Method for improving wettability of carrier transport layer, and perovskite cell

Abstract

The present invention provides a method for improving the wettability of a carrier transport layer, and a perovskite cell. A carrier transport layer passivation layer is coated on a substrate by using a wet coating process; once the carrier transport layer passivation layer undergoes thermal annealing, the carrier transport layer passivation layer is rapidly and contactlessly coated with a modified solvent; and the modified solvent is evaporated by means of waste heat, so that a layer of polar hydrophilic groups is attached to the carrier transport layer passivation layer, to improve the wettability of the carrier transport layer passivation layer. The present invention can effectively alleviate the problem that a perovskite solution fails to fully wet a hydrophobic layer, can obtain a compact and flat perovskite thin film, and mitigates the problem of the presence of multiple holes on a prepared perovskite thin film due to improper interface contact between a hydrophobic passivation layer and perovskite, so that the hydrophobic passivation layer and the perovskite are better combined to improve the performance of perovskite solar cells or crystalline silicon / perovskite tandem solar cells.

Description

A method for improving the wettability of a carrier transport layer and a perovskite battery

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on January 17, 2024, with application number 2024100661012 and invention name “A method for improving the wettability of carrier transport layer and perovskite battery”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the field of perovskite technology, specifically a method for preparing a modified layer on a carrier transport layer, which is used to improve the wettability between perovskite ink and the carrier transport layer, thereby improving the performance of perovskite or crystalline silicon / perovskite stacked solar cells. Background Art

[0003] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0004] Perovskite solar cells utilize perovskite-type organic metal halide semiconductors as light-absorbing materials. They belong to the third generation of solar cells and are one of the most promising solar cells due to their high photoelectric conversion efficiency, low cost, and simple fabrication process. Perovskite cells have a simple structure, typically consisting of an electrode layer, a carrier transport layer, a perovskite layer, a carrier transport layer, and an electrode layer. The carrier transport layer can generally be classified as either a hole transport layer or an electron transport layer. As a crucial component of perovskite solar cells, the hole transport layer primarily collects and transports holes, achieving effective electron-hole separation while protecting the perovskite layer from oxygen and water vapor, significantly impacting cell efficiency and stability. As a crucial component of perovskite cells, the electron transport layer plays a key role in extracting and transporting photogenerated electrons, blocking holes, modifying the interface, regulating interface energy levels, and reducing carrier recombination. Since there are usually problems such as energy level mismatch and interface defects between perovskite active layers, a carrier transport passivation layer is currently formed by adding multiple types of passivation materials to a single carrier transport layer, thereby improving interface carrier transfer, inhibiting carrier recombination caused by defects, reducing carrier transport energy loss, improving device performance and stability, and thus improving the device's energy conversion efficiency.

[0005] However, due to the strong hydrophobicity of the carrier transport passivation layer, the perovskite solution cannot fully infiltrate this layer, making it difficult to obtain a dense and smooth perovskite film. The inappropriate interface contact between the hydrophobic passivation layer and the perovskite leads to a large number of holes in the prepared perovskite film, affecting the performance and stability of solar devices. Application Contents

[0006] In order to overcome the shortcomings of the existing technology, the present invention provides a method for improving the wettability of the carrier transport layer, wherein a carrier transport passivation layer is applied to the carrier transport layer by a wet coating process, and a modified solvent is quickly applied to the carrier transport passivation layer after heating and annealing. The modified solvent is evaporated using the residual heat, so that a layer of polar hydrophilic groups is attached to the carrier transport passivation layer, thereby improving its wettability, reducing the interface defects of the perovskite film prepared thereon, and improving the stability and uniformity of the film.

[0007] A first aspect of the present invention provides a method for improving the wettability of a carrier transport layer, which is applied to a battery and comprises the following steps:

[0008] Step 1: providing a battery substrate, and preparing a carrier transport layer on the battery substrate;

[0009] Step 2: preparing a carrier transport layer passivation layer on the carrier transport layer;

[0010] Step 3: providing a modified solvent, and within 2 to 120 seconds after the completion of step 2, rapidly applying the modified solvent to the carrier transport layer passivation layer in a contactless manner, with the modified solvent liquid volume controlled at 0.1 to 50 uL / cm2;

[0011] Step 4: Prepare a perovskite film with a thickness of 700 nm on the carrier transport layer and passivation layer by a slit coating method.

