Method for preparing solar cell front silver paste slurry

Abstract

The present invention relates to a kind of method of preparing solar cell positive silver paste slurry: 1, the preparation of silver powder: (1) ultrapure water dissolves silver nitrate, adds dispersant, adjusts pH to 3-5; (2) ultrapure water dissolves Reductant, adjust the pH to 3-5; (3) Add silver nitrate solution to the reducing agent solution for reaction at a temperature of 45-55°C, centrifuge to collect the precipitate after fully reacting; (4) Wash and dry the precipitate to obtain silver powder; II, Preparation of organic vehicle: Mix solvent, thickener and thixotropic agent, heat in a water bath at 75-85°C, stir to dissolve, let stand and cool to room temperature; III. Preparation of front silver paste: Now mix silver powder and glass powder evenly , then add the organic vehicle and mix evenly, and grind until the fineness reaches the required value. The slurry prepared by the invention has suitable viscosity, good leveling and thixotropy, good chemical stability, and long storage period. The prepared slurry has strong ability to penetrate the anti-reflection film, and the formed thick film has strong adhesion and good ohmic contact. , the resulting battery sheet should have good electrical properties.

Description

technical field

[0001] The invention belongs to the field of solar cell manufacturing, and in particular relates to a method for preparing a front silver paste of a solar cell. Background technique

[0002] For the silver powder used for the front silver packaging of solar cells, the particle size of micron or submicron is generally required. The research on ultra-fine silver powder at home and abroad has been relatively in-depth. There are a large number of literature reports. Nano is less used. Although nano-silver powder is rarely used in solar cells due to its easy agglomeration, its preparation method has great reference value for the preparation of micron / submicron silver powder. Foreign research on silver powder for solar cells has been relatively mature; while domestically produced silver powders have a certain range of sizes and shapes, but most of them have poor dispersion, severe agglomeration, and low tap density. There is still a considerable distance from th...