WO2023221561A1

WO2023221561A1 - Solar cell

Info

Publication number: WO2023221561A1
Application number: PCT/CN2023/074574
Authority: WO
Inventors: 李子峰; 解俊杰; 吴兆; 徐琛; 孙朱行; 刘童
Original assignee: 隆基绿能科技股份有限公司
Priority date: 2022-05-16
Filing date: 2023-02-06
Publication date: 2023-11-23
Also published as: CN117133822A

Abstract

The present invention relates to the technical field of photovoltaics. Disclosed is a solar cell, which is used for widening the absorption spectrum of a solar cell and improving the efficiency of the solar cell. The solar cell comprises: a first electrode, a first carrier transport layer, a light absorption layer, a second carrier transport layer and a second electrode, which are stacked from bottom to top, wherein the first electrode is a transparent electrode; and the solar cell further comprises at least one conductive reflection structure, wherein a first side of the conductive reflection structure is in electrical contact with the second electrode, and the conductive reflection structure contains a wavelength conversion material and is provided with a reflection surface which inclines relative to an extension plane of the solar cell.

Description

a solar cell

This application claims priority to the Chinese patent application with application number 202210530778.8 and titled "A Solar Cell" submitted to the China Patent Office on May 16, 2022, the entire content of which is incorporated into this application by reference.

Technical field

The present invention relates to the field of photovoltaic technology, and in particular to a solar cell.

Background technique

In the process of converting solar energy into electrical energy, solar cells can usually only absorb light whose energy is within its band gap, while near-infrared light or infrared light below its band gap will pass through the cell and be converted into heat energy.

At present, an up-conversion layer can be set behind the light-absorbing layer of a solar cell to convert the spectral energy that cannot be used by the absorbing layer into photons that can be absorbed by the light-absorbing layer through the up-conversion mechanism and reflect it into the light-absorbing layer. Absorb again to improve the conversion efficiency of perovskite cells.

However, the direct introduction of the up-conversion layer in the existing technology will cause instability in the structure of the corresponding film layer of the solar cell and a decrease in performance, and cannot fully utilize the advantages of up-conversion materials in improving the conversion efficiency of perovskite cells.

Contents of the invention

The object of the present invention is to provide a solar cell for broadening the absorption spectrum of the solar cell and improving the conversion efficiency of the solar cell.

In a first aspect, the present invention provides a solar cell. The solar cell includes a first electrode, a first carrier transport layer, a light absorption layer, a second carrier transport layer and a second electrode that are stacked in sequence. Wherein, the first electrode is a transparent electrode. The solar cell also includes at least one electrically conductive reflective structure. The first side of the conductive reflective structure is in electrical contact with the second electrode. The second side of the conductive reflective structure is in electrical contact with the second carrier transport layer. The conductive reflective structure includes a wavelength conversion material, and the conductive reflective structure has a reflective surface inclined relative to the solar cell extension plane.

When the above technical solution is adopted, the solar cell provided by the present invention includes a first electrode, a first carrier transport layer, a light absorption layer, a second carrier transport layer and a second electrode stacked from bottom to top. The first electrode is a transparent electrode, and the horizontal plane where the first electrode is located is the entrance of light. On the incident surface, sunlight is incident from the first electrode into the solar cell, and the sunlight that conforms to the band gap range of the solar cell is absorbed by the light absorption layer, ensuring the normal absorption of light by the solar cell. The solar cell also includes at least one electrically conductive reflective structure containing a wavelength converting material, the electrically conductive reflective structure having a reflective surface inclined relative to the plane of extension of the solar cell. Based on this, in the incident sunlight, the light that conforms to the band gap range of the solar cell will be directly absorbed and utilized by the light absorption layer, while the invisible light that cannot be absorbed by the solar cell will pass through the light absorption layer and be contained in the conductive reflective structure. The wavelength conversion material converts it into visible light that can be absorbed and utilized by the solar cell. The converted visible light is directed toward the reflective surface of the conductive reflective structure that is inclined relative to the solar cell extension plane. Since the light absorption layer is parallel to the solar cell extension plane, Therefore, the converted visible light directed to the conductive reflective structure will be reflected back to the light absorbing layer at a certain angle, and then be absorbed and utilized by the light absorbing layer. Based on this, the present invention can broaden the absorption spectrum of the solar cell and improve the energy utilization efficiency of the solar cell. And there is a certain angle between the visible light and the light-absorbing layer during reflection. Compared with direct reflection, the optical path of the visible light becomes longer and the time it stays in the light-absorbing layer also becomes longer, which improves the absorption efficiency of the solar cell. In addition, the first side of the conductive reflective structure is in electrical contact with the second electrode, and the second side is in electrical contact with the second carrier transport layer, so that the second electrode and the second carrier transport layer are electrically connected, so that the conductive reflection structure is added The structure can also ensure the normal conductive performance of the solar cell.

In a possible implementation, the conductive reflective structure includes a conductive part and a wavelength conversion material disposed between the second electrode and the second carrier transport layer, and the wavelength conversion material forms the wavelength conversion layer. The conductive part penetrates the wavelength conversion layer. The conductive part has side walls that are inclined relative to the solar cell extension plane.

When the above technical solution is adopted, the wavelength conversion material included in the conductive reflective structure is arranged between the second electrode and the second carrier transport layer in the form of a wavelength conversion layer, and the conductive part penetrates the entire wavelength conversion layer, so that the conductive part The first side can be in electrical contact with the second electrode, and the second side can be in electrical contact with the second carrier transport layer, thereby realizing the electrical connection between the second electrode and the second carrier transport layer. The conductive part has side walls that are inclined relative to the extension plane of the solar cell. Based on this, the extension surface of the side wall of the conductive part does not intersect perpendicularly with the extension plane of the solar cell, but intersects obliquely at a certain angle, so that light absorption from The invisible light transmitted through the layer is converted by the wavelength conversion layer into visible light that can be absorbed and utilized by the solar cell and scattered. The converted visible light scattered on the side wall of the conductive part can be reflected to the light absorbing layer at a certain angle; based on this It broadens the absorption spectrum of the solar cell and improves the energy conversion efficiency of the solar cell; and the invisible light that passes through the light absorption layer and the converted visible light can be reflected obliquely at a certain angle after being directed to the side wall of the conductive part. In the wavelength conversion layer and the light absorption layer, the optical path is longer than that of normal incidence. Since the speed of light is constant, the light passing through the light absorption layer does not Visible light and converted visible light stay longer in the wavelength conversion layer and light absorption layer, which is more conducive to the wavelength conversion layer's absorption of invisible light that passes through the light absorption layer and the light absorption layer's absorption of converted visible light, further improving solar energy Battery efficiency. In addition, the conductive part can electrically connect the second carrier transport layer and the second electrode, so that the second carrier does not need to be transmitted through the wavelength conversion material, thereby avoiding the problem of reduced solar cell efficiency caused by poor conductivity of the wavelength conversion material. , improves the overall efficiency of the solar cell. At the same time, since there is no need to transmit carriers through the wavelength conversion material, there is no need to consider the conductivity issue when selecting the wavelength conversion material, and only need to focus on the conversion performance, broadening the wavelength conversion Material selection.

