Photovoltaic cells, including silicon solar cells, and methods and compositions for making such photovoltaic cells are provided. A silicon substrate having p-type silicon base and an n-type silicon layer is provided with a silicon nitride layer, an exchange metal in contact with the silicon nitride layer, and a non-exchange metal in contact with the exchange metal. This assembly is fired to form a metal silicide contact on the silicon substrate, and a conductive metal electrode in contact with the metal silicide contact. The exchange metal is from nickel, cobalt, iron, manganese, molybdenum, and combinations thereof, and the non-exchange metal is from silver, copper, tin, bismuth, lead, antimony, arsenic, indium, zinc, germanium, gold, cadmium, beryllium, and combinations thereof.