Photovoltaic cell module and photovoltaic power generation system

Abstract

The utility model relates to the field of photovoltaic technology, and discloses a photovoltaic cell assembly and a photovoltaic power generation system. The photovoltaic cell assembly comprises a transparent substrate and a cell film layer. The side face, opposite to the light facing face, of the transparent substrate is a fluctuating face, and the fluctuating face comprises a plurality of convex faces arranged at intervals and concave faces located between the adjacent convex faces. And the cell film layer is attached to the fluctuating surface. According to the utility model, the path length of light on the surface of the cell can be increased, so that the light absorptivity is improved; the light reflection is reduced, the retention time of light in the cell film layer is prolonged, the light utilization rate is improved, and the photoelectric conversion efficiency of the cell is further improved. According to the utility model, the coating and packaging processes of the battery are not changed, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, specifically to photovoltaic cell modules and photovoltaic power generation systems. Background Technology

[0002] Under the dual pressures of the global energy crisis and environmental protection demands, the search for efficient, low-cost, and environmentally friendly new energy technologies has become a crucial issue for the scientific community. While traditional silicon-based solar cells dominate the photovoltaic field, their high manufacturing costs and energy-intensive production processes limit their further widespread adoption. Against this backdrop, perovskite solar cells, with their advantages of low material cost, tunable band structure, high absorption coefficient, simple fabrication process, and long carrier diffusion length, have rapidly emerged as a rising star in the photovoltaic field and have attracted widespread attention.

[0003] Currently, perovskite solar cell modules have relatively low efficiency and power, making it difficult to compete with crystalline silicon modules. Improving the efficiency of perovskite modules has become a hot research topic in the industry. Reflectivity is a crucial parameter for perovskite cells, directly affecting their light-harvesting efficiency and energy conversion capability. In existing technologies, both surfaces of the front glass panel on the light-incident side of perovskite cells are planar structures. Some light incident on the perovskite is reflected by the cell film layer to the outside of the module, causing some light loss and consequently, a partial loss of cell efficiency. However, due to the thinness of perovskite cells and the complexity of their fabrication process, texturing the surface of perovskite cells is difficult, making it challenging to improve their efficiency. Utility Model Content

[0004] In view of this, the present invention provides a photovoltaic cell module and a photovoltaic power generation system to solve the problem of low efficiency of perovskite cells.

[0005] In a first aspect, this utility model provides a photovoltaic cell module, including a transparent substrate and a cell film layer. The side of the transparent substrate opposite to the light-facing surface is a undulating surface, which includes a plurality of spaced convex surfaces and concave surfaces located between adjacent convex surfaces; the cell film layer is attached to the undulating surface.

[0006] Beneficial Effects: The photovoltaic cell module provided by this utility model has an undulating surface on the side of the transparent substrate opposite to the light-facing side, i.e., the cell film layer is deposited on the undulating surface. This allows the light-receiving surface of the perovskite to form a textured surface with an undulating structure, thereby enabling internal reflection of incident light and increasing the refraction angle, reducing light loss and improving cell efficiency. Furthermore, the undulating surface includes several spaced convex surfaces and concave surfaces between adjacent convex surfaces. Compared to the planar structure of the transparent substrate and cell film layer, this utility model can increase the refraction angle of light on the cell surface, making obliquely incident light more biased towards the cell film layer. Moreover, the convex structure reduces light reflection and light loss, thereby improving light absorption rate. This helps to reduce light reflection to the outside, improve light utilization, and thus improve the photoelectric conversion efficiency of the cell.

[0007] In one alternative embodiment, the cell film layer includes a plurality of sub-cell scribing lines, which are located at the bottom of the concave surface and / or the top of the convex surface.

[0008] Beneficial effects: The sub-cell scribing lines are located at the bottom of the concave surface and / or the top of the convex surface, which facilitates laser scribing. More preferably, all sub-cell scribing lines are located at the bottom of the concave surface or at the top of the convex surface, ensuring that the laser power and focus remain constant during laser scribing. Furthermore, since the sub-scibing lines are relatively wide, they are more suitable at the bottom of the concave surface and the top of the convex surface.

