Silicon-perovskite laminated solar cell

Abstract

The utility model relates to a silicon-perovskite laminated solar cell, which comprises a first electrode layer, a silicon cell sheet, a hole transport layer, a perovskite layer, an electron transport layer and a second electrode layer which are laminated in sequence, the first electrode layer and the second electrode layer are two electrodes of the cell, and an aluminum oxide layer and a tantalum oxide layer are arranged between the silicon cell sheet and the first electrode layer. The aluminum oxide layer is close to the silicon cell, the tantalum oxide layer is close to the first electrode layer, a middle buffer layer is arranged between the hole transport layer and the perovskite layer, and a perovskite protection layer is arranged on one side, back to the perovskite layer, of the electron transport layer. According to the laminated solar cell, the aluminum oxide layer and the tantalum oxide layer are arranged between the silicon cell piece and the first electrode layer, the aluminum oxide layer passivates dangling bonds on the back surface of silicon, and the middle buffer layer is arranged between the hole transport layer and the perovskite layer, so that energy level matching between the perovskite layer and the hole transport layer is enhanced, and the perovskite performance is improved. And the interface defect density is reduced through the arrangement on the upper surface of the electron transport layer.

Description

TECHNICAL FIELD

[0001] The present application relates to a silicon-perovskite tandem solar cell, belonging to the field of photovoltaics. BACKGROUND

[0002] With the acceleration of global industrialization, a large amount of fossil energy is consumed, leading to continuous increase of greenhouse gas emissions such as carbon dioxide, causing global climate warming, which has brought serious threat to the survival and development of the ecological system and human society. In response to climate change, the international community has gradually reached a consensus that effective measures need to be taken to control greenhouse gas emissions and protect the ecological environment and climate stability of the earth. Under this background, the concept of carbon neutrality has emerged as the times require, becoming an important goal and direction of action for the global response to climate change.

[0003] As a clean energy, solar energy can meet the growing global energy demand. As a clean energy, solar energy can meet the growing global energy demand.

[0004] The photoelectric conversion efficiency of traditional solar cell has been greatly improved, but the laboratory conversion efficiency of single crystal silicon solar cell is currently around 26%-27%, and the conversion efficiency of polycrystalline silicon solar cell is generally around 20%-22%, and the actual conversion efficiency in large-scale application is even lower. This means that under the same light area and light conditions, the amount of electricity it can generate is relatively limited. With the increase of use time and the continuation of light, the performance of traditional solar cell will gradually decline, and the light-induced degradation phenomenon will occur.

[0005] The theoretical limit conversion efficiency of perovskite battery is relatively high, and the theoretical efficiency of single-junction perovskite battery can reach about 31%, and by forming a tandem battery with other battery technologies, its theoretical efficiency is expected to break through 45%. In comparison, the theoretical limit efficiency of traditional single crystal silicon battery is about 29.4%, and the main raw materials of perovskite battery are widely available and relatively low in price. For example, some metal halides and other materials that make up the perovskite structure have a much lower cost than the high-purity silicon material required for traditional crystalline silicon batteries. Therefore, a silicon-perovskite tandem battery is proposed, but the current tandem battery still has problems of interface defects, ion migration and environmental sensitivity leading to efficiency loss and insufficient stability. In the prior art, single-layer passivation or single interface modification is difficult to solve the problems of charge transport, interface recombination and encapsulation protection at the same time. CONTENT OF THE UTILITY MODEL

[0006] In order to solve the problems of ion migration and environmental sensitivity in the silicon-perovskite tandem battery, a silicon-perovskite tandem solar cell is provided, which sets an aluminum oxide layer and a tantalum oxide layer between the silicon cell and the first electrode layer, passivates the dangling bonds of the silicon back surface through the aluminum oxide layer, sets an intermediate buffer layer between the hole transport layer and the perovskite layer, enhances the energy level matching between the perovskite layer and the hole transport layer, reduces the interface defect density, sets a zirconium oxide layer on the surface of the electron transport layer, cooperates with the tantalum oxide layer to isolate water and oxygen, and prevents the internal battery from being eroded by water and oxygen in the environment.

