Synthesis of micro-sized silver particles suitable for thick film contacts on solar cells

The main goal of the study was to determine parameters for the production of the micro-sized silver powder applicable to the pastes that are in use in solar cell production and maintenance. In all experiments, silver nitrate solution and ascorbic acid were used, as a silver source and reducing agent, respectively. Polyvinylpyrrolidone and gelatine were used as dispersants. The dispersant in this system acts as a protective agent in a way that prevents agglomeration and aggregation processes. The influence of used agents was different, and one of the aims in the research was to determine the pros and cons of them. The optimal parameters of the synthesis were the solution temperature of 45 °C, pH=7, and concentrations of silver and ascorbic acid of 45 g/l and 30 g/l, respectively. Although PVP has proved to be a suitable protecting agent for the goals of the study, the best results were obtained with the use of gelatine as a dispersant in the concentration ratio against the silver ions of 2.5 wt. %.