[0009] In one alternative embodiment, the top of the convex surface and / or the bottom of the concave surface includes a planar platform. The planar platforms located at the top of the convex surface are coplanar or the planar platforms located at the bottom of the concave surface are coplanar, and the planar platforms are parallel to the plane of the transparent substrate, with the sub-cell scribing lines located on the planar platforms.

[0010] In one alternative embodiment, the concave and / or convex surfaces are arranged along the XY direction; along the X direction, the length of the planar platform is d, 0.5mm≤d≤10mm; and / or, along the Y direction, the width of the planar platform is r, 0.5mm≤r≤10mm.

[0011] In one alternative embodiment, the concave and / or convex surfaces are arranged along the XY direction; along the X direction, the length of the concave and / or convex surfaces is L, 0 mm < L ≤ 10 mm; and / or, along the Y direction, the width of the concave and / or convex surfaces is S, 0 mm < S ≤ 10 mm.

[0012] In one optional embodiment, the thickness of the cell film layer is t, and the distance between the bottom end of the concave surface and the top end of the convex surface is h, where h ≥ t, and t ≥ 500 nm.

[0013] In one alternative implementation, the undulating surface is a wave-like surface; or, the undulating surface is a lattice-type raised surface structure.

[0014] In one alternative implementation, a plurality of convex surfaces are arranged at equal intervals, and / or a plurality of concave surfaces are arranged at equal intervals.

[0015] In one optional embodiment, the device further includes an encapsulating film, a backplate, and a sealant; the encapsulating film and the backplate are sequentially encapsulated on the back side of the battery cell film layer; the sealant is filled between the backplate and the transparent substrate, and surrounds the battery cell film layer within it.

[0016] Secondly, this utility model also provides a photovoltaic power generation system, including a battery pack, a charge / discharge controller, an inverter, and photovoltaic cell modules as described above, wherein the photovoltaic cell modules, battery pack, charge / discharge controller, and inverter are electrically connected.

[0017] Beneficial effects: Since photovoltaic power generation systems include photovoltaic cell modules, they have the same effects as photovoltaic cell modules, which will not be elaborated here. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a top view of a transparent substrate in a photovoltaic cell module according to an embodiment of the present invention;

[0020] Figure 2 for Figure 1 A cross-sectional view of the transparent substrate shown;

[0021] Figure 3 This is a cross-sectional view of the transparent substrate and the battery cell film layer;

[0022] Figure 4 This is a cross-sectional view of the photovoltaic cell module encapsulation structure.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Transparent substrate; 11. Concave surface; 12. Planar platform; 2. Cell film layer; 21. Transparent conductive oxide layer; 22. First charge transport layer; 23. Perovskite layer; 24. Second charge transport layer; 25. Back electrode; 26. Sub-cell scribing line; 3. Encapsulating film; 4. Backplate; 5. Sealant. Detailed Implementation

[0025] 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. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] The reflectivity of perovskite solar cells can be reduced in various ways to improve light absorption and conversion efficiency. For example, by using antireflective layers, gradient refractive index, and textured light-trapping structures, reflection from the front surface can be effectively reduced, thereby increasing light capture and improving the energy conversion efficiency of the cell. Specifically, the reflectivity of solar cells can be optimized through the following techniques: First, antireflective layers: adding one or more layers of material with a specific refractive index to the cell surface reduces light reflection and increases the probability of light entering the cell. Second, gradient refractive index: designing a layered structure with gradually changing refractive index allows light to be reflected gradually within the multilayer structure, improving light absorption efficiency. Third, textured light-trapping structures: creating microstructures, such as pyramid shapes, on the cell surface reduces reflection while increasing light scattering and absorption. However, perovskite cells are very thin (nanoscale) and require sophisticated fabrication processes, making surface texturing difficult. This invention provides a photovoltaic cell module that improves efficiency by optimizing the encapsulation structure of perovskite cells.

