| 摘要 |
PURPOSE:To prevent a light emitting efficiency from decreasing by composing a light emitting region of a superlattice laminated with GaAs and AlAs to maintain a direction transition even when the aluminum composition ratio averaged in the entire superlattice is the prescribed value or larger. CONSTITUTION:An N type Ga0.2Al0.3 clad layer 1, a non-doped superlattice active layer 2, a P type Ga0.2Al0.8As clad layer 3, a P type GaAs cap layer, not shown are, for example, continuously grown by an electron beam epitaxial method on an N type GaAs substrate. The layer 2 is formed by alternately laminating a GaAs 3-atom layer 21 and an AlAs 1-atom layer 22 with 0.25 of average aluminum composition ratio and 720nm of oscillating wavelength to obtain 900A/cm<2> of threshold current density. Thus, the influence of the indirect transition conduction band is eliminated, the rise in the threshold current upon shortening of the wavelength is prevented to provide no reduction in implanting efficiency, thereby maintaining low threshold current. |
