| 摘要 |
PURPOSE:To reduce recombination centers, which do not emit light, in the interface of a light emitting layer and to implement a high output characteristic in a double heterojunction structure, by the constitution, wherein a light emitting tube is not in direct contact with a very thin film layer having high concentration, and a second semiconductor layer, which is to become a clad layer, is provided between said tube and layer. CONSTITUTION:An n-type GaAs layer 14 is a light emitting layer. An n<-> type AlGaAs layer 15, whose forbidden band width is larger than that of the layer 14, and a p<+> type AlGaAs layer 13 are provided so as to hold the layer 14. On the n<-> type AlGaAs layer 15, an n<-> type AlGaAs layer 17, which is to become a clad layer, is formed through a very thin p<+> type GaAs layer 16 having high impurity concentration. An n<+> type AlGaAs layer 18, which is to become an emitter layer, and an n<+> GaAs layer 19 are further formed thereon. In this way, the high concentration p<+> GaAs layer 16 is not in direc contact with the n type GaAs layer 14, which is the light emitting layer, and the low concentration AlGaAs layer 15 is provided as the clad layer between the layer 14 and the layer 16. Thus the interface characteristics of the light emitting layer are improved, and a photoelectron bistable element, which can emit light at high output power, can be obtained. |