[0012] Optionally, the modified solvent should meet the following three conditions:

[0013] 1. Boiling point: 70℃~250℃;

[0014] 2. The modified solvent has a hydrophilic polar group, wherein the hydrophilic polar group is at least one of a hydroxyl group (-OH), a carboxyl group (-COOH), an amide group, an amino group (-NH2), an aldehyde group (-CHO), and a carbonyl group (-CO);

[0015] 3. Viscosity range: 1~500cp.

[0016] Optionally, the modified solvent generally includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, deionized water, and ethanol.

[0017] Optionally, the carrier transport layer is deposited by one or more processes such as vacuum coating or atomic layer deposition in a dry process, spraying, slit coating and spin coating in a wet process, and the carrier transport layer is composed of at least one of NIO, PTAA, 2PACz, 4PACz, SnO2, and TiO2, and has a thickness of 0 to 50 nm;

[0018] Specifically, NIO was selected as the material of the carrier transport layer, and magnetron sputtering was used as a deposition method to prepare a 50 nm NIO film as the carrier transport layer.

[0019] Specifically, the carrier transport layer passivation layer is prepared by coating a passivation layer solution on the carrier transport layer and annealing the solution. The passivation layer solution is obtained by dissolving a passivation layer material in a passivation layer solvent.

[0020] The passivation layer material can be a conjugated polymer, a self-assembled monolayer (SAMs) or a composite of multiple materials, specifically, including at least one of PTAA, 2PACz, 4PACz, and Meo-4Pacz; the passivation layer solvent includes but is not limited to one or more of ethanol, methanol, and chlorobenzene.

[0021] Preferably, in the embodiment of the present invention, PTAA is selected as the passivation layer material, and chlorobenzene is used as the passivation layer solvent to prepare a 0.2 mg / mL passivation layer solution.

[0022] Optionally, the carrier transport passivation layer may be prepared by deposition using one of spray coating, slit coating or spin coating;

[0023] Optionally, the passivation layer solution is heated and annealed at a temperature of 80-250° C. after coating and deposition, and the annealing time is 5-50 min. During the heating process, the carrier transport passivation layer material is tightly combined with the carrier transport layer material and does not react with the subsequent modification solvent.

[0024] Preferably, the carrier transport passivation layer is heated and annealed for 28 minutes at a temperature of 170°C.

[0025] Optionally, the contactless coating method of the modified solvent can be a rapid coating process such as slit coating, spraying, etc. that does not contact the substrate. The coating time is completed within 5 to 30 seconds. In order to ensure that the residual heat is completely volatilized, the liquid amount of the modified solvent on the substrate is controlled at 4uL / cm2.

[0026] Optionally, in order to maintain the residual heat of the substrate at 80-240° C., the interval between the completion of the annealing process of the carrier transport layer and the passivation layer and the application of the modified solvent process needs to be completed within 1-100 seconds.

[0027] Optionally, the temperature of the substrate in step 4 needs to be maintained at 80-240° C. If the temperature is too low, the modified solvent cannot be fully volatilized, and if the residual heat is too high, the hydrophilic modified groups may be destroyed.

[0028] Optionally, the method of coating the perovskite film on the modified carrier transport layer and passivation layer can be a wet process such as slit coating, spraying, doctor blade coating and screen printing.

[0029] A second aspect of an embodiment of the present invention provides a perovskite cell, which is prepared using the above-mentioned method for improving the wettability of the carrier transport layer, and includes: a glass substrate, a first electrode layer, a carrier transport layer, a carrier transport layer passivation layer, a perovskite film, a second carrier transport layer, and a second electrode layer.

[0030] A third aspect of an embodiment of the present invention provides a perovskite / crystalline silicon stacked cell, which is prepared using the above-mentioned method for improving the wettability of the carrier transport layer, and includes: a first metal electrode layer, a first transparent electrode layer, a silicon substrate, a second transparent electrode layer, a carrier transport layer, a carrier transport layer passivation layer, a perovskite film, a second carrier transport layer, a third transparent electrode layer, and a second metal electrode layer.

