Cathode interface layer material, cathode interface layer coating liquid and organic photovoltaic module

Abstract

This invention discloses a cathode interface layer material, a cathode interface layer coating solution, and an organic photovoltaic module. The invention provides a compound or polymer modified from naphthalenetetracarboxylic dianhydride or perylenetetracarboxylic dianhydride as a cathode interface layer material. This cathode interface layer material has a piperazine group in its general chemical formula, allowing it to be dissolved in water, methanol, ethanol, isopropanol, or a combination thereof to form a cathode interface layer coating solution. Furthermore, the organic photovoltaic module made using this cathode interface layer material exhibits excellent power conversion efficiency (PCE) and thermal stability.

Description

Technical Field

[0001] This invention provides a compound or polymer modified from naphthalenetetracarboxylic dianhydride (NTCDA) or perylenetetracarboxylic dianhydride (PTCDA) as a cathode interface layer material. The cathode interface layer material has a piperazine group in its general chemical formula, so that the cathode interface layer material can be dissolved in water, methanol, ethanol, isopropanol or a combination thereof to form a cathode interface layer coating solution, and so that the organic photovoltaic module made using the cathode interface layer material has excellent power conversion efficiency (PCE) and thermal stability. Background Technology

[0002] With the evolution of the times, the consumption of energy resources such as coal, oil, natural gas, and nuclear energy has been increasing, leading to a relative emergence of the energy crisis. This has spurred the development of solar power generation. Solar power generation is a renewable and environmentally friendly method that reduces pollution. First-generation solar cells primarily used silicon-based solar cells, which boasted high photoelectric conversion efficiency. Second-generation solar cells were thin-film cadmium telluride (CdTe) solar cells, but the toxicity of their raw materials and the manufacturing process caused significant environmental pollution. Consequently, third-generation organic solar cells emerged, including dye-sensitized solar cells (DSSCs), nanocrystalline cells, and organic photovoltaic (OPV) modules. Compared to inorganic materials that require vacuum deposition processes, organic photovoltaic modules can be manufactured using methods such as dip coating, spin coating, slot coating, screen printing, and inkjet printing, making it easier to achieve low-cost and large-scale production.

[0003] Currently, the industry uses an inverse structure to produce organic photovoltaic modules, and the cathode interface layer material is usually a metal oxide such as zinc oxide (ZnO). However, the use of metal oxides requires high-temperature sintering (>150℃), which is not conducive to the fabrication of large-area flexible substrates. Therefore, Chinese patent publications CN 113582991A (Reference 1) and CN113666927A (Reference 2) propose using derivatives modified from naphthalenetetracarboxylic dianhydride (NTCDA) or perylenetetracarboxylic dianhydride as cathode interface layer materials. However, the derivative proposed in Reference 1 has a linear terminal group, resulting in poor thermal stability of the constructed organic photovoltaic module. The derivative proposed in Reference 2 introduces an imidazole group at the end, which may have higher thermal stability, but results in poor solubility. It cannot be dissolved in common methanol, ethanol, or isopropanol, and trifluoroethanol is required, which will limit its application in organic photovoltaic modules. Summary of the Invention

[0004] Therefore, developing cathode interface layer materials can enable organic photovoltaic modules to possess excellent properties.

[0005] The PET and thermal stability, as well as the solubility in water, methanol, ethanol, isopropanol or a combination thereof, are the research objectives of this invention.

[0006] Therefore, the first object of the present invention is to provide a cathode interface layer material comprising at least one compound as shown in formula (I) or (II):

[0007]

[0008] in,

[0009] for

[0010] R 1 It is H or C1~C 12 Straight-chain, branched-chain, or cyclic alkyl groups;

[0011] R 2 For C1~C 12 Straight-chain, branched-chain, or cyclic alkyl groups;

[0012] X is Cl, Br, or I;

[0013] m is an integer between 1 and 6; and,

[0014] n is an integer between 2 and 6.

[0015] In one embodiment, the cathode interface layer material further comprises polyethyleneimine.

[0016] A second objective of the present invention is to provide a cathode interface layer material comprising at least a polymer, wherein the repeating units of the polymer have piperazine groups.

