Perovskite solar cell

Abstract

The utility model discloses a perovskite solar cell, which comprises a substrate, and a first charge transport layer, a perovskite absorption layer, a second charge transport layer and a first electrode which are stacked on one side of the substrate along a first direction, and is characterized in that the first charge transport layer comprises a first film layer, a first modification layer and a second modification layer which are stacked along the first direction; the first film layer is located on the side, close to the substrate, of the first modification layer, the first film layer, the first modification layer and the second modification layer are each of a first type, the first type is P type or N type, and the first direction is the direction, pointing to the first electrode, of the substrate; the problem that the charge transfer efficiency of a battery is affected due to poor interface wettability of a charge transfer layer in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more specifically, to a perovskite solar cell. Background Technology

[0002] Perovskite solar cells have become a research hotspot in the photovoltaic industry due to their high photoelectric conversion efficiency and low manufacturing cost. Currently, many companies have begun pilot-scale mass production. In perovskite solar cells, the charge transport layer is crucial, effectively extracting charge from the emitting layer and significantly influencing the cell's open-circuit voltage and fill factor. Currently, the industry primarily uses NiO2 prepared by physical vapor deposition (PVD) as the charge transport layer. x Self-Assembled Monolayer (SAM) layers prepared by solution methods and SnO2 layers deposited by atomic layer deposition (ALD) are often limited by the properties of the materials themselves, resulting in problems such as energy level mismatch, poor wettability, and severe recombination at the interface. This leads to significant recombination losses at the transport layer interface, which seriously affects the new performance and long-term stability of the battery. Utility Model Content

[0003] This application provides a perovskite solar cell to solve the problem that poor interfacial wettability of the charge transport layer in related technologies affects the charge transport efficiency of the cell.

[0004] According to one aspect of this application, a perovskite solar cell is provided, comprising a substrate and a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a first electrode stacked along a first direction on one side of the substrate. The first charge transport layer includes a first film layer, a first modification layer, and a second modification layer stacked along the first direction. The first film layer is located on the side of the first modification layer close to the substrate. The first film layer, the first modification layer, and the second modification layer all have a first type, which is either P-type or N-type. The first direction is the direction from the substrate to the first electrode.

[0005] Optionally, the second modification layer is composed of multiple cluster structures, which are formed by the stacking of multiple particles.

[0006] Optionally, the diameter of the particles is 10 to 100 nm.

[0007] Optionally, the diameter of the cluster structure is 10–500 nm.

[0008] Optionally, the first film layer has a first surface facing away from the substrate, and the plurality of cluster structures have a plurality of first projections on the first surface, the first projections having a first area, the first surface having a second area, and the sum of the plurality of first areas being 30 to 60% of the second area.

[0009] Optionally, the thickness of the first film layer in the first direction is 5 to 15 nm.

[0010] Optionally, the thickness of the first film layer in the first direction is greater than or equal to the thickness of the first modification layer in the first direction.

[0011] Optionally, the first modification layer has anchoring functional groups.

[0012] Optionally, the system further includes a conductive layer located between the substrate and the first charge transport layer, the conductive layer comprising a transparent conductive oxide layer.

[0013] Optionally, the substrate includes a glass substrate or a narrow bandgap bottom cell, wherein the narrow bandgap bottom cell includes any one of an intrinsic thin-film heterojunction bottom cell, an oxide passivated contact bottom cell, an interdigitated back contact bottom cell, a back passivated emitter and back fully diffused bottom cell, and a heterojunction back contact bottom cell.

[0014] This application provides a perovskite solar cell. In this perovskite solar cell, the first charge transport layer includes a first film layer, a first modification layer, and a second modification layer. The first film layer, the first modification layer, and the second modification layer all have a first type, enabling the formation of stable charge transport paths. The first and second modification layers modify the interface of the first film layer. Furthermore, the second modification layer, being close to the perovskite absorber layer, can adjust the surface wettability of the first charge transport layer and promote the crystallization of the perovskite absorber layer, further improving charge transport efficiency. In other words, the first film layer, the first modification layer, and the second modification layer constitute a multifunctional composite transport layer (CTL) structure of the first type, which can effectively extract charge at the interface, improve the long-term stability of the device, and simultaneously modify adjacent film layers, effectively improving the crystallinity quality of the perovskite absorber layer. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 This is a schematic cross-sectional view of a single-segment perovskite solar cell according to an embodiment of this application.

