Tray for solar cell film formation
By setting a limiting rod at the edge of the tray bearing area, the problem of non-uniform electromagnetic field and airflow field in the PECVD process was solved, resulting in more uniform film formation and higher battery efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2026-03-03
AI Technical Summary
In the PECVD process, existing solar cell film-forming trays disrupt the uniformity of the electromagnetic field and airflow field on the side between the limiting area and the support area, leading to abnormal film formation at the silicon wafer edge and reduced cell efficiency.
Design a tray for solar cell film deposition, with multiple limiting rods set at the edge of each support area to prevent the silicon wafer from sliding out of the support area, forming a more uniform electromagnetic field and airflow field, and improving the uniformity of film deposition.
By improving the tray structure, the uniformity of the electromagnetic field and airflow field on the silicon wafer was enhanced, thereby improving the film uniformity and the conversion efficiency of the solar cell.
Smart Images
Figure CN223963568U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of solar cell manufacturing, and in particular to a tray for solar cell film formation. Background Technology
[0002] Thin-film / crystalline silicon heterojunction solar cells (hereinafter referred to as heterojunction solar cells, also known as HIT, HJT, or SHJ solar cells) belong to the third generation of high-efficiency solar cell technology. They combine the advantages of first-generation crystalline silicon and second-generation silicon thin film, and have the characteristics of high conversion efficiency and low temperature coefficient. In particular, the conversion efficiency of bifacial heterojunction solar cells can reach more than 26%, and they have broad market prospects.
[0003] When fabricating heterojunction solar cells, the core manufacturing process includes: depositing very thin I-type intrinsic amorphous silicon films and P-type amorphous silicon films on one side of textured N-type crystalline silicon using plasma-enhanced chemical vapor deposition (PECVD), and depositing thin I-type intrinsic amorphous silicon films and N-type amorphous silicon films on the other side of the crystalline silicon. The fabrication of the amorphous silicon films on both sides can be carried out simultaneously or in steps; then depositing transparent oxide conductive (ITO) films on both sides of the cell, and finally fabricating metal electrodes on the ITO films.
[0004] When depositing amorphous silicon thin films on silicon wafers using the PECVD process, methods such as... Figure 1 The prior art tray shown is specifically as follows: Figure 4 The silicon wafer 2 is placed in tray 1 as shown. Figure 1 As shown, the tray 1 for solar cell film formation in the prior art includes multiple connection areas 10 and a support unit 12. Figure 2 and Figure 3 They are respectively Figure 1 The diagram shows the top and cross-sectional views of the supporting unit 12. Figures 2 to 4 As shown, each support unit 12 includes a tray body 120, a vent 121, a support 122, a groove 123, a support area 124, and a limiting area 125. The silicon wafer 2 is supported by the support area 124, and the middle part of the silicon wafer is suspended in the groove 123. The groove 123, the support area 124, and the limiting area 125 form a two-stage stepped structure on the tray body 120. The second step formed by the limiting area 125 can prevent the silicon wafer from sliding, and its height of 0.5-1mm can prevent the silicon wafer from deforming and forming an overlap at high temperatures.
[0005] However, if the airflow and power are high during the PECVD process, the side between the limiting region 125 and the carrier region 124 acts like a high wall close to the silicon wafer, which will disrupt the uniformity of the electromagnetic field and airflow field across the entire silicon wafer, resulting in a significant edge effect. This causes abnormal film formation and reduced cell efficiency in the 1.5mm-2mm edge area of the silicon wafer.
[0006] Therefore, how to provide a tray for solar cell film formation that can improve the uniformity of electromagnetic field and airflow field on the silicon wafer supported in the tray during the PECVD process, thereby improving film formation uniformity and solar cell conversion efficiency, has become a technical problem that urgently needs to be solved in the industry. Summary of the Invention
[0007] To address the aforementioned problems in the prior art, this utility model proposes a tray for solar cell film formation, comprising multiple support units. Each support unit includes a tray body, a groove formed on the tray body, and a support area surrounding the groove for supporting silicon wafers. Each support area has multiple limiting rods at its edge to prevent the silicon wafers from sliding out of the support area.
