An organic solar cell based on a hybrid cathode interface layer and a preparation method thereof

Abstract

The application discloses an organic solar cell based on a hybrid cathode interface layer and a preparation method thereof. The hybrid cathode interface layer is prepared from a cross-linkable organic polymer material and an organic fused-ring N-type material. The application has the advantages that the hybrid cathode interface layer with obviously improved electron transmission capacity is obtained by means of the excellent electron transmission capacity of the photo-induced organic fused-ring N-type material and the trace doping of the organic fused-ring N-type material into the cross-linkable organic polymer material, the energy level interface distribution between the electrode and the active layer can be optimized, the charge separation is improved, the charge transmission capacity is improved, the PCE and stability of the device are obviously improved, and the device has more excellent performance. Meanwhile, the hybrid cathode interface layer also has certain thickness insensitivity, which is of great significance for realizing large-area and high-efficiency industrial production of the cross-linkable interface material.

Description

Technical Field

[0001] The present invention relates to the technical field of organic semiconductor thin-film solar cells, and in particular to an organic solar cell based on a hybrid cathode interface layer and a preparation method thereof. Background Art

[0002] Organic solar cells (OSCs) have become a photovoltaic technology with great development prospects due to their many advantages such as low cost, good flexibility, simple device structure, and printable processing. At present, scientific researchers have adopted many different strategies for improvement, such as developing new active layer materials and interface materials, additive engineering, optimizing device structure and processing methods. The power conversion efficiency (PCE) of OSCs has reached more than 18%. In OSCs, although optimizing the active layer is the key to improving photovoltaic performance, the interface layer also plays an important role. Appropriate interface materials have a direct impact on the performance of the device. In the research process of OSCs, the interface layer acts as a bridge between the photoactive layer and the electrode, which can greatly reduce the obstacles to charge transfer. Therefore, in the process of studying OSCs, we cannot ignore the improvement of interface materials.

[0003] The use of water- and alcohol-soluble polymers and small molecules is also essential for achieving high-efficiency organic solar cells. One representative conjugated material is polydiimide (PDI), which was initially studied and designed as an acceptor for organic solar cells and later developed as a promising interface material. Zhang Zhiguo's group used two materials, PDIN and PDINO, with PDI as the core and amino or amine oxide as side chains, respectively. These materials exhibit high conductivity and are rare small-molecule cathode interface materials that are insensitive to thickness. Furthermore, Huang Fei's group designed a series of n-type water- and alcohol-soluble conjugated polymers with naphthalene diimide (NDI) self-doping. The electron transfer phenomenon between the polar groups and the n-type conjugated backbone improves interface modification and electron transport properties, significantly enhancing the photoelectric performance of the corresponding organic solar cells. In recent years, a number of other cathode interface materials have also been reported. For example, the addition of organic dye molecules to zinc oxide has resulted in an electron transport layer (ZnO:PBI-H) with excellent photoelectric and mechanical properties. At the same time, PDIN was added to PNDIT-F3N to obtain a hybrid cathode interface layer with excellent electron transport performance (PNDIT-F3N:PDIN). These research results show that enhancing charge transport performance through n-doping is an important means to achieve high-performance organic solar cells.

[0004] However, the existing cross-linkable cathode interface is still not ideal for improving the performance of OSCs, and the performance of the device is very sensitive to the thickness of the interface layer, which cannot meet the current research and production needs. Therefore, it is of great significance to develop a cross-linkable hybrid cathode interface layer to improve the performance of organic solar cells. Summary of the Invention

[0005] Based on this, the present invention provides an organic solar cell based on a hybrid cathode interface layer, which adopts a blend of cross-linkable organic polymer materials and organic condensed ring N-type materials as the cathode interface layer, which can significantly improve the PCE and stability of the device, so that the device can obtain better performance. Since the cross-linkable organic polymer is a copolymer based on fluorene, its electron transport ability is relatively poor and it is relatively sensitive to thickness. The film thickness can only be controlled within 5-10nm for the device to obtain relatively good performance, which is incompatible with preparation processes such as scraping, printing, and roll-to-roll, and cannot be achieved for large-scale production. To this end, the present invention uses the excellent electron transport ability of the light-induced organic condensed ring N-type material to dope it into the main material to obtain a hybrid cathode interface layer with excellent electron transport ability, which can optimize the energy level interface distribution between the electrode and the active layer, improve charge separation, and improve charge transport ability. At the same time, the hybrid cathode interface layer also shows a certain thickness insensitivity, which is of great significance for the large-scale and efficient industrial production of cross-linkable interface materials.

