TECHNOLOGY FOCUS - ELECTRONICS - Preferred Methods: The plasma jet is generated by creating electrical discharge using alternating current source at 17000 volts and 9600 Hz. The direct printing is conducted by using plasma jet apparatus with two mutually spaced electrodes. The plasma jet is produced by blowing stream of air between the electrodes and onto the silicon nitride coating and simultaneously creating electrical discharge between electrodes to ionize the air. The solar cell wafer is transported past the plasma jet so that successive areas of the surface of the silicon nitride coating are subjected to the plasma. The solar cell wafer is transported past the plasma jet at a speed so that the entire wafer passes through the plasma jet in 3 seconds. The method also comprises applying conductive metal paste coating on the second surface prior to the first step. A first aluminum-containing metal paste and second silver-coating metal paste are applied to the second surface prior to subjecting silicon nitride coating to air plasma. The heating step is carried out so that the aluminum in the first paste forms an alloy with silicon at the second surface and the silver in the second paste forms an adherent ohmic bond with the second surface of the substrate. Preferred Properties: The silicon substrate is 0.008-0.014 inch thick prior to the first step. The silicon nitride coating is 600-1000 Angstrom thick. The plasma jet has small cross sectional area. The solar cell wafer is rectangular. Preferred Components: The solar cell wafer is aligned so that its two opposite edges are aligned parallel to its direction of transport through the plasma jet. The metal paste comprises aluminum particles and particles alloy with silicon substrate as a result of process. The first metal paste is applied to first area portion(s) of the second surface. The second metal paste is applied to the second area portion(s) of the second surface. The first metal and second metal pastes contact one another.