[0017] In one embodiment, the polymer comprises at least a structural or repeating unit of formula (III) or formula (IV):

[0018]

[0019] In one embodiment, the polymer is obtained by copolymerizing the compound with a modifier having at least two ethylene oxide groups. Preferably, for R 1 H is a integer between 1 and 6.

[0020] In one embodiment, the polymer is obtained by copolymerizing the compound with polyethyleneimine and a modifier having at least two ethylene oxide groups. Preferably, for R 1 H is a integer between 1 and 6.

[0021] In one embodiment, the polymer is formed by copolymerizing the compound with polyethyleneimine and the modifier, followed by reacting it with sulcolepone. The modifier has at least two ethylene oxide groups. Preferably, for R 1 H is a integer between 1 and 6.

[0022] Therefore, the third objective of the present invention is to provide a cathode interface layer coating solution comprising the aforementioned cathode interface layer material, wherein the solvent of the cathode interface layer coating solution is water, methanol, ethanol, isopropanol or a combination thereof.

[0023] Therefore, the fourth objective of this invention is to provide an organic photovoltaic module comprising the aforementioned cathode interface layer material.

[0024] Preferably, the organic photovoltaic module includes a substrate, a first electrode stacked on the substrate, an electron transport layer stacked on the first electrode, an active layer stacked on the electron transport layer, a hole transport layer stacked on the active layer, and a second electrode stacked on the hole transport layer, wherein the electron transport layer comprises the cathode interface layer material.

[0025] Preferably, the organic photovoltaic module includes a substrate, a first electrode stacked on the substrate, a hole transport layer stacked on the first electrode, an active layer stacked on the hole transport layer, an electron transport layer stacked on the active layer, and a second electrode stacked on the electron transport layer, wherein the electron transport layer comprises the cathode interface layer material.

[0026] The advantages of this invention are: using a compound or polymer modified from naphthalenetetracarboxylic dianhydride or perylenetetracarboxylic dianhydride as a cathode interface layer material; utilizing the piperazine group in the general chemical formula of the cathode interface layer material, the cathode interface layer material can be dissolved in water, methanol, ethanol, isopropanol or a combination thereof to form a cathode interface layer coating solution; and enabling organic photovoltaic modules made using the cathode interface layer material to have excellent power conversion efficiency (PCE) and thermal stability. Attached Figure Description

[0027] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein:

[0028] Figure 1 This is a cross-sectional schematic diagram illustrating the first structure of the organic photovoltaic module of the present invention;

[0029] Figure 2 This is a cross-sectional schematic diagram illustrating the second structure of the organic photovoltaic module of the present invention; and

[0030] Figure 3 These are energy conversion efficiency diagrams illustrating the thermal stability of the organic photovoltaic modules used in Comparative Example 2 and Application Example 4. Detailed Implementation

[0031] Examples 1 to 11 below are the cathode interface layer materials of the present invention.

[0032] <Preparation Examples 1-10 and Coating Liquids, Examples 1-5 and 10 are compounds>.

[0033] Preparation of Example 1 and Coating Solution:

[0034]

[0035] Compound 1: 1.0 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 1.3 g of N-aminoethylpiperazine were placed in separate reaction flasks. Dimethylformamide (30 mL) was added, and the mixture was stirred under a nitrogen system and heated at 90 °C for 16–18 hours. After the reaction was completed, the mixture was cooled, precipitated in acetone, and purified by filtration. This process was repeated until the filtrate was clear, yielding a dark green solid, which is Example 1. Alternatively, if Example 1 is diluted with pure water or methanol and the pH is adjusted to 6–7 with acetic acid, a 0.05 wt% dilution solution is obtained, which is the coating solution for Example 1 and is used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0036] Preparation Example 2 and Coating Solution:

[0037]

[0038] The dark green solid of Example 1 (0.5 g) and 1,4-butanesulfonyl lactone (0.67 g) were placed in a reaction flask, and methanol (10 mL) was added. The mixture was stirred under a nitrogen system and heated at 70°C for 16–18 hours. After the reaction was completed and the mixture was cooled, the solid was precipitated with toluene and purified by vacuum filtration. Finally, the solid was washed with acetone, filtered, and dried to obtain the black solid of Example 2. Alternatively, if Example 2 is diluted with pure water or methanol and the pH is adjusted to 6–7 with acetic acid, a 0.05 wt% diluted solution is obtained, which is the coating solution of Example 2, and is used as the cathode interface layer (electron transport layer) to be prepared later.

