results are shown in Table 1.
[0093] Table 1: Electrical performance of Examples 1 to 5 and Comparative Example 1
[0094]
[0095] Results Analysis: Comparing the data from Examples 1 to 5 with Comparative Example 1, it is evident that the electrical performance of the photoactive layer in Examples 1 to 5, which included the process aid acetonitrile, was higher than that in Comparative Example 1, which did not include acetonitrile. Furthermore, comparing the data from Examples 1-5, it was found that the battery performance parameters changed synchronously with the change in the volume fraction of the process aid acetonitrile. Therefore, it can be proven that the process aid acetonitrile improved the battery's electrical performance in the photoactive layer. The battery exhibited the best overall performance when the acetonitrile volume fraction was 1.5%, making Example 3 the preferred choice.
[0096] Tensile property test
[0097] The photoactive layers of Examples 1 to 5 and Comparative Example 1 were subjected to underwater stretching using a HY-0230 stretching machine manufactured by Shanghai Hengyi Precision Instruments Co., Ltd. to test their tensile properties. The results are shown in Table 2.
[0098] Table 2: Tensile properties of Examples 1 to 5 and Comparative Example 1.
[0099]
[0100] Results Analysis: Comparing the data from Examples 1 to 5 with Comparative Example 1, it can be seen that the elongation at break in Examples 1 to 5 with the addition of the process aid acetonitrile is greater than that in Comparative Example 1, and the elastic modulus is less than that in Comparative Example 1. Furthermore, comparing the data from Examples 1 to 5, the tensile properties of the photoactive layer change synchronously when the volume fraction of the process aid acetonitrile changes. Therefore, it can be proven that the process aid acetonitrile improves the tensile properties in the photoactive layer. When the volume fraction of acetonitrile is 1.5%, the photoactive layer exhibits the highest elongation at break, the lowest elastic modulus, and the highest tensile properties, indicating that Example 3 is the preferred embodiment.
[0101] Conclusion: The process additives used in this invention are inexpensive and easy to add, and can simultaneously improve the stretching performance and electrical performance of the photoactive layer of solar cells, with the advantages of being economical and highly efficient.
[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.
Claims
1. A method for improving the tensile and electrical properties of a photoactive layer, characterized in that, The method comprises the following steps: S1: adding an electron donor powder and an electron acceptor fiber into a main solvent to form a photoactive layer solution precursor; S2: adding a process aid into the photoactive layer solution precursor to form a photoactive layer solution; S3: standing the photoactive layer solution; S4: after the photoactive layer solution after standing is spin-coated into a film on an anode interfacial layer, annealing treatment is performed to obtain a photoactive layer; The process aid in step S2 is acetonitrile with a chemical formula of CH3CN; The electron donor powder in step S1 is J52-2F, the electron acceptor fiber is N2200, and the main solvent is chloroform with a chemical formula of CHCl3.
2. The method of claim 1, wherein, The total concentration of the electron donor and the electron acceptor in the photoactive layer solution precursor in step S1 is 8-12 mg / mL, and the volume fraction of the process aid in step S2 is 0.5%-5%.
3. The method of claim 1, wherein, The standing time in step S3 is 12 hours, and the annealing treatment temperature in step S4 is 75-140°C, and the time is 10-12 min.
4. A normal polymer solar cell comprising an anode conductive layer, an anode interface layer, a photoactive layer, a cathode interface layer, and a metal electrode, characterized in that, The photoactive layer is a photoactive layer prepared on the anode interfacial layer according to the method in any one of claims 1-3.
5. The solar cell according to claim 4, characterized in that, The thickness of the anode interfacial layer is 20-30 nm, and the material of the anode interfacial layer is PEDOT:PSS.
6. The solar cell of claim 4, wherein, The thickness of the cathode interfacial layer is 5-15 nm, and the material of the cathode interfacial layer is PFN-Br.
7. The solar cell of claim 4, wherein, The metal electrode is Ag, and the thickness of the metal electrode is 100 nm.
8. A method for producing a normal polymer solar cell, characterized by comprising the steps of: (1) preparing a normal polymer solar cell according to any one of claims 1 to 7; and (2) drying the normal polymer solar cell. The method comprises the following steps: Step 1: spin-coating a dispersion liquid of an anode interfacial layer material on the surface of an anode ITO substrate to form an anode interfacial layer; Step 2: spin-coating a photoactive layer solution on the surface of the anode interfacial layer away from the anode ITO substrate to form a photoactive layer according to the method in any one of claims 1-3; Step 3: spin-coating a dispersion liquid of a cathode interfacial layer material on the surface of the photoactive layer away from the anode interfacial layer to form a cathode interfacial layer; Step 4: evaporating Ag on the surface of the cathode interfacial layer away from the photoactive layer under vacuum to form a metal electrode.
9. The production method according to claim 8, characterized by, The anode ITO substrate in step 1 is pretreated, and the pretreatment comprises cleaning, drying, and UVO treatment.