In some examples, the thickness of the wavelength conversion layer ranges from 20 nm to 300 nm.

In a possible implementation, the conductive reflective structure includes a wavelength conversion material and a conductive portion distributed inside the second carrier transport layer. The wavelength conversion material forms at least one discrete wavelength conversion structure, and the conductive part is connected to the second electrode. The conductive part has sidewalls that are inclined relative to the solar cell extension plane, and are used to reflect light waves entering the second carrier transport layer to the discrete wavelength conversion structure.

When the above technical solution is adopted, the wavelength conversion material and the conductive part included in the conductive reflective structure are both arranged in the second carrier transport layer. Wherein, the wavelength conversion material exists in the form of at least one discrete wavelength conversion structure in the second carrier transport layer, and while converting the invisible light transmitted through the light absorption layer into visible light that the solar cell can absorb and utilize, it reduces the The amount of wavelength conversion material is increased; the conductive part is connected to the second electrode to electrically connect the second electrode to the second carrier transport layer, so that the carriers are between the second carrier transport layer and the second electrode It can be transmitted directly through the conductive part instead of the wavelength conversion material, which solves the problem of reduced solar cell efficiency caused by the poor conductivity of the wavelength conversion material; the conductive part has side walls that are inclined relative to the solar cell extension plane, which can The light waves entering the second carrier transport layer are reflected to the discrete wavelength conversion structure at a certain angle. After that, the discrete wavelength conversion structure converts the invisible light into visible light that can be absorbed by the solar cell and emits it to the light absorption layer. , improving the efficiency of solar cells.

In a possible implementation, the discrete wavelength conversion structure includes at least one of a columnar upconversion structure, a discrete sheet upconversion structure, a mesh upconversion structure, and a discrete point upconversion structure.

When the above technical solution is adopted, the specific form of the discrete wavelength conversion structure can be at least one of a columnar upconversion structure, a discrete sheet upconversion structure, a mesh upconversion structure and a discrete point upconversion structure, based on Therefore, invisible light incident from all directions may enter the discrete wavelength conversion structure, and then be converted into visible light that can be absorbed and utilized by the solar cell. Discrete The specific form of the wavelength conversion structure can be selected according to different needs, which ensures that the invisible light incident from all directions is converted as much as possible while reducing the amount of wavelength conversion material.

In a possible implementation manner, the surface on which the side wall of the conductive part is located is a plane, and there is an angle α between the plane and one side surface of the conductive part. 30°≤α≤75°.

When the above technical solution is adopted, when the surface where the side wall of the conductive part is located is a plane, since the side wall of the conductive part is inclined relative to the solar cell extension plane, the plane where the side wall of the conductive part is located is different from the plane of the conductive part. There is an angle α between the surfaces on one side. When the invisible light or the converted visible light that passes through the light-absorbing layer is incident on the conductive part, it will be reflected into the wavelength conversion material and the light-absorbing layer at a certain angle. After broadening The absorption spectrum of solar cells not only improves the energy conversion efficiency of solar cells, but also increases the optical path length, making the light wave stay longer in the light absorption layer or wavelength conversion material, which is more conducive to the light absorption layer's ability to absorb visible light. Absorption utilization and light conversion further improve the efficiency of solar cells. When the range of the included angle α is 30°≤α≤75°, the light wave reflected by the side wall of the conductive part has a longer light wave. The preferred angle α is 45°. At this time, the optical path of the reflected light wave is the longest, and the light wave stays in the light absorption layer or wavelength conversion material for the longest time, which is conducive to the absorption and conversion of the light wave.

In a possible implementation, the surface where the side wall of the conductive part is located is a concave curved surface.

When the above technical solution is adopted, when the surface where the side wall of the conductive part is located is a concave curved surface, due to the concave structure of the curved surface, the surface where the side wall is located has a good light gathering effect, and the visible light transmitted through the light absorbing layer When directed toward the side wall of the conductive part, the light is concentrated and reflected by the curved side wall to the wavelength conversion material, so that the invisible light reflected by the side wall of the conductive part is converted into visible light by the wavelength conversion material, and is absorbed and utilized by the solar cell. , broadening the absorption spectrum of solar cells and improving the energy conversion efficiency of solar cells. A curved surface should be considered or include a rough curved surface formed by a series of small flat surfaces, as well as a general smooth surface. When the concave curved surface where the side wall of the conductive part is located has a focus, the wavelength conversion material can be placed at the focus of the curved surface, reducing the amount of wavelength conversion material used elsewhere, thereby reducing the cost of the solar cell. Based on this, the conductive part has a better light-concentrating effect, and the amount of wavelength conversion material is reduced further, further reducing the cost of the solar cell.

In a possible implementation, the wavelength conversion material is an upconversion material.

When the above technical solution is adopted, the up-conversion material can be excited by low-energy light and emit high-energy light, so that the wavelength conversion material can convert the incident invisible infrared light and near-infrared light into visible light, and then pass through The reflective surface of the conductive part reflects back into the light absorption layer, thereby improving the energy conversion efficiency of the solar cell.

In a possible implementation, the wavelength conversion material absorbs light in a wavelength range of 750 nm to 1 mm.

When the above technical solution is adopted, the wavelength conversion material can convert the light wave incident into the solar cell with a wavelength of 750 nm to 1 mm into visible light that can be absorbed and utilized by the light absorption layer of the solar cell.

In addition, in a possible implementation, the wavelength conversion material is a down-conversion material, or a wavelength conversion material including an up-conversion material and a down-conversion material.

When the above technical solution is adopted, the down-conversion material can convert the energy from one of ultraviolet light, x-rays and high-energy particles into visible light, and then reflect it back to the light absorption layer through the reflective surface of the conductive part, thereby increasing solar energy Battery energy conversion efficiency.

In a possible implementation, the material forming the wavelength conversion material includes a matrix doped with an activator and a sensitizer. The matrix includes one of fluoride, oxide and complex oxide.

When the above technical solution is adopted, the up-conversion luminescence phenomenon of converting two or more low-energy photons into one high-energy photon can be realized by using a matrix doped with an activator and a sensitizer. Specifically, the matrix is doped with an activator. The matrix material with the sensitizer is excited by light with long wavelength and low frequency, and emits light with short wavelength and high frequency. The matrix can be one of fluoride, oxide and complex oxide.

