Improved quality of AlxGa1-xAs grown on Se-doped AlxGa1-xAs substrate-layers by metalorganic chemical vapor deposition

AlxGa1-xAs epilayers were grown directly on different AlxGa1-xAs substrate-layers by metalorganic chemical vapor deposition (MOCVD). The quality of AlxGa1-xAs layers was significantly improved when Se-doped AlxGa1-xAs substrate-layers were used. Al0.13Ga0.87As epilayers with excellent morphology, optical, and crystal quality were grown on Se-doped Al0.26Ga0.74As. The full width at half maximum of the bound exciton peak as low as 4.51 meV was measured by low-temperature (14.9K) photoluminescence. The improvement is attributed to a Se passivation effect at the surface of Se-doped AlxGa1-xAs substrate-layers. Results suggest that Se will reduce and delay the formation of native oxides.