[0039] Preparation of the coating solutions in Examples 3 and 4:

[0040]

[0041] The dark green solid of Example 1 (2g) obtained in Example 1 was placed in a reaction flask, and anhydrous dimethylformamide (40mL) was added and stirred under a nitrogen system. After cooling to 0°C, 60% sodium hydride (0.252g) was added, and the mixture was stirred at low temperature for 0.5 hours. Then, bromoethane (0.744g) was added, and the mixture was stirred at room temperature for 0.5 hours. After the reaction was completed, the mixture was cooled, and the solid was purified by filtration with acetone precipitation. The purified solid was then dried to obtain 1g of black solid, Example 3. The solid of Example 3 (1g) was placed in a reaction flask, and dimethylformamide (20mL) was added and stirred under a nitrogen system. Finally, bromoethane (1.77g) was added, and the mixture was heated to 90°C and stirred for 18 hours. After the reaction was completed, the solid was cooled, and the solid was purified by filtration with acetone precipitation. The purified solid was then dried to obtain 1.6g of black solid, Example 4. In addition, if Examples 3 and 4 are diluted with pure water or methanol respectively, and the pH value is adjusted to 6-7 with acetic acid, a 0.05wt% diluted solution can be obtained, which are the coating solutions of Examples 3 and 4 respectively, for use in the fabrication of the cathode interface layer (electron transport layer) described later.

[0042] Preparation of Example 5 and Coating Solution:

[0043]

[0044] Solid Example 3 (0.5 g) was placed in a reaction flask, and 50% hydrogen peroxide (0.46 g) was added. The mixture was stirred under a nitrogen system and heated to 100°C for 16–18 hours. After the reaction was complete and the mixture was cooled, the solid was precipitated with acetone, purified by filtration, and dried to obtain the black solid of Example 5. Alternatively, if Example 5 is diluted with pure water or methanol, and the pH is adjusted to 6–7 with acetic acid, a 0.05 wt% diluted solution is obtained, which serves as the coating solution for Example 5 and is used later in the fabrication of the cathode interface layer (electron transport layer).

[0045] <Preparation Example 6 and Coating Solution, Example 6 is a mixture of compound forms>.

[0046] Preparation of Example 6 and Coating Solution:

[0047] Example 6 is a mixture comprising the dark green solid of Example 1 and polyethyleneimine. Example 1 does not chemically react with polyethyleneimine. Branched polyethylenimine (b-PEI) is used, which is composed of primary, secondary, and tertiary amines in an amino group ratio of 33%:41%:26%, for example, with a weight average molecular weight of approximately 25,000 g / mol. Sigma-Aldrich, Product Number: 408727, CAS Number: 9002-98-6. First, polyethyleneimine (0.01 g) is added to 2-butanol (20 g) and stirred to dissolve. Then, a polyethyleneimine dilution solution with a concentration of 0.05 wt% is prepared with water or methanol. Next, the aforementioned 0.05 wt% polyethyleneimine dilution solution and 0.05 wt% of the coating solution of Example 1 are mixed at a volume ratio of 1:1 to form the coating solution of Example 6.

[0048] Preparation of Example 10 and Coating Solution:

[0049]

[0050] Compound 2: 1,4,5,8-naphthalenetetracarboxylic dianhydride (1.0 g) and N-aminoethylpiperazine (1.9 g) were placed in separate reaction flasks, and dimethylformamide (30 mL) was added. The mixture was stirred under a nitrogen system and heated at 90°C for 16–18 hours. After the reaction was completed, the mixture was cooled, poured into acetone to precipitate, and purified by filtration. This process was repeated until the filtrate was clear, yielding a dark green solid, which is Example 10. Alternatively, if Example 10 is diluted with pure water or methanol, and the pH is adjusted to 6–7 with acetic acid, a 0.05 wt% diluted solution is obtained, which is the coating solution for Example 10, used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0051] <Preparation of coating solutions in Examples 7-9 and 11, where Examples 7-9 and 11 are polymers>.

