Electron transport layer for perovskite solar cell, perovskite solar cell and preparation method thereof

Abstract

The application provides an electron transport layer for a perovskite solar cell, a perovskite solar cell and a preparation method thereof. The electron transport layer for the perovskite solar cell comprises an oxide layer and a zinc tin oxide layer. The oxide layer is a metal oxide layer, and the zinc tin oxide layer is deposited on one side surface of the oxide layer. The electron transport layer is formed by combining the oxide layer and the zinc tin oxide layer. The metal oxide layer can promote interface electron extraction, and the zinc tin oxide layer can guarantee high-speed electron transmission. The electron transport layer can jointly inhibit charge recombination, provide a more stable interface environment for a perovskite layer, ensure the stability of the perovskite solar cell, and improve photoelectric conversion efficiency.

Description

Technical Field

[0001] This application belongs to the field of battery technology. Specifically, this application relates to an electron transport layer for perovskite solar cells, a perovskite solar cell, and a method for fabricating the same. Background Technology

[0002] In the field of perovskite solar cells, the electron transport layer is a key component. It enables electrons generated by the perovskite layer after being excited by light to be successfully injected into the conduction band of the electron transport layer, while holes cannot enter the electron transport layer due to energy level barriers. This achieves effective separation of electrons and holes and improves the photoelectric conversion efficiency of the cell.

[0003] In related technologies, the electron transport layer is prone to uneven deposition thickness during molding, making it difficult to ensure the uniformity of the electron transport layer thickness. This, in turn, affects the charge transport efficiency and limits the photoelectric conversion efficiency and stability of perovskite solar cells. Summary of the Invention

[0004] One objective of this application is to provide a new technical solution for an electron transport layer for perovskite solar cells, a perovskite solar cell, and a method for fabricating the same.

[0005] According to a first aspect of the embodiments of this application, an electron transport layer for a perovskite solar cell is provided, comprising: An oxide layer, wherein the oxide layer is a metal oxide layer; A zinc tin oxide layer is deposited on one side surface of the oxide layer, such that the zinc tin oxide layer and the oxide layer are stacked.

[0006] Optionally, the oxide layer is formed using an atomic layer deposition process; The oxide layer is a transition metal oxide layer, and the thickness of the oxide layer is 5nm-20nm.

[0007] Optionally, the oxide layer includes at least one of tungsten oxide, titanium oxide, and zinc oxide.

[0008] Optionally, the zinc tin oxide layer is formed on one side surface of the oxide layer using an atomic layer deposition process; The thickness of the zinc oxide tin layer is 5nm-30nm.

[0009] Optionally, the zinc oxide tin layer comprises alternating layers of zinc oxide deposited films and layers of tin oxide deposited films.

[0010] According to a second aspect of the embodiments of this application, a perovskite solar cell is provided, comprising: Base; The substrate, the hole transport layer, the perovskite layer, and the electron transport layer described in the first aspect are stacked together.

[0011] Optionally, the hole transport layer is disposed on one side surface of the substrate, the perovskite layer is disposed on the side of the hole transport layer away from the substrate, and the electron transport layer is disposed on the side of the perovskite layer away from the hole transport layer.

[0012] Optionally, the perovskite solar cell further includes: An electrode layer is disposed on the side of the electron transport layer away from the perovskite layer, and the thickness of the electrode layer is 10nm-100nm.

[0013] Optionally, the oxide layer is formed on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process; The zinc oxide tin layer is formed on the side of the oxide layer away from the perovskite layer using an atomic layer deposition process.

[0014] Optionally, the hole transport layer is formed on one side surface of the substrate by magnetron sputtering. The thickness of the hole transport layer is 10nm-30nm.

[0015] Optionally, the perovskite layer is coated onto the side of the hole transport layer away from the substrate; The thickness of the perovskite layer is 450nm-600nm.

[0016] Optionally, the perovskite solar cell further includes: A passivation layer is formed between the perovskite layer and the electron transport layer using an atomic layer deposition process; The thickness of the passivation layer is 0.1 nm - 2 nm.

[0017] Optionally, the passivation layer includes at least one of alumina deposited film, magnesium fluoride deposited film, lithium fluoride deposited film, silicon oxide deposited film, silicon carbide deposited film, molybdenum oxide deposited film, and molybdenum nitride deposited film.

[0018] Optionally, the perovskite solar cell further includes: A barrier layer is formed between the electron transport layer and the electrode layer using an atomic layer deposition process. The barrier layer includes at least one of indium tin oxide, indium zinc oxide, and aluminum zinc oxide. The thickness of the barrier layer is 10nm-100nm.

[0019] According to a third aspect of the embodiments of this application, a method for fabricating a perovskite solar cell is provided, comprising: A hole transport layer and a perovskite layer are disposed on the substrate; An electron transport layer is deposited on the perovskite layer; An electrode layer is deposited on the electron transport layer; The electron transport layer comprises an oxide layer and a zinc tin oxide layer stacked together.

[0020] Optionally, depositing an electron transport layer on the perovskite layer includes: An electron transport layer is deposited on the perovskite layer using an atomic layer deposition process, and the thickness of the electron transport layer is 10 nm - 50 nm.

[0021] Optionally, depositing an electrode layer on the electron transport layer includes: An electrode layer is deposited on the electron transport layer using an atomic layer deposition process, and the thickness of the electrode layer is 10 nm-100 nm.

[0022] Optionally, depositing an electron transport layer on the perovskite layer using an atomic layer deposition process includes: An oxide layer is deposited on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process. A zinc tin oxide layer is formed on the side of the oxide layer away from the perovskite layer using an atomic layer deposition process; The thickness of the oxide layer is 5nm-20nm, and the thickness of the zinc tin oxide layer is 5nm-30nm.

[0023] Optionally, the hole transport layer and the perovskite layer are disposed on the substrate, including: A hole transport layer is deposited on one side surface of the substrate using a magnetron sputtering process; A perovskite layer is coated on the side of the hole transport layer away from the substrate; The hole transport layer has a thickness of 10nm-30nm, and the perovskite layer has a thickness of 450nm-600nm.

[0024] Optionally, the preparation method includes: A passivation layer is formed on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process. An electron transport layer is deposited on the side of the passivation layer away from the perovskite layer using an atomic layer deposition process; The passivation layer includes at least one of aluminum oxide deposited film, magnesium fluoride deposited film, lithium fluoride deposited film, silicon oxide deposited film, silicon carbon oxide deposited film, molybdenum oxide deposited film, and molybdenum nitride deposited film, and the thickness of the passivation layer is 0.1 nm - 2 nm.

[0025] Optionally, the preparation method includes: A barrier layer is deposited on the side of the electron transport layer away from the perovskite layer using atomic layer deposition (ALD) technology. An electrode layer is deposited on the side of the barrier layer away from the electron transport layer using an atomic layer deposition process; The barrier layer comprises at least one of indium tin oxide deposited film, indium zinc oxide deposited film, and zinc aluminum oxide, and the thickness of the barrier layer is 10nm-100nm.

[0026] One technical advantage of this application is: This application provides an electron transport layer for perovskite solar cells. The electron transport layer includes an oxide layer and a zinc tin oxide layer. The oxide layer is a metal oxide layer, and the zinc tin oxide layer is deposited on one side surface of the oxide layer. This application forms a composite electron transport layer by stacking the oxide layer and the zinc tin oxide layer. The metal oxide layer promotes interfacial electron extraction, while the zinc tin oxide layer ensures high-speed electron transport. Together, they suppress charge recombination, providing a more stable interfacial environment for the perovskite layer. This ensures the stability of the perovskite solar cell while improving the photoelectric conversion efficiency.

[0027] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0029] Figure 1 A schematic diagram of the structure of a perovskite solar cell provided in one embodiment of this application; Figure 2 This is a schematic diagram of another perovskite solar cell provided in one embodiment of this application; Figure 3 This is a comparison graph showing the normalized efficiency of a packaged device for an electronic transport layer application according to one embodiment of this application and a packaged device for an electronic transport layer application in a comparative example.

[0030] The structure includes: 1. Substrate; 2. Hole transport layer; 3. Perovskite layer; 4. Electron transport layer; 41. Oxide layer; 42. Zinc tin oxide layer; 5. Electrode layer; 6. Passivation layer; 7. Barrier layer. Detailed Implementation

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0032] The embodiments of this application will now be described in detail, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0034] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0037] Reference Figure 1 and Figure 2 This application provides an electron transport layer 4 for perovskite solar cells, the electron transport layer 4 comprising: Oxide layer 41, which is a metal oxide layer; Zinc oxide tin layer 42 is deposited on one side surface of oxide layer 41.