In a possible implementation, the fluoride includes NaYF ₄ , NaGaF ₄ , CaF ₂ , NaSrF ₄ , BaY ₂ F ₄ , LiYF 4 , ScYF ₄ , NaLnF ₄ , SrF ₂ , BaF ₂ _, MnF ₂ , Na(CF ₃ COO) ₃ F ₄ , LaF ₃ , NaLuF ₄ and Cs ₂ GeF ₆ . Oxides include Y ₂ O ₃ , ZrO ₂ , TiO ₂ , Gd2O ₃ , In ₂ O ₃ , SrY ₂ O ₄ , TeO ₂ , Al ₂ O ₃ , ZnO ₂ , Lu ₂ O ₃ , Er ₂ O ₃ , Eu ₂ One of O ₃ , CeO ₂ and La ₂ O ₃ . Composite oxides include LiNbO ₃ , Ln ₂ BaZnO ₂ , ALn(MoO ₄ ) ₂ , GdVO ₄ , YVo ₄ , CaZrO ₃ , CaSc ₂ O ₄ , KLu(WO ₄ ) ₂ , NaY(WO ₄ ) ₂ , CaCs ₂ O _4. One of CaMoO ₄ , BaTiO ₃ , Y ₂ Ti ₂ O ₇ , Y ₂ Si ₂ O ₇ , Y ₂ SiO ₅ , Gd ₃ Ga ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and Y ₂ CaGe ₄ O ₁₂ kind. Activators include Er ³⁺ , Ho ³⁺ , Tm ³⁺ , Gd ³⁺ , Pr ³⁺ , Sm ³⁺ , Ti ²⁺ , Cr ³⁺ , Ni ²⁺ , Mo ³⁺ , Re ⁴⁺ and Os ⁴⁺ at least one of them. The sensitizer includes at least one of Yb ³⁺ and Nd ³⁺ .

When the above technical solution is adopted, by combining different activators, sensitizers and different matrices, the infrared light and near-infrared light incident on the solar cell can be converted into incident light with a specific wavelength, thereby making the light The absorption layer can absorb light outside the band gap range, broadening the absorption spectrum of the solar cell and improving the energy conversion efficiency of the solar cell.

In a possible implementation, the second electrode is a metal electrode or a transparent electrode.

When the above technical solution is adopted, the second electrode is generally made of metal material. The metal material generally has a smooth interface and can form a mirror surface. When the invisible light transmitted through the light-absorbing layer is not guided When reflected at the electrical part, it can be reflected at the second electrode interface. Part of the invisible light is converted into visible light by the wavelength conversion material in the reflection path, and enters the light absorption layer along the reflection path, thereby improving the energy conversion efficiency of the solar cell. The second electrode can also be a transparent electrode to facilitate the penetration of light directed to the back of the solar cell, which is beneficial to improving the efficiency of the solar cell.

In a possible implementation, the material forming the conductive part is a metal or alloy that is conductive and has high gloss.

When the above technical solution is adopted, the material forming the conductive part can be made of conductive and high-gloss metal or alloy. The use of metal or alloy for the conductive part can ensure the normal transmission of carriers in the conductive part. The conductive part is made of high-gloss material. The metal or alloy can ensure the smoothness of the side wall of the conductive part, so that the side wall forms a mirror surface, so that the invisible light incident through the light absorbing layer can be reflected into the wavelength conversion material as much as possible, and then passes through the wavelength conversion material It is converted into visible light and enters the light absorbing layer along the reflection path.

In some examples, the material forming the conductive portion is one or more of silver, aluminum, copper, or gold, or the material of the conductive portion is an alloy including any one of silver, aluminum, copper, or gold.

When the above technical solution is adopted, silver, aluminum, copper or gold have better electrical conductivity and can increase the transmission rate of carriers in the conductive part; among them, the price of aluminum is relatively low, and aluminum is used as the material to form the conductive part. Materials could reduce the cost of solar cells.

In a possible implementation, the material forming the conductive part is the same as the material forming the second electrode. Or, the material forming the conductive portion is different from the material forming the second electrode.

When the above technical solution is adopted, the material forming the conductive portion and the material forming the second electrode may be the same or different. In the process of making a solar cell, when the material forming the conductive part and the material forming the second electrode are different, they are formed separately; when the material forming the conductive part and the material forming the second electrode are the same, they can be formed in the same Formed during the preparation process, it improves efficiency during the production process. In addition, since the area of the first side surface of the conductive part is larger than the area of the second side surface, compared with the conductive part with the same surface area on both sides, the conductive part provided by the present invention is easier to directly form during preparation and does not require rework, and further The formed conductive part has better quality.

The above description is only an overview of the technical solutions of the present application. In order to have a clearer understanding of the technical means of the present application, they can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and understandable. , the specific implementation methods of the present application are specifically listed below.

Description of the drawings

In order to more clearly explain the technical solutions in the embodiments of the present application or related technologies, a brief introduction will be made below to the drawings that need to be used in the description of the embodiments or related technologies. Obviously, the drawings in the following description are of the present invention. For some embodiments of the application, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1(a) and Figure 1(b) are the first structure of a solar cell provided by an embodiment of the present invention;

Figure 2 is a second structure of a solar cell provided by an embodiment of the present invention;

Figure 3 is a third structure of a solar cell provided by an embodiment of the present invention;

Figure 4 is a schematic diagram of a conductive reflective structure in the first structure of a solar cell provided by an embodiment of the present invention;

Figure 5 is a schematic vertical cross-sectional view of the conductive reflective structure in the second structure of the solar cell provided by the embodiment of the present invention;

Figure 6 is a schematic horizontal cross-sectional view of the conductive reflective structure in the second structure of the solar cell provided by the embodiment of the present invention;

Figure 7 is a schematic vertical cross-sectional view of the conductive reflective structure in the third structure of the solar cell provided by the embodiment of the present invention;

8 is a schematic horizontal cross-sectional view of the conductive reflective structure in the third structure of the solar cell provided by the embodiment of the present invention.

Reference signs:
10-first electrode, 11-first carrier transport layer,
12-Light absorption layer, 13-Second carrier transport layer,
14-second electrode, 15-conductive reflective structure,
150-wavelength conversion layer, 151-conductive part,
152-column up-conversion structure, 1510-side wall.

