Silver powder, as the primary component of solar silver paste, significantly influences various aspects of the paste’s performance, including printing, sintering, and conductivity. This study reveals that, beyond the shape and size of the silver powders, their microstructure is a critical factor influencing the performance of both silver powders and silver pastes in solar cell applications. The growth process leads to the formation of either polycrystalline aggregated silver powder or crystal growth silver powder. Analyzing the performance characteristics of these different microstructures provides guidance for selecting silver powders for silver pastes at different sintering temperatures. Polycrystalline aggregated silver powder exhibits higher sintering activity, with a sintering initiation temperature around 450 °C. The resulting silver paste, sintered at 750 °C, demonstrates a low sheet resistance of 2.92 mΩ/sq and high adhesion of 2.13 N. This silver powder is suitable for formulating silver pastes with lower sintering temperatures. The solar cell electrode grid lines have a high aspect ratio of 0.37, showing poor uniformity. However, due to the high sintering activity of the silver powder, the glass layer dissolves and deposits more silver, resulting in excellent conductivity, a low contact resistance of the silver electrode, a low series resistance of the solar cell of 1.23 mΩ, and a high photoelectric conversion efficiency of 23.16%. Crystal growth silver powder exhibits the highest tap density of 5.52 g/cm³. The corresponding silver paste shows improved densification upon sintering, especially at 840 °C, yielding a sheet resistance of 2.56 mΩ/sq and adhesion of 3.05 N. This silver powder is suitable for formulating silver pastes with higher sintering temperatures. The solar cell electrode grid lines are uniform with the highest aspect ratio of 0.40, resulting in a smaller shading area, a high fill factor of 81.59%, and a slightly higher photoelectric conversion efficiency of 23.17% compared to the polycrystalline aggregated silver powder.

Silver powder, as the primary component of solar silver paste, significantly influences various aspects of paste performance, including printing, sintering, and conductivity. Silver powders prepared using the liquid-phase reduction method exhibit different microstructures depending on whether the growth process is dominated by aggregation or crystalline growth. This study explores the impact of different silver powder microstructures on packing density and sintering activity. It is observed that polycrystalline aggregated silver powder possesses higher surface energy, lower packing density, and greater sintering activity. Investigation into the influence of different silver powders on the electrical conductivity, adhesion, and structural density of silver paste reveals that polycrystalline aggregated silver powder is more suitable for lower sintering temperature pastes, whereas crystalline growth-type silver powder is better suited for higher sintering temperature pastes, resulting in a denser sintered silver layer. Finally, an analysis of the impact of various silver powders on the aspect ratio and electrical performance of solar cell silver grid lines yields higher aspect ratios (0.40) and photoelectric conversion efficiency (19.26%).

High-reliability thick-film gold conductor pastes serve as core functional materials for high-end electronic packaging. Traditional lead-containing glass binders suffer from environmental toxicity, restricting their large-scale green applications. Herein, a series of Bi₂O₃–B₂O₃–TeO₂ lead-free glasses with tunable Bi₂O₃/B₂O₃ ratios was prepared to explore the regulation of glass composition in the intrinsic structure, thermal behavior and sintering performance of gold thick films. The Bi₂O₃/B₂O₃ ratio strongly influences melt flow: excessive Bi₂O₃ induces local segregation of the glass phase, while surplus B₂O₃ weakens wettability and pore-filling capacity. Optimized A3 glass achieves synergy between glass flow and sintering kinetics of gold particles. The resulting P3 film has porosity of 3.12%, sheet resistance of 2.92 mΩ/sq and interfacial adhesion of 3.78 N/mm². Its sheet resistance variations remain merely +0.96% and −1.02% after two refiring cycles, delivering good conductivity, strong interfacial bonding and stable electrical behavior upon refiring. This work offers experimental support for compositional design of lead-free glass binders for gold conductor pastes.