This thesis is focused on the development and the optimization of electrochemical metallization techniques allowing the deposition of conductive metals, silver and the copper, by electrolytic deposition or by lip (light-induced plating). Two approaches were studied to realize the front side contacts of silicon solar cells: the thickening of screen-printed contacts and the fabrication of contacts completely by electrochemical deposition without screen-printing. For this solution, the deposition of a seed layer before thickening is necessary to insure a low contact resistivity, a satisfying adhesion and selectivity through the anti-reflection coating. These objectives were reached thanks to the optimization of electroless nickel-phosphorous (nip) deposits, including on low doped emitter. The investigations also allowed a better understanding of the NiP/Si contact formation mechanisms. The feasibility of electrochemical deposition techniques was demonstrated for various applications : cells with electrochemical front side contacts NiP/Ag, type n cells, thickening of fine line screen-printed contacts… very promising results of fill factor ff and efficiency improvement were obtained and allow to realize new structures of high efficiency photovoltaic cells : cells with low doped emitter, cells with selective emitter and with laser ablated anti-reflection coating, rear contact cells…