An analytical investigation on characterizing the properties of glass composition for crystalline silicon solar cells based on the digital microsystem measurement technology

As a significant component of silver paste, glass frit has a nonnegligible effect on crystalline silicon solar cells. The purpose of this research is to obtain an analysis method to explore the performance of glass frit for solar cells. The samples were measured by digital microscopic system, and the three-dimensional layered tinting model was established. Moreover, the longitudinal cutting was carried out. The data of cross section was analyzed to obtain the information of melt height, wetting base angle, and melting included angle, to further infer the relationship between thermal stability, fluidity, wettability with mathematical model of glass frit through theoretical derivation. The curve fitting method was introduced in detail and the law was summarized. Based on relationship of them, the melting characteristics of glass frit could be quantitatively tested. The vertical view and surface topography were measured by the digital microscope and found that the glass frit underwent shrinkage, softening, wetting, spreading, and equilibrium during sintering. Combined with the image, abundant information was detected from the macroscopic structure of glass surface. Meanwhile, the mechanism of spreading was explained. Finally, the screen-printing technology combined with the 3D microscopic view of the silver grid line proved that glass frit with satisfactory performance can effectively reduce the contact resistance of solar cells, improve the photovoltaic conversion efficiency, verify the feasibility and accuracy of the simulation method equally. This study not only enriches the understanding of glass frit for crystalline silicon solar cells, but also provides a theoretical guidance for the research and determination of its performance.