| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting element of improved light extraction efficiency by using a compound semiconductor layer, whose refractive index is smaller than a conventional GaP and AlGaAs mixed crystal as the light- extracting layer. SOLUTION: A double heterostructure layer comprises a light-emitting layer 24, where a first conductive type clad layer 6, an active layer 5, and a second conductive type clad layer 4 are laminated in this order, each of which comprising (AlxGa1-x)yIn1-yP (where, 0<=x, y<=1 and x+y=1) mixed crystal. On at least one side of the light-emitting layer 24, light-extracting layers 10 and 13 are formed which comprises a compound semiconductor, where a refractive index for the light of wavelength band 550-650 nm is 3.2 or smaller. The critical angle of total reflection is improved by about 8-50% as compared to, for example, a conventional value of GaP. Loss due to total reflection is made less likely to occur by the amount increase in the critical angle, for higher light extraction efficiency than in the case when the GaP or AlGaAs mixed crystal is used as the light-extracting layer. |
