CN202796970U - Solar cell with selective emitter electrodes - Google Patents

Abstract

The utility model relates to a solar battery with a selective emitter. The light-receiving surface of the battery is divided into a grid line area and a non-grid line area, and the grid line area is further divided into a thin grid line area and a main grid line area. Fine grid lines are fabricated on the area of the main grid lines, and the main grid lines that collect the current of the fine grid lines are fabricated on the main grid line area. A lightly doped region with a lightly doped layer. The beneficial effects of the utility model are: 1. Reduce the consumption of etching slurry or wax when making the selective emitter, and the reduction rate can reach 50%; 2. According to the current experimental results, the efficiency is increased by more than 0.02%.

Description

Solar cells with selective emitters

technical field

The utility model relates to a solar cell with a selective emitter.

Background technique

The development direction of solar cells is low cost and high efficiency, and the selective emitter structure is one of the promising methods to achieve high efficiency in the production process of p-n crystalline silicon solar cells. The selective emitter structure has two characteristics: 1) high doping is formed under the fine grid line and busbar; 2) low doping is formed in other areas.

One of the purposes of the selective emitter technology is to reduce the series resistance, but at the same time, it also brings adverse effects of recombination increase in the respreading region, which leads to a decrease in current and opening voltage, thereby affecting efficiency.

Utility model content

The technical problem to be solved by the utility model is: to provide a solar cell with a selective emitter to improve the open-circuit voltage and conversion efficiency of the solar cell.

The technical solution adopted by the utility model to solve the technical problem is: a solar cell with a selective emitter, the light-receiving surface of the battery is divided into a grid line area and a non-grid line area, and the grid line area is further divided into a thin grid line area and the main grid line area, the thin grid line is fabricated on the fine grid line area, and the main grid line that collects the fine grid line current is fabricated on the main grid line area, and the thin grid line area is a heavily doped region with a heavily doped layer, The main grid line area and the non-gate line area are lightly doped areas with lightly doped layers.

The main part of the series resistance is in the thin grid line area of the light-receiving surface electrode, so re-diffusion in the thin grid line area can achieve the purpose of reducing the series resistance, but re-diffusion in the main grid line area can neither effectively reduce the series resistance. The role of resistance, and increase the cost of etching slurry to form the re-diffusion layer, so no re-diffusion in the busbar area can achieve the purpose of improving the open circuit voltage and conversion efficiency of the solar cell.

The main grid lines and the thin grid lines are perpendicular to each other, the thin grid lines are parallel to each other, and the main grid lines are also parallel to each other. The number of thin grid lines is 65~85, and the width of the thin grid lines is 0.045~0.100mm. The number of busbar lines is 1~3, and the width of the busbar lines is 1~2mm.

The beneficial effects of the utility model are: 1. Reduce the consumption of etching slurry or wax when making the selective emitter, and the reduction rate can reach 50%; 2. According to the current experimental results, the efficiency is increased by more than 0.02%.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described;

Fig. 1 is the structural representation of the battery of the present utility model;

Fig. 2 is the etched screen figure of the utility model;

In the figure: 1. Fine grid line area, 2. Main grid line area, 3. Marker line.

Detailed ways

As shown in Figure 1, a solar cell with a selective emitter, the light-receiving surface of the cell is divided into a grid line area and a non-grid line area, and the grid line area is further divided into a thin grid line area 1 and a main grid line area 2, The fine grid line is fabricated on the fine grid line area 1, and the main grid line that collects the current of the fine grid line is fabricated on the main grid line area 2. The thin grid line area 1 is a heavily doped region with a heavily doped layer, and the main grid line Region 2 and the non-gate region are lightly doped regions with lightly doped layers.

The main grid lines and the thin grid lines are perpendicular to each other, the thin grid lines are parallel to each other, and the main grid lines are also parallel to each other. The number of thin grid lines is 65~85, and the width of the thin grid lines is 0.045~0.100mm. The number of busbar lines is 1~3, and the width of the busbar lines is 1~2mm.

The electrical performance experimental data of the solar cell without heavy diffusion layer in the busbar area and the traditional solar cell with selective emitter are shown in Table 1

From the electrical performance experimental data in Table 1, it can be seen that the series resistance does not increase due to the removal of the re-expanded busbar, but the opening voltage and efficiency are improved.

Taking the current two selective solar cell products of Changzhou Trina Solar Co., Ltd. as an example, the method of realizing no re-diffusion in busbar area 2 is explained in detail

1. Quadmax solar cell products

The formation process of the re-diffusion layer of Quadmax solar cell products is as follows: the etching printing machine uses the etching screen to print the etching paste, grooves are made on the re-diffusion mask, and then re-diffusion is performed through the grooves. Therefore, by changing the pattern of the etched screen, re-diffusion can be realized only in the area of the fine grid lines. The modified etched screen pattern is shown in Figure 2, and the main gate pattern is removed.

Points to note: Because the main grid lines on the light-receiving surface are asymmetrical, one end is a rectangle, and the other end is an arrow, so in order to ensure the alignment between the etched screen and the grid line during the production process, add Marking line 3, the side with marking line 3 is the direction other than the arrow.

2. S2 solar cell products

The formation process of the heavy diffusion layer of S2 solar cell products is: heavy diffusion, the wax printing machine sprays wax according to the wax spray pattern to form an etching mask, and protects the heavy diffusion area during the subsequent front etching, so the wax spray pattern is changed, Changes to the re-expanded graphics can be realized.

Claims (2)

1. A solar cell with a selective emitter, the light-receiving surface of the cell is divided into a grid line area and a non-grid line area, and the grid line area is further divided into a thin grid line area (1) and a main grid line area (2), Fine grid lines are fabricated on the fine grid line area (1), and busbar lines that collect current from the fine grid lines are fabricated on the main grid line area (2), characterized in that: the fine grid line area (1) has The heavily doped region of the heavily doped layer, the main gate line region (2) and the non-gate line region are lightly doped regions with a lightly doped layer. 2. The solar cell with selective emitter according to claim 1, characterized in that: the main grid lines and the thin grid lines are vertical, the thin grid lines are parallel to each other, and the main grid lines are parallel to each other. Also parallel to each other, the number of thin grid lines is 65~85, the width of thin grid lines is 0.045~0.100mm, the number of main grid lines is 1~3, and the width of main grid lines is 1~2mm.

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