Abstract: n-type wide bandgap semiconductors grown on a p-type layer to form hole injection pn heterojunctions and methods of fabricating the same. In a preferred embodiment, a p-type gallium nitride substrate is used. A first layer, such as a magnesium zinc sulfide layer Mg.sub.x Zn.sub.1-x S is then deposited. Thereafter, a second layer such as an n-type zinc sulfide layer is deposited. The magnesium zinc sulfide layer forms an electron blocker layer, and preferably is adequately thick to prevent significant tunneling of electrons there through. Thus, the primary charge flow across the heterojunction is by way of holes injected into the n-type zinc sulfide region from the p-type gallium nitride region, resulting in electron-hole recombination in the zinc sulfide region to provide light emission in the wide bandgap zinc sulfide material. Alternate embodiments are disclosed.

Abstract: Type-II semiconductor heterojunction light emitting devices formed on a substrate are described wherein a graded injection layer is used to accelerate electrons over the electron barrier formed by the junction. Further, wide band gap semiconductor LEDs and lasers are proposed formed of II-VI materials which emit light in the blue and green wavelengths. Particularly, a system composed of n-CdSe:Al/Mg.sub.x Cd.sub.1-x Se/Mg.sub.y Zn.sub.1-y Te/p-ZnTe are described where the value of y determines the wavelength of the emitted light in the green or blue region and x varies across the graded injection layer for raising the energy levels of excited electrons.

Abstract: A method for in situ growth of an array of single crystals from material deposited on an inert substrate is comprised of (1.0) preparing a surface of the substrate with a closely packed array of concavities which stably contain liquid material by the combined effects of surface tension and geometry, (2.0) depositing the material from which the crystals are to be grown on the prepared surface of the substrate to at least partially fill the concavities, (3.0) removing deposited material from the field by evaporation etching after the next step, and (4.0) crystallizing the material remaining in each concavity. The process may be followed by a further step (5.0) of recrystallizing the material to assure a single crystal in each concavity free of any defects, such as defects resulting from etching.

Abstract: An improved contact material for use in the fabrication of semiconductor devices is provided. This material comprises one of the mercury chalcogenides. The application of this material to a nondegenerate semiconductor may be made by the process of evaporation. The resulting contact is stable in the atmosphere, and is more electronegative than the best contact material, namely gold, that is now used.