[0008] In one embodiment, the number of limiting rods at the edge of each bearing area is 4 to 8, and the limiting rods extend 0.5 mm to 1.2 mm above the bearing area; the cross-section of the limiting rods is circular, rectangular, square, elliptical, or oval, and its cross-sectional area ranges from 0.5 mm². 2 -1.5mm 2 .
[0009] In one embodiment, the number of limiting rods at the edge of each bearing area is 8, and 2 limiting rods are provided at each corner of each bearing area.
[0010] In one embodiment, the number of limiting rods at the edge of each bearing area is 4, and one limiting rod is provided at the middle of each side of the bearing area.
[0011] In one embodiment, the bearing area is a chamfered rectangular bearing area, and the width of the chamfered rectangular bearing area ranges from 0.5mm to 3mm.
[0012] In one embodiment, the depth of the groove is in the range of 0.5mm-1.2mm, and the bottom of the groove is provided with a support member that does not protrude above the groove at the corresponding center position of the silicon wafer or the main gate position.
[0013] In one embodiment, the bottom of the groove is provided with a plurality of ventilation holes passing through the tray body.
[0014] In one embodiment, the solar cell film-forming tray further includes a connection area disposed between adjacent support units, wherein the height of the support area of the support unit is the same as the height of the connection area.
[0015] In one embodiment, the bearing area is adapted to accommodate silicon wafers of 125mm×125mm, 156mm×156mm, 166mm×166mm, 182mm×182mm, 91mm×182mm, 105mm×210mm or 210mm×210mm.
[0016] In one embodiment, the width of the solar cell film-forming tray ranges from 100cm to 200cm, the length ranges from 100cm to 200cm, and the thickness ranges from 0.3cm to 1cm.
[0017] Unlike existing technologies where the sides of the silicon wafer support area resemble high walls, disrupting the uniformity of the electromagnetic and airflow fields across the entire wafer and causing abnormal film formation and reduced cell efficiency in the surrounding area, the solar cell film formation tray of this invention comprises multiple support units. Each support unit includes a tray body, a groove formed in the tray body, and a support area surrounding the groove for supporting the silicon wafer. Multiple limiting rods are provided at the edge of each support area to prevent the silicon wafer from sliding out of the support area. This invention improves the uniformity of the electromagnetic and airflow fields on the silicon wafer supported in the tray during the PECVD process, thereby improving film formation uniformity and the conversion efficiency of the solar cell. Attached Figure Description
[0018] The above-described features and advantages of this invention can be better understood after reading the following detailed description of the embodiments of this disclosure in conjunction with the accompanying drawings. In the drawings, the components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.
[0019] Figure 1 This is an overall top view of a tray used for solar cell film formation in the prior art.
[0020] Figure 2 for Figure 1 A top view of the supporting unit in the diagram.
[0021] Figure 3 for Figure 1 A cross-sectional structural diagram of the supporting unit in the diagram.
[0022] Figure 4 for Figure 1 A cross-sectional view of the structure of the carrier unit carrying silicon wafer 2.
[0023] Figure 5 This is a top view of the tray used for solar cell film formation in this utility model.
[0024] Figure 6 for Figure 5 A top view of the supporting unit in the diagram.
[0025] Figure 7 For along Figure 6 A cross-sectional view of the load-bearing unit along section AA.
[0026] Figure 8 for Figure 5 A cross-sectional view of the structure of the carrier unit carrying silicon wafer 2. Detailed Implementation Plan
[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments to provide a clearer understanding of its objectives, features, and advantages. It should be understood that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way. Unless the context clearly indicates otherwise, the singular forms “a” and “the” include plural referents.
[0028] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. It is worth noting that the embodiments described below do not limit the present invention, and any structural or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present invention.
