Perovskite battery having a hole transport layer with a comb-like fiber structure and its manufacturing method

Abstract

The present application discloses a perovskite battery having a hole transport layer with a comb fiber structure and a method for preparing the same. The perovskite battery includes a transparent electrode layer and a hole transport layer with a comb fiber structure formed on the transparent electrode layer, the hole transport layer with the comb fiber structure being a polythiophene polymer hole material. The method includes depositing an oxidant on the transparent electrode layer, contacting and reacting a solution containing a strong polar acid and a thiophene hole material monomer with the oxidant to obtain a hole transport layer with a comb fiber structure, synthesizing a perovskite absorption layer on the hole transport layer with the comb fiber structure, and then sequentially providing an electron transport layer and an electrode layer on the perovskite absorption layer. The battery has a uniform and dense hole transport layer with a comb fiber structure, and the contact area between the hole transport layer and the absorption layer is increased, and the hole transport layer is a comb fiber structure, and the contact area between the hole transport material and the photovoltaic absorption layer is increased.

Description

[Technical Field]

[0001] The present application relates to the technical field of solar cells, and in particular to perovskite cells having a hole transport layer with a comb-like fiber structure and a method for manufacturing the same.

[0002] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application, application number 202111243277.3, entitled "Perovskite battery with a hole transport layer having a comb-like fiber structure and a manufacturing method thereof," filed with the China Patent Office on October 25, 2021, the entire contents of which are incorporated herein by reference. [Background technology]

[0003] In recent years, perovskite solar cells (PSCs) have attracted considerable attention in academia and industry due to the rapid improvement of their conversion efficiency, the maturation of their manufacturing processes, and their low cost. Current perovskite solar cells can be divided into two main types based on the deposition substrate of the perovskite layer: (1) those in which the deposition substrate is an electron transport layer (ETL) and (2) those in which the deposition substrate is a hole transport layer (HTL). (2) those in which the deposition substrate is a hole transport layer (HTL) are also called trans-perovskite solar cells. Trans-perovskite solar cells are favored in industry due to their high stability, low processing temperature, and simple synthesis equipment.

[0004] The hole transport layer of a trans-perovskite solar cell is typically a thin film, and light-excited holes in the perovskite layer are transported to the hole transport layer through the thin film interface, generating current. During this process, the efficiency and stability of the cell are largely determined by the contact area between the hole transport layer and the perovskite layer. The larger the contact area, the stronger the hole transport ability and the lower the recombination efficiency of light-excited electrons and holes, which improves the efficiency and stability of the cell.

[0005] Japanese Patent JP2011035243A discloses an organic photovoltaic cell comprising two electrode layers, a P-type semiconductor absorption layer and an N-type semiconductor absorption layer. The hole transport layer is made of PEDOT:PSS, which is the only polymeric hole transport layer currently commercially available, spin-coated between the P-type and N-type semiconductor absorption layers due to its water solubility. The interdigitated layer in this patent application is the P-type absorption layer, and its purpose is to increase the contact area of ​​the PN junction. However, increasing the contact area of ​​the PN junction does not effectively prevent electron-hole recombination. Furthermore, during the hole transport process, PEDOT only plays a role in hole transport, while PSS serves only as an insulating material providing water solubility, significantly limiting the efficiency of hole transport and reducing the cell's efficiency. Furthermore, the water absorption of PSS can cause the perovskite layer to be destroyed by environmental corrosion, shortening the service life of the PSC. Currently, secondary dissolution with organic solvents such as dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), and ethylene glycol (EG) cannot completely remove PSS. Summary of the Invention [Problem to be solved by the invention]

[0006] To solve the technical problems in the prior art, the present application provides a perovskite battery with a hole transport layer having a comb fiber structure and a manufacturing method thereof. The perovskite battery reduces the recombination of electrons and holes by increasing the contact area between the perovskite absorption layer and the hole transport layer. The use of a PSS-free comb fiber structured hole transport layer increases the hole transport rate, improving battery efficiency and battery life. [Means for solving the problem]

[0007] According to a first aspect of the present application, there is provided a perovskite battery comprising a transparent electrode layer and a hole transport layer with a comb fiber structure formed on the transparent electrode layer, wherein the comb fiber structure hole transport layer is made of a polythiophene polymer hole material.

[0008] Optionally, the polythiophene polymer hole material is one or more selected from PEDOT, P3HT, P3OHT and P3ODDT.

[0009] Optionally, the hole transport layer of the comb fiber structure is composed of a thin film layer with a thickness of 50 to 200 nm and a comb fiber structure with a length of 500 to 1500 nm.

[0010] Alternatively, the polythiophene polymer hole material is obtained by vapor phase polymerization of thiophene hole material monomers.

[0011] Optionally, the polythiophene polymer hole material is depositing an oxidant on the transparent electrode layer; and contacting a solution containing a strong polar acid and a thiophene hole material monomer with the oxidizing agent to react with each other to obtain a hole transport layer having a comb fiber structure.

[0012] Optionally, the thiophene hole material monomer is one or more selected from 3,4-ethylenedioxythiophene, 3-hexylthiophene, 3-hexyloxythiophene, and 3-dodecyloxythiophene.

[0013] Optionally, the thickness of the oxidant deposited on the transparent electrode layer is 10 to 60 nm.

[0014] Optionally, the method further includes the step of contacting and reacting the solution containing the strong acid and the thiophene hole material monomer with an oxidizing agent, and then washing away impurities in the hole transport layer of the comb fiber structure with a Lewis acid.