[0038] In the above embodiments, the electron transport layer 4 is responsible for smoothly injecting electrons generated after the perovskite layer is excited by light into its conduction band in the perovskite solar cell, while blocking the entry of holes, thus achieving effective separation of electrons and holes and helping to improve the photoelectric conversion efficiency of the perovskite solar cell.

[0039] In the electron transport layer 4, the oxide layer 41 is a metal oxide layer. Metal oxide layers have good electron transport performance and chemical stability, enabling efficient electron transport, reducing recombination losses during electron transport, and improving the photoelectric conversion efficiency of the battery. The zinc tin oxide layer 42 is stacked with the oxide layer 41 to form a composite electron transport layer. The zinc tin oxide layer 42 has high electron mobility and a suitable energy level structure, which can optimize the electron transport performance of the electron transport layer and improve the electron transport speed and efficiency.

[0040] In this embodiment, a combination of metal oxide and zinc tin oxide (ZTO) is used as an inorganic electron transport layer 4 (ETL), which enables energy level alignment and allows for a smooth, stepwise flow of electrons from the perovskite layer to the electrode layer, reducing energy loss while improving the stability of the electron transport layer 4 interface.

[0041] Specifically, the metal oxide layer provided in this application embodiment can promote interface electron extraction, and zinc tin oxide ensures high-speed electron transport. Together, they can suppress charge recombination, provide a more stable interface environment for the perovskite layer, and improve the lifespan of the perovskite solar cell.

[0042] It is worth noting that in the process of preparing electron transport layer 4, an oxide layer 41 of metal oxide material is prepared first, and then a zinc oxide tin layer 42 of zinc oxide material is prepared on the oxide layer 41. The electron transport layer 4 is formed by matching the different energy levels of the oxide layer 41 and the zinc oxide tin layer 42, which ensures the energy level of electron transport layer 4 in perovskite solar cells and is beneficial to charge separation and transport between the conduction band and valence band energy levels of the perovskite active layer, electron transport layer and hole transport layer.

[0043] In some embodiments, the oxide layer 41 is formed using an atomic layer deposition process; The oxide layer 41 is a transition metal oxide layer, and the thickness of the oxide layer 41 is 5nm-20nm.

[0044] In the above embodiments, atomic layer deposition (ALD) has atomic-level precise control capabilities, which can ensure the uniformity of the thickness of the oxide layer 41, ensure the performance consistency of each region of the electron transport layer, and avoid problems such as poor charge transport and increased local recombination caused by uneven thickness, thereby improving the photoelectric conversion efficiency and stability of perovskite solar cells.

[0045] In the above embodiments, the oxide layer 41 is a transition metal oxide layer. The transition metal oxide has a suitable band structure, which is beneficial for receiving electrons generated by the perovskite layer under photoexcitation and can efficiently transport electrons to subsequent electrodes or other transport layers, reducing recombination losses of electrons during transport and improving the photoelectric conversion efficiency of the battery.

[0046] Meanwhile, the thickness of oxide layer 41 is 5nm-20nm, such as 8nm, 12nm or 15nm. This allows oxide layer 41 to have sufficient thickness to efficiently transport electrons and reduce electron loss during transport, while avoiding charge accumulation at the interface due to excessive thickness, which would increase the probability of electron-hole recombination. This achieves a balance between electron transport efficiency and interface recombination, thereby improving the photoelectric conversion efficiency of the battery.

[0047] If the oxide layer 41 is too thin (e.g., the oxide layer 41 is 2nm or 3nm thick), it cannot form a continuous conductive channel, which will hinder electron transport. If the oxide layer 41 is too thick (e.g., the oxide layer 41 is 30nm or 50nm thick), it will increase the electron transport path, causing more scattering and recombination of electrons during transport, thus reducing the transport efficiency.

[0048] In some embodiments, the oxide layer 41 includes at least one of tungsten oxide, titanium oxide, and zinc oxide.

[0049] In the above embodiments, when the oxide layer 41 includes tungsten oxide (WO3), the tungsten oxide has an adjustable band structure. By changing the crystal structure of the tungsten oxide or doping it with other elements, the positions of its conduction band and valence band can be controlled, so that the tungsten oxide can achieve good energy level matching with the perovskite layer. This is beneficial for the efficient injection of electrons from the perovskite layer into the tungsten oxide layer, reducing the recombination loss of electrons at the interface, and improving the open-circuit voltage and photoelectric conversion efficiency of the battery.

[0050] When the oxide layer 41 includes titanium oxide (TiO2), titanium oxide has a high electron mobility, enabling it to transport electrons quickly and efficiently. In perovskite solar cells, titanium oxide can rapidly transport electrons generated in the perovskite layer to the electrodes, reducing electron recombination during transport and improving the cell's short-circuit current and fill factor.

[0051] When the oxide layer 41 includes zinc oxide (ZnO), zinc oxide has a high electron mobility, which enables faster electron transport, reduces electron accumulation and recombination during transport, and improves the photoelectric conversion efficiency of the battery. Moreover, zinc oxide has high transmittance in the visible light region and does not significantly absorb or scatter incident light, which is beneficial for more light to reach the perovskite layer for absorption and utilization, thus improving the light absorption efficiency of the battery.

[0052] In some embodiments, the zinc tin oxide layer 42 is formed on one side surface of the oxide layer 41 using an atomic layer deposition process; The thickness of the zinc tin oxide layer 42 is 5nm-30nm.

[0053] In the above embodiments, by controlling the reaction conditions and deposition parameters of the atomic layer deposition process, the nucleation and growth process of the zinc tin oxide layer 42 can be precisely controlled, which is beneficial to forming a zinc tin oxide layer 42 with good crystal orientation and low defect density, reducing the obstruction of grain boundaries to electron transport, and improving electron transport efficiency and battery performance.

[0054] The zinc tin oxide layer 42, with a thickness of 10nm-30nm, provides a suitable electron transport channel for the electron transport layer 4. For example, the thickness of the zinc tin oxide layer 42 can be 12nm, 15nm, 18nm, 22nm, or 25nm. The zinc tin oxide layer 42 can form a continuous and stable conductive structure, allowing electrons to pass through quickly and smoothly. Moreover, the zinc tin oxide layer 42 has good optical transmittance, which can ensure electron transport performance and improve photoelectric conversion efficiency.

[0055] In some embodiments, the thickness of the electron transport layer 4 is 10nm-50nm. The thin electron transport layer 4 can not affect light transmission and electron tunneling, thereby improving the photoelectric conversion efficiency while ensuring the stability of the perovskite solar cell.

[0056] Furthermore, the embodiments of this application prepare a uniform electron transport layer 4 through atomic layer deposition, which can effectively extract photogenerated electrons from the perovskite layer, help reduce defect states on the surface of the electron transport layer 4, suppress nonradiative recombination, improve the uniformity of the electron transport layer preparation, ensure the stability of the perovskite solar cell, and improve the photoelectric conversion efficiency.

[0057] In some embodiments, the zinc oxide tin layer 42 comprises alternating layers of zinc oxide deposited films and layers of tin oxide deposited films.

[0058] In the above embodiments, by alternating multiple layers of zinc oxide and tin oxide deposited films, a gradient band structure can be formed to more effectively guide electron transport, reduce the potential barrier during electron transport, and decrease the probability of electron recombination, thereby improving electron transport and collection efficiency and enhancing the photoelectric conversion performance of the battery. Simultaneously, the atomic layer deposition process, through precise control of deposition parameters, ensures uniform thickness of each zinc oxide and tin oxide deposited film and allows for accurate adjustment of the zinc oxide to tin oxide ratio, thus achieving precise control over the performance of the zinc oxide-tin layer 42 and improving electron transport efficiency and stability. This application illustrates the electron transport layer for perovskite solar cells through specific embodiments and comparative examples.

