Preparation And Research Of Glass Frit For Front Side Silver Paste Of Crystalline Silicon Solar Cell

Silicon solar cells are constructed by semiconductor materials to achieve photoelectric conversion in order to achieve the purpose of photovoltaic power generation.In order to improve the absorption and utilization of light,a silicon nitride layer with a pyramid texture structure is generally plated on the surface of the silicon wafer.The front side silver paste is printed on the surface of the silicon wafer by screen printing.The electrode formed after sintering can lead out the photogenerated carriers inside the silicon wafer.Although the content of glass frit in the front silver paste is very small,it plays a vital role in the performance of the silver paste.In the sintering process,the glass first corrodes the silicon nitride layer,and then the glass powder builds a bridge between the silver powder and the silicon substrate for electronic conduction.Therefore,the performance of the glass will affect the photoelectric conversion efficiency of the silicon solar cell.TeO₂-PbO system glass is widely used in the market because of its advantages of low melting point and strong corrosion ability.In this experiment,molten glass was used to prepare glass samples.First,determine a reasonable Bi/Pb mass ratio,and study the TeO₂-Bi₂O₃-PbO system glass with a stable glass network structure to provide a basis for subsequent research;then study the effect of doping WO₃ and Cr₂O₃on the performance of TeO₂-Bi₂O₃-PbO system glass;Finally,the effect of single alkali metal oxide?Na₂O?and two alkali metal oxides co-doped?Li₂O and Na₂O?on the performance of TeO₂-Bi₂O₃-PbO system glass is studied.conclusion as below:?1?As the Bi/Pb mass ratio increases,the degree of corrosion of the glass frit on the silicon substrate decreases,and the characteristic temperature tends to decrease first and then increase and then decrease.When Bi:Pb=4:6,the process window of glass reaches the maximum range of 170?.The resistivity tends to decrease first and then increase.When Bi:Pb=4:6,the resistivity reaches the lowest value of 2.17×10¹⁰?·cm,and the glass structure is relatively stable;?2?WO₃ can enhance the stability of the glass structure in TeO₂-Bi₂O₃-PbO system glass.With the increase of WO₃ content,the glass transition temperature shows an upward trend?from 210?to 364??,the overall resistivity increases The trend is that the conductivity of glass decreases,and the resistivity reaches a maximum value of 1.84×10¹¹?·cm when WO₃=8 wt%,and the corrosion ability gradually increases with the increase of WO₃ content;?3?Cr₂O₃ in TeO₂-Bi₂O₃-PbO system glass,due to the low solubility of Cr₂O₃,residues will appear during the sintering process.As the content of Cr₂O₃ increases,the degree of corrosion of the glass frit on the silicon substrate decreases,and the glass transition temperature increases?from210?to 258??.Cr₂O₃ in this glass system will reduce the conductivity of the glass;?4?Na₂O doping in TeO₂-Bi₂O₃-PbO system glass will improve the electrical conductivity of the glass,and the resistivity drops from 2.17×10¹⁰?·cm to 4.7×10⁷?·cm.Na₂O will improve the stability of the chemical structure of the glass.The glass transition of the system glass shows a trend of rising first,then falling and then rising;?5?Na₂O and Li₂O are co-doped in TeO₂-Bi₂O₃-PbO system glass.When the total mass content of the mixed alkali is unchanged,the glass state becomes better with the increase of the Li/Na ratio;when co-doped with 4 wt%The glass transition temperature tends to increase first and then decrease,and the resistivity shows the opposite trend.The glass transition temperature and resistivity both showed an upward trend when co-doped with 5 wt%.When co-doped with 6 wt%,the glass transition temperature showed a downward trend and the resistivity showed an upward trend,indicating that the glass transition temperature and resistivity were affected by the total alkali metal oxide content and the Li/Na ratio.When the Li/Na ratio is 1:3?the alkali metal content is 4 wt%?,the resistivity reaches the lowest value of 3.6×10⁷?·cm.