[0015] Optionally, the comb fiber structure hole transport layer is doped with an acid solution or acid gas to obtain a doped comb fiber structure hole transport layer.

[0016] Optionally, the perovskite battery further comprises a perovskite absorber layer, an electron transport layer and an electrode layer, wherein the perovskite absorber layer is disposed on the hole transport layer of the comb fiber structure, and the electron transport layer and the electrode layer are disposed sequentially on the perovskite absorber layer.

[0017] Optionally, the perovskite absorber layer extends into the gaps of the interdigitated structure of the hole transport layer to form an interdigitated structure.

[0018] Optionally, the thickness of the hole transport layer of the comb fiber structure is less than the thickness of the perovskite absorber layer.

[0019] Optionally, the safe distance between the electron transport layer and the tip of the comb fiber structure in the hole transport layer of the comb fiber structure is 10 nm or more.

[0020] Optionally, the diameter of a single comb fiber in the hole transport layer of the comb fiber structure is 100-1000 nm, and the surface of the single comb fiber is rough.

[0021] According to a second aspect of the present application, depositing an oxidant on the transparent electrode layer; contacting a solution containing a strong polar acid and a thiophene hole material monomer with the oxidizing agent to react with each other to obtain a hole transport layer having a comb fiber structure; synthesizing a perovskite absorber layer on the hole transport layer of the comb fiber structure, and then sequentially providing an electron transport layer and an electrode layer on the perovskite absorber layer.

[0022] Optionally, the thickness of the oxidant deposited on the transparent electrode layer is 10 to 60 nm.

[0023] Optionally, the thiophene hole material monomer is one or more selected from 3,4-ethylenedioxythiophene, 3-hexylthiophene, 3-hexyloxythiophene, and 3-dodecyloxythiophene.

[0024] Optionally, a perovskite solution is spin-coated onto the hole transport layer so that the perovskite absorber layer extends into the gaps of the interdigitated structure.

[0025] Optionally, a perovskite precursor polymer is deposited on the hole transport layer so that the perovskite precursor polymer forms a perovskite absorber layer and extends into the voids of the interdigitated structure.

[0026] The above has roughly described the technical solution of the present application. In order to make the technical solution of the present application more clearly understood and implemented according to the content of the specification, and to make the above and other objectives, features and advantages of the present application more comprehensible, the following particularly sets forth specific embodiments of the present application. [Effects of the Invention]

[0027] The battery of the present application has a uniform and high-density hole transport layer with a comb fiber structure, which increases the contact area between the hole transport layer and the absorber layer. Furthermore, the hole transport layer is not fabricated by aqueous solution spin coating, which eliminates the insulator PSS in conventional hole transport polymer materials, improving the transport efficiency of the hole transport layer. The hole transport layer of the present application has a comb fiber structure, which increases the contact area between the hole transport material and the photovoltaic absorber layer and shortens the hole transport distance, thereby reducing the recombination of electron-hole pairs and improving the battery efficiency and battery life.

[0028] The present invention uses thiophene hole transport material monomers to fabricate a hole transport layer with a comb-like fiber structure, eliminating the need for PSS in conventional hole transport layer fabrication, and improving the transport efficiency of the hole transport layer. [Brief explanation of the drawings]

[0029] In order to more clearly describe the technical solutions in the embodiments of the present application or related technologies, the following will briefly describe the drawings used in the description of the embodiments or related technologies. Of course, the drawings described below are part of the embodiments of the present application, and those skilled in the art can conceive of other drawings based on these drawings without any creative efforts. [Figure 1]FIG. 1 is a cross-sectional schematic diagram of a perovskite battery. [Figure 2] 1 is a schematic diagram of an iron oxide deposition layer structure. [Figure 3] 1 is a schematic diagram of a hole transport layer containing the impurity FeCl2. [Figure 4] FIG. 1 is a schematic diagram of a pure hole transport layer. [Figure 5] 1A and 1B are schematic electron micrographs of a single comb fiber; a) is a schematic diagram of a single comb fiber in a hole transport layer; and b) is a schematic electron micrograph of the morphology of a single comb fiber. DETAILED DESCRIPTION OF THE INVENTION

[0030] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application, and it should be understood that the described embodiments are only a part of the embodiments of the present application, and are not all of the embodiments. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without any creative efforts fall within the scope of protection of the present application.

[0031] It should be noted that the specification and claims use specific terms to refer to specific components. Those skilled in the art will understand that engineers may use different terms to refer to the same component. The specification and claims do not use differences in terms to distinguish components, but rather use differences in the functions of the components as the basis for such distinction. For example, the terms "include" and "comprise" used throughout the specification and claims are open terms and should be interpreted as "including but not limited to." The following description of the specification is a preferred embodiment for implementing the present application, but the description is intended to be a general guide to the specification and does not limit the scope of the present application. The scope of protection of the present application shall be as defined by the appended claims.

[0032] The present application provides a perovskite battery, which, as shown in FIG. 1, includes a transparent electrode layer 5 and a hole transport layer 4 with a comb-like fiber structure formed on the transparent electrode layer, and the comb-like fiber structure hole transport layer 4 is made of a polythiophene polymer hole material.

[0033] In this application, the hole transport layer is creatively fabricated into a comb fiber structure, which increases the contact area between the hole transport layer and the perovskite absorption layer and reduces the recombination of electrons and holes. The hole transport layer fabricated by the inventors is produced by vapor-phase polymerization of thiophene hole material monomers, eliminating the insulating material PSS required in conventional hole transport layer fabrication, thereby significantly improving the transport efficiency of the hole transport layer and improving battery efficiency and battery life.

