Abstract: The present application relates to a transparent cured siloxane material having high transparency and refractive index, long-term heat resistance and ultraviolet resistance, and excellent hardness, and a preparing method using the same. The transparent cured siloxane material is prepared by using an oligosiloxane resin having a vinyl-silicon bond through a hydrolysis-condensation reaction, an oligosiloxane resin having a hydrogen-silicon bond through a hydrolysis-condensation reaction, and a metal catalyst for hydrosilylation. The present application also relates to a light emitting diode encapsulating material including the transparent cured siloxane material and a light emitting diode capsulated by using the light emitting diode encapsulating material.

Abstract: A method of manufacturing a gallium nitride (GaN) substrate and a GaN substrate manufactured by the same. The method includes the steps of growing a GaN film on a base substrate and separating the base substrate from the GaN film. The step of growing the GaN film includes forming pits in the GaN film, the pits inducing an inversion domain boundary to be formed inside the GaN film. The GaN substrate can have a predetermined thickness with which it can be handled during layer transfer (LT) processing, and the warping of the GaN substrate can be minimized, thereby preventing cracks due to warping.

Abstract: An apparatus for easily measuring the quality of gallium nitride (GaN) in normal conditions such as an atmospheric pressure and room temperature. The apparatus includes a light source disposed above a GaN substrate and a measuring unit disposed above the GaN substrate. The light source emits light to a surface of the GaN substrate. The measuring unit measures the quality of the GaN substrate based on the spectrum of light radiated from the GaN substrate.

Abstract: A method of manufacturing a gallium nitride (GaN) substrate and a GaN substrate manufactured thereby. The method includes the steps of growing an aluminum nitride nucleation layer on a base substrate, growing a first gallium nitride film on the base substrate on which the aluminum nitride nucleation layer has been grown, the first gallium nitride film having a first content ratio of nitrogen to gallium, and growing a second gallium nitride film on the first gallium nitride film, the second gallium nitride film having a second content ratio of nitrogen to gallium which is lower than the first content ratio. Self-separation between the base substrate and the GaN substrate is possible during the growth process, thereby precluding mechanical separation, increasing a self-separation area, and minimizing the occurrence of warping.

Abstract: A method of manufacturing a free-standing substrate includes the steps of growing a first thin film on a heterogeneous substrate, forming an ion implantation layer in the first thin film by implanting ions into the first thin film, dividing the first thin film into an upper thin film and a lower thin film with respect to the ion implantation layer, and growing a second thin film on the upper thin film. The free-standing substrate is manufactured without warping or cracking. No additional processes, such as a laser separation process, for separating the free-standing substrate from the heterogeneous substrate are required.