| 摘要 |
PURPOSE:To obtain a high light emission output by providing an active layer composed of a p-n junction on one surface of a low impurity concentration semiconductor substrate. CONSTITUTION:An active layer 12 composed of a p-n junction is provided on one surface of a low impurity concentration semiconductor substrate 10. For instance, on the circumference side part where an insulating layer 15 is not formed, a p-type electrode 16 is provided so as to be brought into contact with a p-type InP layer 11 exposed at the bottom of a recessed part 21 and, on the center part where the insulating layer 15 is not formed, an n-type electrode 17 which is brought into contact with an n-type InGaAsP layer 14 is provided. Moreover, the opposite side of the nondoped InP substrate 10 is shaped into a convex lens form. As light is absorbed only a little by the low impurity concentration semiconductor substrate, the light emitted by the active layer is hardly absorbed and emitted with a high output power. |
