Structural characterization of xTeO₂-(98-x)PbO-2Bi₂O₃ glasses and the application in front silver paste of silicon solar cell

Glass samples of xTeO₂-(98-x)PbO-2Bi₂O₃ (x=40mol%, 45mol%, 50mol%, 55mol%, 60mol%)were prepared by a melt quenching method. The structural changes of glasses were analyzed using Infrared and Raman Spectra. The effects of TeO₂ content on the softening temperature, thermal expansion coefficient and chemical durability of the samples were investigated. The silver paste was fabricated by uniformly mixing with silver power, glass frit and organic carrier at a certain ratio. Then the front contact silver electrodes of solar cells were made through silk-screen printing and rapid sintering by silver paste. The effects of glass frit on the corrosion of antireflection coating, silver film adhesion force and resistivity were analyzed. The results indicate that the basic structural units change from TeO₃ trigonal pyramid and PbO₄ square pyramid to TeO₄ trigonal bypyramid with increasing content of TeO₂. When the TeO₂ content is 55mol%, the dominating structural unit is TeO₃ trigonal pyramid and TeO₄ trigonal bypyramid, and the tellurite glass has excellent performance (T_f=540°C, α=16×10^-6/°C, DR=6.5605×10^-8 g·cm^-2·min^-1). What's more, the corrosion effect of glass frit on antireflection coating is obvious, the silver film adhesion force is big and the resistivity is low (T=4.4 N, ρ=2.617 μΩ·cm).