TOP Con battery back Poly local area laser film opening pattern

Abstract

The utility model discloses a TOP Con battery back Poly local area laser film opening pattern, which is formed on the back of a battery, the laser film opening pattern comprises a Poly reserved area and a plurality of Poly removed areas, back metal auxiliary grid lines are printed on two sides of the Poly reserved area, the plurality of Poly removed areas are arranged between two back metal auxiliary grid lines, and the Poly removed areas are printed on the back metal auxiliary grid lines. The plurality of Poly removal areas are vertically arranged at the middle position of the Poly reserving area; according to the TOP Con cell back Poly local area laser film opening pattern provided by the utility model, through the adjustment of the laser film opening pattern, on the basis of reducing the influence of partial Poly long wave parasitic absorption, the Poly in a non-contact area is reserved as much as possible, the tunneling rate of multiple carriers is ensured, the reduction amplitude of the FF of the cell is obviously improved, and the performance of the cell is improved. And compared with the existing selective Poly battery, the comprehensive efficiency is obviously improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to TOP Con battery technical field especially relates to a kind of TOP Con battery back Poly local area laser film opening pattern. BACKGROUND

[0002] At present, TOP Con battery has become mainstream battery type of photovoltaic industry, it is a new type of passivated contact solar cell, first depositing a layer of 1-2nm ultra-thin oxide layer as tunneling layer on the back of battery, then depositing a layer of doped polysilicon (Poly) layer, both form passivated contact structure, utilize the chemical passivation of silicon oxide and the effect of many electron tunneling, and field passivation of doped polysilicon layer, greatly reduce the surface recombination of back, improve the conversion efficiency of battery.

[0003] Because doped Poly has serious parasitic absorption to light, the optimization mode of present TOP Con battery is selective doped Poly layer, i.e. normal thickness Poly structure is reserved in metal auxiliary grid line contact area, passivated contact Poly between metal auxiliary grid lines is removed, to achieve selective doped Poly structure that neither affects contact recombination of metal grid line, nor reduces long-wave parasitic absorption to light;But because the total area of doped Poly reduces, although current is obviously improved, but it will lead to the weakening of many electron tunneling effect, cause FF (Fill Factor, simply referred to as FF) to reduce, FF reduces at least 0.3-0.5, leading to the efficiency improvement effect of selective Poly structure optimization is less than expected.

[0004] Patent with publication number CN116825896A provides a preparation method of back surface selective passivation layer TOP Con battery, back surface non-emitter grid line area is treated by laser opening, PSG layer is damaged, other contact areas are N+ layer, PSG layer is still protected, Poly in laser film opening area is removed by wet cleaning, and back surface selective passivation structure is formed.

[0005] But in the above scheme, the area of all non-contact area Poly removal is large, which is not conducive to FF, and affects the improvement of battery efficiency. UTILITY MODEL CONTENT

[0006] The purpose of the application is to provide a kind of TOP Con battery back Poly local area laser film opening pattern, to solve the above insufficient in prior art.

[0007] In order to achieve the above object, the utility model discloses the following technical scheme: a kind of TOP Con battery back Poly local laser membrane opening pattern, form in battery back, laser membrane opening pattern includes Poly reserved area and multiple Poly removal area, the both sides of the Poly reserved area are printed with back metal auxiliary grid line, multiple Poly removal area are arranged between two back metal auxiliary grid lines, multiple Poly removal area vertically arranged in the middle position of the Poly reserved area.

[0008] As further description of the above technical solution: according to the spot and area of the Poly removal area, 300-400 μm width PSG is removed.

[0009] As further description of the above technical solution: the size of the Poly removal area is 120*360 μm.

[0010] As further description of the above technical solution: the poly removal area uses longitudinal spot separate arrangement, and the spot energy density is 300-450 mJ / cm 2 .

[0011] As further description of the above technical solution: the Poly reserved area retains a width of 500-700 μm.

[0012] As further description of the above technical solution: after removing PSG from the silicon wafer, a slot machine is used to remove Poly from the back of the battery, and the laser etching area is etched, with a corrosion depth of 2-3.5 μm and a tower base size of 13-22 μm.

[0013] The utility model provides a kind of TOP Con battery back Poly local laser membrane opening pattern.It has the following beneficial effects: by the adjustment of laser membrane opening pattern, on the basis of reducing the influence of part Poly long wave parasitic absorption, as much as possible Poly of non-contact area is retained, the tunneling rate of poly is guaranteed, the reduction amplitude of battery FF is obviously improved, and the comprehensive efficiency is obviously improved compared with existing selective Poly battery;Due to the design of spot separation, the number of spots in the same area is reduced, and the CT time of laser equipment can be significantly reduced, which is beneficial to improve the production capacity of laser process;The width of Ploy reserved area is larger, and the camera edge positioning during screen printing will not be offset, so that the camera modification of screen machine is avoided, the investment cost is saved, and the yield of battery piece output is improved.

[0014] It should be understood that the foregoing general description and the following detailed description are only exemplary and illustrative, but not for limiting the present disclosure.