[0017] Figure 2This is a schematic cross-sectional view of an HTJ stacked perovskite solar cell according to an embodiment of this application.

[0018] Figure 3 This is a schematic cross-sectional view of a Topcon stacked perovskite solar cell according to an embodiment of this application.

[0019] Figure 4 This is a schematic cross-sectional view of an IBC stacked perovskite solar cell according to an embodiment of this application.

[0020] The above figures include the following reference numerals:

[0021] 10. Substrate; 111. Bottom TCO film layer; 112. First hydrogenated amorphous silicon layer; 1131. First intrinsic hydrogenated amorphous silicon layer; 1132. Second intrinsic hydrogenated amorphous silicon layer; 114. Single crystal silicon layer; 115. Second hydrogenated amorphous silicon layer; 116. Second electrode; 121. First substrate; 123. Doped emitter layer; 124. First passivation layer; 125. Second doped layer; 126. Silicon oxide layer; 127. Polycrystalline silicon layer; 128. Second passivation layer; 129. ... Three electrodes; 131, second substrate; 132, front field layer; 133, third passivation layer; 134, emitter; 135, back field layer; 136, fourth passivation layer; 137, fourth electrode; 138, fifth electrode; 20, first charge transport layer; 21, first film layer; 22, first modification layer; 23, second modification layer; 30, perovskite absorber layer; 40, second charge transport layer; 50, first electrode; 60, first conductive layer; 80, buffer layer; 90, second conductive layer. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, products, or devices.

[0025] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element via a third element.

[0026] As described in the background section, the charge transport layer in the prior art is mainly NiO prepared by physical vapor deposition (PVD). x Self-assembled monolayer films (SAM layers) prepared by solution methods and SnO2 layers deposited by ALD are typically limited by the inherent properties of the materials, leading to problems such as energy level mismatch, poor wettability, and severe recombination at the interface. This results in significant recombination losses at the transport layer interface, severely impacting the cell's performance and long-term stability. To address these issues, this application provides a perovskite solar cell.

[0027] According to one aspect of this application, a perovskite solar cell is provided, such as... Figures 1 to 4As shown, the device includes a substrate 10 and a first charge transport layer 20, a perovskite absorption layer 30, a second charge transport layer 40, and a first electrode 50 stacked on one side of the substrate 10 along a first direction A. The first charge transport layer 20 includes a first film layer 21, a first modification layer 22, and a second modification layer 23 stacked along the first direction A. The first film layer 21 is located on the side of the first modification layer 22 close to the substrate 10. The first film layer 21, the first modification layer 22, and the second modification layer 23 all have a first type, which is either P-type or N-type. The first direction A is the direction from the substrate 10 to the first electrode 50. In this perovskite solar cell, the first charge transport layer 20 comprises a three-layer structure: a first film layer 21, a first modification layer 22, and a second modification layer 23. The first film layer 21, the first modification layer 22, and the second modification layer 23 all possess a first type, enabling the formation of stable charge transport paths. The first modification layer 22 and the second modification layer 23 modify the interface of the first film layer. Furthermore, the second modification layer 23, being close to the perovskite absorber layer 30, can adjust the surface wettability of the first charge transport layer 20 and simultaneously promote the crystallization of the perovskite absorber layer 30, further improving charge transport efficiency. In other words, the first film layer 21, the first modification layer 22, and the second modification layer 23 constitute a multifunctional composite transport layer (CTL) structure of the first type, which can effectively extract charge at the interface, improving the long-term stability of the device, while also modifying adjacent film layers, effectively improving the crystallinity of the perovskite absorber layer 30.

