High-quality single GaAs quantum wells grown by metalorganic chemical vapor deposition

Abstract
GaAs-AlxGa1−xAs single and multiquantum well structures grown by metalorganic chemical vapor deposition have been examined for the first time in detail using low-temperature photoluminescence, cathodoluminescence, and transmission electron microscopy. The better heterointerfaces are very uniform with a large scale roughness of approximately plus or minus a monolayer along the interface on a scale of the exciton diameter or larger and a composition gradient width of less than three monolayers across the interface. The GaAs well interface roughness and associated impurity luminescence are not very sensitive to the thickness of the AlxGa1−xAs prelayer. With nonoptimum growth conditions, the quantum well photoluminescence characteristics suggest a substantial amount of band filling due to holes presumably from the AlxGa1−xAs layers.