[0031] The process of the present invention directly applies a modified solvent to the annealed carrier transport passivation layer, using residual heat to rapidly evaporate the solvent to prepare the modified layer. This improves the wettability of the perovskite ink with the carrier transport passivation layer, significantly reducing defects and improving the flatness of the perovskite absorber layer. This process, which requires no additional annealing equipment, is simple and rapid, making it suitable for improving the wettability of the carrier transport layer in industrial perovskite cell production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] FIG1 is a schematic diagram of steps of a method for improving the wettability of a carrier transport layer provided in an embodiment of the present invention;

[0034] FIG2 is a schematic diagram of the structure of a single-junction perovskite cell according to Example 1 of the present invention;

[0035] FIG3 is a schematic diagram of the structure of a perovskite / crystalline silicon tandem battery according to Example 2 of the present invention.

[0036] 11. Glass substrate; 12. First electrode layer; 131. Carrier transport layer; 132. Carrier transport layer passivation layer; 14. Perovskite film; 15. Second carrier transport layer; 16. Second electrode layer;

[0037] 2. Silicon substrate; 211. First metal electrode layer; 212. Second metal electrode layer; 221. First transparent electrode layer; 222. Second transparent electrode layer; 223. Third transparent electrode layer. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more, unless otherwise specifically defined.

[0041] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0042] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and may encompass internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0043] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout this specification, not all references are to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0044] 1 to 3 , the present invention provides a method for improving the wettability of a carrier transport layer, which is applied to a perovskite cell or a perovskite / crystalline silicon tandem cell, comprising the following steps:

[0045] Step 1: Provide a battery substrate, and prepare a carrier transport layer 131 on the battery substrate.

[0046] Optionally, the carrier transport layer 131 is formed by depositing one or more materials including but not limited to NIO, SnO2, TiO2, 2PACz, etc. by processes such as magnetron sputtering, evaporation, spraying, and slit coating. Specifically, in an embodiment of the present invention, NIO is selected as the material of the carrier transport layer 131, and magnetron sputtering is used as a deposition method to prepare a 50nm NIO thin film as the carrier transport layer 131.

[0047] Step 2: preparing a carrier transport layer passivation layer 132 on the carrier transport layer 131 .

[0048] Specifically, the carrier transport layer passivation layer 132 is coated on the carrier transport layer 131 by spraying a passivation layer solution, and is prepared at an annealing temperature of 170°C for 28 minutes. The passivation solution is obtained by dissolving the passivation layer material in a passivation layer solvent. The passivation layer material includes but is not limited to one or more of PTAA, 2PACz, 4PACz, Meo-4Pacz, etc., and the passivation layer solvent includes but is not limited to one or more of ethanol, methanol, chlorobenzene, etc. In an embodiment of the present invention, PTAA is selected as the passivation layer material, and chlorobenzene is selected as the passivation layer solvent to prepare a 0.2 mg / mL passivation layer solution.

[0049] Step 3: Provide a modified solvent. Within 2 to 120 seconds after step 2, quickly apply the modified solvent to the carrier transport layer passivation layer 132 by slit coating. The modified solvent is controlled in a liquid volume of 0.1 to 15 uL / cm 2 The modified solvent applied to the carrier transport layer passivation layer 132 is rapidly volatilized under the action of residual heat, leaving only a small amount of hydrophilic groups, thus completing the modification.

[0050] Optionally, the modified solvent can be selected according to the following criteria:

[0051] 1. Boiling point: 70℃~250℃;

[0052] 2. The modified solvent has hydrophilic polar groups, such as hydroxyl (-OH), carboxyl (-COOH), amide, amino (-NH2), aldehyde (-CHO), carbonyl (-CO), etc.

[0053] 3. Viscosity range: 1~500cp (too high or too low will affect coating coverage).

[0054] In an embodiment of the present invention, the modified solvent is one or more of dimethyl sulfoxide, N,N-dimethylformamide (DMF), deionized water, and ethanol.

[0055] Step 4: Prepare a perovskite film 14 with a thickness of 700 nm on the carrier transport layer passivation layer 132 by slit coating.

