Strain-driven (In,Ga)As growth instability on GaAs (3 1 1)A and (3 1 1)B: self-organization of template for InAs quantum dot nucleation control

We study the growth of (In,Ga)As on GaAs (3 1 1)A and (3 1 1)B substrates by molecular-beam epitaxy (MBE). Wire-like structures and a matrix of closely packed cells develops, respectively, on (3 1 1)A and (3 1 1)B substrates, when the (In,Ga)As layer thickness exceeds a critical value for the onset of surface undulation due to the strain-driven growth instability. The established lateral strain distribution generates a unique template controlling nucleation and growth of (In,Ga)As quantum dots (QDs). On GaAs (3 1 1)B, the InAs QDs formed on the (In,Ga)As template exhibit pronounced improvement of the structural and optical properties.