Silver paste combination for secondary printing of crystalline silicon solar cell

Abstract

The invention discloses a silver paste combination for secondary printing of a crystalline silicon solar cell. The silver paste combination comprises third positive silver paste and fourth positive silver paste, wherein the third positive silver paste is mainly prepared from silver powder I, an organic carrier I and glass powder I; the fourth positive silver paste is mainly prepared from silver powder II, an organic carrier II and glass powder II; Tg of the glass powder I is 200-350 DEG C; and the Tg of the glass powder is 500-700 DEG C. The silver paste combination for secondary printing of the crystalline silicon solar cell comprises special third positive silver paste and special fourth positive silver paste. The contact resistance of the cell can be reduced; and the leakage current Irev1 and Irev2 can be reduced, so that FF is improved and the photoconversion efficiency Eff of the cell is improved.

Description

technical field

[0001] The invention relates to the technical field of solar cells, in particular to a silver paste combination used in the secondary printing process of crystalline silicon solar cells. Background technique

[0002] In the current secondary printing process of crystalline silicon solar cells, there are the following problems: in the printing process, the same paste is used for three and four passes, and the three front-side silver pastes need to take into account the pulling force, which leads to incomplete corrosion of the bottom layer of the sub-gate , so that the actual contact area between the electrode and the silicon wafer is small, resulting in a large contact resistance. Since the contact resistance Rc is an important part of the series resistance Rs, the series resistance Rs is large, thereby reducing FF and Eff; while the four positive The silver paste corrodes the front busbar of the crystalline silicon solar cell too deeply, resulting in a large ...

Examples

Embodiment 1

[0032] Combine 80 g of silver powder (average particle diameter of 2.5 μm) and glass powder (lead tellurate system glass powder T g : 253°C, 2g; bismuth tellurate system glass powder T g : 281°C, 1g) 3.0g, organic vehicle (Texanol: ethyl cellulose: lecithin: triethanolamine is 8.5: 1: 0.3: 0.2 (wt / wt)) 9g is pre-mixed in a mixer, and then mixed in a three-roller Mix and roll on the machine to get three front-side silver pastes.

[0033] Silver powder (average particle size: 2.5 μm) 80g, bismuth tellurate system glass powder (T g : 569°C) 3.0g, organic vehicle (Texanol: ethyl cellulose: lecithin: triethanolamine is 8.5: 1: 0.3: 0.2wt / wt) 9g is pre-mixed in a mixer, and then mixed and rolled on a three-roller machine , to obtain four front-side silver pastes.

[0034]Take the silicon wafer that has been textured, diffused, and PECVD, and screen-print the back silver paste and the back aluminum paste, and then screen-print the three front-side silver pastes and four front-side...

Embodiment 2-4

[0037] In embodiment 2-4, the preparation process of three front silver pastes and four front silver pastes and the cell preparation process are similar to those in Example 1, except that the glass used for three front silver pastes and four front silver pastes is changed. Pink T g outside. The composition and battery performance results of the three-layer front-side silver paste and four-layer front-side silver paste of Examples 2-4 are shown in Table 2 below.

technical field

[0001] The invention relates to the technical field of solar cells, in particular to a silver paste combination used in the secondary printing process of crystalline silicon solar cells. Background technique

[0002] In the current secondary printing process of crystalline silicon solar cells, there are the following problems: in the printing process, the same paste is used for three and four passes, and the three front-side silver pastes need to take into account the pulling force, which leads to incomplete corrosion of the bottom layer of the sub-gate , so that the actual contact area between the electrode and the silicon wafer is small, resulting in a large contact resistance. Since the contact resistance Rc is an important part of the series resistance Rs, the series resistance Rs is large, thereby reducing FF and Eff; while the four positive The silver paste corrodes the front busbar of the crystalline silicon solar cell too deeply, resulting in a large ...

Examples

Embodiment 1

[0032] Combine 80 g of silver powder (average particle diameter of 2.5 μm) and glass powder (lead tellurate system glass powder T g : 253°C, 2g; bismuth tellurate system glass powder T g : 281°C, 1g) 3.0g, organic vehicle (Texanol: ethyl cellulose: lecithin: triethanolamine is 8.5: 1: 0.3: 0.2 (wt / wt)) 9g is pre-mixed in a mixer, and then mixed in a three-roller Mix and roll on the machine to get three front-side silver pastes.

[0033] Silver powder (average particle size: 2.5 μm) 80g, bismuth tellurate system glass powder (T g : 569°C) 3.0g, organic vehicle (Texanol: ethyl cellulose: lecithin: triethanolamine is 8.5: 1: 0.3: 0.2wt / wt) 9g is pre-mixed in a mixer, and then mixed and rolled on a three-roller machine , to obtain four front-side silver pastes.

[0034]Take the silicon wafer that has been textured, diffused, and PECVD, and screen-print the back silver paste and the back aluminum paste, and then screen-print the three front-side silver pastes and four front-side...

Embodiment 2-4

[0037] In embodiment 2-4, the preparation process of three front silver pastes and four front silver pastes and the cell preparation process are similar to those in Example 1, except that the glass used for three front silver pastes and four front silver pastes is changed. Pink T g outside. The composition and battery performance results of the three-layer front-side silver paste and four-layer front-side silver paste of Examples 2-4 are shown in Table 2 below.

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