Specific embodiments

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments These are part of the embodiments of this application, but not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be noted that when an element is referred to as being "fixed to" or "disposed to" another element, it can directly Connected to another component or indirectly connected to the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited. "Several" means one or more than one, unless otherwise expressly and specifically limited.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

As problems such as global energy shortage and environmental pollution become increasingly prominent, solar photovoltaic power generation has become an emerging industry that is generally concerned and focused on development by countries around the world due to its clean, safe, convenient and efficient characteristics. Among them, perovskite solar cells have increased their conversion efficiency from the initial 3.8% to 25.5% after only more than ten years of development, becoming the most promising new solar cell.

In the process of converting solar energy into electrical energy, solar cells can usually only absorb light whose energy is within its band gap, while near-infrared light or infrared light below its band gap will pass through the cell and be converted into heat energy. For example, the band gap of the absorption layer material of existing perovskite cells is usually between 1.4eV and 1.5eV. Energy lower than its band gap cannot be absorbed by the light absorption layer and will pass through the battery or be converted into light in the absorption layer. thermal energy. If a wavelength conversion layer is installed behind the absorption layer, the spectral energy that cannot be utilized by the absorption layer is converted into photons that the absorption layer can absorb through an up-conversion or down-conversion mechanism and is reflected into the absorption layer, and is absorbed again by the absorption layer, which can increase solar energy. The conversion efficiency of the battery, especially in the perovskite battery, can also reduce the thermal effect of the long-wave spectrum on the absorption layer, avoid the thermal decomposition of the perovskite components, and improve the stability of the perovskite battery. However, in the existing technology, on the one hand, directly introducing up-conversion materials or down-conversion materials into the film layers of solar cells will cause instability of the corresponding film layer structure and degradation of performance, and The advantages of wavelength conversion materials in improving solar cell efficiency cannot be fully utilized; on the other hand, the wavelength conversion layer is generally designed to have a whole-layer structure. Due to the poor conductivity of the material forming the wavelength conversion layer, the carrier transport layer cannot be effectively transferred The carriers in the electrode are conducted to the electrode.

Based on this, as shown in Figures 1 to 3, embodiments of the present invention provide a solar cell. The solar cell includes a first electrode 10, a first carrier transport layer 11, a light absorption layer 12, a second carrier transport layer 13 and a second electrode 14 which are stacked in sequence. Wherein, the first electrode 10 is a transparent electrode. The solar cell also includes at least one electrically conductive reflective structure 15 . The first side of the conductive reflective structure 15 is in electrical contact with the second electrode 14 . The second side of the conductive reflective structure 15 is in electrical contact with the second carrier transport layer 13 . The conductive reflective structure 15 includes a wavelength conversion material, and the conductive reflective structure 15 has a reflective surface inclined relative to the solar cell extension plane.

When the above technical solution is adopted, as shown in FIGS. 1 to 3 , the solar cell provided by the present invention includes a first electrode 10 , a first carrier transport layer 11 , a light absorption layer 12 , and a second carrier layer that are stacked in sequence. The flow transport layer 13 and the second electrode 14, of which the first electrode 10 is a transparent electrode. The horizontal plane where the first electrode 10 is located is set as the incident plane of light. Sunlight is incident from the first electrode 10 into the solar cell. The sunlight that conforms to the band gap range of the solar cell is absorbed by the light absorbing layer 12 and the available visible light is ensured. Normal absorption of light by cells. The solar cell also includes at least one conductive reflective structure 15 containing a wavelength converting material, the conductive reflective structure 15 having a reflective surface inclined relative to the plane of extension of the solar cell. Based on this, in the incident sunlight, the light that matches the band gap range of the solar cell will be directly absorbed and utilized by the light absorption layer 12 , while the invisible light that cannot be absorbed by the solar cell will pass through the light absorption layer 12 and be reflected by the conductive reflective structure. The wavelength conversion material contained in 15 is converted into visible light that can be absorbed and utilized by the solar cell. The converted visible light is directed toward the reflective surface inclined relative to the solar cell extension plane of the conductive reflective structure 15. Since the light absorption layer 12 is in contact with the solar cell The extension planes are parallel, so the converted visible light directed to the conductive reflective structure 15 will be reflected back to the light absorbing layer 12 at a certain angle, and then absorbed and utilized by the light absorbing layer 12. Based on this, embodiments of the present invention can broaden the absorption of solar cells. spectrum, improving the energy utilization efficiency of solar cells. Moreover, there is a certain angle between the visible light and the light absorbing layer 12 during reflection. Compared with direct reflection, the optical path of the visible light becomes longer and the time it stays in the light absorbing layer 12 also becomes longer, which improves the absorption efficiency of the solar cell. . In addition, the first side of the conductive reflective structure 15 is in electrical contact with the second electrode 14, and the second side is in electrical contact with the second carrier transport layer 13, electrically connecting the second electrode 14 and the second carrier transport layer 13, Therefore, after adding the conductive reflective structure 15, the normal conductive performance of the solar cell can be ensured.

As a possible implementation, as shown in Figures 1 and 4, the conductive reflective structure 15 includes conductive The electrical part 151 and the wavelength conversion material disposed between the second electrode 14 and the second carrier transport layer 13 form the wavelength conversion layer 150 . The conductive portion 151 penetrates the wavelength conversion layer 150 . The conductive part 151 has side walls 1510 that are inclined relative to the solar cell extension plane. The polyline with an arrow in Figure 4 is a schematic line of the optical path.

Based on this, as shown in FIGS. 1 and 4 , the wavelength conversion material included in the conductive reflective structure 15 is disposed between the second electrode 14 and the second carrier transport layer 13 in the form of a wavelength conversion layer 150 , and the conductive portion 151 penetrates The entire wavelength conversion layer 150 allows the first side of the conductive part 151 to be in electrical contact with the second electrode 14 and the second side to be in electrical contact with the second carrier transport layer 13, thereby realizing the connection between the second electrode 14 and the second current carrier Electrical connection between sub-transmission layers 13. The conductive part 151 has side walls that are inclined relative to the extension plane of the solar cell. Based on this, the extension surface of the side wall 1510 of the conductive part 151 does not intersect perpendicularly with the extension plane of the solar cell, but intersects obliquely at a certain angle, so that The invisible light transmitted from the light absorbing layer 12 is converted by the wavelength conversion layer 150 into visible light that can be absorbed and utilized by the solar cell and then scattered. The converted visible light scattered on the side wall 1510 of the conductive part 151 can be reflected at a certain angle. On the light absorbing layer 12; based on this, the absorption spectrum of the solar cell is broadened and the energy conversion efficiency of the solar cell is improved; and the invisible light transmitted through the light absorbing layer 12 and the converted visible light are directed to the side wall 1510 of the conductive part 151 Afterwards, it can be obliquely reflected into the wavelength conversion layer 150 and the light absorption layer 12 at a certain angle. The optical path is longer than that of normal incidence. Since the speed of light is constant, the invisible light that passes through the light absorption layer 12 and the converted visible light pass through The wavelength conversion layer 150 and the light absorption layer 12 stay in the state longer, which is more conducive to the wavelength conversion layer 150 absorbing the invisible light transmitted through the light absorption layer 12 and the light absorption layer 12 absorbing the converted visible light, further improving the efficiency of the solar cell. . In addition, the conductive part 151 can directly electrically connect the second carrier transport layer 13 and the second electrode 14, so that the second carrier does not need to be transmitted through the wavelength conversion material, avoiding the solar cell failure caused by the poor conductivity of the wavelength conversion material. The problem of reduced efficiency improves the overall efficiency of the solar cell. At the same time, since there is no need to transmit carriers through the wavelength conversion material, there is no need to consider the conductivity issue when selecting the wavelength conversion material, and only focus on the conversion performance. Broadens the options for wavelength conversion materials.

