Research On Key Preparation Technology And Application Of Conductive Silver Paste For Solar Cell

With the rapid development of the global economy,industrial production activities have become increasingly diversified,and the speed of energy consumption has gradually accelerated.Finding alternatives to traditional energy sources is an important method for countries to seek energy independence,and clean energy sources such as solar,nuclear,and wind power are being vigorously developed.The development goal of solar cells has always been to improve the photoelectric conversion efficiency,and the performance and cost of the conductive electrode prepared from conductive silver paste directly affect the photoelectric conversion efficiency and the cost of solar cells.Therefore,the development of high-performance and high-quality conductive silver paste is of great significance for improving the photoelectric conversion efficiency of solar cells and promoting the development of the photovoltaic industry.The important component of conductive silver paste,the organic carrier,has been investigated,with a mass ratio of 5.5%-20%in the paste.The volatility and wetting properties of organic solvents are critical to the performance of the organic carrier.Experiments have shown that turpentine alcohol can be used as the main component of organic solvents,both at high and low temperatures,but it is difficult to control its volatility.When the ratio of turpentine alcohol:glycerol:butyl carbitol is 3:1:6,the mixture of multiple solvents can exhibit excellent characteristics of low-temperature non-volatility and multi-stage hierarchical volatility at high temperatures.The surfactant soybean lecithin plays a role in inhibiting the agglomeration of conductive paste.The influence of lead-free glass powder ratio on the performance of conductive silver paste has been investigated.Lead-free glass powder was prepared by high-temperature melting and planetary ball milling,and after it was made into conductive silver paste,the test results showed that Bi₂O₃,B₂O₃,SiO₂,and ZnO with a mass ratio of 4:3:2:1 can prepare lead-free glass powder with better performance.Lead-free glass powder with different softening points will affect the surface color and glossiness of the sintered silver film layer.Among them,the surface of L3and L4 is smooth,silver-white,shiny,and has good bonding properties.In addition,the lower the softening temperature of lead-free glass powder,the smaller and fewer the pores in the silver film layer,and the better its density,that is,the better the contact between the powder particles,the better the conductivity of the silver film layer,and the smaller the sheet resistance.Among them,the sheet resistance of the silver film layer of L3 is the smallest,at 1.3 mΩ/□.The influence of silver powder on the performance of conductive silver paste has been investigated.The mass percentage of silver powder in the silver paste is usually around 85%.The research results show that the conductive silver paste prepared using silver powder with narrow particle size distribution,smooth surface,and regular shape can obtain a silver film layer with smooth surface,good density,small sheet resistance,and good conductivity after sintering.In addition,the particle size and morphology of the silver powder will also have a certain influence on the printability of the conductive silver paste,as well as the adhesion and conductivity of the silver film layer after sintering.When the particle size is between 1.5-2.5μm,a conductive silver paste with excellent performance can be prepared,and when the content of dendritic silver powder is above 57%after surface modification,a conductive silver paste with excellent performance can be prepared.