[0028] Specifically, the first film layer is used to make complete contact with the underlying interface, promote rapid charge extraction, and improve the long-term stability of the device; the first modification layer is used to adjust the energy level matching between different interfaces, improve the surface tension at the interface, reduce charge recombination loss at the interface, and improve the deposition quality of the upper film; the second modification layer is used to improve the surface wettability of the interface passivation layer, promote the complete coverage of the upper perovskite absorption layer, promote the crystallization of perovskite, and promote charge transport at the interface.

[0029] The material of the first film layer may include a semiconductor material of the first type, thereby forming a stable charge transport path. The material of the first modification layer may include an organic material of the first type, thereby improving the energy level matching of the first charge transport layer and reducing charge recombination. The material of the second modification layer may include a semiconductor material of the first type. During the formation of the perovskite absorber layer, the second modification layer may adjust the surface wettability of the first modification layer and promote the crystallization effect of the perovskite absorber layer.

[0030] In some alternative embodiments, the N-type semiconductor material includes one or more of zinc oxide, titanium oxide, gallium nitride, tin oxide, indium gallium zinc oxide, fluorine-doped tin oxide, and fluorine-doped indium oxide; the P-type semiconductor material includes one or more of nickel oxide, copper oxide, lead dioxide, polymer materials, metal halides, molybdenum sulfide, and cadmium selenide; and the material of the first modification layer includes an organic material having a conductive framework for transporting electrons or holes.

[0031] Specifically, in N-type semiconductor materials, zinc oxide (ZnO) possesses a wide bandgap and high electron mobility, titanium oxide (TiO2) exhibits a high dielectric constant and good stability, gallium nitride (GaN) demonstrates high electron mobility and chemical stability, tin oxide (SnO2) exhibits good electron transport performance and transparency, and indium gallium zinc oxide (IGZO) possesses high mobility and transparency. Further improvements in conductivity and stability can be achieved by doping SnO2 with fluorine to obtain fluorine-doped tin oxide (FTO) or by doping indium oxide with fluorine to obtain fluorine-doped indium oxide (ITO). Nickel oxide (NiO), copper oxides (CuO, Cu2O), lead dioxide (PbO2), molybdenum sulfide (MoS2), and copper oxide (CuO) are also suitable. x Both cadmium selenide (CdSe) and cadmium selenide (CdSe) are P-type semiconductor materials that can be used as hole transport layers in perovskite solar cells. In addition, polymer materials such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and poly(triphenylamine methacrylate) (PTAA) are also excellent P-type hole transport materials. Metal halides such as lead halide perovskites can also be used as P-type semiconductor materials in perovskite solar cells due to their good hole transport capabilities and transparency.

[0032] In the above embodiments, the first charge transport layer and the second charge transport layer are of different types. Specifically, when the first type is P-type, the first film layer and the second modification layer are both P-type semiconductor material layers, and the first modification layer has a conductive framework for transporting holes, then the second charge transport layer is a P-type semiconductor material layer. In this case, the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer. When the first type is N-type, the first film layer and the second modification layer are both N-type semiconductor material layers, and the first modification layer has a conductive framework for transporting electrons, then the second charge transport layer is an N-type semiconductor material layer. In this case, the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer.

[0033] In some optional embodiments, the processes for forming the first film layer and the second charge transport layer include, but are not limited to, physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), and evaporation processes, forming a uniformly covered thin film that can meet the fabrication requirements of large-size batteries; the processes for forming the first modification layer include, but are not limited to, spraying, inkjet printing, coating, immersion, and chain-machine single-sided contact reaction processes, to meet the fabrication requirements of large-size batteries; the processes for forming the second modification layer include, but are not limited to, solution processes such as coating, spraying, and inkjet printing, to deposit non-uniform nanoparticles on a large-size substrate. Those skilled in the art can make reasonable selections according to actual needs, and no specific limitations are imposed.

