| 摘要 |
PURPOSE:To increase the luminous possibility of a layer continuous from the following layer more than that of a layer close to an interface of a P-N junction and thus contrive to improve the light emitting efficiency by increasing the luminous recombination of injection charges by a method wherein a light emitting region is formed of two or more layers of different ratios of mixed crystal. CONSTITUTION:The P type Ga1-XAlXAs region in a diffusion length L is formed of two mixed crystal layers p1 and p2 4 and 5; the ratio of mixed crystal of the p1 layer is: r=0, x=0.35 and r=d1, x=0.37, and that of the p2 layer is: r=d1, x=0.31 and r=L, x=0.35. Since the ratio of mixed crystal of the p2 layer 5 is set smaller than that of the p1 layer 4, the luminous possibility R2 (r) of the p2 layer 5 becomes higher than that R1 (r) of the p1 layer 4. As a result, R2 (r) becomes higher in this structure than the luminous possibility of the region d1<=r<=L in a normal LED, and injection charges emit light first in a p1 layer 6 of 0<=r<=d1 in the LED having such a structure. Next, light is emitted in the region d1<=r<=L in a p2 layer 7, the luminous efficiency improves, because R2 (r) in this region is high. |
