Effect of compositionally graded and superlattice buffer layers on the device performance of graded barrier quantum well heterostructure laser diodes

The device performance of graded barrier quantum well laser diodes with various buffer layer structures grown by metalorganic chemical vapor deposition has been studied. Devices having four structures (a GaAs buffer layer only, a compositionally graded buffer layer, a superlattice buffer layer, or both a graded and a superlattice buffer layer) have been characterized. In contrast with similar studies involving laser devices grown by molecular beam epitaxy, little variation in device performance is observed. These data indicate that the quality of AlGaAs-GaAs heterostructures for optical devices may be dependent on the details of the method used for the epitaxial growth of the layers.