Very low interface recombination velocity in (Al,Ga)As heterostructures grown by organometallic vapor-phase epitaxy

We show that measurements of minority-carrier lifetimes in thin layer (Al,Ga)As double heterostructures grown by organometallic vapor-phase epitaxy can be severely influenced by modulation doping of the layer studied. Samples where this effect has been eliminated exhibit a dominantly nonradiative luminescence decay, from which we deduce an interface recombination velocity of only 18 cm s−1, which is among the lowest ever reported for a GaAs/(Al,Ga)As interface.