It is worth noting that the conductive part 151 in Figures 1 to 4 has the function of allowing the incident light to undergo multiple refractions, thereby increasing the optical path. Therefore, the conductive part 151 can be an inverted trapezoid as shown in Figure 1(a). The portion 151 may be a regular trapezoid in Figure 1(b). The structure of the solar cell in which the conductive part 151 is a right trapezoid is not shown in FIGS. 2 to 4 , but it should be understood that the conductive part 151 may also be a right trapezoid without being shown in FIGS. 2 to 4 .

In some examples, as shown in FIGS. 1 and 4 , conductive portion 151 in wavelength conversion layer 150 One can be provided, or multiple ones can be provided at intervals, so that the invisible light transmitted through the light absorbing layer 12 can be fully utilized. The spacing between adjacent conductive parts 151 may be between 100 μm and 1000 μm, for example, it may be 100 μm, 500 μm, 1000 μm, etc.

In some examples, as shown in FIGS. 1 and 4 , the thickness of the wavelength conversion layer 150 ranges from 20 nm to 300 nm. If the wavelength conversion layer 150 is too thick, the thickness of the solar cell itself will be too large, which is not conducive to the propagation of light and will increase the carrier transmission time; if the wavelength conversion layer 150 is too thin, there will be less wavelength conversion material, making invisible light unable to be absorbed. Fully converted into visible light, reducing the efficiency of solar cells. For example, the thickness of the wavelength conversion layer 150 may be 20 nm, 100 nm, 200 nm, or 300 nm.

As a possible implementation, as shown in FIGS. 2 to 3 and 5 to 8 , the conductive reflective structure 15 includes a wavelength conversion material and a conductive portion 151 distributed inside the second carrier transport layer 13 . The wavelength conversion material forms at least one discrete wavelength conversion structure, and the conductive portion 151 is connected to the second electrode 14 . The conductive part 151 has sidewalls 1510 that are inclined relative to the solar cell extension plane for reflecting light waves entering the second carrier transport layer 13 to the discrete wavelength conversion structure. The broken lines with arrows in Figures 5 to 8 are schematic light path lines.

Based on this, the wavelength conversion material and the conductive portion 151 included in the conductive reflective structure 15 are both disposed in the second carrier transport layer 13 . Wherein, the wavelength conversion material exists in the form of at least one discrete wavelength conversion structure in the second carrier transport layer 13, while converting the invisible light transmitted through the light absorption layer 12 into visible light that the solar cell can absorb and utilize. , reducing the amount of wavelength conversion material; the conductive part 151 is connected to the second electrode 14 to electrically connect the second electrode 14 to the second carrier transport layer 13, so that the carriers are in the second carrier transport layer 13 and the second electrode 14 can be transmitted directly through the conductive part 151 instead of the wavelength conversion material, which solves the problem of reduced solar cell efficiency caused by the poor conductivity of the wavelength conversion material; the conductive part 151 has The solar cell extends the planar inclined sidewall 1510 to reflect the light waves entering the second carrier transport layer 13 to the discrete wavelength conversion structure at a certain angle. After that, the discrete wavelength conversion structure converts the invisible light into The solar cell can absorb visible light and emit it to the light absorbing layer 12, thereby improving the efficiency of the solar cell.

In some examples, as shown in Figures 2, 5, and 6, the discrete wavelength conversion structures include columnar upconversion structures 152, discrete sheet upconversion structures, mesh upconversion structures, and discrete point upconversion structures. of at least one.

Based on this, as shown in Figure 2, Figure 5 and Figure 6, the specific form of the discrete wavelength conversion structure can be a columnar up-conversion structure 152, a discrete sheet-like up-conversion structure, a mesh-like up-conversion structure and a discrete point-like up-conversion structure. At least one of the conversion structures. Based on this, invisible light incident from all directions may enter the discrete wavelength conversion structure, and then be converted into visible light that can be absorbed and utilized by the solar cell. The specific form of the discrete wavelength conversion structure can be selected according to different needs, which ensures that the invisible light incident from all directions is converted as much as possible while reducing the amount of wavelength conversion material.

As a possible implementation manner, as shown in FIGS. 1 and 4 , the surface where the side wall 1510 of the conductive part 151 is located is a plane, and there is an angle α between the plane and one side surface of the conductive part 1510 . 30°≤α≤75°.

Based on this, as shown in FIGS. 1 and 4 , when the side wall 1510 of the conductive part 151 is on a plane, since the side wall 1510 of the conductive part 151 is inclined relative to the solar cell extension plane, the surface of the conductive part 151 There is an angle α between the plane where the side wall 1510 is located and one side surface of the conductive part 151. When the invisible light or the converted visible light that passes through the light absorbing layer 12 is incident on the conductive part 151, it will be reflected at a certain angle. Entering the wavelength conversion material and the light absorption layer 12 not only broadens the absorption spectrum of the solar cell and improves the energy conversion efficiency of the solar cell, but also increases the optical path length, allowing the light wave to stay in the light absorption layer 12 or the wavelength conversion material. The time also becomes longer, which is more conducive to the absorption and utilization of visible light and light conversion by the light absorbing layer 12, further improving the efficiency of the solar cell. When the range of the included angle α is 30°≤α≤75°, the light wave reflected by the side wall 1510 of the conductive part 151 has a longer light wave. The preferred angle α is 45°. At this time, the optical path of the reflected light wave is the longest, and the light wave stays in the light absorption layer 12 or the wavelength conversion material for the longest time, which is conducive to the absorption and conversion of the light wave.

In some examples, as shown in FIGS. 1 and 4 , the included angle α between the side wall 1510 of the conductive part 151 and the first side surface of the conductive part 151 may also be 30°, 40°, 50°, or 75°. etc.