[0056] A second aspect of an embodiment of the present invention provides a perovskite cell, which is prepared using the above-mentioned method for improving the wettability of the carrier transport layer, and includes: a glass substrate 11, a first electrode layer 12, a carrier transport layer 131, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, and a second electrode layer 16.

[0057] A third aspect of an embodiment of the present invention provides a perovskite / crystalline silicon stacked cell, which is prepared using the above-mentioned method for improving the wettability of the carrier transport layer, and includes: a first metal electrode layer 211, a first transparent electrode layer 221, a silicon substrate 2, a second transparent electrode layer 222, a carrier transport layer 131, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, a third transparent electrode layer 223, and a second metal electrode layer 212.

[0058] In order to verify that the process of the embodiment of the present invention can significantly improve the preparation of single-junction perovskite solar cells, the present invention provides Example 1 and three comparative examples for demonstration.

[0059] Example 1: Referring to FIG2 , this embodiment provides a single-junction perovskite solar cell 1, which comprises, from bottom to top, a glass substrate 11, a first electrode layer 12, a carrier transport layer 131, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, and a second electrode layer 16. The specific preparation is as follows:

[0060] Step 1: Select a glass substrate 11 of highly transparent conductive glass and a first electrode layer 12 as the battery substrate. The thickness of the glass substrate 11 is 0.5-5 mm. The first electrode layer 12 is made of fluorine tin oxide (FTO) material with a thickness of 10-1000 nm. Specifically, the thickness of the glass substrate 11 is 2.2 mm, and the thickness of the first electrode layer 12 is 300 nm.

[0061] Step 2: Prepare NIO on the first electrode layer 12 by using a controlled sputtering process. x As the carrier transport layer 131, preferably, NIO x Thickness is 8nm;

[0062] Step 3: Dissolve Meo-2pacz in ethanol solvent to obtain a passivation layer solution with a concentration of 5 mg / mL;

[0063] Step 4: Apply the passivation layer solution prepared in step 3 to the carrier transport material layer 131 using a slit coating process, and anneal at 150° C. for 20 minutes to obtain the carrier transport passivation layer 132;

[0064] Step 5: 5 seconds after the carrier transport passivation layer 132 is annealed, the substrate temperature is 135° C., and a DMF-modified solvent is applied to the carrier transport passivation layer 132 by spraying at a liquid volume of 4 μl / cm2 for 5 seconds. The modified solvent evaporates completely due to the residual heat of the substrate at 135° C., leaving only the hydroxyl (-OH) hydrophilic groups, thus completing the modification.

[0065] Step 6: Prepare a 700 nm thick perovskite film 14 on the carrier transport layer passivation layer 132 by slit coating.

[0066] Step 7. Select C 60 , SnO2 as the second carrier transport layer 15, and sequentially depositing 34nm thick C on the perovskite film 14 by evaporation. 60 , 20nm thickness SnO2.

[0067] Step eight: 150 nm of copper is evaporated on the second carrier transport layer 15 as the second electrode layer 16 to complete the battery preparation.

[0068] Comparative Example 1: This comparative example provides a single-junction perovskite cell having the same cell structure as Example 1, comprising, from bottom to top, a glass substrate 11, a first electrode layer 12, a carrier transport layer 131, a perovskite film 14, a second carrier transport layer 15, and a second electrode layer 16. The difference from Example 1 is that step 5 is omitted in this comparative example, i.e., the carrier transport layer passivation layer 132 is not modified.

[0069] Comparative Example 2: This comparative example provides a single-junction perovskite cell without a passivation structure. From bottom to top, it comprises a glass substrate 11, a first electrode layer 12, a carrier transport layer 131, a perovskite film 14, a second carrier transport layer 15, and a second electrode layer 16. This differs from Example 1 in that steps 4 and 5 are omitted; that is, the carrier transport layer 131 is not passivated or modified.

[0070] Comparative Example 3: This comparative example provides a single-junction perovskite cell without a carrier transport structure. The cell structure, from bottom to top, includes a glass substrate 11, a first electrode layer 12, a carrier transport passivation layer 132, a perovskite light absorption layer 14, a second carrier transport layer 15, and a second electrode layer 16. This differs from Example 1 in that step 2 is omitted and the original carrier transport structure is replaced with a modified passivation layer.