[0006] An object of the present invention is to provide an organic solar cell based on a hybrid cathode interface layer, wherein the structure of the organic solar cell based on the hybrid cathode interface layer comprises, from bottom to top, a substrate, a cathode, a hybrid cathode interface layer, an active layer, an anode interface layer, and an anode;

[0007] in,

[0008] The hybrid cathode interface layer is made of a cross-linkable organic polymer material and an organic condensed ring N-type material;

[0009] The cross-linkable organic polymer material is a main material, and the organic condensed ring N-type material is a doping material;

[0010] The cross-linkable organic polymer material has the following general structural formula:

[0011]

[0012] in,

[0013] R x Containing a cross-linkable group;

[0014] R Y An alkyl chain containing / without an aromatic group, or an alkyl chain containing a water-alcohol-soluble group;

[0015] The organic fused ring N-type material is selected from small molecules or polymers, or a mixture thereof;

[0016] The small molecule has the following general structural formula:

[0017]

[0018] The polymer has the following general structural formula:

[0019]

[0020] in,

[0021] When the organic fused ring N-type material is selected from small molecules, R z is an alkyl chain containing a water-alcohol-soluble group;

[0022] When the organic condensed ring N-type material is selected from a polymer, at least one of the copolymerized units of the polymer contains an alkyl chain containing a water-alcohol soluble group; and the D is an electron-rich donor unit.

[0023] In the present invention, the organic condensed ring N-type material can be selected from a small molecule structure based on perylene imide / naphthyl imide, or a polymer. When it is a small molecule, the R grafted on the N atom of perylene imide / naphthyl imide z It is an alkyl chain of a water-alcohol soluble group; when it is a polymer, since the N atom of the perylene imide / naphthyl imide and the D unit both contain side chain grafting sites, therefore, on the perylene imide / naphthyl imide or the D unit, one of them can be grafted with an alkyl chain of a water-alcohol soluble group, while the other can be grafted with a common alkyl chain segment; or both can be alkyl chains of a water-alcohol soluble group, so that the polymer has a certain water-alcohol solubility.

[0024] For example, when the organic fused ring N-type material of the present invention is a polymer, it may be, but is not limited to, the following structure:

[0025] The alkyl chain described in the present invention may be, but is not limited to, a C1-60 straight-chain alkyl, a C3-60 branched-chain alkyl, or a C3-60 cyclic alkyl.

[0026] Furthermore, the mass ratio of the cross-linkable organic polymer material to the organic condensed ring N-type material is 100:8-100:40.

[0027] The hybrid cathode interface layer prepared by physical blending of cross-linkable organic polymer materials and organic condensed ring N-type materials and then heat treatment can optimize the energy level interface distribution between the electrode and the active layer, improve charge separation, and enhance charge transfer capacity, thereby significantly improving the performance of photovoltaic devices.

[0028] Furthermore, the thickness of the hybrid cathode interface layer is 5-30 nm.

[0029] Furthermore, in the active layer, the donor material is selected from a P-type organic semiconductor based on specific unit 1, and the acceptor material is selected from an N-type organic semiconductor based on specific unit 2; wherein the specific unit 1 is selected from one or more of the following structures:

[0030]

[0031] The specific unit 2 is selected from one or more of the following structures:

[0032]

[0033]

[0034] Wherein, R1-R6 are independently selected from an alkyl group having 1 to 40 carbon atoms, or an alkyl derivative having 1 to 40 carbon atoms;

[0035] One or more carbon atoms in the alkyl derivative are substituted by one or more of hydrogen atoms, oxygen atoms, alkenyl groups, alkynyl groups, aryl groups, hydroxyl groups, amino groups, carbonyl groups, carboxyl groups, ester groups, cyano groups, and nitro groups;

[0036] and / or,

[0037] One or more hydrogen atoms on the alkyl derivative are replaced by one or more of fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms;

[0038] Said X1-X6 are independently selected from one or more of hydrogen atom, fluorine atom, chlorine atom, cyano group and nitro group.

[0039] Furthermore, the donor material is preferably PM6, and the PM6 has the following structural formula:

[0040]

[0041] Furthermore, the receptor material is preferably Y6, and the Y6 has the following structural formula:

[0042]

[0043] Furthermore, the substrate is selected from one or more of glass, flexible materials, metals, alloys and stainless steel films.

