Preparation of micro-sized and monodisperse crystalline silver particles used for silicon solar cell electronic paste

Abstract

In this paper, monodisperse crystalline silver particles in microscale were prepared via chemical reduction method and the reaction conditions were systematically investigated. Gelatin was used as surfactant to prevent the agglomeration of silver particles. The crystallized and mono-disperse silver particles were obtained at the optimal synthesis condition (1.2 mol/L silver nitrate, 0.8 mol/L ascorbic acid, gelatin/silver = 0.025 wt% and pH = 1.5). The average particle size of the silver particles is 1–2 μm and the tap density of silver particles is over 5.0 g/cm3. The pH value is a key factor for preparation of crystallized silver particles. When the pH value increases from 1.0 to 4.0, the morphology of silver particles changes from polyhedron crystalline to spherical particles. The silver particles were used for preparation of the lead-free silver paste for monocrystalline silicon solar cell and the solar cell grid electrode has low resistivity and high adhesion strength.