Ultraviolet light conversion heterojunction cell
Patent Information
- Application Number
- CN202521323015.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-06-26
AI Technical Summary
[0003]太阳电池的光学损失主要包括五个方面，一是反射损失，硅基电池的裸表面反射率可达40%，入射光在电池表面因材料折射率差异被反射，未进入电池参与光电转换；二是栅电极遮光损失，电池表面金属电极（如银栅线）直接遮挡入射光，损失约5%-15%的光照面积；三是透射损失，能量低于材料禁带宽度的光子无法被吸收，直接穿透电池导致损失（如硅对波长>1100nm的光吸收不足）；四是寄生吸收损失，包括非功能层吸收，电池中非活性层（如导电层、封装材料）吸收光子但未产生电流，转化为热能损耗
1.通过在硅片上设置紫外光转层，能够将破坏Si-H键的紫外光转换为蓝光，破从提升了异质结电池光学吸收，增加短路电流，从而提升光电转换效率和可靠性；
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Figure CN224791003U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to an ultraviolet light-transmitting heterojunction battery. Background Technology
[0002] To improve the photoelectric conversion efficiency of solar cells, it is necessary to minimize the optical losses of solar cells. The core contradiction of optical loss lies in maximizing light absorption and minimizing ineffective energy dissipation, which requires synergistic optimization of materials, structure, and processes to achieve a balance.
[0003] Optical losses in solar cells mainly include five aspects: First, reflection loss. The bare surface of silicon-based cells can have a reflectivity of up to 40%. Incident light is reflected at the cell surface due to the difference in refractive index of the materials and does not enter the cell to participate in photoelectric conversion. Second, grid electrode shading loss. Metal electrodes (such as silver grid lines) on the cell surface directly block incident light, resulting in a loss of about 5%-15% of the illuminated area. Third, transmission loss. Photons with energy below the material's bandgap cannot be absorbed and directly penetrate the cell, leading to loss (e.g., silicon's insufficient absorption of light with wavelengths >1100nm). Fourth, parasitic absorption loss, including non-functional layer absorption, where non-active layers in the cell (such as conductive layers and encapsulation materials) absorb photons but do not generate current, converting them into heat energy loss. Inefficient optical path utilization occurs when the photon propagation path inside the cell is too short (e.g., without extending the optical path through surface roughening), leading to incomplete absorption. Fifth, recombination loss, where some photogenerated carriers recombine during transport and cannot contribute current. Although essentially an electrical loss, it is directly related to the light absorption process.
[0004] To address optical losses, common technical solutions include using anti-reflective coatings (such as silicon nitride, magnesium fluoride, etc.) and surface texturing (reducing the reflection angle) to reduce reflection losses; reducing grid line width and optimizing electrode pattern design (such as segmented grid lines and no main grid) to reduce shading losses; and using a back reflective layer, increasing cell thickness, or selecting narrow bandgap materials (such as perovskite stacks) to reduce transmission losses.
[0005] The methods described above improve the light absorption of solar cells. However, for heterojunction cells, due to their unique passivation structure of amorphous silicon (a-Si:H), which contains a large number of Si-H bonds, the high energy of ultraviolet light absorption directly destroys these Si-H bonds, leading to defects in the passivation layer. This causes increased carrier recombination and degradation of the built-in electric field, ultimately resulting in accelerated power decay of the module. Furthermore, the transparent conductive oxide (TCO) layer of HJT cells has a high absorption rate for ultraviolet light (300-400nm), and unused ultraviolet light is converted into heat, accelerating material aging. Utility Model Content
[0006] The purpose of this invention is to provide a UV-transformed heterojunction solar cell, which solves the technical problem that in the prior art, after the HJT cell absorbs ultraviolet light, its high energy directly destroys the Si-H bond, leading to passivation layer defects, causing increased carrier recombination and degradation of the built-in electric field of the cell, ultimately resulting in accelerated power decay of the module.
[0007] This utility model discloses an ultraviolet light-to-heterojunction solar cell, including an ultraviolet light-to-heterojunction layer, wherein transparent conductive layers are disposed on both sides of the ultraviolet light-to-heterojunction layer.
[0008] Working principle: By setting up an ultraviolet light transfer layer, ultraviolet light that disrupts Si-H bonds can be converted into blue light, thereby improving the optical absorption of the heterojunction cell, increasing the short-circuit current, and thus improving photoelectric conversion efficiency and reliability. Adding a transparent conductive layer strengthens and protects the ultraviolet light transfer layer, resulting in better stability than encapsulated films. Encapsulating the ultraviolet light transfer layer with multiple transparent conductive layers further enhances its stability compared to traditional encapsulated films, contributing to the long-term stability of the cell's ultraviolet light transfer process.
[0009] Furthermore, during use, electrodes are disposed on the transparent conductive layer near the silicon wafer, and the electrodes pass through the ultraviolet light source and the transparent conductive layer away from the silicon wafer in a direction away from the silicon wafer.
[0010] Furthermore, an end transparent conductive layer is disposed on the transparent conductive layer away from the silicon wafer, and the end transparent conductive layer covers the electrode.
