| 摘要 |
A group-III-nitride based layer sequence fabricated by means of an epitaxial process on a silicon substrate, the layer sequence comprising at least one doped first group-III-nitride layer (105) having a dopant concentration larger than 1×1018 cm-3, a second group-III-nitride layer (106) having a thickness of at least 50 nm and an n-type or p-type dopant concentration of less than 5×1018 cm-3, and an active region made of a group-III-nitride semiconductor material, wherein the first group-III-nitride layer comprises at least one n-type dopant selected from the group of elements formed by germanium, tin, lead, oxygen, sulphur, selenium and tellurium or a at least one p-type dopant, and wherein the active region has a volume density of either screw-type or edge type dislocations below 5×109 mm-3. |
