Planar ordering of InP quantum dots on (100)In0.48Ga0.52P

Planar ordering of dense self-organized arrays of InP/In0.48Ga0.52P quantum dots is investigated using grazing incidence small-angle X-ray scattering (GISAXS), atomic force microscopy (AFM), and transmission electron microsco py (TEM). Using the two-dimensional Fourier transform of the AFM data toget her with the GISAXS data, we show that the degree of ordering increases wit h increasing InP deposition time and, therefore, with increasing quantum do t density. This increase in ordering is seen both in that the dot period is less variable and in the appearance of longer ranged ordering of the dots on the surface. Intense photoluminescence due to radiative recombination of heavy holes and electrons in the quantum dots is observed at an energy bet ween the band gaps of InP and In0.48Ga0.52P. (C) 2000 Elsevier Science B.V. All rights reserved.