Structural characterization of InAs/GaAs quantum-dot nanostructures

We have performed high-resolution x-ray diffraction measurements on vertica lly aligned InAs/GaAs quantum-dot nanostructures. The measurements were car ried out for both the symmetric (004) and asymmetric (113) and (224) Bragg reflections. Theoretical simulations of the rocking curves indicate that th e x-ray signal is primarily from the pseudomorphically strained (In,Ga)As w etting layers. The average thickness and indium composition in the wetting layers, as determined from simulations of the rocking curves, were, respect ively, 0.72 nm and 88%. Transmission electron microscopy studies show the c reation and annihilation of quantum dots with no observable dislocations. ( C) 2001 American Institute of Physics.