[0007] The technical scheme adopted by the utility model is: a silicon-perovskite tandem solar cell, which comprises a first electrode layer, a silicon cell, a hole transport layer, a perovskite layer, an electron transport layer and a second electrode layer which are sequentially stacked, the first electrode layer and the second electrode layer are the two poles of the battery, characterized in that: an aluminum oxide layer and a tantalum oxide layer are arranged between the silicon cell and the first electrode layer, the aluminum oxide layer is close to the silicon cell, the tantalum oxide layer is close to the first electrode layer, an intermediate buffer layer is arranged between the hole transport layer and the perovskite layer, and a perovskite protective layer is arranged on the side of the electron transport layer opposite to the perovskite layer.

[0008] As a preferred, the thickness of the aluminum oxide layer is 5-8nm, and the thickness of the tantalum oxide layer is 5-20nm.

[0009] As a preferred, the intermediate buffer layer is zinc oxide, and the thickness of the intermediate buffer layer is 1-3nm.

[0010] As a preferred, a continuous distribution of frustum-shaped microstructures is arranged on the surface of the side of the silicon cell facing the perovskite layer, and the frustum-shaped microstructures are prismatic frustum or circular frustum.

[0011] As a preferred, the frustum-shaped microstructures are quadrangular prismatic frustum, the height of the quadrangular prismatic frustum is 5-10μm, and the included angle between the edge and the bottom surface is 50-65°.

[0012] As a preferred, the frustum-shaped microstructures are circular frustum, the height of the circular frustum is 5-10μm, and the included angle between the side surface and the bottom surface is 40-50°.

[0013] As a preferred, the perovskite protective layer is a zirconium oxide layer, and the thickness of the zirconium oxide layer is 10-50nm.

[0014] As a preferred, a composite layer is arranged between the silicon cell and the hole transport layer, the composite layer comprises a first transparent conductive layer, a metal particle layer and a second transparent conductive layer, the first transparent conductive layer is connected to the hole transport layer, the second transparent conductive layer is connected to the silicon cell, and the metal particle layer is a metal particle arranged in a dispersed form in the interlayer between the first transparent conductive layer and the second transparent conductive layer.

[0015] As a preferred, the metal particles are gold particles or silver particles, and the metal particles are nanoparticles.

[0016] As a preferred, the first transparent conductive layer is p-type ITO, and the second transparent conductive layer is n-type ITO.

[0017] As a preferred, the particle size of the metal particles is 1-3 nm, and the coverage of the metal particles on the second transparent conductive layer is 30%-50%.

[0018] The effects produced by the present application will be described in detail in the specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Battery structure schematic diagram;

[0020] Figure 2 Composite layer structure schematic diagram;

[0021] Figure 3 Silicon wafer microstructure distribution schematic diagram;

[0022] Figure 4 Schematic diagram when the microstructure is a prism;

[0023] Figure 5 Schematic diagram when the microstructure is a circular truncated cone;

[0024] In the figure: 1, silicon wafer, 101, microstructure, 2, hole transport layer, 3, zinc oxide layer, 4, perovskite layer, 5, electron transport layer, 6, zirconium oxide layer, 7, aluminum oxide layer, 8, tantalum oxide layer, 9, silver electrode layer, 10, composite layer, 1001, first transparent conductive layer, 1002, second transparent conductive layer, 1003, metal particle layer, 11, prism, 1101, edge, 1102, bottom surface, 12, circular truncated cone. DETAILED DESCRIPTION

[0025] The present application will be further explained in detail in combination with the drawings and specific implementation, but it should be understood that the protection scope of the present application is not limited by the specific implementation. If no special description, any range recorded in the present application includes end value and any numerical value between the end values and any sub-range formed by the end value or any numerical value between the end values.

[0026] The person skilled in the art will understand that the perovskite layer material can be represented by the general formula [A][B][X]3, wherein [A] is at least one monovalent cation, [B] is at least one divalent cation, and [X] is at least one anion. The perovskite layer 4, the hole transport layer 2, the electron transport layer 5, the first electrode layer, and the second electrode layer are all conventional materials used by the person skilled in the art as needed, and no improvement is involved in the materials.

[0027] The drawings are only schematic and the relative dimensions, the absolute dimensions, and the relative proportions of the parts do not correspond exactly to actual proportions. Figure 3 The purpose is to reflect the distribution and shape of the microstructure 101, and does not cover any size-related information.

