Abstract: A small, simple current-injection diamond ultraviolet light-emitting device comprising a high-quality diamond grown by chemical vapor deposition (CVD) method (1), a surface conductive layer (2) provided on the surface of the diamond, and electrodes (4, 5) provided on the surface conductive layer. The device is a free-exciton recombination emission diamond ultraviolet light-emitting device comprising a CVD diamond crystal where the free-exciton recombination radiation (235 nm) caused by current injection is dominant.

Abstract: A diamond ultraviolet luminescent element (10) having a current-injection light-emitting diode structure includes a high-quality boron-doped p-type diamond crystal (semiconductor layer) (1) synthesized by the high pressure and high temperature method; a phosphorous-doped n-type diamond crystal (n-type semiconductor layer) (3) formed on the first diamond surface by the chemical vapor deposition; an electrode (5) formed on the surface of the n-type semiconductor layer (3); and an electrode (7) formed on the surface of the p-type semiconductor layer (1). The luminescence (235 nm) attributed to the recombination of free excitons resulting from current injection dominates in ultraviolet wavelength region (10).

Abstract: A diamond high brightness ultraviolet ray emitting element employs the carrier high-density phase of a diamond as a light-emitting mechanism. It includes a diamond substrate, a first diamond layer formed on the diamond substrate, a second diamond layer formed on the first diamond layer and functioning as an emission layer, a third diamond layer formed on the second diamond layer, a first electrode formed on the first diamond layer, and a second electrode formed on the third diamond layer. The second diamond layer constitutes the carrier high-density phase formed by high-density excitation. The combination of the high-density excitation with the high-quality diamond can implement the device that has stable carrier high-density phase, and emission efficiency higher than a conventional device with low-density excitation.

Abstract: There is provided a diamond crystal in which the (111) oriented plane is of the diamond crystal synthesized on a substrate by a chemical vapor deposition method parallel to a substrate surface, and the area of the (111) oriented plane parallel to the substrate surface is 1/24or less an area of the crystal on the substrate. A source gas is activated on a substrate consisting of a material which is not reactive with carbon. The source gas contains at least carbon and hydrogen in such a manner that the ratio of the number of carbon atoms to the total number of molecules of the source gas is 0.5% or less. Subsequently, a diamond crystal in which the (111) orientation plane is parallel to the substrate surface, and the area of the (111) orientation plane parallel to the substrate surface is precipitated on the substrate. A copper plate is preferably contains used as the substrate.

Abstract: On the surface of a hydrogen-terminated diamond 1 formed by terminating a surface 2 of either a homoepitaxial diamond or a heteroepitaxial diamond or a surface-flattened polycrystal diamond are formed a drain-ohmic contact 4 and a source-ohmic contact 3 of gold or platinum, an insulating layer 5 formed of silicon oxide (SiO.sub.x : 1.ltoreq.X.ltoreq.2) and a gate electrode 6 mounted on said insulating layer, and the surface other than the element forming region is set to be an insulating region being non-hydrogen-terminated, for example, oxygen-terminated, and the elements formed on said region is being isolated.

Abstract: On the surface of a hydrogen-terminated diamond 1 formed by terminating a surface 2 of either a homoepitaxial diamond or a heteroepitaxial diamond or a surface-flattened polycrystal diamond are formed a drain-ohmic contact 4 and a source-ohmic contact 3 of gold or platinum, an insulating layer 5 formed of silicon oxide (SiO.sub.x : 1.ltoreq.X.ltoreq.2) and a gate electrode 6 mounted on said insulating layer, and the surface other than the element forming region is set to be an insulating region being non-hydrogen-terminated, for example, oxygen-terminated, and the elements formed on said region is being isolated.

Abstract: There is provided a diamond crystal in which the (111) oriented plane is of the diamond crystal synthesized on a substrate by a chemical vapor deposition method parallel to a substrate surface, and the area of the (111) oriented plane parallel to the substrate surface is 1/24 or less an area of the crystal on the substrate.