[0059] Example 1 S1. The substrate is placed in an atomic layer deposition apparatus. Tungsten hexafluoride (WF6) and deionized water (H2O) are used as precursors for metallic tungsten and oxygen ions, respectively. High-purity N2 (99.999% purity) is used as the carrier gas and purging gas. To ensure the vacuum level of the reaction chamber, the pressure is maintained between 0.2 and 10 mbar, and the apparatus temperature is controlled between 30 and 200°C. First, tungsten hexafluoride containing the tungsten precursor is introduced, followed by the introduction of inert nitrogen gas to purge the residual precursor. Then, deionized water is introduced as the oxygen source, followed by purging with inert gas. This completes one sub-cycle of tungsten oxide deposition. Ten sub-cycles of deposition are performed to obtain a 20 nm thick tungsten oxide film as the oxide layer.

[0060] S2. The substrate is placed in an atomic layer deposition apparatus, and the temperature of the apparatus is controlled between 80-200℃ and the pressure is maintained between 0.2-10 mbar. First, a zinc-containing precursor, diethylzinc (DEZ), is introduced into the reaction chamber. Then, inert nitrogen gas is introduced to purge the residual precursor. Next, oxygen source deionized water is introduced, followed by inert gas purging. This completes one sub-cycle of zinc oxide deposition. 19 sub-cycles of deposition are performed to obtain a zinc oxide film.

[0061] S3, the temperature of the control device is between 80-200℃ and the pressure is between 0.2-10 mbar. First, a tin-containing precursor tetra(dimethylamino)tin (TDMASn) is introduced, then an inert gas nitrogen is introduced to purge the residual precursor, then an oxygen source deionized water is introduced, and finally an inert gas is introduced to purge. On the substrate where zinc oxide has been deposited, one sub-cycle of tin oxide deposition is completed to obtain a tin oxide film.

[0062] S4. Repeat steps S2 to S3 to obtain a zinc tin oxide layer with a thickness of 10 nm.

[0063] Example 2 The only difference from Example 1 is: The thickness of the tungsten oxide film as the oxide layer is 20 nm, and the thickness of the zinc tin oxide layer is 5 nm.

[0064] Example 3 The only difference from Example 1 is: The thickness of the tungsten oxide film as the oxide layer is 10 nm, and the thickness of the zinc tin oxide layer is 10 nm.

[0065] Example 4 Titanium oxide film is used as the oxide layer. The precursor is titanium tetrachloride (TiCl4), the oxygen source is deionized water, and the thickness of the titanium oxide film is 20 nm.

[0066] Example 5 Zinc oxide film was used as the oxide layer. Diethyl zinc (DEZ) was used as the precursor, and deionized water was used as the oxygen source. First, 20 nm zinc oxide was grown by atomic layer deposition, and then zinc tin oxide film was prepared using the same method as in Example 1.

[0067] Comparative Example 1 (Preparation of Electron Transport Layer via Solution Method) S31, 20 mg of PCBM powder was dissolved in 1 ml of chlorobenzene, and 0.5 mg of BCP powder was dissolved in 1 ml of isopropanol to obtain a 20 mg / ml PCBM solution and a 0.5 mg / ml BCP solution. The PCBM layer and the BCP layer were sequentially deposited by spin coating. The spin coating processes for the PCBM layer and the BCP layer were 2000 r / 30 s and 4000 r / 30 s, respectively, resulting in an electron transport layer with a thickness of 35 nm.

[0068] Comparative Example 2 (Preparation of Electron Transport Layer by Evaporation) S41, in a vacuum degree less than 1*10 -4 Under these conditions, 20 nm C60 was deposited as an electron transport layer at a rate of 0.1~0.3 Å / s, with a thickness of 35 nm.

[0069] In addition, after completing the C60 evaporation, while maintaining the vacuum, 6 nm of BCP was deposited as a hole blocking layer at a rate of 0.1 Å / s.

[0070] The electron transport layers obtained in Examples 1-5 and Comparative Examples 1-2 were used to prepare inverted perovskite solar cells using the same process, and the parameters of the inverted perovskite solar cells were characterized.

[0071] Table 1 Comparison of parameters of inverted perovskite solar cells obtained from the above embodiments and comparative examples

[0072] Note: "scan" refers to both forward and reverse scanning. Due to the hysteresis effect in perovskite solar cells, the parameters will differ when scanning from the positive electrode to the negative electrode and vice versa. Jsc represents current density, Voc represents open-circuit voltage, FF represents fill factor, and PCE represents cell conversion efficiency. A comparison of Examples 1-5 with Comparative Examples 1 and 2 shows that while the perovskite solar cells with organic electron transport layers prepared by solution methods and vapor deposition methods in Comparative Examples 1 and 2 have higher current densities than those with inorganic electron transport layers obtained by atomic deposition in this application (due to the properties of organic and inorganic materials), the perovskite solar cells with inorganic electron transport layers obtained by atomic deposition in this application have higher open-circuit voltage, fill factor, and cell conversion efficiency than those in Comparative Examples 1 and 2. Clearly, the uniform electron transport layer prepared by atomic layer deposition in this application results in a good crystal orientation and low defect density, reducing the obstruction of charge transport by grain boundaries, thereby improving charge transport efficiency and cell performance.

[0073] Furthermore, under room temperature and nitrogen conditions, the operational stability of ALD all-inorganic electron transport layer cells, solution-based electron transport layer cells, and vapor-deposited electron transport layer devices was monitored within the packaged device after aging for over 1000 hours. Figure 3 As shown, the stability and anti-aging performance of ALD all-inorganic electron transport layer devices are significantly improved compared to solution-based and vapor-deposited electron transport layer devices, as demonstrated by T... 1000 >98%.

[0074] In related technologies, the formation of electron transport layers mainly relies on vapor deposition and solution methods. While vapor deposition can achieve the deposition of electron transport layers, it is difficult to ensure the uniformity of electron transport layer thickness when preparing large-area electron transport layers, thus affecting charge transport efficiency. Although solution methods have the advantages of lower cost and relatively simple process, they are also prone to causing uneven electron transport layer thickness during the electron transport layer film formation process.

[0075] Atomic layer deposition (ALD) is a method for depositing ultrathin, uniform, and pinhole-free dense layers using surface-controlled vapor precursors. It features low reaction temperatures and no damage to the perovskite layer. Furthermore, ALD is a self-limiting surface reaction process, where only precursors adsorbed on the substrate surface participate in the reaction. Unreacted precursors can be promptly removed from the reaction chamber, preventing the deposition of materials on non-substrate areas and thus improving the utilization rate of material deposition.

[0076] The perovskite solar cell provided in this application uses an atomic layer deposition process to prepare a uniform electron transport layer, which can effectively extract photogenerated electrons from the perovskite layer, help reduce defect states on the surface of the electron transport layer, suppress nonradiative recombination, improve the uniformity of the electron transport layer preparation, ensure the stability of the perovskite solar cell, and improve the photoelectric conversion efficiency.

[0077] Reference Figure 1 and Figure 2 This application provides a perovskite solar cell, which includes: Base 1; Hole transport layer 2, perovskite layer 3 and electron transport layer 4 are stacked on a substrate 1.

[0078] In the above embodiments, the substrate 1 has a light-incident side and a light-emitting side. The substrate 1 can be a conductive glass substrate, and the light-incident side of the substrate 1 can be a surface on the substrate 1 such as... Figure 1 As shown in the lower surface, the light-emitting side of substrate 1 can be such as the surface on substrate 1. Figure 1 The upper surface shown has an incident light side on the substrate 1 that can receive external light, transmit light through the substrate 1 and transmit the light from the emitting light side to the perovskite layer 3, so as to achieve an effective conversion of light energy into electrical energy.

[0079] See Figure 1 In the perovskite solar cells of this application embodiment, the perovskite solar cell can be either an inverted perovskite solar cell or a conventional perovskite solar cell. The hole transport layer 2 can efficiently transport holes. When the perovskite layer 3 is excited by light to generate electron-hole pairs, the hole transport layer 2 can quickly extract the holes from the perovskite layer 3 and effectively transport them to the electrodes, achieving directional movement of holes. This promotes effective separation of electrons and holes, reduces the probability of recombination of electrons and holes within the perovskite layer 3, and improves the photoelectric conversion efficiency of the cell. The perovskite layer 3 can absorb photons from sunlight, causing electrons to transition from the valence band to the conduction band, thereby generating electron-hole pairs and ensuring the cell's solar energy utilization efficiency and photoelectric conversion efficiency.

