The light-emitting semiconductor device

1. A light-emitting semiconductor device comprising: - A substrate; ! - A first semiconductor layer of n-conductivity type formed on the substrate; ! - A second semiconductor layer of p-type conductivity; ! - An active layer disposed between the first and second layers; ! - A conductive layer disposed on the second layer! - A first contact deposited on the substrate! - A second contact deposited on the conductive layer, wherein the substrate comprises at least one through-hole formed in the shape of a truncated inverted pyramid, wherein the first, second, active and conductive layers are deposited both on the horizontal portion of the substrate and on the internal faces holes. ! 2. The light emitting semiconductor device of claim 1, wherein the amount of said faces of the pyramids is between 3 and 24, the side length of the pyramid base is in the range from 10 microns to 1 mm, the angle of inclination of said lateral faces of the pyramids with respect to the substrate surface ranges from 10 ° to 90 °, the height of the pyramid is severed from 5% to 50% of its full height. ! 3. The light emitting semiconductor device of claim 1, wherein the through holes are arranged in a two-dimensional lattice. ! 4. The light emitting semiconductor device of claim 1, wherein the substrate thickness ranges from 10 microns to 1 mm. ! 5. A light-emitting semiconductor device of claim 1, wherein the substrate is made of gallium nitride. ! 6. The light emitting semiconductor device of claim 1, wherein the substrate is made of silicon carbide. ! 7. A light-emitting semiconductor device of claim 1, wherein the substrate is made of alumina. ! 8. Swe