[0029] Figure 5 This is a top view of the tray used for solar cell film formation in this utility model. Figure 6 for Figure 5 A top view of the load-bearing unit in the diagram. Figure 7 For along Figure 6 A cross-sectional view of the load-bearing unit along section AA. Figure 8 for Figure 5 A cross-sectional view of the structure of the carrier unit carrying silicon wafer 2.
[0030] like Figure 5 As shown, the novel solar cell film-forming tray 3 of this invention includes multiple connecting areas 30 and multiple supporting units 32. The connecting areas 30 are disposed between adjacent supporting units 32 and at the edges of the tray 3. The tray 3 can be a composite tray, which may include a substrate and a coating covering the substrate. The substrate can be made of any one of graphite, carbon fiber, or silicon carbide, and the coating can be made of any one of aluminum, silver, copper, or their alloys. The width of the solar cell film-forming tray 3 ranges from 100cm to 200cm, the length ranges from 100cm to 200cm, and the thickness ranges from 0.3cm to 1cm.
[0031] like Figures 6 to 8 As shown, each support unit 32 includes a tray body 320, a vent 321, a support member 322, a groove 323, multiple limiting rods 324, and a support area 325. The groove 323 is used to suspend the middle of the silicon wafer 2, the support area 325 surrounds each groove 323 and is used to support the silicon wafer 2, and the multiple limiting rods 324 are arranged at the edge of each support area 325 and are used to prevent the silicon wafer 2 from sliding out of the support area 325.
[0032] Several vent holes 321 are disposed at the bottom of the groove 323 and pass through the tray body 320. Each carrier unit 32 may have two or four vent holes 321. When the silicon wafer 2 and the tray 3 are placed in the PECVD reaction chamber and a vacuum is applied, the vent holes 321 can extract residual process gas below the silicon wafer 2 to prevent contamination of the reaction chamber by residual process gas; at the same time, before the silicon wafer 2 is transferred out of the reaction chamber, when atmospheric air is injected into the vacuum reaction chamber, the vent holes 321 can also cause the gas pressure below the silicon wafer 2 to increase with the increase of external pressure, preventing the external pressure from crushing the silicon wafer 2.
[0033] The support member 322 and the pallet body 320 can be integrally formed. Alternatively, the support member 322 and the pallet body 320 can be separate structures, with the support member 322 being snap-fitted onto the pallet body 320 and its support height adjustable.
[0034] The depth of the groove 323 ranges from 0.5mm to 1.2mm. The support 322 is located at the bottom of the groove 323, corresponding to the center position of the silicon wafer or the main gate position, and does not protrude from the groove 323.
[0035] The carrier area 325 and the connecting area 30 are respectively located on the inner and outer sides of the limiting rod 324. The height of the carrier area 325 is the same as the height of the connecting area 30. The carrier area 325 is suitable for accommodating silicon wafers of various sizes used in the industry in the past, present, and future, such as 125mm×125mm, 156mm×156mm, 166mm×166mm, 182mm×182mm, 91mm×182mm, 105mm×210mm, or 210mm×210mm.
[0036] The number of limiting rods 324 at the edge of each bearing area 325 is 4 to 8, and the limiting rods 324 extend 0.5mm-1.2mm above the bearing area 325; the cross-section of the limiting rods 324 can be circular, rectangular, square, elliptical, or oval, etc., and its cross-sectional area is in the range of 0.5mm². 2 -1.5mm 2 (square millimeters).
[0037] In such Figure 5 and Figure 6 In the embodiment shown, there are 8 limiting rods 324 on the edge of each bearing area 325, and 2 limiting rods 324 are provided at each corner of each bearing area 325.
[0038] In other embodiments, the number of limiting rods 324 at the edge of each bearing area 325 may be four, with one limiting rod 324 provided at the middle of each side of the bearing area 325.
[0039] The bearing area 325 is a chamfered rectangular bearing area, and the width of the chamfered rectangular bearing area ranges from 0.5mm to 3mm.