[0027] The following is combined Figures 1 to 4 The following describes embodiments of the present invention.

[0028] According to an embodiment of the present invention, in a first aspect, a photovoltaic cell module is provided, including a transparent substrate 1 and a cell film layer 2. The side of the transparent substrate 1 opposite to the light-facing surface is a undulating surface, which includes a plurality of spaced convex surfaces and concave surfaces 11 located between adjacent convex surfaces; the cell film layer 2 is adhered to the undulating surface.

[0029] The photovoltaic cell module provided in this embodiment of the invention features a undulating surface on the side of the transparent substrate 1 opposite to the light-facing surface. This surface, where the cell film layer 2 is deposited, creates a textured surface on the light-receiving surface of the perovskite. This allows for internal reflection of incident light and increases the refraction angle, reducing light loss and improving cell efficiency. Furthermore, the undulating surface includes several spaced convex surfaces and concave surfaces 11 between adjacent convex surfaces. Compared to the planar structure of the transparent substrate 1 and the cell film layer 2, this invention increases the path length and refraction angle of light on the cell surface, causing obliquely incident light to be more concentrated on the cell film layer 2. The convex structure also reduces light reflection and loss, thereby increasing light absorption. This helps reduce light reflection and increases the residence time of light in the cell film layer 2 (e.g., ...). Figure 3 As shown in the middle beam (a), it improves the utilization rate of light, thereby enhancing the photoelectric conversion efficiency of the battery.

[0030] In some embodiments, the cell film layer 2 includes a plurality of sub-cell scribing lines 26, which are located at the bottom end of the concave surface 11 and / or the top end of the convex surface.

[0031] The sub-cell scribing lines 26 are located at the bottom end of the concave surface 11 and / or the top end of the convex surface. This arrangement facilitates laser scribing. More preferably, all the sub-cell scribing lines 26 are located at the bottom end of the concave surface or at the top end of the convex surface. This arrangement ensures that the laser power and focus remain unchanged during laser scribing. Furthermore, since the width of the sub-cell scribing lines is relatively wide (the dead zone width included by the sub-cell scribing lines 26 is generally 0.3-0.5 mm), it is more suitable to place them at the bottom end of the concave surface and the top end of the convex surface.

[0032] Specifically, "the sub-battery scribing line 26 is located at the bottom end of the concave surface 11 and / or the top end of the convex surface" means that the sub-battery scribing line 26 is located at the bottom end of the concave surface 11; or, the sub-battery scribing line 26 is located at the top end of the convex surface; or, the sub-battery scribing line 26 is located at both the bottom end of the concave surface 11 and the top end of the convex surface. Preferably, the sub-battery scribing lines 26 are located in the same plane, that is, the sub-battery scribing line 26 is located at the bottom end of the concave surface 11 or the sub-battery scribing line 26 is located at the top end of the convex surface, which can improve the accuracy and consistency of the sub-battery scribing lines 26.

[0033] In some embodiments, the top end of the convex surface and / or the bottom end of the concave surface 11 includes a planar platform 12. A plurality of planar platforms 12 located at the top end of the convex surface are coplanarly arranged or a plurality of planar platforms 12 located at the bottom end of the concave surface 11 are coplanarly arranged, and the planar platform 12 is parallel to the plane on which the transparent substrate 1 is located, and the sub-cell scribing line 26 is located on the planar platform 12.

[0034] Specifically, "the top of the convex surface and / or the bottom of the concave surface 11 includes a planar platform 12" means that the top of the convex surface includes a planar platform 12; or, the bottom of the concave surface 11 includes a planar platform 12; or, both the top of the convex surface and the bottom of the concave surface 11 include a planar platform 12.