[0044] Furthermore, the cathode is selected from one or more of ITO and IFO.

[0045] Furthermore, the anode is selected from one or more of aluminum, silver, copper, gold, metal oxide and graphene.

[0046] Furthermore, the anode interface layer is selected from MoO x 、Vox 、NiO x , WO x 、RuO2、GrO x One or more of .

[0047] Furthermore, the R x wherein the cross-linkable group is selected from epoxy, alkenyl or alkynyl.

[0048] The epoxy group may be, but is not limited to, propylene oxide, butylene oxide, and the like.

[0049] Furthermore, the R Y and R Z wherein the water-alcohol soluble group is selected from an amine group or an amine salt group.

[0050] The amino group can be selected from dimethylamino, diethylamino, dipropylamino, etc.;

[0051] The amine salt group has a positive charge on its nitrogen atom and a counterion adsorbed on the nitrogen atom. Generally, the counterion is a halogen ion.

[0052] For example, the cross-linkable organic polymer material of the present invention can be selected from, but not limited to, the following chemical structures:

[0053] The organic fused ring N-type material of the present invention can be selected from, but not limited to, the following chemical structures:

[0054]

[0055] Another object of the present invention is to provide a method for preparing the organic solar cell based on the hybrid cathode interface layer, wherein the method for preparing the organic solar cell based on the hybrid cathode interface layer comprises the following steps:

[0056] S1. A cross-linked organic polymer material and an organic fused ring N-type material are added to a solvent to obtain a polymer solution and a small molecule solution, and then the two solutions are physically blended. The resulting mixture is coated on a cathode and heat treated to obtain a hybrid cathode interface layer;

[0057] S2. Coating a photoactive layer on the hybrid cathode interface layer, and then evaporating an anode interface layer and an anode to obtain the organic solar cell based on the hybrid cathode interface layer.

[0058] Furthermore, in step S1, the solvent is selected from one or more of deionized water, methanol, ethanol, isopropanol, butanol, methoxyethylene glycol, N,N-dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, anisole, methyl anisole, tetrahydrofuran, methyltetrahydrofuran, N-methylpyrrolidone, acetonitrile and γ-butyrolactone.

[0059] Furthermore, in step S1, the heat treatment temperature is 150-200°C, and the treatment time is 10-20 minutes.

[0060] The present invention has the following beneficial effects:

[0061] 1. The raw materials of the present invention are simple and easy to obtain, low-cost, easy to operate, and no high-temperature heat treatment is required during the preparation process.

[0062] 2. Compared with cathode interface layers based on single-component cross-linkable organic polymers, organic fused-ring N-type materials or metal oxides, the hybrid cathode interface layer in the present invention has higher device efficiency and better stability, and its performance has obvious advantages, making it more suitable for organic solar cells.

[0063] 3. Compared with cathode interface layers based on single-component cross-linkable organic polymers, organic fused-ring N-type materials or metal oxides, this hybrid cathode interface layer exhibits a certain thickness insensitivity and is suitable for large-scale industrial production such as printing and roll-to-roll, with good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 The figure shows the structure of the organic solar cell based on the hybrid cathode interface layer of the present invention.

[0065] Figure 2 The voltage-current density curves of Example 1 and Comparative Examples 1-3 are shown.

[0066] Figure 3 The voltage-current density curves of different mass ratios of PFOPy:PDINN in Example 2 are shown.

[0067] Figure 4 The voltage-current density curves of PFOPy:PDINN at different film thicknesses in Example 3 are shown.

[0068] Figure 5 The voltage-current density curve of the PFOPy cathode interface layer at different film thicknesses in Comparative Example 4 is shown.

[0069] Figure 6 The stability of the devices of Example 1 and Comparative Examples 1 and 3 under thermal cycle stress conditions is shown. DETAILED DESCRIPTION

[0070] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0071] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0072] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0073] PFOPy in the embodiment of the present invention has the following structural formula:

[0074]

[0075] PDINN in the embodiment of the present invention has the following structural formula:

[0076]

[0077] PM6 in the embodiment of the present invention has the following structural formula:

[0078]

[0079] Y6 in the embodiment of the present invention has the following structural formula:

[0080]

