| 摘要 |
PURPOSE:To uniformly inject carriers even in a multiple quantum well active layer containing a large number of layers, and provide yellow and green excellent surface emission LEDs that have a sufficiently high luminous efficacy and can be simply manufactured. CONSTITUTION:The title invention relates to a LED that consists of a n-GaAs substrate 11; a double heterostructure section formed on the substrate 11, composed of a multiplex quantum well active layer 15 sandwiched by a n-type cladding layer 14 and a p-type cladding layer 16; a p-GaAlAs current diffusion layer 18 formed on the double hetero structure section; a positive electrode 21 formed on part of the current diffusion layer 18; and a negative electrode 22 formed on the underside of the semiconductor substrate 11. The thickness of the well layer and barrier layer in the multiplex quantum well active layer 15, is gradually varied in the direction of the lamination of the active layer 15 so that the quantum levels of the well layer will be gradually increased from the electron injection side toward the hole infection side. |
