NOVELTY - The paste has a sintering and bonding agent and an organic binding agent provided to sinter a silver-silicon ohmic contact on a silicon face. A sintering and activation material is provided for a front-face grid electrode of a crystal silicon solar cell. Granularity of silver powder is smaller than 15 microns. The sintering and activation material contains a metal element. The silver powder is performed with a conducting heating and annealing process and a light ball grinding process. Heating and annealing temperature is 40-70 degrees Celsius.    USE - Silver paste for a front-face grid electrode of a crystal silicon solar cell.    ADVANTAGE - The paste can meet the requirement of the innovative effective solar cell manufacturing process on high conductivity, low impurity, low corrosion, low diffusion and co-firing film of silver paste. The paste can effectively penetrate the silicon nitride reflection reduction film prepared by the plasma-enhanced catalytic vapor decomposition method in the solar cell sintering curve temperature range so as to protect the function. The sintering and activating material and the action element realize the controlled limited activation method so as to reduce the silver diffusion without damage on the silicon nitride reflection reduction film on periphery and to stop the corrosion of the glass in the silver paste on the silicon face while preventing the complex component in the silver paste from entering the cell and expanding the adaptability rapid sintering process. The paste uses the selected silver powder and the modification method for spatially stacking and covering the particles and for improving the sintering precision and height-and-width ratio of the silver thicken film electrode. The paste uses front-face grid electrode with better electric performance and process performance. The paste can improve the photoelectric conversion efficiency of the crystal silicon solar cell, and can be stably applied to massive industrial production in the effective solar cell product.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) silver powder used for a silver paste for a front-face grid electrode of a crystal silicon solar cell    (2) a method for modifying silver powder.