[0028] As shown in Figure 1 The silicon-perovskite stacked solar cell in the utility model includes a first electrode layer 9, a silicon cell piece 1, a hole transport layer 2, a perovskite layer 4, an electron transport layer 5, and a second electrode layer which are stacked in sequence, the first electrode layer and the second electrode layer form two ends of the cell, the first electrode layer 9 is a back electrode, and the second electrode layer is a top electrode. In the embodiment, the first electrode layer 9 is a silver electrode or an aluminum back electrode, and the second electrode layer is a transparent electrode. An aluminum oxide layer 7 is arranged between the silicon cell piece 1 and the first electrode layer 9, the aluminum oxide can passivate the dangling bonds of the silicon cell piece 1 caused by cutting, and improve the carrier transport efficiency. A tantalum oxide layer 8 is arranged on the side of the aluminum oxide layer 7 away from the silicon cell piece 1, the layer serves as a protective layer of the silicon cell piece 1, prevents environmental erosion of the silicon cell piece 1, and prevents water and oxygen from entering the perovskite layer 4 from the side of the silicon cell piece 1. An intermediate buffer layer is arranged between the hole transport layer 2 and the perovskite layer 4, the layer plays a role in optimizing the energy level matching between the hole transport layer 2 and the perovskite layer 4, and improving the hole transport efficiency. In the embodiment, the intermediate buffer layer is preferably zinc oxide, which not only optimizes the energy level matching between the hole transport layer 2 and the perovskite layer 4, but also reduces the interface defect state density. A zirconium oxide layer 6 is arranged between the electron transport layer 5 and the second electrode layer 9, the zirconium oxide layer 6 serves as a protective layer to prevent water and oxygen from entering the perovskite layer 4, and also prevents part of ultraviolet rays from entering, thereby preventing damage to the cell piece by the ultraviolet rays.

[0029] The thickness of the aluminum oxide layer 7 is 5-8 nm, and the thickness of the tantalum oxide layer 8 is 5-20 nm, which not only enables the carrier to reach the first electrode layer 9 smoothly, but also is beneficial to ensuring the blocking effect of the tantalum oxide on water and oxygen. The thickness of the intermediate buffer layer, i.e., the zinc oxide layer 3, is 1-3 nm, which not only can optimize the energy level difference between the perovskite and the hole transport layer 2, and play a role in connecting the perovskite layer 4 and the hole transport layer 2, but also plays a role in pressing the hole transport layer 2 on the silicon cell sheet 1. Since the hole transport layer 2 is unstable, the connection strength with the silicon substrate is weakened in the use process, which affects the battery efficiency. The 1-3 nm zinc oxide layer 3 can press the hole transport layer 2 material on the silicon substrate, and enhance the connection strength of the hole transport layer 2 and the substrate material. The thickness of the zirconium oxide layer 6 is 10-50 nm, which not only can play a role in isolating water and oxygen, and blocking ultraviolet light, but also has a transmittance of visible light of more than 95%.

[0030] In the present application, the silicon cell sheet 1 side facing the perovskite layer 4 is provided with a continuously distributed conical frustum-shaped microstructure 101, such as Figure 3 The microstructure 101 is a prism frustum Figure 4 ) or a circular frustum Figure 5 The conical frustum structure can be used as an anti-reflection layer to enhance the light absorption rate of the silicon cell sheet 1, and on the other hand, it reduces the influence of the microstructure 101 on the hole transport layer 2 and the perovskite layer 4 coated thereon, and on the other hand, it is helpful to form a uniform film layer. When the conical frustum-shaped microstructure 101 is a quadrangular prism frustum, such as Figure 4 , the height of the quadrangular prism frustum is 5-10 μm, and the included angle between the edge and the bottom surface is 50-65°. When the conical frustum is a circular frustum, such as Figure 5 , the height of the circular frustum is 5-10 μm, and the included angle between the side surface and the bottom surface is 40-50°, which can increase the secondary or multiple reflection of the surface, and finally reduce the reflectivity to less than 10%.