As a possible implementation, as shown in FIGS. 2 to 3 and 5 to 8 , the surface where the side wall of the conductive part is located is a concave curved surface.

Based on this, as shown in FIGS. 2 to 3 and 5 to 8 , when the surface where the side wall 1510 of the conductive part 151 is located is a concave curved surface, due to the concave structure of the curved surface, the surface where the side wall 1510 is located has a Good light concentrating effect. When the invisible light transmitted through the light absorbing layer 12 is directed to the side wall 1510 of the conductive part 151, it is concentrated and reflected by the side wall 1510 with a curved surface to the wavelength conversion material, so that the conductive part 151 The invisible light reflected by the side wall 1510 is converted into visible light by the wavelength conversion material, and is absorbed and utilized by the solar cell, which broadens the absorption spectrum of the solar cell and improves the energy conversion efficiency of the solar cell. A curved surface should be considered or include a rough curved surface formed by a series of small flat surfaces, as well as a general smooth surface. When the concave curved surface where the sidewall 1510 of the conductive part 151 is located has a focus, the wavelength conversion material can be placed at the focus of the curved surface, reducing the amount of wavelength conversion material used elsewhere, thereby reducing the cost of the solar cell. Based on this, the conductive part 151 has a better light condensing effect and has better wave response. The use of long-conversion materials is reduced even further, further reducing the cost of solar cells.

In some examples, as shown in FIGS. 2 to 3 and 5 to 8 , each conductive portion 151 has a side wall 1510 whose surface is a concave curved surface, and a discrete center can be provided at the focal point of each side wall 1510 . A wavelength conversion structure is formed so that the invisible light transmitted through the light absorbing layer 12 can be reflected and utilized as much as possible. The arrangement and quantity of the discrete wavelength conversion structures in Figures 2 to 3 and Figures 5 to 8 are only examples, and the specific number and arrangement of the discrete wavelength conversion structures are not limited. The number of the conductive portion 151 can be one, or multiple ones can be provided at intervals, so that the invisible light transmitted through the light absorbing layer 12 can be fully utilized. The spacing between adjacent conductive parts 151 may be between 100 μm and 1000 μm, for example, it may be 100 μm, 500 μm, 1000 μm, etc.

For example, as shown in Figures 2, 5 and 6, when the wavelength conversion material is disposed inside the second carrier transport layer 13, the discrete wavelength conversion structure formed is a columnar up-conversion structure 152, where the sidewall 1510 is located. When the surface is a generally smooth curved surface and the edge between adjacent side walls 1510 is a straight edge, the focal points of the curved side wall 1510 at multiple horizontal sections distributed along the thickness direction will converge into a parallel line. Along the line in the thickness direction, the columnar up-conversion structure 152 is disposed at the position of the line and penetrates the second carrier transport layer 13; based on this, the conductive portion 151 has a better light-concentrating effect, and the wavelength conversion material forms a columnar shape. The up-conversion structure 152 reduces the amount of wavelength conversion material and reduces the cost of the solar cell.

For another example, as shown in Figures 3, 7 and 8, when the wavelength conversion material is disposed inside the second carrier transport layer 13, the discrete wavelength conversion structure formed is a columnar up-conversion structure 152, where the sidewalls 1510 are located. When the surface is a general smooth curved surface, and the edge between adjacent side walls 1510 is an arc edge, each side wall 1510 with a curved surface has only one focus, that is, all the light rays incident on the same side wall 1510 All will converge on the same focus. At this time, the columnar up-conversion structure 152 only needs to be set at the focus and does not need to be in contact with the second electrode 14. For example, it can be a cubic columnar shape as shown in Figures 3, 7 and 8. The up-conversion structure 152 or the spherical columnar up-conversion structure 152 is not specifically limited here; based on this, the conductive part 151 has a better light-concentrating effect, and the amount of wavelength conversion material is reduced even more, further reducing the energy consumption of the solar cell. cost.

Illustratively, as shown in FIGS. 2 to 3 and 5 to 8 , the embodiment of the present invention does not limit the shape and size of the columnar up-conversion structure 152 , as long as it can cover all the focal points and the corresponding side walls 1510 The amount of the wavelength conversion material is sufficient to fully convert the invisible light reflected by the side wall 1510 into visible light, and at the same time, the amount of the wavelength conversion material can be reduced as much as possible.

Exemplarily, discrete sheet up-conversion structures, mesh up-conversion structures and discrete point structures can also be used. The columnar up-conversion structure 152 is only used as an example here and is not limiting.

As a possible implementation method, the wavelength conversion material is an upconversion material. The up-conversion material can be excited by low-energy light and emit high-energy light, so that the wavelength conversion material can convert the incident invisible infrared light and near-infrared light into visible light, and then reflect the light back through the reflective surface of the conductive part. In the absorption layer, the energy conversion efficiency of the solar cell is improved.

As a possible implementation method, the wavelength conversion material absorbs light in the range of 750nm to 1mm. Based on this, the wavelength conversion material can convert the light wave incident into the solar cell with a wavelength of 750nm to 1mm into visible light that can be absorbed and utilized by the photoabsorbing layer of the solar cell.

As another possible implementation manner, the wavelength conversion material is a down-conversion material, or a wavelength conversion material including an up-conversion material and a down-conversion material.

When the wavelength conversion material is a down-conversion material, the wavelength conversion material can convert the energy from one of ultraviolet light, x-rays and high-energy particles into visible light, and then reflect it back into the light absorption layer through the reflective surface of the conductive part, thereby improving Energy conversion efficiency of solar cells.

Among them, down-conversion materials may include quantum dots, semiconductor materials, alloys of semiconductor materials, scintillation materials and phosphor materials, materials exhibiting X-ray excited luminescence (XEOL), organic solids, metal complexes, inorganic solids, crystals, rare earths One or more combinations of materials (lanthanides), polymers, scintillator, phosphor materials, etc., as well as materials exhibiting excitonic properties.

Based on this, in actual applications, according to the wavelength band of invisible light that may be transmitted in the battery sheet, for example, for thinner batteries, there is a situation where ultraviolet light is transmitted to the wavelength conversion material in the battery, then according to the invention of this application It is contemplated that the wavelength conversion material may be a down-conversion material, or the aforementioned up-conversion structure or up-conversion material may be replaced by a down-conversion structure or material. In addition, in the case where both ultraviolet light or infrared light can be transmitted to the wavelength conversion material of the cell, the wavelength conversion material or wavelength conversion layer or single up-conversion structure in the present invention can also be a composite up-conversion material and a down-conversion material. , or the case of using a composite up-conversion structure and a down-conversion structure.

