Perovskite solar cell with amino acid bridging interface and preparation method thereof

Abstract

The invention belongs to the technical field of perovskite solar cells, and particularly relates to a perovskite solar cell with an amino acid bridging interface and a preparation method of the perovskite solar cell. The perovskite solar cell comprises a substrate, an electron transport layer, a perovskite absorption layer, a hole transport layer, an electrode and amino acid molecules. The amino acid molecules are arranged between the electron transport layer and the perovskite absorption layer, and the amino acid molecules are bonded with the electron transport layer and the perovskite absorption layer at the same time. The amino acid molecules comprise carboxyl and amino, the carboxyl is bonded with the surface of the electron transport layer, and the amino is bonded with the surface of the perovskite absorption layer. The electron transport layer and the perovskite absorption layer are bridged through amino acid molecules, the interface defect state density is remarkably reduced, interface energy level matching is optimized, the interface stability and the carrier transport efficiency are improved, the stability and the photoelectric conversion efficiency of the perovskite solar cell are enhanced, and the perovskite solar cell has good application prospects in the technical field of perovskite solar cells.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and in particular relates to a perovskite solar cell with an amino acid bridge interface and a preparation method thereof. Background Art

[0002] Perovskite solar cells (PSCs), an emerging photovoltaic technology, have garnered widespread attention in academia and industry due to their high energy conversion efficiency, low-cost fabrication process, and excellent optoelectronic properties. Despite the continuous improvement in the efficiency of PSCs in recent years, the interface characteristics and long-term stability of PSCs remain one of the major bottlenecks limiting their practical application (reference: Perovskite solar cells: Stability lies at interfaces, Nature Energy, Vol. 2, 17115, 2017).

[0003] In perovskite solar cells, the interface between the perovskite absorber layer and the electron transport layer (ETL) plays a critical role. Heterogeneities at this interface often manifest as a high density of trap states, mismatched energy level distributions, and inefficient carrier transport (reference: Interface engineering of highly efficient perovskite solar cells, Science, Vol. 345, 542, 2014). These issues directly lead to non-radiative recombination of photogenerated carriers and interfacial transport losses, thereby degrading device performance. Furthermore, interfacial defects accelerate the degradation of the perovskite material, significantly impacting the long-term stability of the device.

[0004] To improve the interface properties between perovskites and electron transport layers, researchers have proposed a variety of interface modification strategies (Reference: Recent Progress of Critical Interface Engineering for Highly Efficient and Stable Perovskite Solar Cells, Advanced Energy Materials, Vol. 12, 2102730, 2022), such as the introduction of organic salts, self-assembling molecules, and metal oxide modification layers. Self-assembling molecules have garnered particular attention due to their ability to simultaneously optimize interfacial chemical bonding and physical properties. However, due to their structural complexity, most self-assembling molecules (such as organosilanes) typically require precise synthesis or complex modification procedures, increasing the cost and process complexity of device fabrication.

[0005] Therefore, exploring new interface modification molecules and their preparation methods is of great significance for improving the stability of perovskite solar cells. Summary of the Invention

[0006] To address the above issues, the present invention provides, in one aspect, a perovskite solar cell with an amino acid-bridged interface, comprising a substrate, an electron transport layer, a perovskite absorber layer, a hole transport layer, electrodes, and amino acid molecules. The amino acid molecules are disposed between the electron transport layer and the perovskite absorber layer, bonding to both layers simultaneously. The amino acid molecules contain carboxyl and amino groups, with the carboxyl groups bonding to the surface of the electron transport layer and the amino groups bonding to the surface of the perovskite absorber layer.

[0007] Amino acids are naturally occurring biomolecules with a wide range of sources and low prices. They do not require complex chemical synthesis processes and can be directly extracted from natural or industrial sources for use. Amino acids are environmentally friendly and non-toxic, making them suitable for applications requiring sustainable development. Amino acid molecules typically consist of an amino group (-NH2) and a carboxyl group (-COOH), with simple side chains. This concise molecular structure of amino acids does not require precise synthesis or complex modification, thus avoiding the complexity of traditional self-assembling molecules. In addition, amino acid molecules are easily soluble in water or common solvents, eliminating the need for expensive organic solvents. Molecular layer deposition can be achieved through simple processes such as spin coating, dip coating, and spray coating, making the process easy to operate. Therefore, amino acid molecules have significant advantages over traditional self-assembling molecules in terms of interface modification.

