Single-crystal layers of AlN have been grown on sapphire substrates between 1000 and 1100 °C by vapor-phase reaction of aluminum chlorides with ammonia. The purity, color, crystallinity, growth morphology, and electrical resistivity of the epitaxial layers have been investigated. Infrared specular reflection measurements showed the presence of an appreciable strain at the AIN-sapphire epitaxy interface. Optical absorption data strongly suggest the AlN is a direct band-gap material with a value of about 6.2 eV at room temperature.

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Some 50 ternary sulfides of the type II‐Ln2‐S4 were explored, where II=false(normalZn,normalCd,normalMg,normaland Cafalse) and normalLn=false(normalSe,Y,normalLa,normalCe,normalPr,normalNd,normalSm,normalGd,normalTb,normalDy,normalHo,normalEr,normalTm,normalYb,normaland Lufalse) . The structure of the compounds, if they were formed, was investigated with x‐ray diffraction techniques using primarily the materials synthesized in powder form. Single crystals were subsequently grown from the powders for several compounds including ZnSc2S4 and CdSc2S4 which were found to have bandgaps of 2.1 and 2.3 eV, respectively, at room temperature. Doping with a variety of impurities provided conducting n‐type specimens for both ZnSc2S4 and CdSc2S4 , and for the latter p‐type specimens were also obtained. Weak cathodoluminescence was observed from several compounds including CaCe2S4 with a green‐yellow and ZnLu2S4 with a blue‐green emission color.

Single-crystal layers of ZnSe, ZnS, and CdS have been grown epJtaxially on GaAs, GaP, and sapphire substrates in an open-tube system by reaction of the metal vapors with the nonmetal hydride gases. Various factors are discussed which were found to affect the epitaxial growth. These include the role of vapor compositions and growth temperatures in controlling stoichiometry and polymorphism, and the choice of substrate materials with particular emphasis on the effects of lattice and thermal expansion match between the substrate and the epitaxial layer. High crystalline quality of the epitaxially grown layers was evidenced by the Kikuchi lines present in their electron diffraction patterns. As-grown layers of ZnSe and ZnS, both undoped and doped, were high resistivity, while CdS was readily grown n-type. These epitaxial layers showed at room temperature a bright, visible cathodoluminescence, and for each compound different emission colors were observed with specimens grown at different temperatures.