[0071] A comparative experiment was conducted between Example 1 of the present invention and Comparative Examples 1 to 3. A standard sunlight intensity calibration was performed using a solar simulator, and a long-term IV test was performed on the comparative example device with an area of ​​1.0 cm2. The starting voltage was set to 0V, the cut-off voltage was set to 1.3V, and the range was set to 100mA. The test results are shown in the following table.

[0072] Device short-circuit current density / Jsc(mA / cm 2 )Open circuit voltage / Voc(mV)Fill factor / FF(%)Photoelectric conversion efficiency / PCE(%)Example 120.881.2182.420.81Comparative example 116.550.98456.79.23Comparative example 219.551.0979.517.4Comparative example 318.541.0375.514.41

[0073] From the comparison of the above tables we can see that:

[0074] 1. From the comparison between Example 1 and Comparative Example 1, it can be seen that if the modified solvent is not used to improve the surface of the passivation layer, the wet film of the perovskite layer cannot evenly cover the surface of the passivation layer during preparation, there are many keyholes, a dense light-absorbing layer cannot be formed, and the battery has too many defects.

[0075] 2. From the comparison between Example 1 and Comparative Example 2, it can be seen that although the wettability of the traditional carrier transport layer material is not a problem, the open circuit voltage and fill factor of the battery obtained without passivation of the carrier transport layer are low, and the battery performance is poor.

[0076] 3. From the comparison between Example 1 and Comparative Example 3, it can be seen that even after the organic passivation layer material is improved in wettability by solvent, it cannot completely replace the carrier transport layer. The light injection passivation effects of Comparative Examples 1 to 3 are not as good as that of Example 1 of the present invention.

[0077] In comparison, Example 1 of the present invention has higher open circuit voltage and photoelectric conversion efficiency.

[0078] In order to verify that the process of the embodiment of the present invention can significantly improve the preparation of crystalline silicon / perovskite tandem cells, the present invention is demonstrated below by providing Example 2 and three comparative examples.

[0079] Example 2: This embodiment of the present invention provides a perovskite / crystalline silicon tandem cell, which comprises, from bottom to top: a first metal electrode layer 211, a first transparent electrode layer 221, a silicon substrate 2, a second transparent electrode layer 222, a carrier transport layer 131, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, a third transparent electrode layer 223, and a second metal electrode layer 212. The specific preparation steps include:

[0080] Step 1: Prepare a first transparent electrode layer 221 on a silicon substrate 2. Optionally, magnetron sputtering is used. The silicon substrate 2 is placed in a magnetron sputtering device, an ITO (Indium Tin Oxide) target is set, and the power is controlled between 10-400W. Specifically, in this embodiment of the present invention, the controlled power is 85W, the operating time is 0.8h, and the film thickness of the first transparent electrode layer 221 is 80nm.

[0081] Step 2: Prepare the first metal electrode layer 211 on the first transparent electrode layer 221. Optionally, the prepared substrate sample is placed on a mask plate and placed in the chamber of the evaporation machine using an evaporation method. The evaporation vacuum is 1×10 -5 ~1×10 -3 Pa, the evaporation temperature is 200-2000°C, and the evaporation rate is 0.1-50Å / S. Specifically, in the embodiment of the present invention, the evaporation vacuum is 8×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, the evaporation rate was controlled at 1.5Å / S, and silver was evaporated onto the film with a thickness of 120nm.

[0082] Step 3: Form a second transparent electrode layer 222 on the other side of the silicon substrate 2. Alternatively, magnetron sputtering can be used. Place the sample in a magnetron sputtering device, set with an ITO (Indium Tin Oxide) target, and control the power between 10 and 400 W. Specifically, in this embodiment, the controlled power is 70 W, the operating time is 1 hour, and the film thickness is 40 nm.

[0083] Step 4: Prepare NIO on the surface of the second transparent electrode layer 222 by using a controlled sputtering process. x As the carrier transport layer 131, preferably, NIO xThickness is 8nm;

[0084] Step 5: Prepare a passivation layer solution for the carrier transport layer passivation layer 132. Specifically, dissolve Meo-2pacz in ethanol to obtain a passivation layer solution with a concentration of 5 mg / mL.