[0031] The present application is provided with a composite layer 10 between the silicon cell sheet 1 and the hole transport layer 2, such as Figure 2As shown, the composite layer 10 is composed of a first transparent conductive layer 1001, a metal particle layer 1003 and a second transparent conductive layer 1002, the first transparent conductive layer 1001 is connected to the hole transport layer 2, and the second transparent conductive layer 1002 is connected to the silicon cell 1. The first transparent conductive layer 1001 serves to guide the holes generated on the perovskite into the metal particle layer 1003, and the second transparent conductive layer 1002 serves to guide the electrons generated on the silicon cell 1 into the metal particle layer 1003. The electrons and holes are recombined at the metal particle layer 1003. The metal in the metal particle layer 1003 is dispersed in the form of nanoparticles, which provides catalytic recombination sites for the recombination of holes and electrons, thereby enhancing the recombination. The particle size of the metal particles is 1-3 nm, and the coverage of the metal particles on the second transparent conductive layer 1002 is 30%-50%. Under this arrangement, the contradiction between the recombination efficiency and the light transmittance can be reconciled. In this embodiment, the first transparent conductive layer 1001 is preferably p-type ITO, and the second transparent conductive layer 1002 is n-type ITO, which is conducive to enhancing the transmission efficiency of holes or electrons. Compared with the control group, i.e., the battery without the aluminum oxide layer 7, the tantalum oxide layer 8, the intermediate buffer layer, the frustum-shaped microstructure 101 and the composite layer 10, which is only an ITO layer, the battery efficiency of this embodiment is increased by 8-12%, the efficiency retention rate of the wet heat test (85℃ / 85%RH) is >90% (the control group is <70%), and the efficiency decay is still less than 5% after 1000 hours of outdoor light exposure.

[0032] The above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A silicon-perovskite tandem solar cell, comprising a first electrode layer, a silicon cell piece, a hole transport layer, a perovskite layer, an electron transport layer and a second electrode layer stacked in sequence, the first electrode layer and the second electrode layer being two poles of the cell, characterized in that: An aluminum oxide layer and a tantalum oxide layer are arranged between the silicon cell and the first electrode layer, the aluminum oxide layer is close to the silicon cell, and the tantalum oxide layer is close to the first electrode layer; an intermediate buffer layer is arranged between the hole transport layer and the perovskite layer; and a perovskite protective layer is arranged on the side of the electron transport layer away from the perovskite layer.

2. The silicon-perovskite tandem solar cell of claim 1, wherein: The thickness of the aluminum oxide layer is 5-8 nm, and the thickness of the tantalum oxide layer is 5-20 nm.

3. The silicon-perovskite tandem solar cell of claim 1, wherein: The intermediate buffer layer is zinc oxide, and the thickness of the intermediate buffer layer is 1-3 nm.

4. The silicon-perovskite tandem solar cell of claim 1, wherein: A continuous distribution of frustum-shaped microstructures is arranged on the side surface of the silicon cell facing the perovskite layer, and the frustum-shaped microstructures are pyramidal frustums or circular frustums.

5. The silicon-perovskite tandem solar cell of claim 4, wherein: The microstructures are one of the following: The frustum-shaped microstructures are square pyramidal frustums, the height of the square pyramidal frustums is 5-10 μm, and the angle between the edge and the bottom surface is 50-65°. The frustum-shaped microstructures are circular frustums, the height of the circular frustums is 5-10 μm, and the angle between the side surface and the bottom surface is 40-50°.

6. The silicon-perovskite tandem solar cell of claim 1, wherein: The perovskite protective layer is a zirconium oxide layer, and the thickness of the zirconium oxide layer is 10-50 nm.

7. The silicon-perovskite tandem solar cell of claim 1, wherein: A composite layer is arranged between the silicon cell and the hole transport layer, the composite layer comprises a first transparent conductive layer, a metal particle layer and a second transparent conductive layer, the first transparent conductive layer is connected to the hole transport layer, the second transparent conductive layer is connected to the silicon cell, and the metal particle layer is a metal particle layer arranged in a dispersed form in the interlayer between the first transparent conductive layer and the second transparent conductive layer.

8. The silicon-perovskite tandem solar cell of claim 7, wherein: The metal particles are gold particles or silver particles, and the metal particles are nanoparticles.

9. The silicon-perovskite tandem solar cell of claim 7, wherein: The first transparent conductive layer is p-type ITO, and the second transparent conductive layer is n-type ITO.

10. The silicon-perovskite tandem solar cell of claim 7, wherein: The particle size of the metal particles is 1-3 nm, and the coverage of the metal particles on the second transparent conductive layer is 30%-50%.

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