Defect-free growth of Al x Ga1− x As by liquid-phase epitaxy on V-grooved (001) GaAs substrates

The crystalline quality of AlxGa1−xAs grown on a V-grooved (001) GaAs substrate is characterized by low-temperature cathodoluminescence and transmission electron microscopy. High-crystalline perfection visualized by narrow neutral donor bound exciton luminescence is attained above the groove. Growth of (Al, Ga) As in the groove takes place without significant change of the aluminium distribution. An order of magnitude increase of silicon acceptor concentration induced by As-vacancy creation is detected at the interface n-GaAs substrate/V groove. Transmission electron microscopy pictures taken from sample cross sections do not show any kind of defects in the groove.