A light emitting diode is provided with a window layer of ZnSSe semiconductor material having a second conductivity type. The second conductivity type ZnSSe window layer has a low electrical resistivity so that it can be used as a current spreading layer, and a bandgap higher than that of the active layer so that it is transparent to light emitted from the active layers. The second conductivity type ZnSSe window layer can be doped with a donor concentration of more than 10.sup.18 cm.sup.-3. Furthermore, its lattice constant is close to that of the active layers and confining layers so that deterioration in optical characteristic due to lattice mismatch is minimized.