[0008] The carboxyl group and amino group in amino acid molecules are both polar functional groups. Carboxyl groups are usually negatively charged, while amino groups are nucleophilic and tend to be positively charged. Carboxyl groups are electrophilic and can form coordination bonds or hydrogen bonds with active sites (such as hydroxyl groups or metal ions) on the surface of the electron transport layer (metal oxide); amino groups are nucleophilic and can form coordination bonds or hydrogen bonds with uncoordinated cations (such as Pb) on the surface of the perovskite absorption layer. 2+ ) or anions (such as I - ) combination. The two functional groups of the amino acid molecule are located at different ends, and the molecular structure is simple and directional, which enables it to stably and orderly connect the electron transport layer and the perovskite absorption layer at the interface. The amino acid molecule fills the defect states on the surface of the electron transport layer and the perovskite absorption layer through the carboxyl group and the amino group, respectively, reducing the defect state density, making the chemical environment of the interface more uniform, the surface energy distribution smoother, and improving the interfacial charge transfer efficiency. In addition, the bridging effect of the amino acid molecule improves the nucleation and growth conditions of the perovskite absorption layer, helping to form a perovskite film with high crystallinity and low defect density, thereby enhancing the thermal stability, wet stability and light stability of the device.

[0009] Furthermore, the amino acid molecules use one or more of proline, glycine, glutamic acid, serine, and lysine. These amino acid molecules all have a bifunctional structure, which can effectively bridge the electron transport layer and the perovskite absorption layer, thereby improving the interface bonding quality, reducing interface defects, and improving the performance and stability of the device. Among the amino acid molecules, overly complex and hydrophobic amino acids are not suitable, such as phenylalanine and leucine. In addition, amino acid derivatives lacking bifunctional groups are not suitable, such as esterified or amidated amino acids. In addition, unstable or easily degradable amino acids are also not suitable for the application of the present invention, such as cysteine.

[0010] Furthermore, the electron transport layer is a metal oxide. Furthermore, the electron transport layer is tin dioxide, titanium dioxide or zinc oxide. The surface of the metal oxide is rich in hydroxyl groups or metal ions, and these active sites can form chemical bonds or hydrogen bonds with the carboxyl groups of the amino acid molecules. Materials that lack chemical activity, such as electron-rich organic conductive polymers (such as polythiophene derivatives), are not suitable for the electron transport layer of the present invention. These materials lack surface active sites, and the carboxyl groups of the amino acid molecules are difficult to form effective chemical bonds or electrostatic bonds on the surface, and a stable bridging interface cannot be achieved. In addition, metal oxides that require high temperature preparation are also not suitable for the application of the present invention, such as nickel oxide or aluminum oxide. This is because the high temperature sintering process will lead to a decrease in surface hydroxyl groups, and the carboxyl groups of the amino acid molecules need to be bound through hydroxyl groups, which reduces the interface bonding effect.

[0011] Furthermore, the perovskite absorption layer is an organic-inorganic hybrid perovskite with the general formula ABX3, wherein: A is a methylamine ion, a formamidine ion, or a cesium ion; B is a lead ion or a tin ion; and X is an iodide ion, a bromide ion, or a chloride ion. For this type of perovskite material, the uncoordinated ions on the surface of the perovskite absorption layer can form coordination bonds and electrostatic interactions with the amino groups of the amino acid molecules, giving full play to the passivation and interface optimization functions of the amino acid bridging molecules. All-inorganic perovskites, such as CsPbBr3 and CsPbCl3, have relatively inert surface chemical properties and lack uncoordinated ions, which significantly reduces the bridging effect of amino acid molecules. In addition, perovskite materials that require high-temperature treatment to prepare are also not suitable for the application of the present invention. This is because high-temperature treatment causes the amino acid molecules to decompose or chemically fail, destroying their bridging effect.