[0034] In some alternative implementations, the second modification layer consists of multiple cluster structures, which are formed by the stacking of multiple particles.

[0035] Specifically, the second modification layer is located between the first modification layer and the perovskite absorber layer, and is in contact with the perovskite absorber layer. The second modification layer consists of a cluster structure composed of multiple particles, which increases the surface area in contact with the perovskite absorber layer, improving charge transport efficiency. Furthermore, the cluster structure can regulate the energy level matching between different film layers, increase interface roughness, reduce the energy barrier at the interface, and improve the battery's electrical performance. Simultaneously, it improves the wettability between the first modification layer and the perovskite absorber layer and modifies the first modification layer, allowing the perovskite absorber layer to make closer contact with the passivation layer during deposition, reducing voids and defects, improving film quality, and lowering the probability of non-radiative recombination. In addition, the cluster structure can disperse the stress generated by the difference in thermal expansion coefficients between different film layers, mitigating cracking or peeling of the perovskite absorber layer under extreme environmental conditions, and improving the battery's mechanical stability and long-term reliability.

[0036] The cluster structure can include irregular structures, which can scatter incident light, increase the residence time and optical path of light in the perovskite absorption layer, thereby improving the light absorption efficiency and further enhancing the photoelectric conversion efficiency of the battery.

[0037] In some alternative implementations, the particle diameter is 10–100 nm.

[0038] Specifically, multiple particles with diameters of 10–100 nm constitute a cluster structure. These nanoparticles, with their high specific surface area, provide more charge transport interfaces, accelerating charge extraction from the perovskite absorber layer to the first charge transport layer, reducing interfacial recombination losses, and thus improving the battery's fill factor and open-circuit voltage. The nanoparticles in the cluster structure can also serve as nucleation sites during the perovskite crystallization process, promoting uniform perovskite crystal growth, reducing the formation of vacancies and other defects in the perovskite absorber layer, improving crystal quality, and thereby enhancing the battery's photoelectric conversion efficiency and stability.

[0039] In some alternative implementations, the diameter of the cluster structure is 10–500 nm.

[0040] Specifically, the cluster structure in the first modification layer increases the roughness of the film, thereby increasing the contact area between the first charge transport layer and the perovskite absorber layer. This facilitates rapid charge transport, reduces charge recombination, and improves the extraction efficiency of holes or electrons. The cluster structure has a diameter of 10–500 nm, which is a nanoscale cluster structure. These nanoscale clusters can act as crystal nuclei, promoting uniform crystallization of the perovskite material, reducing crystallization defects, and improving the crystal quality and stability of the perovskite absorber layer, thus increasing battery efficiency. The nanoscale cluster structure also exhibits high surface activity, improving the wettability of the perovskite material on the first charge transport layer, resulting in a more uniform deposition of the perovskite absorber layer and reducing the formation of voids and defects. Furthermore, the smaller nanoscale cluster structure further optimizes charge transport between the perovskite absorber layer and the electrode, reducing interfacial barriers, improving charge transport efficiency, and further enhancing the long-term stability and durability of the battery.

[0041] In some alternative embodiments, the first film layer has a first surface facing away from the substrate, and multiple cluster structures have multiple first projections on the first surface. The first projections have a first area, and the first surface has a second area. The sum of the multiple first areas is 30 to 60% of the second area.

[0042] Specifically, the cluster structure of the first modification layer has a coverage of 30%–60%, forming a non-complete coverage. This non-completely covered cluster structure can serve as a bridging point for the first charge transport, effectively promoting the rapid extraction of charge from the perovskite absorber layer to the first charge transport layer, forming an effective charge transport network. The low coverage means less material is used, thus reducing fabrication costs and facilitating large-scale production of perovskite solar cells. Furthermore, a completely covered film may lead to increased optical absorption or scattering, as well as losses due to excessively long electrical paths. The non-completely covered cluster structure can reduce these negative effects, maintaining good optical transparency and electrical conductivity.