[0080] In the above embodiments, the electron transport layer 4 corresponds to the hole transport layer 2. After the perovskite layer 3 is excited by light to generate electron-hole pairs, the electron transport layer 4 can quickly extract electrons from the perovskite layer 3 and rapidly transport them to the electrode, while blocking holes from entering. This further promotes the effective separation of electrons and holes, reduces recombination losses during electron transport, improves electron collection efficiency and transport speed, and thus enhances the photoelectric conversion efficiency and performance stability of the battery.

[0081] In some embodiments, see Figure 1Hole transport layer 2 is disposed on one side surface of substrate 1, perovskite layer 3 is disposed on the side of hole transport layer 2 away from substrate 1, and electron transport layer 4 is disposed on the side of perovskite layer 3 away from hole transport layer 2.

[0082] In the above embodiments, the hole transport layer 2 can be disposed on the light-emitting side of the substrate 1, the perovskite layer 3 can be disposed on the side of the hole transport layer 2 away from the substrate 1, and the electron transport layer 4 can be disposed on the side of the perovskite layer 3 away from the hole transport layer 2; see also Figure 1 Hole transport layer 2, perovskite layer 3, and electron transport layer 4 are sequentially disposed on the light-emitting side of substrate 1. After being excited by light, perovskite layer 3 generates electron-hole pairs. Hole transport layer 2 transports the holes generated by light excitation in perovskite layer 3, while electron transport layer 4 transports the electrons. The hole transport layer 2, perovskite layer 3, and electron transport layer 4 work together to achieve effective separation and transport of electrons and holes, ensuring the stability of the current generated by the perovskite solar cell.

[0083] In some embodiments, see Figure 1 Perovskite solar cells also include: Electrode layer 5 is disposed on the side of electron transport layer 4 away from perovskite layer 3, and the thickness of electrode layer 5 is 10nm-100nm.

[0084] In the above embodiment, the electrode layer 5 is disposed on the side of the electron transport layer 4 away from the perovskite layer 3. The electrode layer 5 is a bridge connecting the perovskite solar cell and the external circuit. It can collect electrons transmitted from the electron transport layer 4 and export the electrons to the external circuit, thereby forming a complete current loop and realizing the power output of the perovskite solar cell.

[0085] In one embodiment, the electrode layer 5 is formed on the side of the electron transport layer 4 away from the perovskite layer 3 by an atomic layer deposition process. The electrode layer 5 can be a copper electrode deposition film with a thickness of 10nm-100nm, such as 20nm, 30nm, 50nm or 80nm. This can improve the conductivity of the electrode layer 5, enabling the electrode layer 5 to effectively collect and transport electrons, and also ensure the bonding stability between the electrode layer 5 and the electron transport layer 4.

[0086] In some embodiments, see Figure 2 The oxide layer 41 is formed on the side of the perovskite layer 3 away from the hole transport layer 2 using an atomic layer deposition process. The zinc oxide tin layer 42 is formed on the side of the oxide layer 41 away from the perovskite layer 3 using an atomic layer deposition process.

[0087] In the above embodiments, during the preparation of the electron transport layer 4, an oxide layer 41 of metal oxide material can be prepared first using atomic layer deposition (ALD), and then a zinc oxide tin layer 42 of zinc oxide material can be prepared on the oxide layer 41 using ALD. The electron transport layer 4 is formed by matching the different energy levels of the oxide layer 41 and the zinc oxide tin layer 42, which ensures the energy level of the electron transport layer 4 in the perovskite solar cell and is beneficial to charge separation and transport between the conduction band and valence band energy levels of the perovskite active layer, electron transport layer and hole transport layer.

[0088] Specifically, atomic layer deposition (ALD) ensures the formation of a uniform oxide film of consistent thickness and quality on the surface of the perovskite layer 3. Even when there are microscopic undulations or irregularities on the surface of the perovskite layer 3, ALD can ensure that the oxide layer 41 adheres tightly and uniformly, avoiding localized areas of excessive thickness or thinness, and reducing problems such as impeded electron transport or increased local recombination caused by film inhomogeneity.

[0089] Meanwhile, the zinc oxide tin layer 42 is deposited using atomic layer deposition (ALD), which also ensures the uniformity of the zinc oxide tin layer 42 film. Zinc oxide tin itself possesses high electron mobility and a suitable energy level structure. The zinc oxide tin layer 42 formed through ALD can better leverage these electron mobility advantages, achieving high-speed and efficient electron transport within the layer. Furthermore, the uniform zinc oxide film can reduce electron scattering and recombination during transport, improving electron collection efficiency.

[0090] This application employs atomic layer deposition (ALD) technology to deposit a multilayer electron transport layer 4, enabling precise control over the thickness of the electron transport layer 4 film and ensuring its uniformity. Furthermore, ALD technology, through the rational design of the reaction chamber and gas distribution system, allows for the uniform distribution of the precursor on a large-area substrate surface, achieving large-area uniform deposition, which is beneficial for fabricating large-area perovskite solar cells. When fabricating the electron transport layer 4 over a large area, the uniform thickness of each layer can be guaranteed, effectively avoiding the problem of reduced charge transport efficiency caused by uneven thickness, thus improving the film quality and transport performance of the electron transport layer 4.

[0091] Meanwhile, in the production process of perovskite solar cells, multiple films formed by atomic layer deposition (ALD) processes, such as oxide layer 41 and zinc tin oxide layer 42, can be integrated into one or more complete ALD equipment. In other words, after depositing a thin film in an ALD equipment under vacuum, there is no need to take the perovskite solar cell out to another ALD equipment under vacuum to deposit the next film layer. This realizes in-situ deposition of multiple films in perovskite solar cells, improving the production cycle and growth efficiency of perovskite solar cells. It is worth noting that the atomic layer deposition technique involves multiple deposition cycles when depositing the oxide layer 41 and the zinc tin oxide layer 42. Each deposition cycle includes introducing a metal precursor source, purging with an inert gas, introducing an oxygen source, and purging with an inert gas in the deposition chamber. The oxide layer 41 and the zinc tin oxide layer 42 are deposited only after multiple deposition cycles.

[0092] In some embodiments, see Figure 2 The oxide layer 41 is formed on the side of the perovskite layer 3 away from the hole transport layer 2 using an atomic layer deposition process. The thickness of oxide layer 41 is 5nm-20nm.

[0093] In the above embodiments, the oxide layer 41 can be directly deposited on the side of the perovskite layer 3 away from the hole transport layer 2 using an atomic layer deposition process, or the oxide layer 41 obtained by the atomic layer deposition process can be located on the side of the perovskite layer 3 away from the hole transport layer 2, and the oxide layer 41 and the perovskite layer 3 are not in direct contact.

[0094] Atomic layer deposition (ALD) is a process based on a self-limiting chemical reaction of a gaseous precursor on a substrate surface. By precisely controlling the pulse time and reaction cycle of the precursor, the growth of the thin film can be precisely controlled at the atomic scale. This process can produce dense, uniform, and repeatable oxide layers 41 on substrates of different shapes and sizes, effectively avoiding local defects caused by uneven film formation, reducing electron scattering and recombination during transport, improving electron transport efficiency, and ensuring the consistency of battery performance.

[0095] In one embodiment, the oxide layer 41 is directly deposited on the side of the perovskite layer 3 away from the hole transport layer 2 using atomic layer deposition (ALD). This creates a good interface between the oxide layer 41 and the perovskite layer 3, facilitating the smooth injection of electrons from the perovskite layer 3 into the oxide layer 41, reducing interface resistance, and further improving the photoelectric conversion performance of the battery. Furthermore, the surface of the perovskite layer 3 may have minor undulations. ALD has excellent step coverage, enabling the formation of a uniform oxide layer 41 on complex surfaces, ensuring the performance consistency of the entire battery structure.

[0096] In some embodiments, the hole transport layer 2 is formed on one side surface of the substrate 1 by magnetron sputtering. The thickness of hole transport layer 2 is 10nm-30nm.

[0097] In the above embodiments, a magnetic field is used to control the trajectory of electrons in the plasma of the hole transport layer 2, increasing the probability of collisions between electrons and gas molecules. This enables the formation of a uniform, dense, and strongly adherent hole transport layer 2 on the surface of the substrate 1, ensuring uniform hole transport throughout the entire hole transport layer 2, reducing charge accumulation and recombination caused by local thickness unevenness, and improving hole transport efficiency.

