Abstract: An apparatus for photochemical vapor deposition includes an outer reactor shell and a concentric inner shell which define a photochemical reaction zone. A radiation source is centrally located within the transparent inner shell, which isolates the radiation source from the vapor phase reactants present in the reaction zone. A rotating gas manifold is located within the reaction zone to uniformly distribute the vapor phase reactants within the reaction zone. Protective liquid is continually applied to the outer surface of the inner shell and spread into a thin film by wiper blades, to prevent deposition of reaction products onto the outer wall of the inner shell. The central location of the radiation source, along with the protective liquid film, make optimum usage of the reaction-inducing radiation generated by the radiation source. In addition, the rotating gas manifold promotes uniform deposition of layers of selected materials on substrates placed within the reaction zone.

Abstract: An apparatus for photochemical vapor deposition includes an outer reactor shell and a concentric inner shell which define a photochemical reaction zone. A radiation source is centrally located within the transparent inner shell, which isolates the radiation source from the vapor phase reactants present in the reaction zone. A rotating gas manifold is located within the reaction zone to uniformly distribute the vapor phase reactants within the reaction zone. Protective liquid is continually applied to the outer surface of the inner shell and spread into a thin film by wiper blades, to prevent deposition of reaction products onto the outer wall of the inner shell. The central location of the radiation source, along with the protective liquid film, make optimum usage of the reaction-inducing radiation generated by the radiation source. In addition, the rotating gas manifold promotes uniform deposition of layers of selected materials on substrates placed within the reaction zone.

Abstract: A method of making transmission mode glass-sealed negative electron affinity (NEA) gallium arsenide (GaAs) photocathodes, utilizing germanium (Ge) as the seed crystal and multilayers of GaAs and gallium aluminum arsenide (GaAlAs) grown by metal alkyl-hydride vapor-phase epitaxy. The GaAs serves as the photoemitting layer and the GaAlAs serves as the passivating layer. The Ge, GaAs,GaAlAs combination is sealed to a glass support substrate which serves as the input window for the device. Finally, the Ge is removed and the GaAs is activated.

Abstract: A method of fabricating high performance transmission mode negative elect affinity III-V compound photocathodes which eliminates recurrent liquid phase epitaxial growth surface defects and solves the "wipe-off" problem incurred during the termination of the growth cycle.