[0035] This configuration places the sub-cell scribing line 26 on a flat surface, reducing errors caused by substrate unevenness during scribing and ensuring the accuracy and reliability of the scribing lines. Simultaneously, laser scribing on the planar platform 12 simplifies the scribing process, making the scribing depth easier to control, while reducing manufacturing difficulty and cost. Furthermore, it ensures that the laser power and focus remain constant during laser scribing, guaranteeing that each film layer can be accurately severed by the laser.

[0036] In some embodiments, the thickness of the cell film layer 2 is t, and the distance between the bottom end of the concave surface 11 and the top end of the convex surface is h, where h ≥ t, and t ≥ 500 nm.

[0037] Generally, the thickness of the perovskite cell film layer is in the range of 500nm-1.2μm. By controlling the distance h between the bottom end of the concave surface 11 and the top end of the convex surface to be greater than or equal to t, the cell film layer between the top ends of the two convex surfaces is located within the concave surface region. This increases the path length of light on the cell surface, thereby improving the light absorption rate. When light enters the cell, it undergoes multiple reflections between the convex and concave surfaces 11, increasing the residence time of light in the cell film layer 2, which helps more photons to be absorbed and improves the photoelectric conversion efficiency. Simultaneously, when light undergoes multiple reflections between the convex and concave surfaces 11, some light is absorbed by the cell film layer 2, thereby reducing reflection loss. This helps improve the photoelectric performance of the cell. Furthermore, increasing h increases the surface area of ​​the undulating surface of the transparent substrate 1, allowing the cell film layer 2 to better adhere to the undulating surface. This helps improve the adhesion and uniformity of the film layer, reduces voids and gaps between the film layer and the substrate, and improves the quality of the cell film layer 2. It can also increase the total area of ​​the deposition surface of the cell film layer 2, that is, increase the total power generation area of ​​the cell film layer 2.

[0038] This configuration ensures that the cell film layer 2 is completely located within the concave surface 11, thereby maximizing the utilization of light refracted and reflected by the convex surface and improving photoelectric conversion efficiency.

[0039] Specifically, when a planar platform 12 is provided on a convex surface, the planar platform 12 is the top of the convex surface.

[0040] In some embodiments, the concave surface 11 and / or the convex surface are arranged along the XY direction; along the X direction, the length of the planar platform 12 is d, 0.5mm≤d≤10mm.

[0041] Specifically, the directions of X and Y are as follows: Figure 1 As shown. The length d of the planar platform 12 is the dimension along the X direction.

[0042] The length d of the several planar platforms 12 can be equal or unequal. When the length d of the several planar platforms 12 is equal, that is, when the several planar platforms 12 are evenly distributed along the X direction.

[0043] The length d of the planar platform 12 must be greater than the width required for the sub-cell scribing area. Controlling the length d of the planar platform 12 between 0.5 mm and 10 mm ensures that the sub-cell scribing line 26 is located on a more stable plane, guaranteeing sufficient width for laser scribing to form the sub-cell scribing line 26.

[0044] In some embodiments, the width of the planar platform 12 along the Y direction is r, where 0.5mm ≤ r ≤ 10mm.

[0045] Specifically, the width r of the planar platform 12 is the dimension along the Y direction.

[0046] Similarly, the width r of several planar platforms 12 can be equal or unequal. When the value of r is equal, the several planar platforms 12 are evenly distributed along the Y direction.

[0047] By controlling the width r of the planar platform 12 between 0.5 mm and 10 mm, it can be ensured that the sub-cell scribing line 26 is located on a more stable plane, reducing the damage of the scribing line to the cell film layer 2.

[0048] In some embodiments, the concave surface 11 and / or the convex surface are arranged along the XY direction; along the X direction, the length of the concave surface 11 and / or the convex surface is L, where 0 mm < L ≤ 10 mm.

[0049] Specifically, the length L of the concave surface 11 and / or the convex surface is a dimension along the X direction. The length L of the concave surface 11 and the convex surface can be equal or unequal.

