NOVELTY - The method comprises providing a layer of silicon to be crystallized, where an average grain size of the silicon layer is less than 10 mu m, placing the silicon layer to be crystallized in contact with a liquid composition partially made up of a metal solvent, and exposing the assembly to a thermal treatment suitable for crystallizing the silicon layer with the expected grain size. The thermal treatment includes heating the assembly made up of the silicon layer in contact with the liquid composition to a temperature that is equal to an eutectic temperature in a solvent-silicon phase diagram.    USE - The method is useful for forming a crystallized silicon layer made up of grains having an average size of greater than 20 mu m (claimed), where the silicon layer is used in the manufacturing of photovoltaic cells.    ADVANTAGE - The crystallized silicon layer can be easily and economically formed with high solidification rate and good crystalline quality, and enhances energy conversion efficiencies of the photovoltaic cells.    DETAILED DESCRIPTION - The method comprises providing a layer of silicon to be crystallized, where an average grain size of the silicon layer is less than 10 mu m, placing the silicon layer to be crystallized in contact with a liquid composition partially made up of a metal solvent, and exposing the assembly to a thermal treatment suitable for crystallizing the silicon layer with the expected grain size. The thermal treatment includes heating the assembly made up of the silicon layer in contact with the liquid composition to a temperature that is lower than 1410 degrees C and equal to an eutectic temperature in a solvent-silicon phase diagram. The heat treatment is carried out at a temperature going of 1000-1200 degrees C and carried out until the total evaporation of the metal solvent is taken. The silicon layer in the providing step is a cohesive layer. The placing and exposing steps are carried out in a simultaneous manner. The obtained silicon layer has a mean grain size of greater than or equal to 100 mu m. The silicon layer of the providing step is sintered. The liquid composition is formed prior to contacting with the silicon layer to be crystallized. The liquid composition is formed in contact with the silicon layer crystallizing a surface through the provision of the silicon layer of a composition in a solid phase comprising the metal solvent for forming the liquid composition.