[0052] Preparation of Example 7 and Coating Solution:

[0053]

[0054] Glyceryl diglycidyl ether (0.25 g; modifier) ​​and Example 1 (0.20 g) were placed in separate reaction flasks, and dimethyl sulfoxide (20 mL) was added and stirred to dissolve. The mixture was heated at 80°C for 12–16 hours under a nitrogen system. After cooling, a brown liquid product, the polymer form of Example 7, was obtained. Example 7 was diluted with pure water or methanol, and the pH was adjusted to 6–7 with acetic acid to obtain a 0.05 wt% diluted solution, which served as the coating solution for Example 7, used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0055] Preparation of Example 8 and Coating Solution:

[0056] Polyethyleneimine (1.0 g), glycerol diglycidyl ether (0.25 g; modifier, crosslinking agent), and Example 1 (0.20 g) were placed in separate reaction flasks, and dimethyl sulfoxide (20 mL) was added and stirred to dissolve. The mixture was heated at 80°C for 12–16 hours under a nitrogen system. After cooling, a brown liquid product, Example 8, was obtained. Example 8 is a polymer formed by the ring-opening polymerization of the secondary amine group of Example 1 with the primary amine group of polyethyleneimine and the epoxy group on the glycerol diglycidyl ether. The polymerization mechanism can be found in Example 7 and Taiwan Patent I740188. Example 8 was diluted with pure water or methanol, and the pH was adjusted to 6–7 with acetic acid to obtain a 0.05 wt% diluted solution, which is the coating solution for Example 8, used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0057] Preparation of Example 9 and Coating Solution:

[0058] The brown liquid of Example 8 (23.53 g) and 1,4-butanesulfonyl lactone (0.15 g; modifier, crosslinking agent) were placed in a reaction flask and heated at 70°C for 16-18 hours. After cooling, the brown liquid of Example 9, which is a polymer, was obtained. The secondary and tertiary amines of Example 8 reacted with the sulfonyl lactone to open their rings and form the zwitterionic polymer Example 9 (refer to Taiwan Invention Patent I740188). Example 9 was diluted with pure water or methanol, and the pH was adjusted to 6-7 with acetic acid to obtain a 0.05 wt% diluted solution, which is the coating solution of Example 9, used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0059] Preparation of Example 11 and Coating Solution:

[0060]

[0061] Glyceryl diglycidyl ether (0.25 g; modifier) ​​and Example 10 (0.20 g) were placed in separate reaction flasks, and dimethyl sulfoxide (20 mL) was added and stirred to dissolve. The mixture was heated at 80°C for 12–16 hours under a nitrogen system. After cooling, a brown liquid product, the polymer form of Example 11, was obtained. Example 11 was diluted with pure water or methanol, and the pH was adjusted to 6–7 with acetic acid to obtain a 0.05 wt% diluted solution, which served as the coating solution for Example 11, used later in the fabrication of the cathode interface layer (electron transport layer).

[0062] It should be noted that the coating liquids in Examples 1 to 11 are the cathode interface layer coating liquids of the present invention.

[0063] <Preparation of Comparative Examples 1-2 and coating solutions, where Comparative Example 1 is a compound and Comparative Example 2 is a polymer>.

[0064] Comparative Example 1 and Coating Solution:

[0065] The structure of Comparative Example 1 (PDINO) is explained below:

[0066] Comparative Example 1 is a derivative modified from perylenetetracarboxylic dianhydride as mentioned in Reference 1, and its terminal group is a straight chain. Comparative Example 1 was diluted with methanol, and the pH was adjusted to 6-7 with acetic acid to obtain a 0.05 wt% diluted solution, which is the coating solution of Comparative Example 1, and is used as the cathode interface layer (electron transport layer) to be prepared later.

[0067] Preparation of Comparative Example 2 and Coating Solution:

[0068] Polyethyleneimine (1.0 g) and glycerol diglycidyl ether (0.25 g; modifier) ​​were placed in separate reaction flasks, and dimethyl sulfoxide (20 mL) was added and stirred to dissolve. The mixture was heated at 80°C for 12–16 hours under a nitrogen system. After cooling, a colorless liquid product, Comparative Example 2, was obtained. Comparative Example 2 is the polyethyleneimine with zwitterionic groups described in Taiwan Invention Patent I740188. Comparative Example 2 was diluted with pure water or methanol, and the pH was adjusted to 6–7 using acetic acid to obtain a 0.05 wt% diluted solution, which served as the coating solution for Comparative Example 2 and was used in the fabrication of the cathode interface layer (electron transport layer) described later.