[0081] Example 1

[0082] An organic solar cell based on a hybrid cathode interface layer, whose structure from bottom to top is: glass substrate (700 μm) / ITO (135 nm) / PFOPy:PDINN (100:10, m / m) (5 nm) / PM6:Y6 (7:8.4, m / m) (100 nm) / MoO3 (10 nm) / Ag (100 nm);

[0083] The method for preparing the organic solar cell based on the hybrid cathode interface layer comprises the following steps:

[0084] S1. PFOPy and PDINN were separately dissolved in methanol. Then, 1.0 mL of a 0.25 mg / mL PFOPy solution and 0.0125 mL of a 2 mg / mL PDINN solution were physically blended. The resulting mixture was allowed to stand in a glove box for 8 h before being spin-coated onto an ITO-coated glass substrate at 2000 rpm for 30 s. Annealing was performed at 180°C for 10 min to form a hybrid cathode interface layer.

[0085] S2. Under N2 atmosphere, 1 mL of chloroform and 5 μL of CN were added to 7 mg of PM6 and 8.4 mg of Y6, and stirred at 30 °C for 2 h to obtain an active layer solution;

[0086] The active layer solution was spin-coated onto the hybrid cathode interface layer at 3000 rpm / 30 s and annealed at 85°C for 5 min to obtain an active layer. -4 The anode interface layer MoO3 and the Ag electrode are evaporated under a pressure of Pa to obtain the organic solar cell based on the hybrid cathode interface layer.

[0087] Figure 1 The figure shows the structure of the organic solar cell based on the hybrid cathode interface layer of the present invention.

[0088] Example 2

[0089] An organic solar cell based on a hybrid cathode interface layer, whose structure from bottom to top is: glass substrate (700 μm) / ITO (135 nm) / PFOPy:PDINN (ratio varies in the range of 100:8-100:40, m / m) (5 nm) / PM6:Y6 (7:8.4, m / m) (100 nm) / MoO3 (10 nm) / Ag (100 nm);

[0090] The method for preparing the organic solar cell based on the hybrid cathode interface layer comprises the following steps:

[0091] S1. PFOPy and PDINN were dissolved in methanol, respectively. Then, 1 mL of a 0.25 mg / mL PFOPy solution was physically blended with 0.01, 0.0125, 0.0167, 0.025, and 0.05 mL of a 2 mg / mL PDINN solution. The resulting mixtures were allowed to stand in a glove box for 10 h before being spin-coated onto an ITO-coated glass substrate at 2000 rpm for 30 s. Annealing was performed at 180°C for 10 min to form a hybrid cathode interface layer.

[0092] S2. Under N2 atmosphere, 1 mL of chloroform and 5 μL of CN were added to 7 mg of PM6 and 8.4 mg of Y6, and stirred at 30 °C for 2 h to obtain an active layer solution;

[0093] The active layer solution was spin-coated onto the hybrid cathode interface layer at 3000 rpm / 30 s and annealed at 85°C for 5 min to obtain an active layer. -4 The anode interface layer MoO3 and the Ag electrode are evaporated under a pressure of Pa to obtain the organic solar cell based on the hybrid cathode interface layer.

[0094] Example 3

[0095] An organic solar cell based on a hybrid cathode interface layer, whose structure from bottom to top is: glass substrate (700 μm) / ITO (135 nm) / PFOPy:PDINN (100:10, m / m) (thickness varies in the range of 5-30 nm) / PM6:Y6 (7:8.4, m / m) (100 nm) / MoO3 (10 nm) / Ag (100 nm);

[0096] The method for preparing the organic solar cell based on the hybrid cathode interface layer comprises the following steps:

[0097] S1. PFOPy and PDINN were dissolved in methanol, respectively. Then, 1 mL of PFOPy solution at concentrations of 0.25, 0.5, and 1.0 mg / mL was physically blended with 0.0125, 0.025, and 0.05 mL of PDINN solution at a concentration of 2 mg / mL. The resulting mixtures were allowed to stand in a glove box for 10 h. Thin films of 10, 20, and 30 nm in thickness were then spin-coated onto ITO-coated glass substrates at 2000 rpm for 30 s. The films were then annealed at 180°C for 10 min to form a hybrid cathode interface layer.

[0098] S2. Under N2 atmosphere, 1 mL of chloroform and 5 μL of CN were added to 7 mg of PM6 and 8.4 mg of Y6, and stirred at 30 °C for 2 h to obtain an active layer solution;

[0099] The active layer solution was spin-coated onto the hybrid cathode interface layer at 3000 rpm / 30 s and annealed at 85°C for 5 min to obtain an active layer. -4 The anode interface layer MoO3 and the Ag electrode are evaporated under a pressure of Pa to obtain the organic solar cell based on the hybrid cathode interface layer.

