Optimization of the Synthesis of Micron‐Sized Spherical Silver Powder by Liquid Phase Reduction Method for Use in Photovoltaic Applications

Abstract Photovoltaic silver powder, a key component of silver paste, accounts for more than 74% of its cost and plays a critical role in determining battery efficiency. In this study, a liquid‐phase reduction method was used to prepare micron‐sized spherical silver powder. Silver nitrate served as the silver source, ascorbic acid as the reducing agent, and arabic gum (AG) and polyvinylpyrrolidone (PVP) as dispersants. By optimizing parameters such as reaction temperature, pH, and reducing agent concentration, the optimal experimental conditions were determined: a water bath temperature of 40 °C, pH = 3, a VC/AgNO₃ ratio of 1.3:1, and a reaction time of 30 min. The resulting silver powder had a particle size of 4.24 µm and a tapped density of 4.8 g/cm 3 . Further trials showed that the silver paste prepared from this powder meets the performance requirements for front silver paste in the TOPCon organic system, indicating its potential for industrial application.