[0034] The present application does not impose any limitations on the transparent electrode layer 5 as long as it can perform its function. For example, the transparent electrode layer may be made of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), etc.

[0035] In one embodiment, the polythiophene polymer hole material is one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT, for example, it may be one, two, three, or four selected therefrom.

[0036] In one embodiment, the comb fiber structure hole transport layer 4 comprises a thin film layer 41 and a comb fiber structure 42, the thickness of the thin film layer 41 is 50-200 nm, and the length of the comb fiber structure 42 is 500-1500 nm.

[0037] For example, the thickness of the thin film layer 41 may be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, or any range therebetween.

[0038] The length of the comb fiber structure 42 may be 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm or any range therebetween.

[0039] Within this scale, the thinner the film, the higher the hole transport efficiency, and the longer the comb fiber, the larger its specific surface area per unit area, the larger the contact area with the perovskite absorber layer, and the easier the hole transport. However, the thickness of the perovskite absorber layer is generally 1500 nm or less, so the length of the comb fiber structure 42 needs to be controlled.

[0040] In one embodiment, the polythiophene polymer hole material is obtained by vapor phase polymerization of thiophene hole material monomers.

[0041] In one embodiment, the polythiophene polymer hole material is prepared by a method comprising the steps of: As shown in FIG. 2, an oxidizing agent 7 is deposited on the transparent electrode layer 5, and the oxidizing agent preferably has an oxidation potential of 0.7 to 1V. The solution containing the strong polar acid and the thiophene hole transport material monomer is brought into contact with the oxidizing agent 7 to react with each other, thereby obtaining the hole transport layer 4 having a comb fiber structure. The reaction is a gas phase synthesis reaction.

[0042] Preferably, the present application does not limit the oxidizing agent having an oxidation potential of 0.7 to 1 V as long as it can perform the corresponding function. For example, the oxidizing agent may be an iron oxide-containing substance, a silver ion (Ag + ), OCl - , OBr - may be.

[0043] The present application does not impose any limitations on the thickness of the deposited oxidizer 7, provided that it can be manipulated to achieve the described effects, for example, the thickness of the deposition is 10-60 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, or any range therebetween.

[0044] A strong polar acid is used to dissolve the oxidizing agent, such as the iron oxide-containing material, and may be, for example, concentrated hydrochloric acid, concentrated nitric acid, formic acid, acetic acid, or the like.

[0045] Preferably, the volume of the strong polar acid is 10 to 40 μL, and for example, the volume of the strong polar acid is 10 μL, 15 μL, 20 μL, 25 μL, 30 μL, 35 μL, 40 μL, or any range therebetween.

[0046] Preferably, the volume of the thiophene hole material monomer is 100 to 300 μL, for example, the thiophene hole material monomer may be 100 μL, 110 μL, 120 μL, 130 μL, 140 μL, 150 μL, 160 μL, 170 μL, 180 μL, 190 μL, 200 μL, 210 μL, 220 μL, 230 μL, 240 μL, 250 μL, 260 μL, 270 μL, 280 μL, 290 μL, 300 μL, or any range therebetween.

[0047] Preferably, the concentration of the thiophene hole material monomer is 0.8-2M.

[0048] For example, the concentration of the thiophene hole material monomer may be 0.8M, 0.9M, 1.0M, 1.1M, 1.2M, 1.3M, 1.4M, 1.5M, 1.6M, 1.7M, 1.8M, 1.9M, 2.0M, or any range therebetween.

[0049] Preferably, the solution containing a strong acid and a thiophene hole material monomer is an organic solution containing a strong acid and a thiophene hole material monomer, and may be, for example, a benzene solution, a chlorobenzene solution, or a toluene solution.

[0050] Preferably, the reaction temperature is 110 to 150°C and the reaction time is 1 to 2 hours.

[0051] The thiophene hole material monomer can be a poorly soluble thiophene hole material monomer or a soluble thiophene hole material monomer, for example, the poorly soluble thiophene hole material monomer can be 3,4-ethylenedioxythiophene (EDOT), and the soluble thiophene hole material monomer can be 3-hexylthiophene (3HT), 3-hexyloxythiophene (3OHT), or 3-dodecyloxythiophene (3ODDT).

[0052] This application uses thiophene hole material monomers to fabricate a hole transport layer with a comb-like fiber structure, without using conventional PEDOT:PSS in the fabrication, and improves the hole transport speed, thereby improving the battery efficiency and battery life.

[0053] In one embodiment, the method further comprises the step of washing out impurities in the comb fiber structured hole transport layer 4 with a Lewis acid after contacting and reacting the solution containing the strong polar acid and the thiophene hole material monomer with an oxidizing agent.

[0054] The present application does not impose any limitations on the Lewis acid as long as it can wash away impurities in the hole transport layer having a comb fiber structure. For example, the Lewis acid may be isopropyl alcohol (IPA), methanol, ethanol, etc., and the impurities may be washed away with, for example, hydrochloric acid, preferably 6 to 12 M hydrochloric acid, to obtain a pure hole transport layer 4 having a comb fiber structure.

[0055] In one embodiment, the comb fiber structure hole transport layer 4 is doped with an acid solution or acid gas to obtain a doped comb fiber structure hole transport layer 4 .