[0100] Comparative Example 1

[0101] An organic solar cell, the difference between this comparative example and Example 1 is that: this comparative example uses PFOPy as the cathode interface layer; step S1 is replaced by: spin coating 0.045 mL, 0.25 mg / mL PFOPy-methanol solution onto ITO at 2000 rpm / 30 s, annealing at 180°C for 10 min to obtain a cathode interface layer; other structures and preparation methods are the same as Example 1.

[0102] Comparative Example 2

[0103] An organic solar cell is disclosed. This comparative example differs from Example 2 in that: PDINN is used as the cathode interface layer in this comparative example; step S1 is replaced by spin coating 0.045 mL of a 2 mg / mL PDINN-methanol solution onto ITO at 2000 rpm / 30 s, and annealing at 180°C for 10 min to obtain a cathode interface layer; the other structures and preparation methods are the same as those in Example 1.

[0104] Comparative Example 3

[0105] An organic solar cell is disclosed. This comparative example differs from Example 1 in that ZnO is used as a cathode interface layer in this comparative example. Step S1 is replaced by preparing a solution by mixing 0.1 g of zinc acetate, 0.937 ml of ethylene glycol methyl ether, and 28.29 μL of ethanolamine in a certain ratio, stirring the solution at room temperature for 12 hours to obtain a sol-gel ZnO precursor solution. The prepared ZnO precursor solution is then filtered through a 0.45 μm organic filter head, spin-coated onto ITO at 4000 rpm / 30 seconds, and annealed at 200° C. for 1 hour to obtain a ZnO cathode interface layer (having a thickness ranging from 30 to 40 nm). The remaining structures and preparation methods are the same as those in Example 1.

[0106] Comparative Example 4

[0107] An organic solar cell, the difference between this comparative example and Example 3 is that: this comparative example uses different concentrations of PFOPy as the cathode interface layer; step S1 is replaced by: 0.045 mL of PFOPy-methanol solution with concentrations of 0.25, 0.5, and 1.0 mg / mL, respectively, is spin-coated onto ITO at 2000 rpm / 30 s to prepare thin films with thicknesses of 10, 20, and 30 nm, respectively, and annealed at 180°C for 10 min to obtain the cathode interface layer; the other structures and preparation methods are the same as those in Example 3.

[0108] Test Example 1

[0109] The performance of the organic solar cells prepared in Example 1 and Comparative Examples 1-3 was tested.

[0110] Test method:

[0111] In the AM1.5G spectrum (100mW / cm 2 ) The open circuit voltage, current density, fill factor, power conversion efficiency (PCE) and other indicators of the organic solar cells prepared in Example 1 and Comparative Examples 1-3 were tested.

[0112] Test results:

[0113] Table 1 shows the performance test results of Example 1 and Comparative Examples 1-3.

[0114] Table 1 Performance test results of Example 1 and Comparative Examples 1-3

[0115]

[0116] Figure 2 The voltage-current density curves of Example 1 and Comparative Examples 1-3 are shown.

[0117] According to Table 1 and Figure 2 It can be concluded that compared with Comparative Examples 1-3, the energy conversion efficiency of the device in Example 1 is 16.645%, wherein the open circuit voltage is 0.843 V and the current density is 27.012 mA / cm 2 , with a fill factor of 73.093%, exhibiting better photoelectric performance and the highest energy conversion efficiency of the device. This indicates that the cathode interface layer prepared using PFOPy and PDINN produces a synergistic effect, which can optimize the energy level interface distribution between the electrode and the active layer, improve charge separation, and enhance charge transfer capacity. Its performance is significantly improved compared to structures containing only PFOPy or PDINN, and is also superior to metal oxide cathode interface layers, achieving an improvement in the energy conversion efficiency of organic solar cells.

[0118] Test Example 2

[0119] The effects of different mass ratios of PFOPy:PDINN in the hybrid cathode interface layer provided in Example 2 on the device performance were tested.

[0120] Test method: Under AM1.5G spectrum (100mW / cm 2 ) The open circuit voltage, current density, fill factor, energy conversion efficiency and other indicators of the organic solar cell prepared in Example 2 were tested, wherein the PDINN:PFOPy ratio of Example 2 varied in the range of (8-40):100.