[0043] In some alternative embodiments, the thickness of the first film layer in the first direction is 5 to 15 nm.

[0044] Specifically, the thickness of the first film layer is set between 5 and 15 nm, based on a comprehensive optimization of coverage, optical, and electrical performance. If the thickness of the first film layer is too thin (less than 5 nm), it will not form a complete film layer, insufficient to fully cover the surface of the underlying material, leading to discontinuous charge transport, increased recombination losses at the interface, and potentially unstable battery performance under harsh conditions (such as high temperature and humidity), with more significant efficiency degradation after long-term operation. Furthermore, a thinner first film layer may not form stable interfacial contacts, affecting effective charge extraction and thus reducing the battery's fill factor and open-circuit voltage. If the thickness of the first film layer is too thick (greater than 15 nm), it will increase the absorption of incident light, reducing the effective light reaching the perovskite absorption layer and thus reducing the battery's photoelectric conversion efficiency. An excessively thick charge transport layer will impair light transmittance, and further, an excessively thick charge transport layer will increase the path length and resistance of charge transport, affecting charge transport efficiency. The thickness of the first film layer, ranging from 5 to 15 nm, ensures complete coverage of the underlying material, forming a good charge transport interface without causing excessive optical and electrical losses. Furthermore, within this thickness range, the film layer exhibits good physical stability and chemical compatibility, reducing performance fluctuations caused by environmental changes and improving the long-term stability of the battery.

[0045] In some alternative implementations, such as Figures 1 to 4 As shown, the thickness H1 of the first film layer 21 in the first direction A is greater than or equal to the thickness H2 of the first modification layer 22 in the first direction A.

[0046] Specifically, the first film layer is the main charge transport layer of the first charge transport layer. The first modification layer, while transporting charge, also has a passivation effect, adjusting the energy level matching between different interfaces, improving surface tension at the interface, reducing charge recombination losses at the interface, and improving the deposition quality of the upper film. The thickness of the first film layer is greater than the thickness of the first modification layer, providing a continuous and stable charge transport path, helping to reduce recombination losses caused by poor material contact, improving charge transport efficiency at the interface, and thus improving the overall performance of the battery. Furthermore, the thickness of the first modification layer is less than the thickness of the first film layer, which, while providing passivation, reduces manufacturing costs, avoids material waste, and facilitates large-scale production.

[0047] In the above embodiments, the thickness of the first modification layer can be 1 to 5 nm. The actual thickness depends on the post-processing method of the interface passivation layer, and this application does not make a specific limitation.

[0048] In some alternative implementations, the first modification layer has anchoring functional groups.

[0049] Specifically, the material of the first modification layer has anchoring functional groups. These anchoring functional groups can form chemical bonds with the surface molecules of the first film layer material or the perovskite material, thereby harmonizing energy level differences and promoting charge transport between the perovskite absorber layer and the transport layer. This energy level harmonization can reduce charge recombination at the interface and improve the charge extraction efficiency of the battery. During the formation of the perovskite material, surface defects may occur. These defects can trap and confine charges, leading to non-radiative recombination and reducing battery efficiency. The anchoring functional groups of the interface passivation layer can bind to these defect sites, passivating surface defects, reducing charge recombination, and improving battery performance. Simultaneously, the anchoring functional groups can improve the wettability between the first modification layer and the upper layer material, promoting uniform deposition of the upper layer material, contributing to the formation of a denser and more uniform film, reducing voids and cracks, improving film integrity, and thus improving the stability and efficiency of the battery.

[0050] In some alternative implementations, such as Figures 1 to 4 As shown, the perovskite solar cell also includes a first conductive layer 60, which is located between the substrate 10 and the first charge transport layer 20. The first conductive layer 60 includes a transparent conductive oxide layer.