[0012] In another aspect, the present invention provides a method for preparing a perovskite solar cell having an amino acid bridged interface, comprising the following steps: Step 1: preparing an electron transport layer on a substrate; Step 2: preparing a modification solution containing amino acid molecules and coating the modification solution on the surface of the electron transport layer; Step 3: preparing a perovskite absorption layer on the amino acid molecules; Step 4: preparing a hole transport layer on the perovskite absorption layer; Step 5: Prepare an electrode on the hole transport layer.

[0013] Furthermore, in step 2, the deposition process of the amino acid molecules is carried out with the assistance of an external electric field.

[0014] Furthermore, the direction of the electric field is perpendicular to the electron transport layer.

[0015] Furthermore, the electric field is applied through two parallel electrodes, with the negative electrode in contact with the electron transport layer and the positive electrode located above the modification solution.

[0016] The present invention enhances the effect of amino acid molecules bridging the interface by applying an external electric field, including the directional adsorption of amino acid molecules by the electric field, strengthening the interface binding, and optimizing the molecular arrangement. Specifically, amino acid molecules have carboxyl and amino functional groups. Under the action of the external electric field, the carboxyl group is negatively charged and is attracted to the surface of the electron transport layer (negative electrode) by the electric field, and the surface metal ions (such as SnO2, TiO2) of the metal oxide (such as SnO2, TiO2) are bonded to the surface of the electron transport layer (negative electrode). 4+ or Ti 4+ ) are firmly bound by coordination bonds or electrostatic interactions; the amino group is positively charged, pointing to the surface of the perovskite absorption layer (positive electrode), and binds to the uncoordinated Pb in the perovskite. 2+ ions or halide ions (such as I -) through coordination bonds or hydrogen bonds. This mechanism of electric field-guided directional molecular adsorption significantly improves the binding strength and adsorption efficiency of amino acid molecules to the interface material. In addition, the electric field can effectively reduce the agglomeration of amino acid molecules due to intermolecular interactions during solution deposition, and guide the molecules to form an orderly arrangement through electrostatic effects, so that the bridging molecular layer is more evenly covered between the electron transport layer and the perovskite absorption layer, thereby reducing interface defect states and discontinuous areas. The directional arrangement of amino acid molecular layers can also optimize the interface energy level matching between the electron transport layer and the perovskite absorption layer, reduce the interface potential difference, improve the carrier transport efficiency, and inhibit non-radiative recombination at the interface. By reducing the interface trap state density and optimizing the molecular layer arrangement, the electric field-assisted bridging interface significantly improves the device's fill factor (FF), open circuit voltage (Voc), and photoelectric conversion efficiency (PCE). The present invention enhances the bridging effect of amino acid molecules at the interface through an external electric field, providing an innovative solution for achieving efficient and stable perovskite solar cells.

[0017] Beneficial effects of the present invention: (1) The present invention bridges the electron transport layer and the perovskite absorption layer by amino acid molecules, significantly reducing the interface defect state density, optimizing the interface energy level matching, improving the interface stability and carrier transport efficiency, and enhancing the stability and photoelectric conversion efficiency of perovskite solar cells.

[0018] (2) The present invention guides the directional arrangement of amino acid molecules through an external electric field to form a uniform and orderly bridging molecular layer, further strengthening the interface bonding strength, reducing non-radiative recombination, and improving the long-term stability and environmental adaptability of the device.

[0019] In view of the above beneficial effects, the present invention has good application prospects in the field of perovskite solar cell technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a perovskite solar cell with an amino acid-bridged interface.

[0021] In the figure: 1. Substrate; 2. Electron transport layer; 3. Perovskite absorption layer; 4. Hole transport layer; 5. Electrode; 6. Amino acid molecule. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of this application more clear, the application is further described in detail below with reference to the accompanying drawings and examples.

[0023] Example 1 The present invention provides a perovskite solar cell with an amino acid bridged interface, such as Figure 1As shown, it includes a substrate 1, an electron transport layer 2, a perovskite absorption layer 3, a hole transport layer 4, an electrode 5 and an amino acid molecule 6. Each part is described in detail below.

[0024] (1) Substrate 1: The substrate is glass coated with a conductive oxide, preferably FTO glass, with a thickness of approximately 2 mm. Substrate 1 provides mechanical support and serves as a transparent conductive electrode for collecting electrons and conducting them to the external circuit.