[0056] For example, the hole transport layer 4 of the comb fiber structure can be doped with a solution or gas of HCl, HBr, H2SO4, etc., with a theoretical maximum doping degree of 33%.

[0057] Regarding doping, those skilled in the art can dope it by a common method, for example, by adding Cl - , Br - or SO4 2-can be doped into the hole transport layer 4 of the comb fiber structure, increasing the carrier concentration and thereby further improving the hole transport rate.

[0058] In one embodiment, the perovskite battery further comprises a perovskite absorber layer 6, an electron transport layer 2, and an electrode layer 1, as shown in FIG.

[0059] The perovskite absorber layer 6 is provided on the hole transport layer 4 of the comb fiber structure, and then the electron transport layer 2 and the electrode layer 1 are provided on the perovskite absorber layer 6 in sequence.

[0060] The electrode layer 1 may be, for example, a metal electrode layer or a transparent electrode layer.

[0061] The perovskite absorber layer extends into the gaps of the interdigitated structure of the hole transport layer to form an interdigitated structure.

[0062] Regarding the manufacturing method of the perovskite absorber layer 6, general perovskite manufacturing methods (spin coating and vapor deposition) can be used to synthesize the perovskite absorber layer 6. For example, a perovskite solution is spin coated on the hole transport layer so that the perovskite absorber layer extends into the gaps of the comb-shaped structure.

[0063] The hole transport layer 4 of the comb fiber structure has high wettability with the solvent of the perovskite solution, such as polar solvents such as DMF, DMSO, NMP, etc., so that the perovskite can form good contact with the thin film layer 41 and the comb fiber structure 42.

[0064] The perovskite absorber layer 6 may also be fabricated using a vapor deposition method, for example by depositing a perovskite precursor polymer on the hole transport layer, so that the perovskite precursor polymer forms a perovskite absorber layer and extends into the voids of the interdigitated structure.

[0065] The perovskite precursor polymer may be, for example, PbI2 and FAI, and the preparation method is, for example, as follows. (1) First, PbI2 is evaporated onto the hole transport layer, and then formamidinium iodide (FAI) is spin-coated to react with the PbI2. (2) PbI2 and FAI are co-evaporated to form a perovskite layer in one step. The vapor-phase synthesis method of co-evaporating PbI2 and FAI is preferred because it allows gas molecules to more easily penetrate the thin film layer 41 and the comb-like fiber structure 42 and form good contact. Because it is a vapor-phase method, the comb-like fiber structure is not a constraint, and the deposited perovskite layer and the comb-like fiber hole transport layer adhere closely without any gaps, providing electrical connection between the two.

[0066] The present application does not impose any limitations on the electron transport layer, and it may be, for example, PCBM, graphene, tin oxide (SnO2), tungsten oxide (WO3), titanium oxide (TiO2), vanadium oxide (VO2), or the like.

[0067] The present application does not limit the thickness of the electron transport layer, as long as it can ensure that the perovskite absorber layer does not come into contact with the electrode layer.

[0068] In one embodiment, to avoid short-circuiting of the device due to contact between the comb fiber structure 42 and the electron transport layer 2, the thickness of the hole transport layer 4 of the comb fiber structure is smaller than the thickness of the perovskite absorber layer 6. The thickness of the perovskite absorber layer 6 is a thickness commonly used by those skilled in the art, for example, typically 1500 nm or less.

[0069] In one embodiment, as shown in FIG. 1, the safety distance 3 between the electron transport layer 2 and the tip of the comb fiber structure 42 (i.e., the layer thickness excluding the comb fibers) is 10 nm or more to ensure that the device does not short circuit.

[0070] In one embodiment, as shown in FIG. 1, the perovskite battery includes a transparent electrode layer 5 and a comb-like fiber hole transport layer 4 formed on the transparent electrode layer. The comb-like fiber hole transport layer 4 is a polythiophene polymer hole material, which may be one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT. The comb-like fiber hole transport layer 4 comprises a thin film layer 41 and comb-like fiber structures 42. The thickness of the thin film layer 41 is 50-200 nm, and the length of the comb-like fiber structures 42 is 500-1500 nm. The polythiophene polymer hole material is fabricated by a method including the following steps: As shown in FIG. 2, an oxidant 7 is deposited on the transparent electrode layer 5, preferably with an oxidation potential of 0.7-1 V. A solution containing a strong polar acid and a thiophene hole material monomer is contacted with the oxidant 7 to react with the oxidant 7, thereby obtaining the comb-like fiber hole transport layer 4.

[0071] In one embodiment, as shown in FIG. 1, the perovskite battery includes a transparent electrode layer 5 and a comb-like fiber hole transport layer 4 formed on the transparent electrode layer. The comb-like fiber hole transport layer 4 is a polythiophene polymer hole material, which may be one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT. The comb-like fiber hole transport layer 4 comprises a thin film layer 41 and comb-like fiber structures 42. The thickness of the thin film layer 41 is 50-200 nm, and the length of the comb-like fiber structures 42 is 500-1500 nm. The polythiophene polymer hole material is fabricated by a method including the following steps: As shown in FIG. 2, an oxidant 7 is deposited on the transparent electrode layer 5, preferably with an oxidation potential of 0.7-1 V. A solution containing a strong polar acid and a thiophene hole material monomer is contacted with the oxidant 7 to react with the oxidant 7, thereby obtaining the comb-like fiber hole transport layer 4. The thickness of the hole transport layer 4 of the comb fiber structure is smaller than the thickness of the perovskite absorption layer 6, and the safety distance 3 between the electron transport layer 2 and the tip of the comb fiber structure 42 (i.e., the layer thickness excluding the comb fibers) is 10 nm or more.