[0069] <Organic Photovoltaic Module Structure>

[0070] Figure 1 This is a cross-sectional view of a first structure of the organic photovoltaic module used in this invention. The organic photovoltaic module includes a substrate 70, a first electrode 80 deposited on the substrate 70, an organic photovoltaic layer 90 deposited on the first electrode 80, and a second electrode 100 deposited on the organic photovoltaic layer 90. The organic photovoltaic layer 90 includes an electron transport layer (cathode interface layer) 91 deposited on the first electrode 80, a photoactive layer 92 deposited on the electron transport layer 91, and a hole transport layer (anode interface layer) 93 deposited on the photoactive layer 92.

[0071] Figure 2 This is a cross-sectional view of a second structure of the organic photovoltaic module used in this invention. The organic photovoltaic module includes a substrate 70, a first electrode 80 deposited on the substrate 70, an organic photovoltaic layer 90 deposited on the first electrode 80, and a second electrode 100 deposited on the organic photovoltaic layer 90. The organic photovoltaic layer 90 includes a hole transport layer (anode interface layer) 93 deposited on the first electrode 80, a photoactive layer 92 deposited on the hole transport layer 93, and an electron transport layer (cathode interface layer) 91 deposited on the photoactive layer 92.

[0072] <Modulation of photoactive layer solution>

[0073] A photoactive layer solution was prepared by mixing a p-type donor material, a non-fullerene acceptor material, and a fullerene acceptor material in a weight ratio of 1:1.2:0.2, and then using xylene as a solvent. The p-type donor material comprises a repeating unit structure as shown in the following formula:

[0074] The non-fullerene acceptor material is:

[0075] The fullerene acceptor material is:

[0076]

[0077] <Preparation of Organic Photovoltaic Modules (OPV)>

[0078] The organic photovoltaic modules prepared by Comparative Examples 1-2 and Examples 1, 2, 3, 5, 6, 8 and 9 used in Table 1 below are application comparative examples and application examples, where application comparative example 1 is without an electron transport layer, and the other preparation methods are the same.

[0079] Before fabricating the organic photovoltaic module, a patterned ITO (indium tin oxide) glass substrate [with a resistivity of 12 Ω / □ (ohms / square)] is sequentially cleaned for 10 minutes each in an ultrasonic oscillation bath using a cleaning agent, deionized water, acetone, and isopropanol. After ultrasonic cleaning, the ITO glass substrate undergoes surface treatment in a UV-ozone cleaner for 30 minutes. The glass substrate is the aforementioned substrate 70, and the ITO is the aforementioned first electrode 80. Figure 1 In the structure, this is the cathode.

[0080] The coating solutions of Comparative Examples 1-2 and Examples 1, 2, 3, 5, 6, 8 and 9 were respectively spin-coated onto an ITO glass substrate and baked at 100°C for 5 minutes under nitrogen to complete the corresponding electron transport layer 91.

[0081] The aforementioned photoactive layer solution was spin-coated onto the aforementioned electron transport layer 91 and baked at 100°C under nitrogen for 10 minutes to form the aforementioned photoactive layer 92 on the electron transport layer 91.

[0082] Next, the material is introduced into a vacuum chamber, where molybdenum trioxide (MoO3) is deposited at a depth of approximately 10 nm to form the aforementioned hole transport layer 93 on the photoactive layer 92. Following this, Ag metal (approximately 100 nm) is deposited at a depth of approximately 100 nm as the aforementioned second electrode 100. Figure 1 In the structure, this is the anode.

[0083] <Electrical Analysis of Organic Photovoltaic Modules>

[0084] The measurement area of ​​the organic photovoltaic module is defined as 0.04 cm with a metal shield. 2 The Keithley 2400 was used as the power supply, programmed via LabVIEW, at an illuminance of 100 mW / cm². 2 The electrical properties of organic photovoltaic modules were measured under AM 1.5G simulated sunlight (SAN-EI XE S-40S 3) and recorded by computer program.

