Compound semiconductor light-emitting diode

A compound semiconductor light-emitting diode comprising a light-emitting layer composed of a Group III-V compound semiconductor, and a current diffusion layer provided on the light-emitting layer and composed of a Group III-V compound semiconductor, characterized in that the current diffusion layer is composed of a conductive boron-phosphide-based semiconductor and has a bandgap at room temperature wider than that of the light-emitting layer,

• wherein the diode includes, in a thickness direction between the current diffusion layer and the light-emitting layer, a cladding layer composed of a Group III-V compound semiconductor, and the cladding layer has a bandgap at room temperature wider than that of the light-emitting layer and equal to or narrower than that of the current diffusion layer,
• wherein the current diffusion layer is composed of a boron-phosphide-based semiconductor having a boron compositional gradient such that the bandgap increases from the bottom surface of the current diffusion layer closest to the light-emitting layer to a top surface of the current diffusion layer,
• wherein the cladding layer is composed of a Group III-V compound semiconductor containing aluminum, gallium, and indium, and the current diffusion layer is composed of a boron-phosphide based semiconductor containing at least one species selected from among aluminum, gallium and indium, and
• wherein an Ohmic contact electrode is joined to the current diffusion layer.