[0121] The test results are shown in Table 2 and Figure 3 shown.

[0122] Table 2 Performance test results of hybrid cathode interface layer with different mass ratios of PDINN:PFOPy in Example 2

[0123]

[0124] Figure 3 The voltage-current density curves of different mass ratios of PDINN:PFOPy in Example 2 are shown.

[0125] According to Table 2 and Figure 3 It can be concluded that based on the hybrid cathode interface PDINN:PFOPy, as the PDINN content decreases, the open circuit voltage, current density, fill factor and energy conversion efficiency of the device show a trend of first increasing and then decreasing, and the best performance is achieved when the PDINN:PFOPy ratio is 10:100.

[0126] Test Example 3

[0127] When the optimal mass ratio (PDINN:PFOPy=10:100) is tested, the effects of the hybrid cathode interface layers with different film thicknesses provided in Example 3 on the device performance are investigated.

[0128] Test method: Under AM1.5G spectrum (100mW / cm 2 ) The open circuit voltage, current density, fill factor, energy conversion efficiency and other indicators of the organic solar cell prepared in Example 3 were tested, and the thickness of the hybrid cathode interface layer varied in the range of 5-30 nm.

[0129] The test results are shown in Table 3 and Figure 4 shown.

[0130] Table 3 Performance test results of hybrid cathode interface layer PFOPy:PDINN at different thicknesses in Example 3

[0131]

[0132] Figure 4 The voltage-current density curves of hybrid cathode interface layers of different thicknesses in Example 3 are shown.

[0133] According to Table 3 and Figure 4 The hybrid cathode interface layer-based organic solar cell of the present invention exhibits an energy conversion efficiency of 15.001-16.538% when the hybrid cathode interface layer thickness is between 5 and 30 nm. Compared to the optimal performance, the device performance decreases minimally when the thickness increases to 30 nm. This indicates that the energy conversion efficiency of the hybrid cathode interface layer-based organic solar cell of the present invention is relatively insensitive to the thickness of the interface layer, making it more suitable for future roll-to-roll printing of high-performance OSCs and showing promising application prospects.

[0134] Test Example 4

[0135] At the same time, the effect of the PFOPy cathode interface layer of different thicknesses on the device performance of comparative example 4 was tested.

[0136] Test method: Under AM1.5G spectrum (100mW / cm 2 ) The open circuit voltage, current density, fill factor, energy conversion efficiency and other indicators of the organic solar cell prepared in Comparative Example 4 were tested.

[0137] The test results are shown in Table 4 and Figure 5 shown.

[0138] Table 4 Performance test results of PFOPy cathode interface layer at different thicknesses in Comparative Example 4

[0139]

[0140]

[0141] Figure 5 The voltage-current density curves of the PFOPy cathode interface layer at different thicknesses in Comparative Example 4 are shown.

[0142] According to Table 4 and Figure 5 It can be concluded that the device performance of the pure PFOPy cathode interface layer is very sensitive to the thickness of the interface layer. Compared with Comparative Example 4, the results of Example 3 are more ideal. The addition of an appropriate amount of PDINN is beneficial to improving the device performance of the PFOPy cathode interface layer and has a certain thickness insensitivity.

[0143] Test Example 5

[0144] The stability of the organic solar cell devices of Example 1 and Comparative Examples 1 and 3 under thermal cycle stress conditions was tested.

[0145] Test method: The organic solar cell devices prepared in Example 1 and Comparative Examples 1 and 3 were placed in a refrigerator (2°C) for 5 hours after packaging, then placed at room temperature for 1 hour and then heated on a heating table at 50°C for 5 hours. After the devices returned to room temperature, the devices were tested under the AM1.5G spectrum (100 mW / cm 2 ) The open circuit voltage, current density, fill factor, energy conversion efficiency and other indicators of the organic solar cells prepared in Example 1 and Comparative Examples 1 and 3 were tested.

[0146] The test results are shown in Table 5 and Figure 6 shown.

[0147] Table 5 Performance test results of the devices of Example 1 and Comparative Examples 1 and 3 under thermal cycle stress conditions

[0148]

[0149] Figure 6 The PCE stability curves of the devices of Example 1 and Comparative Examples 1 and 3 under thermal cycle stress conditions are shown.

