Minority-carrier lifetime in Al_xGa_{1- x}As grown by molecular-beam epitaxy

Al_xGa_1-xAs (x>0.30) double heterostructures are grown by molecular-beam epitaxy (MBE) and the minority-carrier lifetimes are measured by time-resolved photoluminescence. The data indicate that the minority-carrier lifetimes in high aluminum (x>0.30) Al_xGa _1-xAs grown by MBE are comparable to the previously published lifetimes of material grown by liquid-phase epitaxy. The lifetimes in MBE materials appear to be somewhat larger than those measured in materials grown by metalorganic chemical vapor deposition. Factors affecting AlGaAs minority-carrier lifetime, such as the growth temperature, the aluminum concentration, and the confinement layer composition will be discussed.