[0040] When performing PECVD on silicon wafers that have completed cleaning and texturing, silicon wafer 2 is first arranged as follows: Figure 8 As shown, the silicon wafer 2 is placed on the support area 325 of the solar cell film-forming tray 3. The central area of the silicon wafer 2 is suspended in the groove 323, and the central part or main grid line of the silicon wafer 2 is supported by the support member 322. Then, the tray 3 is transferred to the PECVD process chamber by means of a robotic arm or rollers. After that, the PECVD process chamber is evacuated and the reactive gas is introduced. The RF power supply is turned on. Because the support area 325 and the connection area 30 have the same height and the limiting rod 324 is very small, the electromagnetic field and the airflow field are basically uniform on the same silicon wafer. The film thickness of the edge area and the center area of the silicon wafer is basically the same, thereby avoiding the adverse effects of edge effects.
[0041] This invention relates to a solar cell film-forming tray comprising multiple support units. Each support unit includes a tray body, a groove formed on the tray body, and a support area surrounding the groove for supporting silicon wafers. Multiple limiting rods are provided at the edge of each support area to prevent the silicon wafer from sliding out of the support area. This invention improves the uniformity of the electromagnetic field and airflow field on the silicon wafer supported in the tray during the PECVD process, thereby improving film uniformity and the conversion efficiency of the solar cell.
[0042] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0043] The above embodiments are provided for those skilled in the art to implement or use the present invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope that conforms to the innovative features mentioned in the claims.
Claims
1. A tray for solar cell film deposition, comprising multiple support units, each support unit comprising a tray body, a groove formed on the tray body, and a support area surrounding the groove for supporting silicon wafers, characterized in that, Each bearing area has multiple limiting rods at its edge to prevent the silicon wafer from sliding out of the bearing area.
2. The solar cell film-forming tray according to claim 1, characterized in that, The number of limiting rods at the edge of each bearing area is 4 to 8, and the limiting rods extend 0.5 mm to 1.2 mm above the bearing area; the cross-section of the limiting rods is circular, rectangular, elliptical, or oval, and its cross-sectional area ranges from 0.5 mm². 2 -1.5 mm 2 .
3. The solar cell film-forming tray according to claim 1 or 2, characterized in that, The number of limiting rods at the edge of each bearing area is 8, and 2 limiting rods are provided at each corner of each bearing area.
4. The solar cell film-forming tray according to claim 1 or 2, characterized in that, The number of limiting rods at the edge of each bearing area is 4, and one limiting rod is set at the middle of each side of the bearing area.
5. The solar cell film-forming tray according to claim 1, characterized in that, The bearing area is a chamfered rectangular bearing area, and the width of the chamfered rectangular bearing area ranges from 0.5 mm to 3 mm.
6. The solar cell film-forming tray according to claim 1, characterized in that, The depth of the groove ranges from 0.5 mm to 1.2 mm, and the bottom of the groove is provided with a support member that does not protrude above the groove at the corresponding center position of the silicon wafer or the main gate position.
7. The solar cell film-forming tray according to claim 1, characterized in that, The bottom of the groove is provided with several ventilation holes that pass through the tray body.
8. The solar cell film-forming tray according to claim 1, characterized in that, The solar cell film-forming tray also includes a connection area disposed between adjacent support units, wherein the height of the support area of the support unit is the same as the height of the connection area.
9. The tray for solar cell film formation according to claim 1, characterized in that, The bearing area is suitable for accommodating silicon wafers of 125mm×125mm, 156mm×156mm, 166mm×166mm, 182mm×182mm, 91mm×182mm, 105mm×210mm or 210mm×210mm.
10. The solar cell film-forming tray according to claim 2, characterized in that, The width of the tray used for solar cell film formation ranges from 100cm to 200cm, the length ranges from 100cm to 200cm, and the thickness ranges from 0.3cm to 1cm.