| 摘要 |
PURPOSE:To avoid the lowering of light emitting efficiency due to the leakage of electrons or holes generated with the increase of currents by forming a layer, which is separated from at least one heterointerface of a double heterojunction only by a distance within a diffusion distance of a small number of carriers and has approximately the same forbidden band width as an active layer. CONSTITUTION:Light emitting atoms are constituted by five layers of an N type InP layer (a), an N type InGaAsP layer (b), a P type InP layer (c), a P type InGaAsP layer (d) and a P type InP layer (e). Accordingly, the double heterojunction consisting of three layers of the layers (a), (b) and (c), the layer (d) is separated from an interface of the layers (b) and (c) only by the distance (d) shorter than the diffusion distance of electrons, and the layer (d) is given approximately the same forbidden band width Eg' as the forbidden band width Eg of the active layer (b). Consequently, electron leaked from the active layer (b) are confined to the layer (d) by an adjacent layer (e), light with the same wavelength as the layer (b) can be generated, luminous energy increases and light emitting efficiency is improved. |