[0098] The hole transport layer 2, with a thickness of 10nm-30nm, provides a suitable channel for hole transport. For example, the thickness of the hole transport layer 2 can be 12nm, 15nm, 18nm, 22nm, or 25nm. Within the thickness range of 10nm-30nm, the hole transport layer 2 can form a continuous and stable conductive structure, allowing holes to pass through quickly and smoothly. While meeting the requirements for hole transport, it does not cause excessive absorption or reflection of light, thus balancing optical and electrical performance. This allows the battery to achieve a better synergistic effect in absorbing light energy and transporting charge, thereby improving photoelectric conversion efficiency.

[0099] In some embodiments, see Figure 1 and Figure 2 The perovskite layer 3 is coated on the side of the hole transport layer 2 away from the substrate 1. The thickness of the perovskite layer 3 is 450nm-600nm.

[0100] In the above embodiments, the perovskite layer 3 is directly deposited on the hole transport layer 2 using a blade coating process, which allows for a tight contact between the hole transport layer 2 and the perovskite layer 3. This good interfacial contact facilitates efficient hole injection from the perovskite layer 3 into the hole transport layer 2, reduces charge recombination at the interface, and improves charge collection efficiency.

[0101] The perovskite layer 3 has excellent light absorption performance. A thickness of 450nm-600nm allows the perovskite layer 3 to fully absorb visible light from sunlight. For example, if the thickness of the perovskite layer 3 is 480nm, 520nm, 550nm or 580nm, the light can be absorbed and utilized multiple times in the perovskite layer 3, thereby improving the battery's light energy capture efficiency, enabling electrons and holes to be transported to the corresponding transport layers relatively smoothly, reducing recombination losses, and improving the battery's fill factor and photoelectric conversion efficiency.

[0102] In some embodiments, see Figure 1 and Figure 2 Perovskite solar cells also include: Passivation layer 6 is formed between perovskite layer 3 and electron transport layer 4 using atomic layer deposition. The thickness of passivation layer 6 is 0.1nm-2nm, for example, the thickness of passivation layer 6 is 0.2nm, 0.5nm, 1.0nm or 1.5nm.

[0103] In the above embodiments, the atomic layer deposition process for depositing the passivation layer 6 achieves low-temperature compatibility; for example, the deposition temperature can be carried out at 80–120°C, avoiding thermal decomposition of the perovskite. It also improves the purity and density of the passivation layer 6.

[0104] The passivation layer 6, with a thickness of 0.1nm-2nm, can effectively passivate the surface defects of the perovskite layer 3 without hindering charge transport, thus enabling the battery to achieve synergy in absorbing light energy and transporting charge, thereby improving photoelectric conversion efficiency.

[0105] In some embodiments, the passivation layer 6 includes at least one of an alumina deposited film, a magnesium fluoride deposited film, a lithium fluoride deposited film, a silicon oxide deposited film, a silicon carbide deposited film, a molybdenum oxide deposited film, and a molybdenum nitride deposited film.

[0106] In the above embodiments, the atomic layer deposition process for depositing the passivation layer 6 involves alternately introducing the same or different aluminum, magnesium, lithium, silicon, or molybdenum precursors to perform an atomic-scale deposition reaction on the perovskite film surface. Precursor molecules adsorb onto the perovskite surface, forming an ultrathin passivation layer. The growth of the passivation layer 6 can be precisely controlled at the atomic scale, resulting in a highly uniform and dense passivation layer 6 capable of covering perovskite layers with high surface roughness. Furthermore, byproducts of the deposition process can be removed by purging, reducing impurities in the deposited film and improving the passivation layer 6's ability to block water and oxygen.

[0107] For example, after depositing an alumina film on the surface of the perovskite layer 3, the alumina film can chemically react or physically adsorb with unsaturated chemical bonds and grain boundary defects on the perovskite surface, effectively reducing the surface defect state density. When the passivation layer 6 includes a magnesium fluoride deposition film, the magnesium fluoride can reduce light reflection loss at the interface, improving the cell's light energy capture efficiency. Simultaneously, the magnesium fluoride film can also act as an antireflection film, further optimizing the cell's optical performance and increasing photocurrent density. In perovskite solar cells, depositing a lithium fluoride deposition film on the surface of the perovskite layer 3 can lower the injection barrier of electrons from the perovskite layer to the electron transport layer, promoting efficient electron injection and helping to improve the cell's short-circuit current density and fill factor, thereby enhancing the cell's photoelectric conversion performance. In some embodiments, see... Figure 1 and Figure 2 Perovskite solar cells also include: The barrier layer 7 is formed between the electron transport layer 4 and the electrode layer 5 using an atomic layer deposition process. The barrier layer 7 includes at least one of indium tin oxide deposition film, indium zinc oxide deposition film and zinc aluminum oxide deposition film. The thickness of the barrier layer 7 is 10nm-100nm, for example, the thickness of the barrier layer 7 is 20nm, 30nm, 50nm or 80nm.

[0108] In the above embodiments, atomic layer deposition (ALD) can deposit the material of the barrier layer 7 layer by layer (one layer can be deposited in one deposition cycle) between the electron transport layer 4 and the electrode layer 5. For example, ALD can be used to deposit an indium tin oxide (ITO), indium zinc oxide (IZO), or aluminum zinc oxide (AZO) film on the surface of the electron transport layer 4. Indium tin oxide (ITO) has good conductivity and transparency, which can provide a good electron transport channel while ensuring light transmittance, allowing electrons to pass smoothly through the barrier layer 7 to reach the electrode layer 5. Indium zinc oxide (IZO) has high electron mobility, which can quickly transport electrons, reduce the residence time of electrons in the barrier layer 7, and reduce the recombination probability. Aluminum zinc oxide (AZO) has high conductivity and good optical transmittance. Aluminum zinc oxide can effectively transport electrons without affecting the light absorption of the battery, and can also block the penetration of impurity ions, thus protecting the internal structure of the battery and helping to improve the overall performance and stability of the battery.

[0109] In addition, by precisely controlling deposition parameters such as precursor pulse time and reaction temperature, the composition, thickness and microstructure of the barrier layer 7 can be precisely adjusted, thereby obtaining a high-quality barrier layer with uniform performance, which effectively blocks ion migration between the electron transport layer 4 and the electrode layer 5.

[0110] See the following example for details: Example 6 A 10 nm thick hole transport layer 2 and a 500 nm thick perovskite layer 3 are deposited on a substrate 1. Then, an atomic layer deposition method is used to deposit a 0.5 nm thick aluminum oxide or silicon oxide film as a passivation layer 6, a 10 nm thick tungsten oxide film combined with a 10 nm thick zinc tin oxide film as an electron transport layer 4, a 30 nm thick indium tin oxide film as a barrier layer 7, and a 30 nm thick copper electrode as an electrode layer 5. The specific steps include the following: S101, NiOx is sputtered on a conductive glass substrate using magnetron sputtering to obtain a hole transport layer with a thickness of 10 nm. S102, MA0.7FA0.3PbI3 (FAMA mixed cationic perovskite, concentration 1.6M) was coated on the surface of the hole transport layer and then heat-annealed at 110℃ for 20 min to obtain a perovskite layer with a thickness of 500 nm. In S103, the substrate is placed in an atomic layer deposition (ALD) apparatus. Trimethylaluminum (TMA) and deionized water (H2O) are used as precursors for metallic aluminum and oxygen ions, respectively. High-purity nitrogen (99.999% purity) is used as the carrier gas and purging gas. To ensure the vacuum level in the reaction chamber, the reaction pressure is maintained between 0.2 and 10 mbar. The temperature of the ALD apparatus is controlled between 80 and 200°C. First, the aluminum-containing precursor trimethylaluminum is introduced into the reaction chamber, followed by the introduction of inert nitrogen gas to purge the residual chemical source precursor. Then, oxygen source deionized water is introduced into the reaction chamber, followed by purging with inert nitrogen gas. This completes one sub-cycle of alumina film deposition. Through five sub-cycles of deposition, an alumina film with a thickness of 0.5 nm is obtained.

