Abstract: Vaporized silicon halide is mixed with a vaporized alkali metala in a reactor chamber in an exothermic reaction producing liquid silicon droplets and gaseous alkali metal halide, and then passed out of the reactor chamber through a nozzle in a supersonic jet. The supersonic jet is produced by utilizing vacuum means to maintain the exit chamber at a lower pressure than the reactor chamber. Separation of the silicon from the salt by-products is performed by shock wave impaction separation technique wherein the products of the complete reaction between the alkali metal and silicon halide are made to impinge upon an unrestricted, flat surface so that the direction of flow of the gas changes abruptly and a shock zone is created above the flat surface. The silicon droplets are carried by their large forward momentum through the shock zone onto the separating surface where they are deposited. The gaseous alkali metal halide flows across the surface and is thus separated from the silicon product.

Abstract: Compounds having the formula (MX.sub.3).sub.n M'X.sub.4-n wherein M and M' are different Group 4A atoms, at least one of M and M' is silicon, X is hydrogen, halogen or mixtures thereof, and n is an integer between 1 and 4, inclusive, are useful as deposition feedstock materials in the formation of hydrogenated amorphous silicon alloys useful in the fabrication of photovoltaic and other electronically active devices.Dopants having the formula (SiX.sub.3).sub.m L X.sub.3-m wherein L is a Group 5A atom selected from the group of phosphorous, arsenic, antimony and bismuth, X is hydrogen, halogen or mixtures thereof and m is an integer between 1 and 3, inclusive, are useful in the fabrication of negatively-doped hydrogenated amorphous silicon alloys useful in the fabrication of photovoltaic and other electronically active devices.Dopants having the formula YJX.sub.

Abstract: A method of forming laser-patterned conductive elements on a thin film of semiconductor material in a semiconductor device by fabricating a thin film of metal on the semiconductor material and scribing the semiconductor film along a desired pattern with a laser operated at a power density sufficient to ablate the semiconductor material along the desired pattern. The ablation of the semiconductor material produces gases that structurally weaken and burst through the metal film along the desired pattern to form gaps separating the metal film into a plurality of conductive elements, for example, back electrodes on a thin-film photovoltaic module.

Abstract: A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Abstract: A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Abstract: Compounds having the formula (MX.sub.3).sub.n M'X.sub.4-n wherein M and M' are different Group 4A atoms, at least one of M and M' is silicon, X is hydrogen, halogen or mixtures thereof, and n is an integer between 1 and 4, inclusive, can be activated by dehydrogenation or dehalogenation. These compounds are useful as deposition feedstock materials in the formation of hydrogenated amorphous silicon alloys useful in the fabrication of photovoltaic and other electronically active devices.Dopants having the formula (SiX.sub.3).sub.m L X.sub.3-m wherein L is a Group 5A atom selected from the group of phosphorus, arsenic, antimony and bismuth, X is hydrogen, halogen or mixtures thereof and m is an integer between 1 and 3, inclusive, can be activated by dehydrogenation or dehalogenation. These compounds are useful in the fabrication of negatively-doped hydrogenated amorphous silicon alloys useful in the fabrication of photovoltaic and other electronically active devices.Dopants having the formula YJX.sub.

Abstract: A method for forming disilane comprises flowing monosilane gas into a reaction vessel while maintaining a glow discharge in the monosilane and flowing the reaction product comprising the disilane out of the reaction vessel at a rate such that the monosilane gas resonance time in the reaction vessel is less than about one second. An apparatus for forming disilane comprises a source of flowing monosilane, a reaction vessel and electrical means for maintaining a glow discharge in the flowing monosilane in the reaction vessel.