As a possible implementation, the material forming the wavelength conversion material includes a matrix doped with an activator and a sensitizer. The matrix includes one of fluoride, oxide and complex oxide.

Based on this, the upconversion luminescence phenomenon of converting two or more low-energy photons into one high-energy photon can be realized by using a matrix doped with activators and sensitizers. Specifically, a matrix doped with activators and sensitizers can be realized. The matrix material is excited by light with long wavelength and low frequency and emits light with short wavelength and high frequency. The matrix can be one of fluoride, oxide and complex oxide.

In some examples, fluorides include NaYF ₄ , NaGaF ₄ , CaF ₂ , NaSrF ₄ , BaY ₂ F ₄ , LiYF 4 , ScYF ₄ , NaLnF ₄ , SrF ₂ , BaF ₂ , MnF ₂ _, Na(CF ₃ COO) ₃ One of F ₄ , LaF ₃ , NaLuF ₄ and Cs ₂ GeF ₆ . Oxides include Y ₂ O ₃ , ZrO ₂ , TiO ₂ , Gd2O ₃ , In ₂ O ₃ , SrY ₂ O ₄ , TeO ₂ , Al ₂ O ₃ , ZnO ₂ , Lu ₂ O ₃ , Er ₂ O ₃ , Eu ₂ One of O ₃ , CeO ₂ and La ₂ O ₃ . Composite oxides include LiNbO ₃ , Ln ₂ BaZnO ₂ , ALn(MoO ₄ ) ₂ , GdVO ₄ , YVo ₄ , CaZrO ₃ , CaSc ₂ O ₄ , KLu(WO ₄ ) ₂ , NaY(WO ₄ ) ₂ , CaCs ₂ O _4. One of CaMoO ₄ , BaTiO ₃ , Y ₂ Ti ₂ O ₇ , Y ₂ Si ₂ O ₇ , Y ₂ SiO ₅ , Gd ₃ Ga ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and Y ₂ CaGe ₄ O ₁₂ kind. Activators include Er ³⁺ , Ho ³⁺ , Tm ³⁺ , Gd ³⁺ , Pr ³⁺ , Sm ³⁺ , Ti ²⁺ , Cr ³⁺ , Ni ²⁺ , Mo ³⁺ , Re ⁴⁺ and Os ⁴⁺ at least one of them. The sensitizer includes at least one of Yb ³⁺ and Nd ³⁺ .

Based on this, by combining different activators, sensitizers and different matrices, the infrared light and near-infrared light incident into the solar cell can be converted into incident light with a specific wavelength, so that the light absorption layer 12 can absorb Light outside the band gap range broadens the absorption spectrum of solar cells and improves the energy conversion efficiency of solar cells.

In terms of material selection, as a possible implementation manner, the second electrode is a metal electrode or a transparent electrode. Based on this, the second electrode is generally made of metal material. The metal material generally has a smooth interface and can form a mirror surface. When the invisible light passing through the light-absorbing layer is not reflected at the conductive part, it can be reflected at the second electrode interface. Reflection, part of the invisible light is converted into visible light by the wavelength conversion material in the reflection route, and enters the light absorption layer along the reflection route, which improves the energy conversion efficiency of the solar cell. The second electrode can also be a transparent electrode to facilitate the penetration of light directed to the back of the solar cell, which is beneficial to improving the efficiency of the solar cell.

In terms of solar cell selection, solar cells with light transmittance are generally selected. Commonly used are various types of thin film solar cell materials, such as perovskite cells, cadmium telluride cells, copper indium gallium selenide cells and organic solar cells. In addition, when the thickness of the crystalline silicon cell is reduced to the point where an ultra-thin crystalline silicon cell can be formed (for example, when the thickness is less than 50 μm), it also has light transmittance and can also be used as a solar cell used in the present invention.

In terms of size selection of each layer in the solar cell, when the first carrier transport layer is an electron transport layer and the second carrier transport layer is a hole transport layer, the thickness range of the first carrier transport layer is 50nm～200nm, for example, it can be 50nm, 100nm, 200nm, etc. The thickness range of the second carrier transport layer is 100nm～300nm, for example, it can be 100nm, 200nm, 300nm, etc. The first carrier can also be a hole, The second carrier can also be an electron, and in this case the thickness range can be exchanged. When the second electrode is a metal electrode, the thickness of the second electrode ranges from 50 nm to 200 nm, for example, it can be 50nm, 100nm, 200nm, etc. When the solar cell is a perovskite solar cell, the light absorption layer is the perovskite light absorption layer. At this time, the thickness of the light absorption layer ranges from 800nm to 1200nm, for example, it can be 800nm, 1000nm, 1200nm, etc.

As a possible implementation manner, the material forming the conductive part is a metal or alloy that is conductive and has high gloss. The use of metal or alloy in the conductive part can ensure the normal transmission of carriers in the conductive part. The use of high-gloss metal or alloy in the conductive part can ensure the smoothness of the side walls of the conductive part, so that the side walls form a mirror surface, thereby making the incoming light pass through. The invisible light injected into the light absorption layer can be reflected into the wavelength conversion material as much as possible, and then converted into visible light through the wavelength conversion material, and then enters the light absorption layer along the reflection route.

In some examples, the material forming the conductive portion is one or more of silver, aluminum, copper, or gold, or the material of the conductive portion is an alloy including any one of silver, aluminum, copper, or gold. Silver, aluminum, copper or gold all have good electrical conductivity and can increase the transmission rate of carriers in the conductive part. Among them, the price of aluminum is relatively low, and using aluminum as a material to form the conductive part can reduce the cost of solar cells. The material forming the conductive part can also be other metals, or an alloy containing any one of silver, aluminum, copper or gold can be selected as long as it has good conductivity and gloss. For example, it can be aluminum alloy, copper Alloys etc.

In the process of making a solar cell, parts other than the conductive reflective structure can be made using the general method of making a solar cell, and there are no special restrictions in the embodiments of the present invention. Regarding the wavelength conversion material, when making the wavelength conversion layer, taking into account the compatibility with the underlying material, solvent compatibility, and light transmittance of the layer, magnetron sputtering can be used to prepare it. Magnetron sputtering is easy to obtain better quality products. A good wavelength conversion layer will help improve the overall efficiency of solar cells. In addition, the wavelength conversion layer can also be prepared using a solvent method. In this case, only the solvent compatibility between the wavelength conversion layer and the lower second carrier transport layer, light absorption layer and first carrier transport layer can be considered. That’s it. The following uses specific materials as an example to illustrate how to prepare the wavelength conversion layer by the solution method: for example, you can use isopropyl alcohol as the solvent, uniformly disperse NaYF ₄ in the isopropyl alcohol, and spin-coat it on the second carrier transport layer. Regarding the columnar up-conversion structure and the conductive part, it can be prepared by drilling holes in the wavelength conversion layer or the second carrier transport layer, or a mold with corresponding hole positions can be prepared in advance, and then the wavelength conversion layer can be prepared on the mold Or the second carrier transport layer, laser etching is generally used when drilling holes; after the holes are formed, the method of preparing the columnar up-conversion structure can be the method of preparing the wavelength conversion layer, and the method of preparing the conductive part can be general Deposition methods, such as sputter deposition, thermal evaporation, etc.