[0111] Alternatively, the substrate is placed in an atomic layer deposition (ALD) apparatus, using diisopropylaminosilane (DIPAS) and ozone (O3) as silicon and oxygen ion precursors, and high-purity N2 (99.999% purity) as the carrier gas and purging gas. To maintain the vacuum level in the reaction chamber, the pressure is maintained between 0.2 and 10 mbar. The temperature of the ALD apparatus is controlled between 200 and 350°C. First, the silicon-containing precursor diisopropylaminosilane is introduced into the reaction chamber, followed by the introduction of inert nitrogen gas to purge any remaining chemical source precursors. Next, oxygen source O3 is introduced into the reaction chamber, followed by purging with inert gas, completing one sub-cycle of silicon oxide deposition. Five sub-cycles of deposition are then performed to obtain a 1 nm thick silicon oxide film.

[0112] In S104, the substrate is placed in an atomic layer deposition apparatus. Tungsten hexafluoride (WF6) and deionized water (H2O) are used as precursors for metallic tungsten and oxygen ions, respectively. High-purity N2 (99.999% purity) is used as the carrier gas and purging gas. To ensure the vacuum level in the reaction chamber, the pressure is maintained between 0.2 and 10 mbar, and the apparatus temperature is controlled between 30 and 200°C. First, tungsten hexafluoride containing the tungsten precursor is introduced, followed by the introduction of inert nitrogen gas to purge the residual precursor. Then, deionized water is introduced as the oxygen source, followed by another purge with inert gas, completing one sub-cycle of tungsten oxide deposition. Multiple sub-cycles of deposition are performed to obtain a tungsten oxide film with a thickness of 10 nm.

[0113] S105, Step 1: Place the substrate in an atomic layer deposition apparatus, control the apparatus temperature between 80-200℃, and maintain the pressure between 0.2-10 mbar. First, introduce the zinc-containing precursor diethylzinc (DEZ) into the reaction chamber, then introduce inert nitrogen gas to purge the residual precursor, then introduce oxygen source deionized water, and then introduce inert gas to purge again, completing one sub-cycle of zinc oxide deposition. Perform 19 sub-cycles of deposition to obtain a zinc oxide film.

[0114] Step 2: Control the temperature of the device between 80-200℃ and the pressure between 0.2-10 mbar. First, introduce the tin-containing precursor tetra(dimethylamino)tin (TDMASn), then introduce the inert gas nitrogen to purge the residual precursor, then introduce the oxygen source deionized water, and finally introduce the inert gas to purge. Complete one sub-cycle of tin oxide deposition on the substrate on which zinc oxide has been deposited to obtain a tin oxide film.

[0115] Step 3: Repeat steps 1 and 2 above, and perform a specific number of deposition cycles according to the target thickness. The elemental ratio of Sn to Zn can be adjusted according to the number of cycles of zinc oxide and tin oxide deposition during the atomic layer deposition process.

[0116] S106, Step 1: Place the substrate in an atomic layer deposition apparatus, control the apparatus temperature between 80-200℃ and the pressure between 0.2-10 mbar. First, introduce the indium-containing precursor cyclopentadiene indium, then introduce the inert gas nitrogen to purge the residual precursor, then introduce the first oxygen source deionized water, then introduce the inert gas to purge, and finally introduce the second oxygen source oxygen and then introduce the inert gas to purge, completing one sub-cycle of indium oxide deposition. Perform 19 sub-cycles of deposition to obtain an indium oxide thin film.

[0117] Step 2: Control the temperature of the device between 80-200℃ and the pressure between 0.2-10 mbar. First, introduce the tin-containing precursor tetra(dimethylamino)tin, then introduce the inert gas nitrogen to purge the residual precursor, then introduce the oxygen source deionized water, and finally introduce the inert gas to purge. Complete one sub-cycle of tin oxide deposition on the substrate on which indium oxide has been deposited to obtain a tin oxide film.

[0118] Step 3: Repeat steps 1 and 2 above. The number of deposition cycles can be set according to the target thickness of 30nm. In the indium oxide deposition step, two oxygen sources need to be selected. H2O, H2O2, O2 and oxygen plasma can be freely replaced. However, ozone is not selected as an oxygen source for deposition because it will reduce the oxygen vacancies in the indium oxide film.

[0119] S107 After preparing the passivation layer, electron transport layer and barrier layer using atomic layer deposition technology, the surface of the electron transport layer is scribed, and then Cu is sputtered using magnetron sputtering to obtain a Cu electrode layer with a thickness of 30 nm. The Cu electrode is electrically connected to the bottom electrode through the scribed channel, thereby completing the series connection of the top electrode of one sub-cell with the bottom electrode of the adjacent sub-cell.

[0120] Example 7 The only difference from Example 6 is: The passivation layer has a thickness of 1 nm.

[0121] Example 8 The only difference from Example 6 is: The passivation layer has a thickness of 1.5 nm.

[0122] Example 9 The only difference from Example 6 is: The passivation layer has a thickness of 2 nm.

[0123] In the above embodiments of this application, a perovskite solar cell formed with an alumina deposition film as the passivation layer is used as an example. Referring to Table 2 below, when the thickness of the alumina deposition film is between 0.5 nm and 1 nm, the alumina deposition film has the effect of defect passivation and reducing non-radiative recombination at the interface, thus improving the efficiency of the perovskite solar cell; however, when the thickness of the alumina deposition film reaches 1.5 nm or more, due to the insulation of the alumina deposition film, the conductivity of the perovskite solar cell decreases, thereby increasing the series resistance and reducing the efficiency of the perovskite solar cell.

[0124] Table 2. Thickness of alumina deposited thin film and its performance parameters in perovskite solar cells

[0125] This application also provides a method for fabricating a perovskite solar cell, the method comprising: S201, a hole transport layer and a perovskite layer are disposed on the substrate; The substrate provides the supporting foundation for the entire solar cell. A hole transport layer is placed on the substrate, providing a channel for the directional transport of holes. The hole transport layer selectively allows holes to pass through while blocking the reverse transport of electrons, achieving effective charge separation and directional movement. Furthermore, the hole transport layer improves the properties of the substrate surface, providing suitable interfacial conditions for the deposition of the perovskite layer. This facilitates the uniform and stable growth of the perovskite material on the substrate, ensuring the solar cell has high photoelectric conversion efficiency and good stability.

[0126] S202, depositing an electron transport layer on a perovskite layer; The electron transport layer comprises stacked oxide layers and zinc-tin oxide layers. This layer efficiently transports electrons. After the perovskite layer is photoexcited to generate electron-hole pairs, the electron transport layer rapidly extracts the electrons from the perovskite layer and quickly transports them to the corresponding electrodes. The electron transport layer provides a directional transport channel for electrons, reducing the probability of recombination within the perovskite layer and improving electron collection efficiency.

[0127] For example, atomic layer deposition (ALD) can be used to deposit an electron transport layer on a perovskite layer. ALD offers atomic-level precision control, allowing for the layer-by-layer deposition of electron transport layer material on the perovskite surface. Furthermore, by precisely adjusting deposition parameters such as precursor pulse time and reaction temperature, the thickness, composition, and microstructure of the electron transport layer can be precisely controlled. This helps to obtain a uniform and stable electron transport layer, ensuring consistent battery performance and reliability. Moreover, ALD enables the formation of tight chemical bonds and physical adsorption between the electron transport layer and the perovskite layer, achieving excellent interfacial bonding. This effectively reduces charge recombination at the interface and improves the charge transport efficiency between the perovskite and electron transport layers.

[0128] In addition, the electron transport layer forms a protective barrier on the surface of the perovskite layer, which can block harmful substances such as oxygen and moisture in the external environment from corroding the perovskite layer, extend the service life of the perovskite layer, and improve the stability and reliability of the battery.

[0129] In the above embodiments, the electron transport layer includes a stacked oxide layer and a zinc tin oxide layer. Introducing the oxide layer into the electron transport layer can ensure the transmission of light through the battery, allowing more light to reach the perovskite layer for absorption, and can also provide an efficient electron transport channel, reduce energy loss at the interface, and improve the photoelectric conversion efficiency of the battery.

[0130] Zinc tin oxide (ZTI) has a high electron mobility, enabling rapid and efficient electron transport. Adding a ZTI layer to the electron transport layer ensures rapid electron transport within the battery, reduces recombination losses during transport, and improves the battery's short-circuit current density and photoelectric conversion efficiency.

[0131] In some embodiments, depositing an electron transport layer on a perovskite layer includes: An electron transport layer was deposited on the perovskite layer using atomic layer deposition, with a thickness of 10 nm to 50 nm.

