Gallium phosphide light-emitting diode

摘要

A gallium phosphide light-emitting diode comprises n-type layers (21 to 23) formed successively on an n-type substrate (20). The impurity concentration of the first n-type layer (21) is higher than the impurity concentration of the n-type substrate (20), (1 to 3)x1017cm-3, and is for example (5 to 8)x1017cm-3. The impurity concentration of the second n-type layer (23) is lower than that of the n-type substrate (20) and is for example (0.6 to 3)x1016cm-3. Since the impurity concentration of the second n-type layer (23) is decreased, a high electroluminescence efficiency can be obtained. Furthermore, since the first n-type layer (21) has a high impurity concentration, perfection of crystal can be attained for each n-type layer and accordingly, switching operation is not caused.