[0011] Furthermore, the ultraviolet light transfer layer is provided with a laser isolation region, which is used to place electrodes and separate the electrodes from the ultraviolet light transfer layer.
[0012] Furthermore, the laser isolation region has a width of 10-60 nm and a depth of 10-50 nm.
[0013] Furthermore, the laser isolation area is filled with the end transparent conductive layer.
[0014] By strategically positioning the electrodes, a nano-structure is created within the laser-isolated region, facilitating electrode current collection and preventing ultraviolet light transfer from obstructing metal electrode contact. Furthermore, the addition of a transparent conductive layer at the ends repairs the laser-isolated region, mitigating laser-induced film damage and improving battery conversion efficiency.
[0015] Furthermore, the ultraviolet light transfer layer has at least two layers, and a transparent conductive layer is disposed between adjacent ultraviolet light transfer layers.
[0016] By setting the UV transfer layer to at least two layers, even if one UV transfer layer fails, another layer can still be used, ensuring that the UV transfer layer can work normally.
[0017] Furthermore, the ultraviolet light transfer layer consists of two layers.
[0018] Furthermore, the transparent conductive layer closest to the silicon wafer is the first transparent conductive layer, and the layers further away from the silicon wafer are, in sequence, the first ultraviolet light transfer layer, the second transparent conductive layer, the second ultraviolet light transfer layer, and the third transparent conductive layer.
[0019] By setting a first transparent conductive layer, current can be collected on the one hand, and the problem of increased recombination caused by the migration of ultraviolet light transfer agent to other layers on the other hand can be prevented.
[0020] Furthermore, the third transparent conductive layer has an end transparent conductive layer in the direction away from the silicon wafer.
[0021] Furthermore, the first transparent conductive layer is provided with a doped microcrystalline silicon layer, an intrinsic amorphous silicon layer and a silicon wafer in sequence in the direction close to the silicon wafer.
[0022] Furthermore, the thickness of the first transparent conductive layer is greater than the thickness of the second transparent conductive layer, which in turn is greater than the thickness of the third transparent conductive layer.
[0023] Furthermore, the thickness of the first transparent conductive layer is 40-50 nm, the thickness of the second transparent conductive layer is 10-20 nm, and the thickness of the third transparent conductive layer is 5-10 nm.
[0024] Since three transparent conductive layers need to be deposited later, the thickness of the first transparent conductive layer is relatively small in order not to affect light absorption and current collection. The thickness of the first layer is usually 80-100nm.
[0025] Compared with the prior art, the beneficial effects of this utility model are: 1. By setting an ultraviolet light transfer layer on a silicon wafer, ultraviolet light that breaks Si-H bonds can be converted into blue light, thereby improving the optical absorption of the heterojunction cell, increasing the short-circuit current, and thus improving the photoelectric conversion efficiency and reliability; 2. By adding a transparent conductive layer, the ultraviolet light transfer layer can be reinforced and protected, exhibiting better stability than the adhesive film; 3. By setting multiple transparent conductive layers to encapsulate the ultraviolet light transfer layer, the stability is better than that of traditional encapsulation, which is beneficial to the long-term stability of the battery's ultraviolet light transfer. 4. By setting the electrode position, a nano-vertical structure is formed in the laser isolation area, which is conducive to electrode current collection and avoids the ultraviolet light transfer layer blocking the metal electrode contact. 5. By setting a transparent conductive layer at the end, the laser isolation area can be repaired, improving the film damage caused by the laser and thus improving the battery conversion efficiency; 6. By setting the UV transfer layer to at least two layers, if one UV transfer layer fails, another layer can still be used, ensuring that the UV transfer layer can work normally; 7. By setting a first transparent conductive layer, current can be collected on the one hand, and the problem of increased recombination caused by the migration of ultraviolet light transfer agent to other layers on the other hand can be prevented. Attached Figure Description
[0026] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of the ultraviolet light-to-heterojunction battery structure of this utility model.
[0028] Figure 2 This is a schematic diagram of the structure of the violet laser isolation region of this utility model.
[0029] Figure 3 This is a schematic diagram of the structure after the violet laser isolation area of this utility model is filled.
[0030] In the above figures, the meanings of each mark are as follows: 1-silicon wafer, 2-intrinsic amorphous silicon layer, 3-doped microcrystalline silicon layer, 4-first transparent conductive layer, 5-first ultraviolet light transfer layer, 6-second transparent conductive layer, 7-second ultraviolet light transfer layer, 8-third transparent conductive layer, 9-electrode, 10-laser isolation region, 11-end transparent conductive layer. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments.
[0032] Example 1 The technical solution adopted in this embodiment is as follows: like Figures 1-3 As shown, a UV-to-heterojunction solar cell includes a UV-to-heterojunction layer. Transparent conductive layers are disposed on both sides of the UV-to-heterojunction layer. In use, an electrode 9 is disposed on the transparent conductive layer near the silicon wafer 1, and the electrode 9 passes through both the UV-to-heterojunction layer and the transparent conductive layer away from the silicon wafer 1, with the electrode 9 extending away from the silicon wafer 1.
