Group-iii-nitride semiconductor element, multi-wavelength-emitting group-iii-nitride semiconductor layer, and method for forming multi-wavelength-emitting group-iii-nitride semiconductor layer

A group-III-nitride semiconductor element includes: a substrate; and a group-III-nitride semiconductor layer formed on the substrate, having donor impurities and acceptor impurities added thereto, and containing gallium (element symbol: Ga) as an essential constituent element thereof. The group-III-nitride semiconductor element is characterized in that the group-III-nitride semiconductor layer includes a multi-wavelength-emitting group-III-nitride semiconductor monolayer that contains a greater stoichiometric amount of group III elements including gallium than group V elements including nitrogen and that simultaneously emits at least three beams of light aside from the band-edge emission and having different wavelengths in a region with wavelengths longer than the band-edge emission. Thus, a semiconductor element, such as a white LED, is provided easily and with a simple structure.