[0072] In one embodiment, as shown in FIG. 1, the perovskite battery includes a transparent electrode layer 5 and a comb-like fiber hole transport layer 4 formed on the transparent electrode layer. The comb-like fiber hole transport layer 4 is a polythiophene polymer hole material, which may be one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT. The comb-like fiber hole transport layer 4 comprises a thin film layer 41 and comb-like fiber structures 42. The thickness of the thin film layer 41 is 50-200 nm, and the length of the comb-like fiber structures 42 is 500-1500 nm. The polythiophene polymer hole material is fabricated by a method including the following steps: As shown in FIG. 2, an oxidant 7 is deposited on the transparent electrode layer 5, preferably with an oxidation potential of 0.7-1 V. A solution containing a strong polar acid and a thiophene hole material monomer is contacted with the oxidant 7 to react with the oxidant 7, thereby obtaining the comb-like fiber hole transport layer 4. The thickness of the hole transport layer 4 of the comb fiber structure is smaller than that of the perovskite absorption layer 6, and the safe distance 3 between the electron transport layer 2 and the tip of the comb fiber structure 42 (i.e., the layer thickness excluding the comb fiber) is 10 nm or more. The method further includes contacting a solution containing a strong polar acid and a thiophene hole material monomer with an oxidizing agent to react them, and then washing away impurities in the hole transport layer 4 of the comb fiber structure with a Lewis acid.

[0073] In one embodiment, as shown in FIG. 1, the perovskite battery includes a transparent electrode layer 5 and a comb-like fiber hole transport layer 4 formed on the transparent electrode layer. The comb-like fiber hole transport layer 4 is a polythiophene polymer hole material, which may be one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT. The comb-like fiber hole transport layer 4 comprises a thin film layer 41 and comb-like fiber structures 42. The thickness of the thin film layer 41 is 50-200 nm, and the length of the comb-like fiber structures 42 is 500-1500 nm. The polythiophene polymer hole material is fabricated by a method including the following steps: As shown in FIG. 2, an oxidant 7 is deposited on the transparent electrode layer 5, preferably with an oxidation potential of 0.7-1 V. A solution containing a strong polar acid and a thiophene hole material monomer is contacted with the oxidant 7 to react with the oxidant 7, thereby obtaining the comb-like fiber hole transport layer 4. The thickness of the comb fiber hole transport layer 4 is smaller than that of the perovskite absorption layer 6, and the safe distance 3 between the electron transport layer 2 and the tip of the comb fiber structure 42 (i.e., the layer thickness excluding the comb fiber) is 10 nm or more. The method further includes contacting a solution containing a strong polar acid and a thiophene hole material monomer with an oxidizing agent to react, and then washing out impurities in the comb fiber hole transport layer 4 with a Lewis acid. The comb fiber hole transport layer 4 is then doped with an acid solution or acid gas to obtain a doped comb fiber hole transport layer 4.

[0074] In one embodiment, as shown in FIG. 1, the perovskite battery includes a transparent electrode layer 5 and a comb-like fiber hole transport layer 4 formed on the transparent electrode layer. The comb-like fiber hole transport layer 4 is a polythiophene polymer hole material, which may be one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT. The comb-like fiber hole transport layer 4 comprises a thin film layer 41 and comb-like fiber structures 42. The thickness of the thin film layer 41 is 50-200 nm, and the length of the comb-like fiber structures 42 is 500-1500 nm. The polythiophene polymer hole material is fabricated by a method including the following steps: As shown in FIG. 2, an oxidant 7 is deposited on the transparent electrode layer 5, preferably with an oxidation potential of 0.7-1 V. A solution containing a strong polar acid and a thiophene hole material monomer is contacted with the oxidant 7 to react with the oxidant 7, thereby obtaining the comb-like fiber hole transport layer 4. The thickness of the comb fiber hole transport layer 4 is smaller than that of the perovskite absorption layer 6, and the safe distance 3 between the electron transport layer 2 and the tip of the comb fiber structure 42 (i.e., the layer thickness excluding the comb fiber) is 10 nm or more. The method further includes contacting a solution containing a strong polar acid and a thiophene hole material monomer with an oxidizing agent to react, and then washing out impurities in the comb fiber hole transport layer 4 with a Lewis acid. The comb fiber hole transport layer 4 is then doped with an acid solution or acid gas to obtain a doped comb fiber hole transport layer 4. The perovskite battery further includes a perovskite absorber layer 6, an electron transport layer 2, and an electrode layer 1, where the perovskite absorber layer 6 is disposed on the hole transport layer 4 with the comb-like fiber structure, and then the electron transport layer 2 and the electrode layer 1 are disposed on the perovskite absorber layer 6 in sequence, with the perovskite absorber layer 6 entering the voids of the comb-like structure of the hole transport layer 4 to form an interdigitated structure.

[0075] In one embodiment, the diameter of a single comb fiber in the transport layer of the comb fiber structure is 100-1000 nm, and the surface of the single comb fiber is rough (as shown in FIG. 5).

[0076] The smaller the diameter of a single interdigital fiber, the greater the number of single interdigital fibers per unit area, and the larger the specific surface area, which increases the contact area with the perovskite absorber layer and reduces the recombination of electrons and holes.

[0077] For example, the diameter of a single comb fiber may be 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, or any range therebetween.