[0050] By controlling the length L of the concave surface 11 and / or the convex surface within the range of 0 mm to 10 mm, the number of light reflections can be effectively increased without being overly complex, thus facilitating manufacturing and control. Furthermore, this length range provides sufficient surface area, allowing the cell film layer 2 to better adhere to the undulating surface. This helps improve the adhesion and uniformity of the film layer, reduces bubbles and voids between the film layer and the substrate, and improves the quality of the film layer.

[0051] In some embodiments, the width of the concave surface 11 and / or the convex surface along the Y direction is S, where 0 mm < S ≤ 10 mm.

[0052] Specifically, the width S of the concave surface 11 and / or the convex surface is a dimension along the Y direction.

[0053] The width S of some concave surfaces 11 and some convex surfaces can be equal or unequal.

[0054] Controlling the width S of the concave surface 11 and / or the convex surface between 0 mm and 10 mm increases the path length of light on the battery surface. When light undergoes multiple reflections between the convex and concave surfaces 11, the residence time of light in the cell film layer 2 is increased, which helps more photons to be absorbed and improves photoelectric conversion efficiency. Simultaneously, it provides sufficient surface area, allowing the cell film layer 2 to better adhere to the undulating surface. This helps improve the adhesion and uniformity of the film layer, reduces bubbles and voids between the film layer and the substrate, and improves the quality of the film layer.

[0055] Furthermore, controlling L, d, S, and r within the aforementioned ranges can simplify the manufacturing process, making the scribing process easier to control and reducing manufacturing difficulty and costs.

[0056] In some embodiments, the undulating surface is a wave surface. Specifically, the cross-section of the wave surface includes a sine wave, a triangular wave, a rectangular wave, or a trapezoidal wave.

[0057] In some embodiments, the undulating surface is a lattice-type ridge structure, specifically, the lattice-type ridge structure includes a square pyramid shape, a cone shape, or a hump shape.

[0058] In some embodiments, a plurality of convex surfaces are arranged at equal intervals, and / or a plurality of concave surfaces 11 are arranged at equal intervals.

[0059] Arranging several convex or concave surfaces 11 at equal intervals can increase the refraction angle, making obliquely incident light rays more biased toward the cell film layer 2. Moreover, the convex structure reduces the reflection of incident light rays, reduces light loss, and thus improves the utilization rate of light.

[0060] In some embodiments, the device further includes an encapsulating film 3, a backplate 4, and a sealant 5; the encapsulating film 3 and the backplate 4 are sequentially encapsulated on the backlight side of the battery cell film layer 2; the sealant 5 is filled between the backplate 4 and the transparent substrate 1, and surrounds the battery cell film layer 2 within it.

[0061] Specifically, the encapsulation film 3 includes a TPO film: TPO (Thermoplastic Olefin) film has good thermoplasticity and adhesion properties, which can effectively seal the cell film layer 2, prevent moisture and air from entering, and improve the reliability and durability of the encapsulation.

[0062] Backing plate 4: Backing plate 4 protects the cell film layer 2 from the influence of the external environment. Backing plate 4 can be transparent or opaque. A transparent backing plate 4 can maintain transparency and not affect the light transmittance.

[0063] Specifically, the sealant 5 includes butyl rubber: Butyl rubber has excellent sealing and waterproof properties, which can effectively fill the gap between the backplate 4 and the transparent substrate 1, forming a closed environment and further improving the reliability of the encapsulation. At the same time, it increases the bonding force between the backplate 4 and the transparent substrate 1, improving the overall mechanical stability.

[0064] Perovskite solar cells are encapsulated using existing packaging processes.

[0065] In some embodiments, along the direction away from the undulating surface, the battery cell film layer 2 includes a transparent conductive oxide layer 21, a first charge transport layer 22, a perovskite layer 23, a second charge transport layer 24, and a back electrode 25, which are sequentially stacked. The first charge transport layer 22 and the second charge transport layer 24 can be independently electron transport layers or charge transport layers, and together constitute an electron-hole transport layer.

