Paste compositions, methods of making a paste composition, photovoltaic cells, and methods of making a photovoltaic cell contact are disclosed. The paste composition can include a conductive metal component such as aluminum, phosphate glass, phosphorus compounds such as alky! phosphate, and a vehicle. The contact can be formed on a passivation layer on a silicon wafer by applying the paste on the passivation layer and firing the paste. During firing, the metal component can fire through the passivation layer, thereby electrically contacting the silicon substrate.