[0051] Specifically, transparent conductive oxides (TCOs) exhibit high transmittance and low resistivity within the visible light spectrum (380 nm–780 nm). Using TCOs as the first conductive layer can effectively reduce contact resistance and improve current transmission efficiency, thereby increasing the fill factor of the battery. Simultaneously, the transparency of TCOs allows more photons to reach the perovskite absorption layer, increasing the battery's light absorption efficiency. Furthermore, ITO possesses excellent chemical stability, protecting the substrate material from the effects of chemical reagents used in subsequent processing, reducing inter-material chemical reactions, and maintaining the long-term stability and reliability of the battery.

[0052] In some optional embodiments, the transparent conductive oxide material includes one or more of indium zinc oxide (IZO), indium tin oxide (ITO), indium hydroxide-doped (In2O3:H), aluminum-doped zinc oxide (AZO), zirconium-doped indium oxide (IZrO), and zinc-doped tin oxide (ZTO). Those skilled in the art can make reasonable selections according to actual needs, and no specific limitations are made in this application.

[0053] In some alternative implementations, such as Figures 1 to 4As shown, a buffer layer 80 and a second conductive layer 90 are also included between the second charge transport layer 40 and the first electrode 50. The buffer layer 80 reduces the charge accumulation and interface energy level mismatch caused by the interface influence between the second charge transport layer 40 and the perovskite absorber layer 30, thereby improving the efficiency of the solar cell. The second conductive layer 90 has good conductivity and transparency, which can effectively transfer electrons and allow light to penetrate to the perovskite absorber layer, while also protecting the perovskite absorber layer from erosion or damage by the external environment.

[0054] The buffer layer and the second charge transport layer have the same semiconductor material. The material of the second conductive layer includes, but is not limited to, one or more of the following: indium zinc oxide (IZO), indium tin oxide (ITO), indium hydroxide (In2O3:H), aluminum zinc oxide (AZO), zirconium-doped indium oxide (IZrO), and zinc tin oxide (ZTO).

[0055] In some alternative embodiments, the substrate includes a glass substrate or a narrow bandgap bottom cell, which includes any one of an intrinsic thin-film heterojunction bottom cell, an oxide passivated contact bottom cell, an interdigitated back contact bottom cell, a back passivated emitter and back fully diffused bottom cell, and a heterojunction back contact bottom cell.

[0056] Specifically, the perovskite solar cell of this application can be as follows: Figure 1 The perovskite single-junction solar cell shown includes a substrate 10 that may include a glass substrate. Specifically, the perovskite solar cell may include FTO conductive glass, ITO conductive glass, AZO conductive glass, and a conductive flexible substrate. The fabrication process for perovskite single-junction solar cells is mature, enabling large-area fabrication, and it exhibits high stability.

[0057] The perovskite solar cell in this application can also be used for, for example Figures 2 to 4The perovskite tandem solar cell structure shown is illustrated. Specifically, the substrate is a solar cell, which includes one of the following: an intrinsic thin-film heterojunction (HJT) solar cell (i.e., a crystalline silicon solar cell), a tunnel oxide passivated contact (Topcon) solar cell, a passivated emitter and rear cell (PERC), an interdigitated back contact (IBC) solar cell, and a hybrid passivated back contact (HBC) solar cell. This application does not impose any specific limitations on the solar cell.

[0058] For example, the substrate 10 in a perovskite solar cell can be an HJT bottom cell, such as... Figure 2 As shown, the HJT bottom cell may include: a bottom TCO film layer 111 and a first hydrogenated amorphous silicon layer 112, a first intrinsic hydrogenated amorphous silicon layer 1131, a monocrystalline silicon layer 114, a second intrinsic hydrogenated amorphous silicon layer 1132, and a second hydrogenated amorphous silicon layer 115, which are sequentially formed on the first surface of the bottom TCO film layer 111 perpendicular to the first surface. The surface of the second hydrogenated amorphous silicon layer 115 facing away from the bottom TCO film layer 111 is the front side of the bottom cell, i.e., the front side of the substrate 10. The solar bottom cell may also include a second electrode 116 formed on the back side of the bottom TCO film layer 111.