[0078] The perovskite battery described in this application uses a thiophene hole material monomer to fabricate a hole transport layer with a comb-like fiber structure, which improves the hole transport rate, cell efficiency, and cell life. Furthermore, the use of a comb-like structured hole transport layer increases the contact area between the perovskite absorber layer and the hole transport layer, reducing the recombination of electrons and holes.

[0079] The perovskite cells described in this application are also applicable to other systems, such as perovskite-based stacked cells, including crystalline silicon-perovskite stacked cells, perovskite-perovskite stacked cells, organic photovoltaic-perovskite stacked cells, etc., and also have good versatility and compatibility with dye-sensitized cells.

[0080] This application is depositing an oxidant on the transparent electrode layer; contacting a solution containing a strong polar acid and a thiophene hole material monomer with the oxidizing agent to react with each other to obtain a hole transport layer having a comb fiber structure; synthesizing a perovskite absorber layer on the hole transport layer with the comb fiber structure, and then sequentially providing an electron transport layer and an electrode layer on the perovskite absorber layer.

[0081] The thickness of the oxidant deposited on the transparent electrode layer is 10 to 60 nm, and the thiophene hole material monomer is one or more selected from EDOT, 3HT, 3OHT, and 3ODDT.

[0082] In one embodiment, the perovskite solution is spin-coated onto the hole transport layer such that the perovskite absorber layer falls within the voids of the interdigitated structure.

[0083] For example, by spin-coating a solution of PbI2 and N,N-dimethylformamide or a mixed-halogen perovskite precursor polymer onto a hole transport layer, the resulting perovskite absorption layer enters the gaps of the comb-shaped structure, forming an interdigitated structure.

[0084] In one embodiment, the perovskite precursor polymer is deposited onto the hole transport layer, so that the perovskite precursor polymer forms a perovskite absorber layer and enters into the voids of the interdigitated structure.

[0085] The perovskite precursor polymer is, for example, PbI2 and FAI, and its preparation method is as follows: PbI2 and FAI are deposited on the hole transport layer and reacted in situ to form a FAPbI3 thin film, and the thin film (perovskite absorption layer) thus formed enters the gaps in the comb structure of the hole transport layer, forming an interdigitated structure.

[0086] The electrode layer may be, for example, a metal electrode layer or a transparent electrode layer.

[0087] The oxidizing agent has an oxidation potential of 0.7 to 1 V, and is, for example, an iron oxide-containing substance, a silver ion (Ag + ), OCl - , OBr - may be.

[0088] The strong polar acid may be, for example, concentrated hydrochloric acid, concentrated nitric acid, formic acid, acetic acid, etc., and the volume of the strong polar acid may be, for example, 10 to 40 μL, and the volume of the thiophene hole material monomer may be 100 to 300 μL.

[0089] In the prior art, polythiophene hole materials are insoluble in conventional solvents and cannot be produced using conventional solvent methods, and conventional non-solvent methods for producing polythiophene hole materials can only produce layered structures, not interdigitated fiber structures. The present application uses the above-mentioned method to produce perovskite batteries, and uses thiophene hole material monomers to produce hole transport layers with interdigitated fiber structures, thereby improving hole transport speed and battery efficiency and lifespan.

[0090] <Example> This application generally and / or specifically describes the materials and test methods used in the tests, and in the following examples, unless otherwise specified, % stands for wt%, i.e., weight percentage. If the manufacturer of the reagents or equipment used is not specified, conventional reagent products can be obtained from commercial sources.

[0091] Example 1 As shown in Figure 1, the hole transport layer 4 consists of a 50 nm PEDOT thin film layer 41 and a 500 nm PEDOT interdigitated fiber structure 42. The perovskite absorber layer 6 is 600 nm thick, with a safety distance 3 of 50 nm. As shown in Figure 5, the diameter of a single PEDOT interdigitated fiber structure is 100 nm, and scanning electron microscopy (JEOL 7001LVF FE-SEM) revealed that its surface was rough.

[0092] Fabrication of the PEDOT layer A 20 nm iron oxide layer 7 was deposited on the transparent electrode layer 5 by physical vapor deposition (see Figure 2). Then, 10 μL of concentrated hydrochloric acid and 100 μL of a 1.56 M EDOT solution in chlorobenzene were placed in a glass reactor and reacted at 130°C for 1.5 hours, ultimately yielding a PEDOT thin film containing FeCl2 impurities and a comb-like fiber structure (see Figure 3). This was then washed with 6 M HCl to yield a pure hole transport layer consisting of a PEDOT thin film and a comb-like fiber structure (see Figure 4).

[0093] Fabrication of perovskite absorber layers A 1M solution of PbI2 in N,N-dimethylformamide was prepared and heated to 60°C with stirring for 30 min. It was then spin-coated onto the hole-transport layer at 5000 rpm for 20 s and dried at 50°C and 100°C for 3 and 5 min, respectively. To form the MAPbI3 perovskite, a 10 mg / mL solution of MAI (CH3NH3I) in anhydrous isopropyl alcohol was spin-coated onto the PbI2 thin film and spin-coated at 2000 rpm for 20 s. Finally, the excess MAI was removed by rinsing with IPA, and the film was dried at 100°C for 5 min. The perovskite absorber layer extended into the interdigitated voids of the hole-transport layer, forming an interdigitated structure with the hole-transport layer.

[0094] The thin film layer 41 of the obtained hole transport layer 4 is thin, and the aspect ratio of the fibers is large, which contributes to hole transport and improves efficiency, and the hole transport layer and the perovskite absorption layer can be in good contact with each other. The following examples also have similar effects.