[0132] In the above embodiments, atomic layer deposition (ALD) technology enables precise control of the electron transport layer film growth at the atomic level. Depositing the electron transport layer on the perovskite layer using ALD ensures the uniformity of the electron transport layer film. Even with microscopic undulations or complex structures on the perovskite layer surface, the embodiments of this application can ensure a uniform electron transport layer covering the perovskite layer surface, avoiding the problem of localized excessive thickness or thinness of the electron transport layer. A uniform electron transport layer provides a stable and smooth transport channel for electrons, improving electron collection efficiency.

[0133] In some embodiments, the thickness of the electron transport layer is 10nm-50nm. A thin electron transport layer does not affect light transmission and electron tunneling, thereby improving photoelectric conversion efficiency while ensuring the stability of the perovskite solar cell. Furthermore, the embodiments of this application use atomic layer deposition to prepare a uniform electron transport layer, which effectively extracts photogenerated electrons from the perovskite layer, helps reduce defect states on the surface of the electron transport layer, suppresses nonradiative recombination, improves the uniformity of the electron transport layer preparation, and enhances the photoelectric conversion efficiency while ensuring the stability of the perovskite solar cell.

[0134] S203, depositing an electrode layer on the electron transport layer; The electrode layer collects electrons from the electron transport layer and holes from the hole transport layer, thus generating current output in a perovskite solar cell. The electrode layer acts as a bridge connecting the cell to an external circuit, converting photogenerated carriers into usable electrical energy, thereby achieving the conversion of solar energy into electrical energy.

[0135] For example, in the embodiments of this application, an electrode layer is deposited on the electron transport layer using atomic layer deposition (ALD), which can obtain a uniform and dense electrode film. This ensures that charge is efficiently collected from the electron transport layer and conducted to the external circuit, reducing the contact resistance between the electrode and the electron transport layer. Moreover, the electrode layer formed by ALD has a good interfacial bond with the electron transport layer, which can enhance the interfacial stability of the entire battery structure.

[0136] In some embodiments, depositing an electrode layer on the electron transport layer includes: An electrode layer is deposited on the electron transport layer using an atomic layer deposition process, and the thickness of the electrode layer is 10nm-100nm.

[0137] In this embodiment, an atomic layer deposition process is used to deposit the electrode layer on the electron transport layer, which ensures that the electrode layer film is uniformly distributed on the surface of the electron transport layer. A uniform electrode layer helps to ensure uniform current distribution across the entire electrode surface, reducing problems such as heat generation caused by excessive local current density, and improving the stability and reliability of the battery.

[0138] In one embodiment, the electrode layer is formed on the side of the electron transport layer away from the perovskite layer by atomic layer deposition. The electrode layer can be a copper electrode deposited thin film with a thickness of 10nm-100nm, such as 20nm, 30nm, 50nm or 80nm. This can improve the conductivity of the electrode layer, enabling the electrode layer to effectively collect and transport electrons, and also ensure the bonding stability between the electrode layer and the electron transport layer.

[0139] In some embodiments, depositing an electron transport layer on a perovskite layer using an atomic layer deposition process includes: An oxide layer with a thickness of 5 nm to 20 nm is deposited on the side of the perovskite layer away from the hole transport layer using atomic layer deposition technology. Atom layer deposition is used to form a zinc oxide tin layer on the side of the oxide layer away from the perovskite layer, and the thickness of the zinc oxide tin layer is 5nm-30nm.

[0140] In this embodiment of the application, when depositing an oxide layer on the side of the perovskite layer away from the hole transport layer, the thickness, composition, and microstructure of the oxide layer can be precisely controlled through atomic layer deposition (ALD) technology, thereby optimizing electron transport performance to match the requirements of the perovskite layer and improving electron mobility.

[0141] Meanwhile, depositing the zinc oxide tin layer atomically on the side of the oxide layer away from the perovskite layer further optimizes the overall electron transport performance of the electron transport layer. After initial transport through the oxide layer, electrons can transport more quickly and efficiently in the zinc oxide tin layer, reducing electron loss and recombination during transport, improving electron collection efficiency, and thus enhancing the photoelectric conversion efficiency of the perovskite solar cell.

[0142] In some embodiments, forming a hole transport layer and a perovskite layer on a substrate includes: A hole transport layer is deposited on one side surface of the substrate using a magnetron sputtering process; A perovskite layer is coated on the side of the hole transport layer away from the substrate; The hole transport layer has a thickness of 10nm-30nm, and the perovskite layer has a thickness of 450nm-600nm.

[0143] In the above embodiments, a magnetic field is used to control the trajectory of electrons in the plasma of the hole transport layer, increasing the probability of collisions between electrons and gas molecules. This enables the formation of a uniform, dense, and strongly adherent hole transport layer on the substrate surface, ensuring uniform hole transport throughout the entire hole transport layer, reducing charge accumulation and recombination caused by local thickness unevenness, and improving hole transport efficiency.

[0144] A hole transport layer with a thickness of 10nm-30nm provides a suitable channel for hole transport; for example, the thickness of the hole transport layer is 12nm, 15nm, 18nm, 22nm, or 25nm. Within the 10nm-30nm thickness range, the hole transport layer can form a continuous and stable conductive structure, allowing holes to pass through quickly and smoothly. While meeting the requirements for hole transport, it does not excessively absorb or reflect light, thus balancing optical and electrical performance. This allows the battery to achieve a better synergistic effect in absorbing light energy and transporting charge, improving photoelectric conversion efficiency.

[0145] In the above embodiments, the perovskite layer is directly deposited on the hole transport layer using a blade coating process, which allows for a tight contact between the hole transport layer and the perovskite layer. Good interfacial contact facilitates efficient hole injection from the perovskite layer into the hole transport layer, reduces charge recombination at the interface, and improves charge collection efficiency.

[0146] The perovskite layer has excellent light absorption properties. A thickness of 450nm-600nm allows the perovskite layer to fully absorb visible light from sunlight. For example, if the thickness of the perovskite layer is 480nm, 520nm, 550nm, or 580nm, the light can be absorbed and utilized multiple times in the perovskite layer, thereby improving the battery's light energy capture efficiency. This allows electrons and holes to be transported to the corresponding transport layers relatively smoothly, reducing recombination losses and improving the battery's fill factor and photoelectric conversion efficiency.

[0147] In some embodiments, the preparation method includes: A passivation layer is formed on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process. An electron transport layer is deposited on the side of the passivation layer away from the perovskite layer using an atomic layer deposition process; that is, the passivation layer is located between the perovskite layer and the electron transport layer.

[0148] The passivation layer includes at least one of aluminum oxide deposited film, magnesium fluoride deposited film, lithium fluoride deposited film, silicon oxide deposited film, silicon carbon oxide deposited film, molybdenum oxide deposited film, and molybdenum nitride deposited film. The atomic layer deposition cycle of the passivation layer is 5-20 times, and the thickness of the passivation layer is 0.1nm-2nm.

[0149] In the above embodiments, the atomic layer deposition process for depositing the passivation layer achieves low-temperature compatibility; for example, the deposition temperature can be carried out at 80–120°C, avoiding thermal decomposition of the perovskite. It also improves the purity and density of the passivation layer. Furthermore, a passivation layer with a thickness of 0.1 nm–2 nm ensures effective passivation of surface defects in the perovskite layer without hindering charge transport, enabling the battery to achieve synergy in light energy absorption and charge transport, thereby improving photoelectric conversion efficiency.

[0150] In the above embodiments, the atomic layer deposition process for depositing the passivation layer involves alternately introducing the same or different aluminum, magnesium, lithium, silicon, or molybdenum precursors to perform an atomic-scale deposition reaction on the perovskite film surface. The precursor molecules adsorb onto the perovskite surface, forming an ultrathin passivation layer. This allows for precise control of the passivation layer growth at the atomic scale, producing a highly uniform and dense passivation layer capable of covering perovskite surfaces with high roughness. Furthermore, byproducts of the deposition process can be removed by purging, reducing impurities in the deposited film and improving the passivation layer's ability to block water and oxygen.

[0151] For example, after depositing an alumina film on the surface of the perovskite layer, the alumina film can chemically react or physically adsorb with unsaturated chemical bonds and grain boundary defects on the perovskite surface, effectively reducing the surface defect state density. When the passivation layer includes a magnesium fluoride deposition film, the magnesium fluoride can reduce light reflection loss at the interface, improving the cell's light energy capture efficiency. Simultaneously, the magnesium fluoride film can also act as an antireflection coating, further optimizing the cell's optical performance and increasing photocurrent density. In perovskite solar cells, depositing a lithium fluoride deposition film on the perovskite layer surface can lower the injection barrier of electrons from the perovskite layer to the electron transport layer, promoting efficient electron injection, which helps improve the cell's short-circuit current density and fill factor, thereby enhancing the cell's photoelectric conversion performance.