[0059] In another example, the substrate 10 in a perovskite solar cell can be a Topcon substrate, such as... Figure 3 As shown, the Topcon tandem solar cell may include a first substrate 121, which has a front side and a back side. The Topcon tandem solar cell may also include a first doped emitter layer 123 and a first passivation layer 124 stacked on the front side of the first substrate 121 along a direction perpendicular to the front side. The Topcon tandem solar cell may also include a second doped layer 125, a silicon oxide layer 126, a second doped polycrystalline silicon layer 127, a second passivation layer 128, and a third electrode 129 stacked on the back side of the first substrate along a direction perpendicular to the back side. This perovskite tandem solar cell structure combines the advantages of perovskite solar cells, broadens the absorption spectrum of the solar cell, and achieves higher photoelectric conversion efficiency.

[0060] In yet another example, the substrate 10 in a perovskite solar cell can be an IBC substrate, such as... Figure 4As shown, the IBC bottom cell may include: a second substrate 131 having a first doping type; a front field layer 132 having a first doping type located on the front side of the second substrate 131; a third passivation layer 133 disposed on the front field layer 132; an emitter 134 of the second doping type and a back field layer 135 of the first doping type alternately disposed on the back side of the second substrate 131; a fourth passivation layer 136 disposed on the side of the emitter 134 and the back field layer 135 facing away from the second substrate 131; a fourth electrode 137 and a fifth electrode 138 penetrating the fourth passivation layer 136, wherein the fourth electrode 137 is connected to the emitter 134 and the fifth electrode 138 is connected to the back field layer 135.

[0061] The perovskite solar cells provided in this application will be further described below with reference to embodiments and comparative examples.

[0062] Example 1

[0063] This embodiment provides a perovskite solar cell, comprising:

[0064] An ITO tunneling layer is formed on the front side of the HTJ bottom cell; a 5nm thick NiO layer is formed on the ITO tunneling layer opposite to the HTJ bottom cell. x The system consists of a first film layer, a 1 nm thick 2PACz layer as a first modification layer, and a 30% coverage Al2O3 nanoparticle layer as a second modification layer. The nanoparticles are composed of 10 nm clusters, with each cluster containing 10 nm particles. The first film layer, first modification layer, and second modification layer constitute a hole transport layer. A 600 nm thick perovskite absorber layer, a 20 nm thick second charge transport layer, a 20 nm thick buffer layer, a 100 nm thick second conductive layer, and a first electrode are sequentially stacked on the hole transport layer. The material of the second charge transport layer is C. 60 The buffer layer is made of SnO2, the second conductive layer is made of IZO, and the first electrode is made of Ag.

[0065] Example 2

[0066] This embodiment provides a perovskite solar cell, which differs from Embodiment 1 in that:

[0067] The first film layer is NiO with a thickness of 15 nm. x The first modification layer is a 2PACz layer with a thickness of 1 nm; the second modification layer is Al2O3 nanoparticles with a coverage of 60%, wherein the nanoparticles are composed of 500 nm cluster structures and the particle diameter in the cluster structure is 100 nm.

[0068] Example 3

[0069] This embodiment provides a perovskite solar cell, which differs from Embodiment 1 in that:

[0070] The first film layer is NiO with a thickness of 10 nm. x The first modification layer is a 2PACz layer with a thickness of 1 nm; the second modification layer is Al2O3 nanoparticles with a coverage of 45%, wherein the nanoparticles are composed of a 260 nm cluster structure and the particle diameter in the cluster structure is 55 nm.

[0071] Example 4

[0072] This embodiment provides a perovskite solar cell, which differs from Embodiment 3 in that:

[0073] The first film layer is NiO with a thickness of 20 nm. x layer.

[0074] Example 5

[0075] This embodiment provides a perovskite solar cell, which differs from Embodiment 3 in that:

[0076] The second modification layer consists of Al2O3 nanoparticles with a coverage of 80%, wherein the nanoparticles are composed of a 260nm cluster structure and the particle diameter in the cluster structure is 55nm.