[0085] <Power Conversion Efficiency (PCE) Analysis of Organic Photovoltaic Modules>

[0086] Table 1 below shows the organic photovoltaic modules used in comparative and application examples, which exhibit different electrical properties after the aforementioned electrical analysis. In Table 1, Voc represents open voltage, Jsc represents short-circuit current, FF represents fill factor, and PCE represents energy conversion efficiency. Open voltage and short-circuit current are the intercepts of the voltage-current density curves on the X-axis and Y-axis, respectively. Increasing these two values ​​improves the efficiency of the organic photovoltaic module. The fill factor is calculated by dividing the area plotted on the curve by the product of the short-circuit current and open-circuit voltage. The energy conversion efficiency is obtained by dividing the open-circuit voltage, short-circuit current, and fill factor by the amount of irradiated light, with higher values ​​being preferred. The thermal stability test is performed after the above components are packaged (initial efficiency value is PCE0), heated at 120℃ for 10 minutes, and then heated at 140℃ for 10 minutes. The efficiency value after this is PCE1. Thermal stability = PCE1 / PCE0.

[0087] Table 1

[0088]

[0089]

[0090] As can be seen from the results in Table 1, Comparative Example 1 lacks the assistance of an electron transport layer (cathode interface layer material), and the electrons generated by the light absorption of the photoactive layer cannot be successfully collected to the cathode. Therefore, the PCE is only 4.6%, which is far lower than the other comparative examples and application examples. Thus, Comparative Example 1 is a non-compliant organic photovoltaic module.

[0091] Table 1 is reorganized into Tables 2 and 3 according to whether the cathode interface layer material of the electron transport layer used in organic photovoltaic modules is a compound or a polymer.

[0092] Table 2 (Cathode interface layer material is a compound)

[0093]

[0094] Comparative Example 2 uses Comparative Example 1 as the cathode interface layer material to prepare an organic photovoltaic module with a PCE of 11.5%. Comparative Example 1 is a derivative modified from perylene dianhydride, as mentioned in Reference 1, with a linear terminal group. Application Example 1 uses Example 1 as the cathode interface layer material. Electrons are transferred to the cathode through an appropriate energy level, resulting in an organic photovoltaic module PCE of 14.1%. Example 1 uses a compound modified from perylene dianhydride as the cathode interface layer material, and the chemical formula of this cathode interface layer material contains a piperazine group. Next, Example 1 is modified into Examples 2 and 3 by modifying the chemical structure, so that the energy levels of Application Example 2 (using Example 2) and Application Example 3 (using Example 3) are more consistent with electron transfer. The voltage is increased from 0.780V in Application Example 1 to 0.800V in Application Example 2 and 0.810V in Application Example 3, with the PCE optimally increased to 14.6%. In addition, Example 6, which is used in Application Example 5, is a mixture of Example 1 and polyethyleneimine. The better film-forming properties of polyethyleneimine polymer are used to assist Example 1, thereby reducing the interfacial energy transfer loss. The voltage is increased from 0.780V in Application Example 1 to 0.810V in Application Example 5, and the PCE is increased from 14.1% to 14.8%.

[0095] Furthermore, Comparative Example 2 used Comparative Example 1 as the cathode interface layer material. Comparative Example 1, as mentioned in Reference 1, is a derivative modified from perylene dianhydride with a linear terminal group. However, Examples 1-3 and 5-6 used in Application Examples 1-5 were compounds modified from perylene dianhydride as the cathode interface layer material. The piperazine group in the general chemical formula of this cathode interface layer material is more stable than the linear terminal group of Comparative Example 1. Therefore, the thermal stability of Application Examples 1-5 (96.61%-99.03%) is higher than that of Comparative Example 2 (80.15%). Please also refer to [reference missing]. Figure 3 The thermal stability test results are shown in the figure, illustrating the thermal stability of the organic photovoltaic modules in Comparative Example 2 and Application Example 4.