[0015] The present application provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the full scope or all features of the disclosed technology. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a TOP Con battery with a localized laser-etched pattern on the back.

[0017] Figure 2 This is a schematic diagram of the laser-induced film-opening spot pattern of this utility model.

[0018] Legend:

[0019] 1. Poly removal area; 2. Poly retention area; 3. Backside metal sub-gate line. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0021] Reference Figures 1-2 A localized laser-etched poly pattern on the back of a TOP Con battery is disclosed, formed on the back of the battery. The laser-etched pattern includes a poly retention area 2 and multiple poly removal areas 1. Back metal sub-grid lines 3 are printed on both sides of the poly retention area 2. The multiple poly removal areas 1 are disposed between two back metal sub-grid lines 3 and are vertically arranged in the middle of the poly retention area 2. This patented TOP Con battery back-side poly localized laser-etched pattern, through adjustment of the laser-etched pattern, reduces the influence of long-wavelength parasitic absorption of some poly while retaining as much poly as possible in the non-contact area, ensuring majority carrier tunneling efficiency, significantly improving the reduction in battery FF, and resulting in a significantly higher overall efficiency compared to existing selective poly batteries.

[0022] As a preferred technical solution in this embodiment, such as Figure 1 and Figure 2 As shown, PSG with a width of 300-400 μm is removed according to the spot size and area of ​​the Poly removal region 1; the PSG is then removed using a specially designed laser film-opening pattern (the spot size and area of ​​the Poly removal region 1 are as shown in the figure). Figure 1 and Figure 2 As shown), remove the 300-400μm wide phosphosilicate glass (PSG). First, remove the PSG from the poly, and then use a trough-type machine to remove the poly from the back of the battery.

[0023] As the preferred technical scheme of the embodiment, the size of the Poly removal area 1 is 120*360 mu; by adjusting the laser opening film pattern, the influence of the long-wave parasitic absorption of the reduced Poly is reduced, and the Poly retention area 2 is retained as much as possible, the tunneling rate of the Poly is ensured, the reduction of the FF of the battery is obviously improved, and the comprehensive efficiency is obviously improved compared with the existing selective Poly battery.

[0024] As the preferred technical scheme of the embodiment, the poly removal area adopts longitudinal spot arrangement, and the spot energy density is 300-450 mJ / cm 2 ; due to the design of the spot separation, the number of spots in the same area is reduced, the CT time of the laser equipment can be obviously reduced, and the production capacity of the laser process is improved.

[0025] As the preferred technical scheme of the embodiment, the Poly retention area 2 has a retention width of 500-700 mu; the width of the Poly retention area 2 is large, the camera edge grabbing alignment will not be offset during screen printing, the camera of the screen printing machine is exempted from modification, the investment cost is saved, and the yield of the battery piece production is improved.

[0026] As the preferred technical scheme of the embodiment, after the silicon wafer is removed from the PSG, a groove type machine is used to remove the Poly on the back of the battery, and the etching laser opening film area is etched to a depth of 2-3.5 mu, and the tower base size of the etching area is 13-22 mu; in the manufacturing process of the TOP Con battery, the RCA anti-plating and etching steps are mainly used for removing the phosphosilicate glass (PSG) on the surface of the Poly and removing the Poly and etching the silicon wafer of the laser opening film area, and at the same time, the step also includes removing the Poly on the back of the battery, and etching the laser opening film area in particular, so as to achieve the purpose of selective passivation contact and optimize the battery performance.

[0027] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0028] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A TOP Con cell backside Poly local laser opening film pattern formed on the backside of the cell, characterized in that: The laser opening film pattern comprises a Poly reserved area (2) and a plurality of Poly removed areas (1), both sides of the Poly reserved area (2) are printed with back metal auxiliary grid lines (3), the plurality of Poly removed areas (1) are arranged between the two back metal auxiliary grid lines (3), and the plurality of Poly removed areas (1) are vertically arranged in the middle position of the Poly reserved area (2).

2. A backside Poly local laser opening film pattern for a TOP Con cell according to claim 1, characterized in that, According to the spot and area of the Poly removed area (1), 300-400 mu m width of PSG is removed.

3. A backside Poly local laser opening film pattern for a TOP Con cell according to claim 2, characterized in that, The size of the Poly removed area (1) is 120*360 mu m.

4. The backside Poly local laser opening film pattern of a TOP Con cell according to claim 2, characterized in that, The Poly removal zone (1) adopts longitudinal light spot arrangement, and the energy density of the light spot is 300-450 mJ / cm 2 .

5. A backside Poly local laser opening film pattern for a TOP Con cell according to claim 4, characterized in that, The Poly reserved area (2) reserves a width of 500-700 mu m.

6. A backside Poly local laser opening film pattern for a TOP Con cell according to claim 4, characterized in that, After removing the PSG of the silicon wafer, the back of the battery is removed by using a slot type machine, and the laser opening film area is etched, the etching depth is 2-3.5 mu m, and the tower base size of the etching area is 13-22 mu m.

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