[0066] This configuration can improve photoelectric conversion efficiency, enhance carrier transport and separation, improve device stability, optimize optical management, and improve device fabrication process compatibility.

[0067] The coating and encapsulation processes for each layer of perovskite remain unchanged; only the glass pattern on the substrate needs to be improved, resulting in low cost.

[0068] The photovoltaic cell module provided in this embodiment of the present invention can reduce the reflection loss of incident light on the perovskite surface, increase light scattering and absorption and the light-receiving area of ​​the perovskite, thereby improving the efficiency of the cell module.

[0069] According to an embodiment of the present invention, in a second aspect, a photovoltaic power generation system is also provided, including a battery pack, a charge / discharge controller, an inverter, and a photovoltaic cell module as described in the above embodiments, wherein the photovoltaic cell module, the battery pack, the charge / discharge controller, and the inverter are electrically connected.

[0070] Since photovoltaic power generation systems include photovoltaic cell modules and have the same effect as photovoltaic cell modules, they will not be elaborated on here.

[0071] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A photovoltaic cell module, characterized in that, include: A transparent substrate (1) has a undulating surface on one side opposite to the light-facing surface. The undulating surface includes a plurality of spaced convex surfaces and concave surfaces (11) located between adjacent convex surfaces. The battery cell film layer (2) is attached to the undulating surface.

2. The photovoltaic cell module according to claim 1, characterized in that, The cell film layer (2) includes a plurality of sub-cell scribing lines (26), which are located at the bottom end of the concave surface (11) and / or the top end of the convex surface.

3. The photovoltaic cell module according to claim 2, characterized in that, The top end of the convex surface and / or the bottom end of the concave surface (11) includes a planar platform (12). The planar platforms (12) located at the top end of the convex surface are coplanar or the planar platforms (12) located at the bottom end of the concave surface are coplanar. The planar platforms (12) are parallel to the plane of the transparent substrate (1). The sub-cell scribing line (26) is located on the planar platform (12).

4. The photovoltaic cell module according to claim 3, characterized in that, The concave surface (11) and / or the convex surface are arranged along the XY direction; Along the X direction, the length of the planar platform (12) is d, 0.5mm≤d≤10mm; And / or, along the Y direction, the width of the planar platform (12) is r, 0.5mm≤r≤10mm.

5. The photovoltaic cell module according to claim 2, characterized in that, The concave surface (11) and / or the convex surface are arranged along the XY direction; Along the X direction, the length of the concave surface (11) and / or the convex surface is L, 0mm < L ≤ 10mm; And / or, along the Y direction, the width of the concave surface (11) and / or the convex surface is S, 0mm < S ≤ 10mm.

6. The photovoltaic cell module according to claim 5, characterized in that, The thickness of the cell film layer (2) is t, and the distance between the bottom end of the concave surface (11) and the top end of the convex surface is h, where h≥t, and t≥500nm.

7. The photovoltaic cell module according to any one of claims 1 to 6, characterized in that, The undulating surface is a wave-like surface; Alternatively, the undulating surface may be a lattice-type ridge structure.

8. The photovoltaic cell module according to any one of claims 1 to 6, characterized in that, The convex surfaces are arranged at equal intervals, and / or the concave surfaces (11) are arranged at equal intervals.

9. The photovoltaic cell module according to any one of claims 1 to 6, characterized in that, It also includes an encapsulating film (3), a backplate (4), and a sealant (5); the encapsulating film (3) and the backplate (4) are sequentially encapsulated on the back side of the battery cell film layer (2); the sealant (5) is filled between the backplate (4) and the transparent substrate (1), and surrounds the battery cell film layer (2) inside.

10. A photovoltaic power generation system, characterized in that, include: Battery pack; Charge / discharge controller; Inverter; The photovoltaic cell module according to any one of claims 1 to 9, wherein the photovoltaic cell module, the battery pack, the charge / discharge controller and the inverter are electrically connected.

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