[0096] Table 3 (Cathode interface layer material is polymer)

[0097]

[0098]

[0099] Comparative Example 3 uses Comparative Example 2 as the cathode interface layer material to prepare an organic photovoltaic module with a PCE of 14.5%. Comparative Example 2 is the polyethyleneimine with zwitterionic groups described in Taiwan Invention Patent I740188. Application Example 6 uses Example 8, which differs from Comparative Example 2 in that Example 8 incorporates the polymerization modification from Example 1. Therefore, Application Example 6 significantly improves the performance of the organic photovoltaic module, achieving a more suitable energy level combination between indium tin oxide and the photoactive layer, increasing the PCE to 15.9%. Application Example 7 uses Example 9, which differs from Example 8 in that Example 9 further zwitterionicizes the material using sulfonolactone, enhancing electron transport and increasing the PCE to 16.7%.

[0100] Therefore, as can be seen from the foregoing results, the present invention uses a compound or polymer modified from perylene tetracarboxylic dianhydride as a cathode interface layer material. By utilizing the piperazine group in the general chemical formula of the cathode interface layer material, the organic photovoltaic module made using the cathode interface layer material has excellent power conversion efficiency (PCE) and thermal stability.

[0101] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification shall still fall within the scope of the patent of the present invention.

[0102] [Symbol Explanation]

[0103] 70: Substrate

[0104] 80: First electrode

[0105] 90: Organic photovoltaic layer

[0106] 91: Electron Transport Layer

[0107] 92: Active Layer

[0108] 93: Hole Transport Layer

[0109] 100: Second electrode

Claims

1. A cathode interface layer material, the cathode interface layer material comprising at least one compound, the compound being of formula (I) or (II): [Formula (I)] [Equation (II)]; in, for , , or ; R 1 It is H or C1~C 12 Straight-chain, branched-chain, or cyclic alkyl groups; R 2 C1~C 12 Straight-chain, branched-chain, or cyclic alkyl groups; X is Cl, Br, or I; m is an integer between 1 and 6; and, n is an integer between 2 and 6.

2. The cathode interface layer material as described in claim 1, wherein, The cathode interface layer material also contains polyethyleneimine.

3. A cathode interface layer material, the cathode interface layer material comprising at least a polymer, the polymer comprising at least structural or repeating units of formula (III) or formula (IV): [Formula (III)], [Formula (IV)].

4. The cathode interface layer material as described in claim 3, wherein, The polymer is formed by copolymerization of a compound with a modifier having at least two ethylene oxide groups, and the compound is shown in formula (I) or (II) below: [Formula (I)] [Equation (II)]; in, for ; R 1 For H; and, m is an integer between 1 and 6.

5. The cathode interface layer material as described in claim 3, wherein, The polymer is synthesized by copolymerization of a compound, polyethyleneimine, and a modifier having at least two ethylene oxide groups. The compound is shown in formula (I) or (II) below: [Formula (I)] [Equation (II)]; in, for ; R 1 For H; and, m is an integer between 1 and 6.

6. The cathode interface layer material as described in claim 3, wherein, The polymer is formed by copolymerizing a compound, polyethyleneimine, and a modifier, followed by reacting them with a sulfonyl lactone. The modifier has at least two ethylene oxide groups. The compound is shown in formula (I) or (II) below: [Formula (I)] [Equation (II)]; in, for ; R 1 For H; and, m is an integer between 1 and 6.

7. A cathode interface layer coating solution comprising the cathode interface layer material as described in any one of claims 1 to 6, wherein the solvent of the cathode interface layer coating solution is water, methanol, ethanol, isopropanol or a combination thereof.

8. An organic photovoltaic module comprising a cathode interface layer material as described in any one of claims 1 to 6.

9. The organic photovoltaic module as described in claim 8, wherein, The organic photovoltaic module includes a substrate, a first electrode stacked on the substrate, an electron transport layer stacked on the first electrode, an active layer stacked on the electron transport layer, a hole transport layer stacked on the active layer, and a second electrode stacked on the hole transport layer, wherein the electron transport layer comprises the cathode interface layer material.

10. The organic photovoltaic module as described in claim 8, wherein, The organic photovoltaic module includes a substrate, a first electrode stacked on the substrate, a hole transport layer stacked on the first electrode, an active layer stacked on the hole transport layer, an electron transport layer stacked on the active layer, and a second electrode stacked on the electron transport layer, wherein the electron transport layer comprises the cathode interface layer material.

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