[0085] Step 6: Apply the passivation layer solution prepared in step 5 onto the carrier transport layer 131 using a slit coating process, and anneal at 150° C. for 20 minutes to obtain the carrier transport layer passivation layer 132;

[0086] Step 7: After the carrier transport layer passivation layer 132 is annealed at 150° C. for 5 seconds, the substrate temperature is 135° C., and a DMF modified solvent is applied to the carrier transport layer passivation layer 132 by spraying. The liquid volume is 4 uL / cm2 and the coating time is 5 seconds. The modified solvent evaporates completely due to the residual heat of the substrate at 135° C., leaving behind hydroxyl (-OH) hydrophilic groups, completing the modification;

[0087] Step eight: prepare a 700 nm thick perovskite film 14 on the carrier transport layer passivation layer 132 by slit coating.

[0088] Step 9. Select C 60 , SnO2 as the second carrier transport layer 15, and 34nmC 60 、20nmSnO2.

[0089] Step ten: forming a third transparent electrode layer 223 on the second carrier transport layer 15 .

[0090] Optionally, the transparent electrode material may be sputtered onto the surface of the second carrier transport layer 14 by using a magnetron sputtering method, with the power controlled to be 30-200W.

[0091] Step 11: Prepare the second metal electrode layer 212 on the third transparent electrode layer 223. Specifically, the process is similar to preparing the first metal electrode layer 211, except that the mask is different and the thickness is 100 nm.

[0092] Comparative Example 4: Comparative Example 4 provides a perovskite / crystalline silicon tandem cell having the same device structure as Example 2, comprising, from bottom to top: a first metal electrode layer 211, a first transparent electrode layer 221, a silicon substrate 2, a second transparent electrode layer 222, a carrier transport layer 131, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, a third transparent electrode layer 223, and a second metal electrode layer 212. Compared to Example 2, this comparative example omits step 7, meaning that the carrier transport layer passivation layer 132 in this comparative example does not undergo modification.

[0093] Comparative Example 5: Comparative Example 5 provides a perovskite / crystalline silicon tandem cell without a passivation layer structure, comprising, from bottom to top: a first metal electrode layer 211, a first transparent electrode layer 221, a silicon substrate 2, a second transparent electrode layer 222, a carrier transport layer 131, a perovskite film 14, a second carrier transport layer 15, a third transparent electrode layer 223, and a second metal electrode layer 212. Compared to Example 2, this comparative example omits steps five and six. That is, in this comparative example, the carrier transport layer 131 is not passivated, and modification and preparation of the perovskite film 14 are performed directly on the carrier transport layer.

[0094] Comparative Example 6: Comparative Example 6 provides a perovskite / crystalline silicon tandem cell without a carrier transport structure, comprising, from bottom to top: a first metal electrode layer 211, a first transparent electrode layer 221, a silicon substrate 2, a second transparent electrode layer 222, a carrier transport layer passivation layer 132, a perovskite film 14, a second carrier transport layer 15, a third transparent electrode layer 223, and a second metal electrode layer 212. Compared to Example 2, this comparative example omits step 4, i.e., the modified carrier transport layer passivation layer 132 is used in place of the carrier transport structure.

[0095] Example 2 of the present invention was subjected to comparative experiments with comparative examples 4 to 6. A standard solar light intensity calibration was performed using a solar simulator, and a long-term IV test was performed on the comparative example device with an area of ​​1.0 cm2. The starting voltage was set to 0V, the cut-off voltage was set to 2.0V, and the range was set to 100mA. The test results are shown in the following table.

[0096] From the comparison of the above tables we can see that:

[0097] 1. Comparison between Example 2 and Comparative Example 4 demonstrates that using a modified solvent to improve the surface of the passivation layer can improve the wettability of the perovskite layer during preparation, allowing the perovskite wet film to evenly cover the surface of the passivation layer, forming a dense, crater-free light-absorbing layer. The test results of Example 2 also demonstrate a high fill factor.

[0098] 2. From the comparison between Example 2 and Comparative Example 5, it can be seen that although the wettability of the traditional carrier transport layer material is not a problem, the open circuit voltage and fill factor of the battery obtained without passivation of the carrier transport layer are low, and the battery performance is poor.

