| 摘要 |
PURPOSE:To improve luminous efficiency by a method wherein an n-type GaP layer with the step-wise changing donor concentration is formed on an n-type Gap substrate and on said layer a p-type GaP layer with the step-wise changing acceptor concentration is formed. CONSTITUTION:On an n-type GaP substrate, an n-type GaP layer consisting of the first n-layer with the stepwise decreasing donor concentration and the second n-layer is formed. And on the n-type GaP layer, a p-type GaP layer consisting of the first p-layer with the step-wise increasing acceptor concentration and the second p-type GaP layer is formed. In this way, even in the condition of the luminous center concentration, the lifetime of a few number of carriers of the n-type GaP layer becomes extremely long and the luminous efficiency is improved. |
