Abstract: Silicon solar cells are made by subjecting semiconductor substrates to a diffusion junction forming process wherein a liquid source material containing a selected dopant is sprayed onto one side of the substrates, and thereafter the substrates are fired in an oxygen-containing environment under conditions calculated to cause the dopant to diffuse into the substrates so as to form a shallow p-n junction in each substrate.

Abstract: A method and apparatus are provided for forming grid electrodes for solar cells, the method and apparatus essentially involving dispensing a viscous ink through a hollow pen tip onto a selected horizontally oriented solar cell blank, so that the discharged ink forms a ribbon or line on the blank, with the pen tip being spaced far enough above the solar cell blank so that it does not ride on the deposited ribbon or line, whereby the width and height of the written ribbon or line are not determined by the o.d. of the pen tip or any pressure exerted by the pen tip.

Abstract: A solar cell fabrication procedure is described in which an excimer laser is used to cut a trench in a flat solar cell substrate so as to electrically isolate front and back regions of the substrate. The trench is cut around the perimeter of the cell. The advantage of using an excimer laser is that it will ablate a trench without diffusing conductive material deeper into the cell.

Abstract: A solar cell fabrication procedure is described in which a trench is cut in the substrate so as to electrically isolate front and back regions of a flat solar cell. The trench is preferably cut around the perimeter of the rear side of the cell. The trench is preferably formed by an excimer laser which may be used to ablate a trench without diffusing conductive material deeper into the cell.

Abstract: A method of bulk passivating a crystalline or polycrystalline substrate made from silicon, germanium, gallium arsenide or other III-V compounds, and II-VI compounds by exposing the substrate to a fluorine ion beam created by a Kaufman ion source. The Kaufman ion source is controlled so that the intensity of and duration of exposure to the fluorine ion beam is sufficient to bulk passivate the substrate. Preferably, the substrate is preheated to a selected temperature prior to the ion beam exposure.

Abstract: An improved optical match to a subsequently-formed antireflection overcoating is achieved by providing a silicon solar cell substrate with an altered surface layer that is formed by an ion-beam process, and has a refractive index between about 3.4 and about 3.6 at 633 nm and between about 3.6 and about 3.8 at 442 nm. The surface layer is formed by adding between about 2% and about 10% methane, by volume, to the hydrogen flow in a Kaufman type broad beam ion source.

Abstract: A solar cell fabrication procedure is described in which a hydrogen ion passivation step is used to form, inter alia, an altered silicon substrate surface layer to which immersion plated nickel will not readily adhere. The altered surface layer is formed by shadow casting an ion beam in a pattern corresponding to the desired front surface interelectrode configuration.