[0033] Working principle: By setting up an ultraviolet light transfer layer, ultraviolet light that disrupts Si-H bonds can be converted into blue light, thereby improving the optical absorption of the heterojunction cell, increasing the short-circuit current, and thus improving photoelectric conversion efficiency and reliability. Adding a transparent conductive layer strengthens and protects the ultraviolet light transfer layer, resulting in better stability than encapsulated films. Encapsulating the ultraviolet light transfer layer with multiple transparent conductive layers further enhances its stability compared to traditional encapsulated films, contributing to the long-term stability of the cell's ultraviolet light transfer process.
[0034] Example 2 This embodiment is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 1-3 As shown, based on Embodiment 1, the following improvement is disclosed: an end transparent conductive layer 11 is provided on the transparent conductive layer away from the silicon wafer 1, the end transparent conductive layer 11 covers the electrode 9, and a laser isolation region 10 is provided between the electrode 9 and the transparent conductive layer and the ultraviolet light transfer layer, the laser isolation region 10 is filled by the end transparent conductive layer 11.
[0035] By setting the position of electrode 9, the laser isolation region 10 forms a nano-vertical structure, which facilitates current collection by electrode 9 and avoids the ultraviolet light transfer layer blocking the contact of metal electrode 9. By setting the end transparent conductive layer 11, the laser isolation region 10 can be repaired, improving the film damage caused by laser and improving battery conversion efficiency.
[0036] Example 3 This embodiment is a preferred embodiment of the present invention, and its specific structure is as follows: Figures 1-3 As shown, based on Embodiment 1, the following improvement is disclosed: the ultraviolet light transfer layer consists of two layers, with the transparent conductive layer close to the silicon wafer 1 being the first transparent conductive layer 4, and the layers away from the silicon wafer 1 being the first ultraviolet light transfer layer 5, the second transparent conductive layer 6, the second ultraviolet light transfer layer 7, and the third transparent conductive layer 8 in sequence.
[0037] The third transparent conductive layer 8 is provided with an end transparent conductive layer 11 in the direction away from the silicon wafer 1, and the first transparent conductive layer 4 is provided with a doped microcrystalline silicon layer 3, an intrinsic amorphous silicon layer 2 and the silicon wafer 1 in sequence in the direction close to the silicon wafer 1.
[0038] The thickness of the first transparent conductive layer 4 is 40-50 nm, the thickness of the second transparent conductive layer 6 is 10-20 nm, and the thickness of the third transparent conductive layer 8 is 5-10 nm.
[0039] By setting the first transparent conductive layer 4, current can be collected on the one hand, and the problem of increased recombination caused by the migration of ultraviolet light transfer agent to other layers on the other hand can be prevented.
[0040] Since three transparent conductive layers need to be deposited later, the thickness of the first transparent conductive layer is relatively small in order not to affect light absorption and current collection. The thickness of the first layer is usually 80-100nm.
[0041] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.
Claims
1. A UV-to-heterojunction solar cell, characterized in that: It includes an ultraviolet light transfer layer, wherein a transparent conductive layer is provided on both sides of the ultraviolet light transfer layer; In use, an electrode (9) is provided on the transparent conductive layer close to the silicon wafer (1), and the electrode (9) passes through the ultraviolet light and away from the transparent conductive layer away from the silicon wafer (1) in a direction away from the silicon wafer (1). An end transparent conductive layer (11) is provided on the transparent conductive layer away from the silicon wafer (1), and the end transparent conductive layer (11) covers the electrode (9); The ultraviolet light transfer layer is provided with a laser isolation region (10), which is used to place the electrode (9) and separate the electrode (9) from the ultraviolet light transfer layer. The width of the laser isolation region is 10-60nm and the depth is 10-30nm.
2. The ultraviolet-to-heterojunction solar cell according to claim 1, characterized in that: The laser isolation region (10) is filled with the end transparent conductive layer (11).
3. The ultraviolet-to-heterojunction solar cell according to claim 1, characterized in that: The thickness of the transparent conductive layer closer to the silicon wafer is greater than that of the transparent conductive layer farther away from the silicon wafer.
4. A UV-to-heterojunction solar cell according to any one of claims 1-3, characterized in that: The ultraviolet light transfer layer has at least two layers, and a transparent conductive layer is disposed between adjacent ultraviolet light transfer layers.
5. The ultraviolet-to-heterojunction solar cell according to claim 4, characterized in that: The ultraviolet light transfer layer consists of two layers.
6. The ultraviolet-to-heterojunction solar cell according to claim 5, characterized in that: The transparent conductive layer close to the silicon wafer (1) is the first transparent conductive layer (4), and the layers away from the silicon wafer (1) are, in sequence, the first ultraviolet light transfer layer (5), the second transparent conductive layer (6), the second ultraviolet light transfer layer (7), and the third transparent conductive layer (8).
7. The ultraviolet-to-heterojunction solar cell according to claim 6, characterized in that: The thickness of the first transparent conductive layer (4) is 40-50 nm, the thickness of the second transparent conductive layer (6) is 10-20 nm, and the thickness of the third transparent conductive layer (8) is 5-10 nm.