[0025] (2) Electron transport layer 2: Electron transport layer 2 is placed on substrate 1. Electron transport layer 2 is made of tin dioxide, which is prepared by solution spin coating and annealed at 150°C to form a dense tin dioxide layer. The thickness of the tin dioxide layer is about 30 nanometers. Electron transport layer 2 transports electrons generated by perovskite absorption layer 3 while blocking holes, reducing carrier recombination losses.

[0026] (3) Amino acid molecule 6: Amino acid molecule 6 is placed on the electron transport layer 2. Amino acid molecule 6 is proline, which is bound to the surface of tin dioxide through its carboxyl group, and its amino group is bound to the surface of the perovskite absorption layer 3. The thickness of the amino acid molecule bridge layer is 0.5 to 2 nanometers, which improves the interface bonding quality, reduces interface defect states, optimizes the interface energy level matching, and improves the electron injection efficiency and device stability.

[0027] (4) Perovskite absorption layer 3: The perovskite absorption layer 3 is placed on the amino acid molecule 6. The perovskite absorption layer 3 is an organic-inorganic hybrid perovskite, and FAPbI3 is selected. The thickness of the perovskite absorption layer 3 is 400 to 500 nanometers. FAPbI3 has excellent light absorption ability and can efficiently absorb visible light and generate photogenerated carriers.

[0028] (5) Hole transport layer 4: Hole transport layer 4 is placed on perovskite absorber layer 3. Hole transport layer 4 is made of Spiro-OMeTAD with a thickness of 100 to 150 nanometers. Hole transport layer 4 transports holes generated by perovskite absorber layer 3 while blocking electrons, reducing carrier recombination losses.

[0029] (6) Electrode 5: Electrode 5 is placed on the hole transport layer 4. Electrode 5 is made of gold and has a thickness of 80 to 100 nanometers. It serves as a back electrode to collect holes and conduct them to the external circuit.

[0030] Through the design of the above materials and structures, the perovskite solar cell of the present invention uses amino acid molecules 6 as a bridging interface, successfully reducing the interface defect state density between the electron transport layer 2 and the perovskite absorption layer 3, and improving the carrier transmission efficiency.

[0031] In addition, a combination of proline and glutamic acid is used as an amino acid bridge layer to improve the performance of perovskite solar cells. The ratio of the two ranges from 1:1 to 3:1. Proline contains amino and carboxyl groups, which can form coordination with metal ions on the surface of tin dioxide, optimizing the interface between the electron transport layer 2 and the perovskite absorber layer 3. In addition to amino and carboxyl groups, glutamic acid also contains an additional amino side chain. Its polarity and coordination ability enable it to better bind to the Pb in the perovskite absorber layer 3. 2+ ions or halogen ions, thereby enhancing interface stability. The combination of the two can simultaneously act on the interface between the electron transport layer 2 and the perovskite absorption layer 3, providing multiple coordination binding points, enhancing interface bonding, reducing interface defect states, optimizing energy level matching, and thus improving the transmission efficiency of electrons and holes.

[0032] Example 2 The present invention provides a method for preparing a perovskite solar cell with an amino acid bridged interface, comprising the following steps: Step 1: Prepare an electron transport layer 2 on a substrate 1. Specifically, a tin dioxide solution is coated on a FTO glass substrate 1 using a solution spin coating method with a layer thickness of about 30 nanometers. Then, an annealing treatment is performed at 150°C. Preferably, a plasma treatment is applied to the tin dioxide layer to increase the hydrophilicity of the electron transport layer 2 and enhance the adsorption capacity of the amino acid molecules 6 under the action of an electric field. Preferably, the surface roughness of the tin dioxide layer is increased by modulating the annealing temperature, thereby increasing the contact area between the amino acid molecules 6 and the electron transport layer 2 and enhancing the effect of the electric field.

