Abstract: A solar cell fabrication procedure is described which is characterized by (1) formation of a "polysilazane" coating on a silicon substrate, (2) photo-lithography of the polysilazane coating to form a plating mask pattern, (3) a heating step which removes residual photoresist and converts the polysilazane coating to a denser form of silicon nitride having a reduced etch rate, and (4) use of densified silicon nitride as a mask for the plating of electrode metal and also as an anti-reflection coating.

Abstract: Method and apparatus for using a gas mixture containing an additive gas capable of beneficially altering the physical or chemical properties of a crystallized body grown from a melt by means of a shaping member. A suitable mixture of an inert gas and the additive gas is directed substantially uniformly over the entire melt surface of the meniscus existing between the top of the shaping member and the liquid/solid growth interface at which the crystallized body is formed. The method and apparatus are particularly suited to the growing of silicon ribbons from graphite crucibles for use in the production of photovoltaic solar cells, as evidenced by a substantial increase in the average minority carrier diffusion length in the silicon ribbon grown when the gas additive is a source of oxygen.

Abstract: Apparatus for growing hollow tubular crystalline bodies from the melt includes, in a preferred embodiment, a capillary die of the desired shape, a seed holder having a cross section of similar shape and to which a plurality of elongate seeds may be attached, and an inner after heater of substantially similar shape but smaller size supported from the die by an inner radiation shield.

Abstract: An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

Abstract: The invention pertains to growth of silicon bodies from a melt and comprises enveloping the liquid/solid interface with a mixture of an inert gas and more than a trace amount of a carbon-containing gas. The carbon-containing gas may be a compound of carbon and oxygen such as CO or CO.sub.2, and oxygen gas also may be introduced to the growth zone.

Abstract: A novel apparatus is disclosed for use in controlling in a known and predictable manner the temperature of the top surface of a capillary die and the adjacent meniscus during the growth of a crystalline body. The novel apparatus comprises an adjustable heat shield assembly with relatively movable members which can be positioned in such a manner as to provide improved temperature control at the top end of the die which assists in ensuring that a crystalline body grown by means of the capillary die will have a substantially constant cross-sectional size.

Abstract: A novel apparatus is disclosed for controlling the temperature of the top surface of the capillary die and the adjacent meniscus during growth of a crystalline body. The apparatus includes a tiltable heat shield located so that by appropriately positioning it about its tilt axis it is possible to adjust the temperature distribution about the top end of the capillary die. This temperature control assists in ensuring that a crystalline body grown by means of the capillary die process will have a substantially constant cross-sectional size.

Abstract: A solar cell having a periodic front surface electrode is provided with a transparent cover chosen and configured to provide refractive discontinuities of the same spatial frequency as and aligned with the conductive grid. The refractive discontinuities are so controlled, through selection of the shape, disposition, and refractive index of the cover, as to cause a ray initially normal to the surface of the cell which would otherwise be intercepted by the electrode to miss the electrode and fall on the photosensitive material.