Semiconductor light-emitting device having a cladding layer composed of an InGaAlp-based compound

A semiconductor light-emitting element comprising:

• a compound semiconductor substrate;
• a double-hetero structure formed on said compound semiconductor substrate and composed of a first cladding layer of a first conductivity type, a second cladding layer of a second conductivity type, and an active layer of said first conductivity type interposed between said first cladding layer and said second cladding layer, wherein said active layer, said first cladding layer, and said second cladding layer are composed of a combination of materials such that a valence band difference between said active layer and at least one of said first cladding layer and said second cladding layer is larger than a conduction band difference therebetween;
• and
• an intermediate band gap layer interposed between said active layer and said second cladding layer, said intermediate band gap layer having an intermediate band gap of band gaps of said active layer and said second cladding layer, wherein said active layer is composed of a material selected from a group consisting of GaAs, GaAlAs, and InGaAs, and wherein said first cladding layer and said second cladding layer are composed of a material represented by a formula In.sub.y (Ga.sub.1-x Al.sub.x).sub.y P, x being in the range of 0.3 to 0.7 and y being in the range of 0.45 to 0.55.

A semiconductor light-emitting element comprising:

• a compound semiconductor substrate;
• a double-hetero structure formed on said compound semiconductor substrate and composed of a first cladding layer of a first conductivity type, a second cladding layer of a second conductivity type, and an active layer of said first conductivity type interposed between said first cladding layer and said second cladding layer, wherein said active layer, said first cladding layer, and said second cladding layer are composed of a combination of materials such that a valence band difference between said active layer and at least one of said first cladding layer and said second cladding layer is larger than a conduction band difference therebetween;
• a first intermediate band gap layer interposed between said active layer and said second cladding layer, said first intermediate band gap layer having an intermediate band gap of band gaps of said active layer and said second cladding layer;
• and
• a second intermediate band gap layer interposed between said active layer and said first cladding layer, said second intermediate band gap layer having an intermediate band gap of band gaps of said active layer and said first cladding layer, wherein said active layer is composed of a material selected from a group consisting of GaAs, GaAlAs, and InGaAs, and wherein said first cladding layer and said second cladding layer are composed of a material represented by a formula In.sub.y (Ga.sub.1-x Al.sub.x).sub.y P, x being in the range of 0.3 to 0.7 and y being in the range of 0.45 to 0.55.