[0152] In some embodiments, the preparation method includes: A barrier layer is deposited on the side of the electron transport layer away from the perovskite layer using atomic layer deposition (ALD) technology. An electrode layer is deposited on the side of the barrier layer away from the electron transport layer using an atomic layer deposition process; The barrier layer includes at least one of indium tin oxide deposited film, indium zinc oxide deposited film and aluminum zinc oxide, and the thickness of the barrier layer is 10nm-100nm, for example, the thickness of barrier layer 7 is 20nm, 30nm, 50nm or 80nm.

[0153] In the above embodiments, atomic layer deposition (ALD) can deposit barrier layer materials layer by layer (one layer can be deposited in one deposition cycle) between the electron transport layer and the electrode layer. For example, ALD can be used to deposit indium tin oxide (ITO), indium zinc oxide (IZO), or aluminum zinc oxide (AZO) films on the surface of the electron transport layer. Indium tin oxide (ITO) has good conductivity and transparency, which can provide a good electron transport channel while ensuring light transmittance, allowing electrons to pass smoothly through the barrier layer to the electrode layer. Indium zinc oxide (IZO) has high electron mobility, which can quickly transport electrons, reduce the residence time of electrons in the barrier layer, and reduce the probability of recombination. Aluminum zinc oxide (AZO) has high conductivity and good optical transmittance. Aluminum zinc oxide can effectively transport electrons without affecting the light absorption of the battery, and can also block the penetration of impurity ions, thus protecting the internal structure of the battery and helping to improve the overall performance and stability of the battery.

[0154] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An electron transport layer for perovskite solar cells, characterized in that, include: Oxide layer (41), wherein the oxide layer (41) is a metal oxide layer; A zinc tin oxide layer (42) is deposited on one side surface of the oxide layer (41) so that the zinc tin oxide layer (42) and the oxide layer (41) are stacked.

2. The electron transport layer according to claim 1, characterized in that, The oxide layer (41) is formed using an atomic layer deposition process; The oxide layer (41) is a transition metal oxide layer, and the thickness of the oxide layer (41) is 5nm-20nm.

3. The electron transport layer according to claim 1, characterized in that, The oxide layer (41) includes at least one of tungsten oxide, titanium oxide and zinc oxide.

4. The electron transport layer according to claim 1, characterized in that, The zinc tin oxide layer (42) is formed on one side surface of the oxide layer (41) using an atomic layer deposition process; The thickness of the zinc tin oxide layer (42) is 5 nm - 30 nm.

5. The electron transport layer according to claim 1, characterized in that, The zinc oxide tin layer (42) comprises alternating layers of zinc oxide deposited films and layers of tin oxide deposited films.

6. A perovskite solar cell, characterized in that, include: Base (1); The hole transport layer (2), the perovskite layer (3) and the electron transport layer (4) according to any one of claims 1-5 are stacked together, wherein the substrate (1), the hole transport layer (2), the perovskite layer (3) and the electron transport layer (4) are stacked together.

7. The perovskite solar cell according to claim 6, characterized in that, The hole transport layer (2) is disposed on one side surface of the substrate (1), the perovskite layer (3) is disposed on the side of the hole transport layer (2) away from the substrate (1), and the electron transport layer (4) is disposed on the side of the perovskite layer (3) away from the hole transport layer (2).

8. The perovskite solar cell according to claim 7, characterized in that, Perovskite solar cells also include: An electrode layer (5) is disposed on the side of the electron transport layer (4) away from the perovskite layer (3), and the thickness of the electrode layer (5) is 10nm-100nm.

9. The perovskite solar cell according to claim 6, characterized in that, The oxide layer (41) is formed on the side of the perovskite layer (3) away from the hole transport layer (2) using an atomic layer deposition process; The zinc oxide tin layer (42) is formed on the side of the oxide layer (41) away from the perovskite layer (3) using an atomic layer deposition process.

10. The perovskite solar cell according to claim 6, characterized in that, The hole transport layer (2) is formed on one side surface of the substrate (1) by magnetron sputtering. The hole transport layer (2) has a thickness of 10nm-30nm.

11. The perovskite solar cell according to claim 6, characterized in that, The perovskite layer (3) is coated onto the side of the hole transport layer (2) away from the substrate (1); The thickness of the perovskite layer (3) is 450 nm - 600 nm.

12. The perovskite solar cell according to claim 6, characterized in that, The perovskite solar cell also includes: A passivation layer (6) is formed between the perovskite layer (3) and the electron transport layer (4) using an atomic layer deposition process. The passivation layer (6) has a thickness of 0.1 nm - 2 nm.

13. The perovskite solar cell according to claim 12, characterized in that, The passivation layer (6) includes at least one of the following: aluminum oxide deposited film, magnesium fluoride deposited film, lithium fluoride deposited film, silicon oxide deposited film, silicon carbon oxide deposited film, molybdenum oxide deposited film, and molybdenum nitride deposited film.

14. The perovskite solar cell according to claim 8, characterized in that, The perovskite solar cell also includes: A barrier layer (7) is formed between the electron transport layer (4) and the electrode layer (5) using an atomic layer deposition process. The barrier layer (7) includes at least one of an indium tin oxide deposition film, an indium zinc oxide deposition film, and an aluminum zinc oxide deposition film. The thickness of the barrier layer (7) is 10nm-100nm.

15. A method for preparing a perovskite solar cell, characterized in that, include: A hole transport layer and a perovskite layer are disposed on the substrate; An electron transport layer is deposited on the perovskite layer; An electrode layer is deposited on the electron transport layer; The electron transport layer comprises an oxide layer and a zinc tin oxide layer stacked together.

16. The preparation method according to claim 15, characterized in that, Depositing an electron transport layer on the perovskite layer includes: An electron transport layer is deposited on the perovskite layer using an atomic layer deposition process, and the thickness of the electron transport layer is 10 nm - 50 nm.

17. The preparation method according to claim 15, characterized in that, The electrode layer deposited on the electron transport layer includes: An electrode layer is deposited on the electron transport layer using an atomic layer deposition process, and the thickness of the electrode layer is 10 nm-100 nm.

18. The preparation method according to claim 16, characterized in that, The electron transport layer deposited on the perovskite layer using an atomic layer deposition process includes: An oxide layer is deposited on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process. A zinc tin oxide layer is formed on the side of the oxide layer away from the perovskite layer using an atomic layer deposition process; The thickness of the oxide layer is 5nm-20nm, and the thickness of the zinc tin oxide layer is 5nm-30nm.

19. The preparation method according to claim 15, characterized in that, The process of setting a hole transport layer and a perovskite layer on a substrate includes: A hole transport layer is deposited on one side surface of the substrate using a magnetron sputtering process; A perovskite layer is coated on the side of the hole transport layer away from the substrate; The hole transport layer has a thickness of 10nm-30nm, and the perovskite layer has a thickness of 450nm-600nm.

20. The preparation method according to claim 15, characterized in that, The preparation method includes: A passivation layer is formed on the side of the perovskite layer away from the hole transport layer using an atomic layer deposition process. An electron transport layer is deposited on the side of the passivation layer away from the perovskite layer using an atomic layer deposition process; The passivation layer includes at least one of aluminum oxide deposited film, magnesium fluoride deposited film, lithium fluoride deposited film, silicon oxide deposited film, silicon carbon oxide deposited film, molybdenum oxide deposited film, and molybdenum nitride deposited film. The atomic layer deposition cycle of the passivation layer is 5-20 times, and the thickness of the passivation layer is 0.1nm-2nm.

21. The preparation method according to claim 15, characterized in that, The preparation method includes: A barrier layer is deposited on the side of the electron transport layer away from the perovskite layer using atomic layer deposition (ALD) technology. An electrode layer is deposited on the side of the barrier layer away from the electron transport layer using an atomic layer deposition process; The barrier layer comprises at least one of indium tin oxide deposited film, indium zinc oxide deposited film, and zinc aluminum oxide, and the thickness of the barrier layer is 10nm-100nm.

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