[0150] According to Table 5 and Figure 6 It can be concluded that compared with ZnO devices, cross-linked PFOPy and PFOPy:PDINN based devices exhibit significantly better stability; at the same time, the stability of the device with the hybrid PFOPy:PDINN cathode interface layer is better than that of the device with the pure PFOPy cathode interface layer.

[0151] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0152] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An organic solar cell based on a hybrid cathode interface layer, characterized in that: The structure of the organic solar cell based on the hybrid cathode interface layer comprises, from bottom to top, a substrate, a cathode, a hybrid cathode interface layer, an active layer, an anode interface layer, and an anode; in, The hybrid cathode interface layer is made of a cross-linkable organic polymer material and an organic condensed ring N-type material; The preparation method comprises: adding a cross-linked organic polymer material and an organic condensed ring N-type material into a solvent respectively to obtain a polymer solution and a small molecule solution, then physically blending the two solutions, coating the obtained mixed solution on a cathode, and heat treating the mixed solution to obtain a hybrid cathode interface layer; The cross-linkable organic polymer material is a main material, and the organic condensed ring N-type material is a doping material; The cross-linkable organic polymer material has the following general structural formula: in, R x Containing a cross-linkable group; R Y An alkyl chain containing / without an aromatic group, or an alkyl chain containing a water-alcohol-soluble group; The organic fused ring N-type material is selected from small molecules; The small molecule has the following general structural formula: in, R z is an alkyl chain containing a water-alcohol-soluble group; The mass ratio of the cross-linkable organic polymer material to the organic condensed ring N-type material is 100:8-100:40; The thickness of the hybrid cathode interface layer is 5-30 nm.

2. The organic solar cell based on the hybrid cathode interface layer according to claim 1, characterized in that: In the active layer, the donor material is selected from a P-type organic semiconductor based on specific unit 1, and the acceptor material is selected from an N-type organic semiconductor based on specific unit 2; wherein the specific unit 1 is selected from one or more of the following structures: The specific unit 2 is selected from one or more of the following structures: Wherein, R1-R6 are independently selected from an alkyl group having 1 to 40 carbon atoms, or an alkyl derivative having 1 to 40 carbon atoms; One or more carbon atoms in the alkyl derivative are substituted by one or more of hydrogen atoms, oxygen atoms, alkenyl groups, alkynyl groups, aryl groups, hydroxyl groups, amino groups, carbonyl groups, carboxyl groups, ester groups, cyano groups, and nitro groups; and / or, One or more hydrogen atoms on the alkyl derivative are replaced by one or more of fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; Said X1-X6 are independently selected from one or more of hydrogen atom, fluorine atom, chlorine atom, cyano group and nitro group.

3. The organic solar cell based on the hybrid cathode interface layer according to claim 1, characterized in that: The anode interface layer is selected from MoO x , VO x 、NiO x , WO x 、RuO2、GrO x One or more of .

4. The organic solar cell based on the hybrid cathode interface layer according to claim 1, characterized in that: The R x wherein the cross-linkable group is selected from epoxy, alkenyl or alkynyl.

5. The organic solar cell based on the hybrid cathode interface layer according to claim 1, characterized in that: The R Y and R Z wherein the water-alcohol soluble group is selected from an amine group or an amine salt group.

6. The method for preparing an organic solar cell based on a hybrid cathode interface layer according to any one of claims 1 to 5, characterized in that: The method for preparing an organic solar cell based on a hybrid cathode interface layer comprises the following steps: S1. A cross-linked organic polymer material and an organic fused ring N-type material are added to a solvent to obtain a polymer solution and a small molecule solution, and then the two solutions are physically blended. The resulting mixture is coated on a cathode and heat treated to obtain a hybrid cathode interface layer; S2. Coating a photoactive layer on the hybrid cathode interface layer, and then evaporating an anode interface layer and an anode to obtain the organic solar cell based on the hybrid cathode interface layer.

7. The method for preparing an organic solar cell based on a hybrid cathode interface layer according to claim 6, characterized in that: In step S1, the solvent is selected from one or more of deionized water, methanol, ethanol, isopropanol, butanol, methoxyethylene glycol, N,N-dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, anisole, methyl anisole, tetrahydrofuran, methyltetrahydrofuran, N-methylpyrrolidone, acetonitrile and γ-butyrolactone.

8. The method for preparing an organic solar cell based on a hybrid cathode interface layer according to claim 6, characterized in that: In step S1, the heat treatment temperature is 150-200° C., and the treatment time is 10-20 minutes.

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