Abstract: A process for obtaining borazane (NH3—BH3) includes introducing anhydrous liquid ammonia (NH3(l)) into a reactor thermostatically regulated to between a temperature ?1 and 40° C.; introducing, with stirring, into the reactor an amine borane complex (Am.BH3), the corresponding amine (Am) of which is soluble in anhydrous liquid ammonia only to a proportion of less than 10 g in 100 g of ammonia at 20° C., being introduced in an amount such that the mole ratio R=(NH3(l))/(Am.BH3) is greater than or equal to 5; stirring the mixture; stopping the stirring to obtain two demixed phases: a light phase constituted essentially of a solution of anhydrous liquid ammonia (NH3(l)) containing borazane; and a heavy phase constituted essentially of the amine corresponding to the amine borane complex introduced; isolating the borazane and drying under vacuum thereof; the temperature ?1 being greater than or equal to the melting point of the amine borane complex.

Abstract: A process for obtaining borazane (NH3—BH3) includes introducing anhydrous liquid ammonia (NH3(l)) into a reactor thermostatically regulated to between a temperature ?1 and 40° C.; introducing, with stirring, into the reactor an amine borane complex (Am.BH3), the corresponding amine (Am) of which is soluble in anhydrous liquid ammonia only to a proportion of less than 10 g in 100 g of ammonia at 20° C., being introduced in an amount such that the mole ratio R=(NH3(l))/(Am.BH3) is greater than or equal to 5; stirring the mixture; stopping the stirring to obtain two demixed phases: a light phase constituted essentially of a solution of anhydrous liquid ammonia (NH3(l)) containing borazane; and a heavy phase constituted essentially of the amine corresponding to the amine borane complex introduced; isolating the borazane and drying under vacuum thereof; the temperature ?1 being greater than or equal to the melting point of the amine borane complex.

Abstract: An electroluminescent semiconductor device includes a monocrystalline substrate, an n-type gallium nitride layer on the substrate, an active gallium nitride layer on the n-type layer which is doped to at least full compensation of the natural donor impurities with acceptor impurities, a surface electrode for contacting the active layer and means for contacting the n-type layer. A part of the n-type layer, which extends parallel to the active layer and adjoins the active layer, is doped to less than full compensation by means of the acceptor impurities, and the net concentration of donor impurities is smaller than the concentration of natural impurities and is substantially homogeneous in the layer portion. Electroluminescent semiconductor devices in accordance with the invention feature improved efficiency as well as better reproducibility than prior art devices.

Abstract: Method of manufacturing gallium nitride crystals by reaction of galium halide and ammonia in which free hydrogen chloride is introduced into the reaction and deposition zones.