[0033] Step 2: Prepare a modification solution containing amino acid molecules 6 and apply the modification solution to the surface of the electron transport layer 2. Specifically, dissolve proline in water to prepare the modification solution containing amino acid molecules 6 at a concentration between 0.1 and 1.0 mg / mL. Use a spin coating method to evenly apply the modification solution containing amino acid molecules 6 to the surface of the electron transport layer 2. After application, the sample is dried at room temperature to ensure stable adsorption of the amino acid molecules. Preferably, during the coating process, an electric field is applied perpendicular to the electron transport layer 2, with an electric field strength ranging from 0.1 to 10 kV / cm. The electric field is applied via two parallel electrodes, with the negative electrode in contact with the electron transport layer 2 and the positive electrode positioned above the modification solution. The electric field causes the carboxyl groups of the amino acid molecules to adsorb toward the electron transport layer 2 (negative electrode) and the amino groups to adsorb toward the perovskite absorption layer 3 (positive electrode), thereby promoting oriented alignment of the amino acid molecules 6 under the action of the electric field. The duration of the electric field is controlled to ensure sufficient time for the amino acid molecules 6 to adsorb and align under the action of the electric field. Preferably, a negative pressure device is used to apply external pressure to the substrate 1 during the spin coating process to help the modification liquid to be more evenly distributed and accelerate the deposition process of the amino acid molecules 6 on the surface of the substrate 1.

[0034] To further enhance the bridging effect of amino acid molecules between the electron transport layer 2 and the perovskite absorption layer 3, the electron transport layer 2 is preferably pretreated before applying the amino acid modification solution. This enhances the chemical activity and physical affinity of the electron transport layer 2 surface, thereby promoting the directional adsorption and stable binding of the amino acid molecules 6, and improving the quality and efficiency of the interface modification. Plasma treatment or UV-ozone treatment is used to activate the surface of the electron transport layer 2. Plasma treatment (such as oxygen plasma) removes residual organic contaminants on the surface and simultaneously introduces a large number of active functional groups, such as hydroxyl groups (–OH), onto the metal oxide surface. These hydroxyl groups have good coordination and hydrogen bonding with the carboxyl groups in the amino acid molecules 6, thereby enabling the amino acid molecules 6 to bond to the electron transport layer 2. UV-ozone treatment can also increase the surface oxygen content and hydrophilicity, improving interfacial binding capacity. It is simple, gentle, and suitable for large-area applications. Furthermore, a moderate surface roughness of the electron transport layer 2 also helps enhance the physical adsorption capacity and deposition uniformity of the amino acid molecules 6. Therefore, after metal oxide deposition, it is preferred to moderately enhance its surface microstructure by controlling the annealing temperature, thereby providing more abundant binding sites for amino acid bridging. These pretreatment methods not only enhance the chemical bonding between the carboxyl groups of amino acid molecules 6 and the electron transport layer 2, but also provide a good surface foundation for the subsequent directional adsorption and alignment of amino acid molecules 6 under the assistance of an electric field. These pretreatment strategies enhance the stability and uniformity of the amino acid bridging layer, further reduce the interface defect density between the electron transport layer 2 and the perovskite absorption layer 3, optimize the interface energy level matching, and improve carrier injection efficiency and device stability.

[0035] Step 3: Prepare a perovskite absorber layer 3 on the amino acid molecules 6. Specifically, a FAPbI3 precursor (such as PbI2 and FAI) is dissolved in an appropriate solvent (such as DMSO or GBL) to prepare a perovskite precursor solution. The perovskite precursor solution is applied to the amino acid bridging layer using a spin coating method. The perovskite absorber layer 3 after coating has a thickness of approximately 400 to 500 nanometers. The sample coated with the perovskite absorber layer 3 is annealed, typically at a temperature of 100-150°C, to ensure the crystallinity of the perovskite absorber layer 3. Preferably, an electric field is maintained during the coating of the perovskite absorber layer 3, as the electric field promotes the orderly arrangement of the perovskite molecules on the amino acid bridging layer and reduces interface defects.

[0036] Step 4: Prepare a hole transport layer 4 on the perovskite absorber layer 3. Specifically, a Spiro-OMeTAD solution is applied to the surface of the perovskite absorber layer 3 using a spin coating method. The hole transport layer 4 is generally 100 to 150 nanometers thick. It is then annealed at a relatively low temperature to improve its conductivity and stability.