[0077] Example 6

[0078] This embodiment provides a perovskite solar cell, which differs from Embodiment 3 in that:

[0079] The second modification layer consists of Al2O3 nanoparticles with a coverage of 45%, wherein the nanoparticles are composed of 800nm ​​cluster structures and the particle diameter in the cluster structure is 55nm.

[0080] Example 7

[0081] This embodiment provides a perovskite solar cell, which differs from Embodiment 3 in that:

[0082] The second modification layer consists of Al2O3 nanoparticles with a coverage of 45%, wherein the nanoparticles are composed of a 260nm cluster structure and the particle diameter in the cluster structure is 200nm.

[0083] Comparative Example 1

[0084] This comparative example provides a perovskite solar cell, which differs from Example 3 in that:

[0085] Excluding the second modification layer, i.e., a perovskite absorber layer with a thickness of 600 nm is formed on the first modification layer.

[0086] The perovskite solar cells provided in the examples and comparative examples were subjected to spectral distribution AM1.5G and illumination intensity of 1000 mW / cm², respectively. 2 Using an AAA solar simulator as the light source, all components were simply encapsulated and unpackaged. The photoelectric performance of the solar cell was measured in an atmospheric environment. The effective area of ​​the device was 1.0 cm². 2 The JV curve was obtained by measuring with a Keithly 2400 digital source meter, and the photoelectric performance test parameters were then obtained. The results are shown in Table 1.

[0087] Table 1

[0088]

[0089] As shown in Table 1, compared with Comparative Example 1, the open-circuit voltage Voc, fill factor FF, and conversion efficiency EFF of the solar cells in Examples 1 to 7 based on a multilayer first charge transport layer are significantly improved. This indicates that the charge transport layer adopts a three-layer film configuration, and the material in the middle film layer is an organic material, which can improve the photoelectric conversion efficiency of the solar cell.

[0090] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0091] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A perovskite solar cell, characterized in that, The device includes a substrate and a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a first electrode stacked along a first direction on one side of the substrate. The first charge transport layer includes a first film layer, a first modification layer, and a second modification layer stacked along the first direction. The first film layer is located on the side of the first modification layer close to the substrate. The first film layer, the first modification layer, and the second modification layer all have a first type, which is either P-type or N-type. The first direction is the direction from the substrate to the first electrode.

2. The perovskite solar cell according to claim 1, characterized in that, The second modification layer is composed of multiple cluster structures, which are formed by the stacking of multiple particles.

3. The perovskite solar cell according to claim 2, characterized in that, The diameter of the particles is 10 to 100 nm.

4. The perovskite solar cell according to claim 2, characterized in that, The diameter of the cluster structure is 10–500 nm.

5. The perovskite solar cell according to claim 2, characterized in that, The first film layer has a first surface facing away from the substrate, and the plurality of cluster structures have a plurality of first projections on the first surface. The first projections have a first area, and the first surface has a second area. The sum of the plurality of first areas is 30 to 60% of the second area.

6. The perovskite solar cell according to claim 1, characterized in that, The thickness of the first film layer in the first direction is 5 to 15 nm.

7. The perovskite solar cell according to claim 1, characterized in that, The thickness of the first film layer in the first direction is greater than or equal to the thickness of the first modification layer in the first direction.

8. The perovskite solar cell according to claim 1, characterized in that, The first modified layer has anchoring functional groups.

9. The perovskite solar cell according to claim 1, characterized in that, The perovskite solar cell further includes a conductive layer located between the substrate and the first charge transport layer, the conductive layer comprising a transparent conductive oxide layer.

10. The perovskite solar cell according to any one of claims 1 to 9, characterized in that, The substrate includes a glass substrate or a narrow bandgap bottom cell, wherein the narrow bandgap bottom cell includes any one of an intrinsic thin-film heterojunction bottom cell, an oxide passivated contact bottom cell, an interdigitated back contact bottom cell, a back passivated emitter and a back fully diffused bottom cell, and a heterojunction back contact bottom cell.

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