Optimal Growth Conditions of AlGaAs/GaAs Quantum Wells by Flow-Rate Modulation Epitaxy

Abstract
AlGaAs/GaAs single quantum wells with narrow photoluminescence linewidths were grown at 570°C by modified metal-organic chemical vapor deposition, flow-rate modulation epitaxy, using optimal arsine flow rates. The full widths at half maximum of low-temperature photoluminescence spectra strongly depended on arsine flow rates. Under optimal conditions, their values were 8.8, 6.7, 5.0 and 4.8 meV for 1.7, 3.4, 5.1 and 6.8 nm-wide wells, respectively. The resulting narrow photoluminescence linewidths indicate that the heterointerfaces are very flat on an atomic scale, probably as a result of enhanced surface migration of Ga and Al atoms.