[0037] Step 5: Prepare an electrode 5 on the hole transport layer 4. Specifically, gold is selected as the material of the electrode 5, and the gold electrode 5 is coated on the surface of the hole transport layer 4 by evaporation or sputtering technology. The thickness of the electrode 5 is 80 to 100 nanometers.

[0038] The device for applying an electric field of the present invention includes two parallel electrodes, a spin coating system, a movable bracket and an electric field adjustment module. The electrode material is a conductive metal or a transparent conductive material, the negative electrode is in contact with the electron transport layer 2, the positive electrode is located above the modification liquid, and the electrode spacing is adjustable to precisely control the electric field strength. The electric field strength (0.1 to 10 kV / cm) is adjusted by a voltage source to ensure that the electric field is applied vertically to the surface of the substrate 1, and the electric field action time is adjusted at the same time. The spin coating system is used to evenly coat the amino acid solution and directional arrange the amino acid molecules 6 under the action of the electric field. The movable bracket can adjust the distance between the electrode and the substrate 1 to optimize the electric field distribution. The device can effectively improve the directional adsorption of the amino acid molecules 6 in the electric field and optimize the interface quality.

[0039] Preferably, in step 2, the electric field is first strong and then weak. Applying a strong electric field initially helps quickly orient the amino acid molecules 6 and guide them to the ideal position between the electron transport layer 2 and the perovskite absorber layer 3. The strong electric field provides sufficient driving force, enabling rapid adsorption and orderly arrangement of the molecules according to their polarity (carboxyl groups facing the electron transport layer 2 and amino groups facing the perovskite absorber layer 3), thus preventing intermolecular aggregation and irregular deposition. This rapid orientation process significantly improves the binding efficiency of the amino acid molecules 6 to the interface, thereby reducing the density of interface defect states, optimizing interface energy level matching, and improving carrier transport efficiency. As the electric field gradually weakens, the amino acid molecules 6 are stably adsorbed on the surface under the guidance of the electric field, reducing the risk of molecular desorption or over-adsorption caused by excessively strong electric fields. The weaker electric field helps maintain molecular stability, allowing the amino acid molecules 6 to further consolidate their arrangement without interference from the strong electric field, ultimately ensuring the uniformity and stability of the bridging layer. Weakening the electric field also prevents the negative effects of long-term strong electric fields on the amino acid molecules and the interface, further improving the long-term stability of the device.

[0040] Preferably, when amino acid molecules are arranged on the electron transport layer 2, an alternating electric field is applied first, and then a steady electric field is applied. In the early stage of the alternating electric field, the electric field strength changes periodically to promote the uniform distribution of amino acid molecules 6 on the surface, avoid excessive adsorption or agglomeration, and help to break the electrostatic bond between molecules, making them more active and dispersed. Subsequently, applying a steady electric field can accurately orient the arrangement of amino acid molecules 6, ensure that the molecules are adsorbed between the electron transport layer 2 and the perovskite absorption layer 3 in an orderly manner according to their polarity, optimize the interface quality and reduce defects. Through this first alternating and then steady electric field effect, not only the uniformity of the molecular arrangement is improved, but also the stability of the interface and the carrier transfer efficiency are enhanced, thereby improving the overall performance and stability of the device.

[0041] In the present invention, the spin coating system is equipped with an airflow assist device to optimize the coating quality of the modification liquid and the uniform distribution of the amino acid molecules 6 on the electron transport layer 2. The airflow assist device includes an adjustable airflow nozzle located on the side of the spin-coated electron transport layer 2. The airflow nozzle is connected to the air source through a pipe to adjust the intensity, direction and stability of the airflow as needed. The airflow ejected from the airflow nozzle acts on the surface of the modification liquid through the controller direction and flow rate, promoting the uniform expansion of the modification liquid and avoiding local uneven flow on the liquid surface. In addition, the airflow can also help the solvent of the modification liquid to evaporate during the spin coating process, preventing excessive accumulation in a certain area, so that the modification liquid is evenly coated on the surface of the electron transport layer 2 and forms a stable bridging layer. The guiding effect of the airflow improves the uniform adsorption of the amino acid molecules 6 under the action of the electric field, optimizes the interface quality, and improves the stability, uniformity and device performance of the final coating.

