Abstract: A substrate for epitaxial growth of the present invention comprises: a single crystal part comprising a material different from a GaN-based semiconductor at least in a surface layer part; and an uneven surface, as a surface for epitaxial growth, comprising a plurality of convex portions arranged so that each of the convex portions has three other closest convex portions in directions different from each other by 120 degrees and a plurality of growth spaces, each of which is surrounded by six of the convex portions, wherein the single crystal part is exposed at least on the growth space, which enables a c-axis-oriented GaN-based semiconductor crystal to grow from the growth space.

Abstract: A nitride semiconductor light-emitting diode element 1 includes a nitride semiconductor layer 12 having a bottom surface and an upper surface and containing a light emitting layer 12b inside, and a supporting substrate 11 made from a metal is bonded to the bottom surface of the nitride semiconductor layer 12. A light reflecting depression A1 to reflect light generated in the light emitting layer 12b is formed in the bottom surface of the nitride semiconductor layer 12. According to the nitride semiconductor light-emitting diode element 1, since the light generated from the light emitting layer 12b and propagated in the nitride semiconductor layer 12 in a layer direction is reflected by the light reflecting depression A1 and its travel direction is changed, the ratio of the light incident upon the upper surface of the nitride semiconductor layer 12 within a critical angle is increased.

Abstract: A substrate for epitaxial growth of the present invention comprises: a single crystal part comprising a material different from a GaN-based semiconductor at least in a surface layer part; and an uneven surface, as a surface for epitaxial growth, comprising a plurality of convex portions arranged so that each of the convex portions has three other closest convex portions in directions different from each other by 120 degrees and a plurality of growth spaces, each of which is surrounded by six of the convex portions, wherein the single crystal part is exposed at least on the growth space, which enables a c-axis-oriented GaN-based semiconductor crystal to grow from the growth space.

Abstract: A nitride semiconductor light-emitting diode element 1 includes a nitride semiconductor layer 12 having a bottom surface and an upper surface and containing a light emitting layer 12b inside, and a supporting substrate 11 made from a metal is bonded to the bottom surface of the nitride semiconductor layer 12. A light reflecting depression A1 to reflect light generated in the light emitting layer 12b is formed in the bottom surface of the nitride semiconductor layer 12. According to the nitride semiconductor light-emitting diode element 1, since the light generated from the light emitting layer 12b and propagated in the nitride semiconductor layer 12 in a layer direction is reflected by the light reflecting depression A1 and its travel direction is changed, the ratio of the light incident upon the upper surface of the nitride semiconductor layer 12 within a critical angle is increased.

Abstract: A nitride semiconductor light emitting element having a laminate S made of a semiconductor crystal layer, wherein the laminate S includes an n-type layer 2, a light emitting layer 3 and a p-type layer 4. The p-type layer 4 has a p-type contact layer 42 to be in contact with the p-side electrode P2. The p-type contact layer 42 comprises a first contact layer 42a and a second contact layer 42b. The first contact layer 42a is in contact with the p-side electrode P2 on one surface and in contact with the second contact layer 42b on the other surface. The first contact layer 42a is made of Alx1Iny1Gaz1N (0<x1?1, 0?y1?1, 0?z1?1), and the second contact layer 42b is made of Alx2Iny2Gaz2N (0?x2?1, 0?y2?1, 0?z2?1). 0?x2<x1, 0?y1?y2, and the first contact layer 42a has a thickness of 0.5 nm-2 nm.