Optical recombination-emission characteristics and surface morphologies of InAs quantum dots grown on misoriented GaAs substrate by MOCVD

The InAs quantum dot (QD) structures grown on (100) 2°, 6°, 10°, 15° off-angles to (111)A GaAs substrate have been investigated by atomic force microscopy (AFM) and cryogenic photoluminescence (PL). The exact-angle InAs/GaAs is used as the reference sample. The blue shift of PL peak spectra with increasing misoriented scales has also been observed experimentally. In this work, we demonstrated that different off-angle substrates would influence the distribution and uniformity of QD due to variant surface potential energies, which are responsible for the two-stage process (migration and nucleation) of InAs adatoms on the off-angle substrates.