Abstract: A foldable display is disclosed. In one aspect, the foldable display includes a display panel including: a plurality of flat regions and a folding region interposed between the flat regions. Each of the flat regions includes a fixed region and a semi-fixed region interposed between the fixed region and the folding region. The foldable display also includes a plurality of substrates respectively attached to the flat regions and a plurality of fixed adhesive members respectively interposed between the fixed regions and the substrates. The fixed adhesive members respectively attach the substrates to the fixed regions. The foldable display further includes a plurality of semi-fixed adhesive members respectively interposed between the semi-fixed regions and the substrates. The semi-fixed adhesive members are configured to respectively attach/detach the semi-fixed adhesive regions to/from the substrates based on the degree to which the display panel is folded.

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 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: 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.