Silver powder for printing size for solar cell electrodes and preparation process thereof

Abstract

The invention provides silver powder for printing size for solar cell electrodes and a preparation process thereof. The silver powder is composed of spherical, dendritic and random shaped silver powder bodies, the tap density is 3.96-5.21g / mL, the mean particle size is 0.6-3.5 microns, and the apparent density is 2.35-2.72g / mL. The preparation process includes preparing a silver nitrate solution and a reducing agent solution; respectively adding in a dispersing agent for dispersion; adding a silver precursor solution dropwise into a reducing mixed solution for reaction and standing; separating out liquid and solids; washing the solids with deionized water and ethanol respectively; and soaking in a protective agent and drying to obtain the silver powder for the printing size for the solar cell electrodes. The silver powder prepared through the process has a good crystallization surface and high dispersibility, a single particle size is large, the silver powder in various particle forms is mixed and can achieve high photoelectric converting efficiency when used on conductive fillers of conductive paste required by forming of front silver electrodes of crystalline silicon solar cells, and better filling and electric properties are provided compared with commonly used silver powder.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and relates to a method for preparing silver powders in various forms by a chemical reduction method, in particular to a novel silver powder for printing paste for solar cell electrodes and a preparation method thereof. Background technique [0002] Solar energy is a kind of green energy. People pay more and more attention to it because of its advantages of no pollution, inexhaustibility, and no limitation of geographical resources. Therefore, solar cells have emerged as the times require. A solar cell is a semiconductor device that can convert solar energy into electrical energy. Under the condition of light, the solar cell will generate current, collect and transmit electricity through grid lines and electrodes. The front electrodes and grid lines of solar cells are made of conductive silver paste through high-speed and high-precision screen printing, low-temperature drying, and high-temper...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is that in the sintering process of the silver paste prepared by the silver powder in the prior art, the electrodes and the grid lines form breakpoints and broken lines, which makes it difficult to effectively transmit the current generated by the battery sheet. , and finally make the photoelectric conversion efficiency low, and provide a new type of silver powder in the silver paste for the front electrode of the solar cell and the grid line and its preparation method. The silver powder in the silver paste adopts a mixture of spherical, dendritic and random shapes Silver powder, which makes electrodes and grid lines without breaks and disconnections, and obtains excellent solar cells

Images