[0042] In addition, during the spin coating process, the rotation speed can also be further optimized: first low speed and then high speed. In this way, at the initial low speed, the modification liquid is more evenly distributed on the surface of the electron transport layer 2, and the effect of the electric field is more uniform, so that the amino acid molecules 6 are better oriented under the action of the electric field; when the rotation speed increases, the liquid is already evenly distributed, and the effect of the electric field can better guide the directional arrangement of the molecules and enhance the interface quality. In addition, such a design also improves the interface quality: the low speed stage allows the modification liquid to spread steadily and slowly on the surface of the electron transport layer 2 to form a more uniform initial layer. By reducing the rapid flow of the liquid during the coating process, cracks or unevenness at the interface are avoided; the high speed can effectively remove excess solvent, promote rapid drying of the coating, and ensure that the final coating is uniform and dense, thereby improving the bonding force and interface stability between the amino acid molecules 6 and the electron transport layer 2.

[0043] In summary, the present invention proposes a perovskite solar cell with an amino acid-bridged interface and a method for preparing the same. By introducing a bridging layer of amino acid molecules 6 between the electron transport layer 2 and the perovskite absorption layer 3, the interface quality is significantly optimized and the carrier transport efficiency is improved. An electric field strategy is employed to optimize interface energy level matching and reduce interface defect states. This method not only improves the photoelectric conversion efficiency of the perovskite solar cell but also enhances the device's stability, solving the problems of interface defects and carrier recombination in traditional perovskite solar cells and promoting the development of perovskite solar cell interface engineering. The electric field control technology and interface optimization methods can also be extended to the research and development of other optoelectronic devices, providing new ideas for the design of efficient and stable optoelectronic materials.

[0044] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. 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 perovskite solar cell with an amino acid bridged interface, comprising a substrate, an electron transport layer, a perovskite absorption layer, a hole transport layer and an electrode, characterized in that: It also includes amino acid molecules, which are arranged between the electron transport layer and the perovskite absorption layer, and the amino acid molecules are bonded to the electron transport layer and the perovskite absorption layer at the same time.

2. The perovskite solar cell with an amino acid bridged interface according to claim 1, wherein: The amino acid molecule includes a carboxyl group and an amino group, the carboxyl group is bonded to the surface of the electron transport layer, and the amino group is bonded to the surface of the perovskite absorption layer.

3. The perovskite solar cell with an amino acid bridged interface according to claim 1, wherein: The amino acid molecules are one or more of proline, glycine, glutamic acid, serine and lysine.

4. The perovskite solar cell with an amino acid bridged interface according to claim 1, wherein: The electron transport layer is a metal oxide.

5. The perovskite solar cell with an amino acid bridged interface according to claim 4, wherein: The electron transport layer is tin dioxide, titanium dioxide or zinc oxide.

6. The perovskite solar cell with an amino acid bridged interface according to claim 1, wherein: The perovskite absorption layer is an organic-inorganic hybrid perovskite with a general formula of ABX3, wherein: A is a methylamine ion, a formamidine ion or a cesium ion; B is a lead ion or a tin ion; and X is an iodide ion, a bromide ion or a chloride ion.

7. A method for preparing a perovskite solar cell with an amino acid bridged interface, characterized in that: The steps include: Step 1: preparing an electron transport layer on a substrate; Step 2: preparing a modification solution containing amino acid molecules and coating the modification solution on the surface of the electron transport layer; Step 3: preparing a perovskite absorption layer on the amino acid molecules; Step 4: preparing a hole transport layer on the perovskite absorption layer; Step 5: Prepare an electrode on the hole transport layer.

8. The method for preparing a perovskite solar cell having an amino acid bridged interface according to claim 7, wherein: In step 2, the deposition of amino acid molecules is carried out with the assistance of an external electric field.

9. The method for preparing a perovskite solar cell having an amino acid bridged interface according to claim 8, wherein: The electric field direction is perpendicular to the electron transport layer.

10. The method for preparing a perovskite solar cell having an amino acid bridged interface according to claim 9, wherein: The electric field is applied through two parallel electrodes, the negative electrode is in contact with the electron transport layer, and the positive electrode is located above the modification solution.

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