[0099] 4. From the comparison between Example 2 and Comparative Example 6, it can be seen that even after the organic passivation layer material is improved in wettability by solvent, it cannot completely replace the carrier transport layer. The light injection passivation effects of Comparative Examples 4 to 6 are not as good as those of the present invention.

[0100] In comparison, Example 2 of the present invention has higher open circuit voltage and photoelectric conversion efficiency.

[0101] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for improving the wettability of a charge carrier transport layer, applied to a battery, characterized in that, Including the steps: Step 1: Provide a battery substrate and prepare a carrier transport layer on the battery substrate; Step 2: Prepare a carrier transport layer passivation layer on the carrier transport layer; Step 3: Provide a modified solvent. Within 2 to 120 s after Step 2 is completed, quickly apply the modified solvent to the carrier transport layer passivation layer in a non-contact manner, and the liquid volume of the modified solvent is controlled at 0.1 to 50 μL / cm2; Step 4: Prepare a perovskite thin film with a thickness of 700 nm on the carrier transport layer passivation layer by slit coating.

2. The method for improving the wettability of the charge transport layer according to claim 1, wherein The modified solvent meets the following conditions: Boiling point: 70 °C to 250 °C; The modified solvent has a hydrophilic polar group, and the hydrophilic polar group is at least one of a hydroxyl group (-OH), a carboxyl group (-COOH), an amide group, an amino group (-NH2), an aldehyde group (-CHO), and a carbonyl group (-CO); Viscosity range: 1 to 500 cp.

3. The method for improving the wettability of the charge transport layer according to claim 2, wherein The modified solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, deionized water, and ethanol.

4. The method for improving the wettability of the charge transport layer according to claim 1, wherein The carrier transport layer is deposited by one or more of vacuum coating by dry process, atomic layer deposition, spraying, slit coating, and spin coating in wet process. The carrier transport layer is composed of at least one of NIO, PTAA, 2PACz, 4PACz, SnO2, and TiO2, and the thickness is 0 to 50 nm.

5. The method for improving the wettability of the charge transport layer according to claim 4, wherein Select NIO as the material of the carrier transport layer, and prepare a 50 nm NIO thin film as the carrier transport layer by magnetron sputtering as the deposition method.

6. The method for improving the wettability of the charge transport layer according to claim 1, wherein The preparation of the carrier transport layer passivation layer is obtained by coating a passivation layer solution on the carrier transport layer and annealing. The passivation layer solution is obtained by dissolving a passivation layer material in a passivation layer solvent.

7. The method for improving the wettability of the charge transport layer according to claim 6, wherein, The passivation layer material is composed of one or more materials such as a conjugated polymer and a self-assembled monolayer (SAMs); the passivation layer solvent includes but is not limited to one or more of ethanol, methanol, chlorobenzene, etc.

8. The method for improving the wettability of the charge transport layer according to claim 1, characterized in that The non-contact coating method of the modified solvent is at least one of slit coating and spraying, and the coating time is completed within 5 to 30 s. The liquid volume of the modified solvent on the substrate is controlled at 4 μL / cm2.

9. The method for improving the wettability of the charge transport layer according to claim 6 or 7, characterized in that, The interval time from the completion of the annealing process of the carrier transport layer passivation layer to the application process of the modified solvent is within 1 to 100 s.

10. A perovskite solar cell, prepared by the method for improving the wettability of the charge carrier transport layer according to any one of claims 1 to 9, characterized in that, From bottom to top, it sequentially includes: a glass substrate, a first electrode layer, a carrier transport layer, a carrier transport layer passivation layer, a perovskite thin film, a second carrier transport layer, and a second electrode layer.

11. A perovskite / silicon heterojunction tandem solar cell, prepared by the method for improving the wettability of the charge transport layer according to any one of claims 1 to 9, characterized in that, From bottom to top, it sequentially includes: a first metal electrode layer, a first transparent electrode layer, a silicon substrate, a second transparent electrode layer, a carrier transport layer, a carrier transport layer passivation layer, a perovskite thin film, a second carrier transport layer, a third transparent electrode layer, and a second metal electrode layer.

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