[0095] <Example 2> As shown in Figure 1, the hole transport layer 4 consists of a 200 nm PEDOT thin film layer 41 and a 1200 nm PEDOT interdigitated fiber structure 42. The perovskite absorber layer 6 is 1500 nm thick, with a safety distance 3 of 100 nm. As shown in Figure 5, the diameter of a single PEDOT interdigitated fiber structure is 200 nm, and its surface is rough.

[0096] Fabrication of the PEDOT layer A 60 nm iron oxide layer 7 was deposited on the transparent electrode layer 5 by physical vapor deposition (see Figure 2). Then, 40 μL of concentrated hydrochloric acid and 200 μL of a 1.56 M EDOT solution in chlorobenzene were placed in a glass reactor and reacted at 150°C for 2 hours, ultimately yielding a PEDOT thin film containing FeCl2 impurities and a comb-like fiber structure (see Figure 3). This was then washed with 12 M HCl to yield a pure hole transport layer consisting of a PEDOT thin film and a comb-like fiber structure (see Figure 4).

[0097] Fabrication of perovskite absorber layers 10 -6At a vacuum of 100 mbar, 99.999% pure PbI2 and FAI were heated to 200-300°C and 80-150°C, respectively. The heating power of the two crucibles was controlled to maintain the deposition rate of PbI2 at 0.8 Å / s and the deposition rate of FAI at 1.5 Å / s. The two reacted in situ on the substrate to form a FAPbI3 thin film. The deposition was terminated when the film reached a thickness of 800 nm. The film was then annealed at 150°C for 15 minutes, during which the perovskite absorber layer extended into the interdigitated gaps of the hole transport layer, forming an interdigitated structure with the hole transport layer.

[0098] Example 3 As shown in Figure 1, the hole transport layer 4 is composed of a 100 nm P3HT thin film layer 41 and an 800 nm P3HT comb-like fiber structure 42. The perovskite absorber layer 6 is 1000 nm thick, with a safety distance of 100 nm. As shown in Figure 5, the diameter of a single P3HT comb-like fiber structure is 150 nm, and its surface is rough.

[0099] Fabrication of the P3HT layer A 40 nm iron oxide layer 7 was deposited on the transparent electrode layer 5 by physical vapor deposition (see Figure 2). 30 μL of concentrated hydrochloric acid and 300 μL of a 1.2 M 3-hexylthiophene chlorobenzene solution were placed in a glass reactor and reacted at 150°C for 1 hour, ultimately yielding a P3HT thin film containing FeCl2 impurities and a comb-like fiber structure (see Figure 3). This was then washed with 6 M HCl to yield a pure hole transport layer consisting of a P3HT thin film and a comb-like fiber structure (see Figure 4).

[0100] The manufacturing method of the perovskite absorber layer is the same as in Example 2.

[0101] Example 4 As shown in Figure 1, the hole transport layer 4 is composed of a 50 nm P3OHT thin film layer 41 and a 950 nm P3OHT interdigitated fiber structure 42. The perovskite absorber layer 6 is 1000 nm thick, with a safety distance of 50 nm. As shown in Figure 5, the diameter of a single P3OHT interdigitated fiber structure is 100 nm, and its surface is rough.

[0102] Manufacturing method of P3OHT layer A 10 nm iron oxide layer 7 was deposited on the transparent electrode layer 5 by physical vapor deposition (see Figure 2). Then, 10 μL of concentrated hydrochloric acid and 100 μL of a 1.56 M 3OHT solution in chlorobenzene were placed in a glass reactor and reacted at 110°C for 2 hours, ultimately yielding a thin film of POHT containing FeCl2 impurities and a comb-like fiber structure (see Figure 3). This was then washed with 6 M HCl to yield a pure hole transport layer consisting of a thin film of POHT and a comb-like fiber structure (see Figure 4).

[0103] The manufacturing method of the perovskite absorber layer is the same as in Example 2.

[0104] <Example 5> As shown in Figure 1, the hole transport layer 4 consists of a 50 nm P3ODDT thin film layer 41 and a 900 nm P3ODDT interdigitated fiber structure 42. The perovskite absorber layer 6 is 1000 nm thick, with a safety distance of 100 nm. As shown in Figure 5, the diameter of a single P3ODDT interdigitated fiber structure is 150 nm, and its surface is rough.

[0105] Manufacturing method of P3ODDT layer A 20 nm iron oxide layer 7 was deposited on the transparent electrode layer 5 by physical vapor deposition (see Figure 2). Then, 10 μL of concentrated hydrochloric acid and 100 μL of a 1.56 M 3ODDT solution in chlorobenzene were placed in a glass reactor and reacted at 130°C for 1.5 hours, ultimately yielding a thin film of P3ODDT containing FeCl2 impurities and a comb-like fiber structure (see Figure 3). This was then washed with 6 M HCl to yield a pure hole transport layer consisting of a thin film of P3ODDT and a comb-like fiber structure (see Figure 4).

[0106] The manufacturing method of the perovskite absorber layer is the same as in Example 2.

[0107] Example 6 As shown in Figure 1, the hole transport layer 4 consists of a 50 nm PEDOT thin film layer 41 and a 550 nm PEDOT interdigitated fiber structure 42. The perovskite absorber layer 6 is 600 nm thick, with a safety distance of 50 nm. As shown in Figure 5, the diameter of a single PEDOT interdigitated fiber structure is 50 nm, and its surface is rough.