Wherein, the material forming the conductive part is the same as the material forming the second electrode. Or, the material forming the conductive portion is different from the material forming the second electrode. That is, the material forming the conductive portion and the material forming the second electrode The materials can be the same or different. In the process of making a solar cell, when the material forming the conductive part and the material forming the second electrode are different, they are formed separately, and the conductive part is formed first, and then the second electrode is formed; when the material forming the conductive part is different from the material forming the second electrode, When the materials of the electrodes are the same, they can be formed in the same preparation process, which can improve the efficiency of the manufacturing process. In addition, since the area of the first side surface of the conductive part is larger than the area of the second side surface, compared with the conductive part with the same surface area on both sides, the conductive part provided by the present invention is easier to directly form during preparation and does not require rework, and further The formed conductive part has better quality.

In the above description of the embodiments, specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

The device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in One location, or it can be distributed across multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Persons of ordinary skill in the art can understand and implement the method without any creative effort.

Reference herein to "one embodiment," "an embodiment," or "one or more embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. In addition, please note that the examples of the word "in one embodiment" here do not necessarily all refer to the same embodiment.

In the instructions provided here, a number of specific details are described. However, it is understood that embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent substitutions are made to some of the technical features; however, these modifications or substitutions do not make the corresponding technologies The essence of the technical solution deviates from the spirit and scope of the technical solution of each embodiment of the present application.

Claims

A solar cell, characterized in that the solar cell includes a first electrode, a first carrier transport layer, a light absorption layer, a second carrier transport layer and a second electrode that are stacked in sequence;

Wherein, the first electrode is a transparent electrode; the solar cell further includes at least one conductive reflective structure, the first side of the conductive reflective structure is in electrical contact with the second electrode, and the second side of the conductive reflective structure In electrical contact with the second carrier transport layer, the conductive reflective structure includes a wavelength conversion material, and the conductive reflective structure has a reflective surface inclined relative to the solar cell extension plane.
The solar cell according to claim 1, wherein the conductive reflective structure includes a conductive part and a wavelength conversion material disposed between the second electrode and the second carrier transport layer, and the wavelength conversion material The conversion material forms a wavelength conversion layer, and the conductive part penetrates the wavelength conversion layer; the conductive part has side walls that are inclined relative to the solar cell extension plane.
The solar cell according to claim 2, wherein the thickness of the wavelength conversion layer ranges from 20 nm to 300 nm.
The solar cell according to claim 1, wherein the conductive reflective structure includes the wavelength conversion material and a conductive portion distributed inside the second carrier transport layer, and the wavelength conversion material forms at least one A discrete wavelength conversion structure, and the conductive part is connected to the second electrode;

The conductive part has sidewalls that are inclined relative to the solar cell extension plane for reflecting light waves entering the second carrier transport layer to the discrete wavelength conversion structure.
The solar cell according to claim 4, wherein the discrete wavelength conversion structure includes at least one of a columnar upconversion structure, a discrete sheet upconversion structure, a mesh upconversion structure and a discrete point upconversion structure. A sort of.
The solar cell according to any one of claims 2 to 5, wherein the surface on which the side wall of the conductive part is located is a plane, and there is an angle α between the plane and one side surface of the conductive part, 30°≤α≤75°.
The solar cell according to any one of claims 2 to 5, wherein the surface on which the side wall of the conductive part is located is a concave curved surface.
The solar cell according to any one of claims 1 to 5, wherein the wavelength conversion material is an up-conversion material or a down-conversion material, or a wavelength conversion material including an up-conversion material and a down-conversion material.
The solar cell according to claim 8, wherein the upconversion material absorbs light in a wavelength range of 750 nm to 1 mm.
The solar cell according to any one of claims 1 to 5, wherein the wavelength conversion material includes a matrix doped with an activator and a sensitizer, and the matrix includes fluoride, oxide and composite oxide. one of them.
The solar cell according to claim 10, wherein the fluoride includes NaYF 4 , NaGaF 4 , CaF 2 , NaSrF 4 , BaY 2 F 4 , LiYF 4 , ScYF 4 , NaLnF 4 , SrF 2 , BaF 2 , MnF 2 , Na(CF 3 COO) 3 F 4 , LaF 3 , NaLuF 4 and one of Cs 2 GeF 6 ;

The oxides include Y 2 O 3 , ZrO 2 , TiO 2 , Gd2O 3 , In 2 O 3 , SrY 2 O 4 , TeO 2 , Al 2 O 3 , ZnO 2 , Lu 2 O 3 , Er 2 O 3 , One of Eu 2 O 3 , CeO 2 and La 2 O 3 ;

The composite oxide includes LiNbO 3 , Ln 2 BaZnO 2 , ALn(MoO 4 ) 2 , GdVO 4 , YVo 4 , CaZrO 3 , CaSc 2 O 4 , KLu(WO 4 ) 2 , NaY(WO 4 ) 2 , CaCs 2 O 4 , CaMoO 4 , BaTiO 3 , Y 2 Ti 2 O 7 , Y 2 Si 2 O 7 , Y 2 SiO 5 , Gd 3 Ga 5 O 12 , Y 3 Al 5 O 12 and Y 2 CaGe 4 O 12 a kind of;

The activators include Er 3+ , Ho 3+ , Tm 3+ , Gd 3+ , Pr 3+ , Sm 3+ , Ti 2+ , Cr 3+ , Ni 2+ , Mo 3+ , Re 4+ and Os At least one of 4+ ;

The sensitizer includes at least one of Yb 3+ and Nd 3+ .
The solar cell according to any one of claims 1 to 5, wherein the second electrode is a metal electrode or a transparent electrode.
The solar cell according to any one of claims 2 to 5, wherein the material forming the conductive portion is a metal or alloy that is conductive and has high gloss.
The solar cell according to claim 13, characterized in that the material forming the conductive part is one or more of silver, aluminum, copper or gold, or the material of the conductive part is made of silver, aluminum, An alloy of either copper or gold.
The solar cell according to any one of claims 2 to 5, wherein the conductive portion is made of the same material as the second electrode, or the conductive portion is made of the same material as the second electrode. The material of the second electrode is different.