Patent ID: 7498612

Claim:
A pn-heterojunction compound semiconductor light-emitting device comprising a crystalline substrate; a lower cladding layer formed on a surface of the crystalline substrate and composed of an n-type Group III-V compound semiconductor; a light-emitting layer formed on a surface of the lower cladding layer and composed of an n-type Group III-V compound semiconductor; an upper cladding layer formed on a surface of the light-emitting layer and composed of p-type boron phosphide; an n-type electrode attached to the lower cladding layer; and a p-type electrode attached to the upper cladding layer, the lower and upper cladding layers being opposed to each other and sandwiching the light-emitting layer, thereby forming, together with the light-emitting layer, a light-emitting portion of a pn-heterojunction structure, wherein the light-emitting device has an intermediate layer composed of an n-type boron-containing Group III-V compound between the light-emitting layer and the upper cladding layer; and wherein the light-emitting layer has an outermost layer composed of an n-type layer of Ga x In 1−x N, in which 0≦X≦1, having a crystal face orientation of (0001) and the n-type intermediate layer is composed of an undoped n-type boron-containing (111)-Group III-V compound having a crystal face orientation of (111) and a direction of <110> parallel to an a-axis of an n-type (0001)-Ga x In 1−x N, in which 0≦X≧1, and is formed on the outermost layer of the light-emitting layer.