[0108] Fabrication of the PEDOT layer The manufacturing method is the same as in Example 1.

[0109] The manufacturing method of the perovskite absorber layer is the same as in Example 2.

[0110] [Table 1]

[0111] In summary, the perovskite battery described in this application uses PEDOT as a hole transport layer in an interdigitated fiber structure, resulting in a thin film layer and a large fiber aspect ratio, which contributes to hole transport and improves efficiency. Furthermore, the hole transport layer in the interdigitated fiber structure is fabricated using a thiophene hole material monomer, which improves the hole transport rate and battery efficiency and lifespan.

[0112] The above description is only a preferred embodiment of the present application and is not intended to limit the present application in any way. Those skilled in the art can use the technical content disclosed above to make modifications or modify equivalent embodiments that are equivalently changed, but any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical substance of the present application without departing from the content of the technical solution of the present application still fall within the protection scope of the technical solution of the present application.

[0113] The above-described device embodiments are merely illustrative, and the units described herein as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. According to actual needs, some or all of the modules may be selected to achieve the objectives of the solutions of the present embodiment. Those skilled in the art can understand and implement the present invention without any creative effort.

[0114] The terms "one embodiment," "embodiment," or "one or more embodiments" used herein mean that a particular feature, structure, or characteristic described by the embodiment is included in at least one embodiment of the present application. Note also that various references to "in one embodiment" in this specification do not necessarily refer to the same embodiment.

[0115] In the specification provided herein, numerous specific details have been set forth. However, it will be understood that embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure the understanding of this specification.

[0116] Finally, it should be noted that the above examples are only for illustrating the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above examples, it is naturally understood by those skilled in the art that modifications to the technical solutions described in the above examples or equivalent substitutions for some technical features thereof are possible, and such modifications or substitutions do not deviate the essence of the relevant technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application. [Explanation of symbols]

[0117] 1 Metal electrode layer 2 Electron transport layer 3 Safety distance 4. Hole transport layer with comb-like fiber structure 5 Transparent electrode layer 6 Perovskite absorber layer 7 Iron oxide layer 8. FeCl2 impurity

Claims

1. a transparent electrode layer and a hole transport layer having a comb-like fiber structure formed on the transparent electrode layer, the comb-like fiber structure hole transport layer being made of a polythiophene polymer hole material; The hole transport layer of the comb-like fiber structure is composed of a thin film layer having a thickness of 50 to 200 nm and a comb-like fiber structure having a length of 500 to 1500 nm.

2. 2. The perovskite battery of claim 1, wherein the polythiophene polymer hole material is one or more selected from PEDOT, P3HT, P3OHT, and P3ODDT.

3. 2. The perovskite battery of claim 1, wherein the polythiophene polymer hole material is a polymer of thiophene hole material monomers.

4. The perovskite battery according to claim 3, wherein the thiophene hole material monomer is one or more selected from the group consisting of 3,4-ethylenedioxythiophene, 3-hexylthiophene, 3-hexyloxythiophene, and 3-dodecyloxythiophene.

5. 2. The perovskite battery of claim 1, further comprising a perovskite absorber layer, an electron transport layer, and an electrode layer, wherein the perovskite absorber layer is disposed on the hole transport layer of the comb fiber structure, and the electron transport layer and the electrode layer are disposed sequentially on the perovskite absorber layer.

6. 6. The perovskite battery of claim 5, wherein the perovskite absorber layer extends into voids of the interdigitated structure of the hole transport layer to form an interdigitated structure.

7. 6. The perovskite battery of claim 5, wherein the thickness of the hole transport layer of the interdigitated fiber structure is less than the thickness of the perovskite absorber layer.

8. The perovskite battery according to claim 5 , wherein a safe distance between the electron transport layer and tips of the comb fiber structure in the hole transport layer having the comb fiber structure is 10 nm or more.

9. 9. The perovskite cell of claim 8, wherein the diameter of a single comb fiber in the hole transport layer of the comb fiber structure is 100 to 1000 nm, and the surface of the single comb fiber is rough.

10. depositing an oxidant on the transparent electrode layer; contacting a solution containing a strong polar acid and a thiophene hole material monomer with the oxidizing agent to react with each other to obtain a hole transport layer having a comb fiber structure; synthesizing a perovskite absorber layer on the hole transport layer of the comb fiber structure, and then sequentially providing an electron transport layer and an electrode layer on the perovskite absorber layer.

11. The method of claim 10, wherein the thickness of the oxidant deposited on the transparent electrode layer is 10 to 60 nm.

12. spin-coating a perovskite solution onto the hole transport layer so that the perovskite absorber layer extends into the voids of the interdigitated structure; or 11. The method of claim 10, wherein the perovskite precursor polymer is deposited on the hole transport layer, such that the perovskite precursor polymer forms a perovskite absorber layer and extends into the voids of the interdigitated structure.

13. 11. The method of claim 10, wherein the hole transport layer of the comb fiber structure is a polythiophene polymer hole material and is polymerized into the polythiophene polymer hole material by vapor phase polymerization of the thiophene hole material monomer.

14. 11. The method of claim 10, further comprising the step of washing away impurities in the hole transport layer of the comb fiber structure with a Lewis acid after contacting and reacting a solution containing a strong acid and a thiophene hole material monomer with the oxidizing agent.

15. 11. The method of claim 10, wherein the comb fiber structure hole transport layer is doped with an acid solution or an acid gas to obtain a doped comb fiber structure hole transport layer.

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