| 摘要 |
PURPOSE:To reduce misfit dislocation and the like on a heteroboundary and improve luminous efficiency by lessening the width of the forbidden band of a P layer constituting a PN junction is comparison with that of an N layer and further by specifying the carrier density of the P and N layers respectively in a GaAlAs heterojunction diode. CONSTITUTION:On a P type GaAs substrate 1 are laminated and grown epitaxially a P type Ga1-xAlxAs layer 2 serving as a luminous part and an N type Ga1-yAl7As layer 3 and to the back surface of the substrate 1 is connected an electrode 4, while also on the central surface of the layer 3 is formed an electrode 5. In such a constitution, the width of the forbidden band of the N type layer 3 through the intermediary of the PN heterojunction is made larger than that of the P type layer 2, and at the same time the carrier density p of the P type layer 2 is set to be 4.5- 10<17>cm<-3p<2.5X10<18>cm<-3> by using Zn impurity, while the density n of the N type layer 3 is also set to be 2X10<17>cm<-3n<1X10<18>cm<-3>. In this way, defects on the hetero-boundary are removed and the luminous efficiency is improved. |
