Origin of size distributions in ZnSe self-organized quantum dots grown on ZnS layers

Main factors which determine the size, the standard deviations which show t he degree of the size fluctuations for the average dot height and diameter, and density in ZnSe self-organized quantum dots (QDs) grown on ZnS layers were studied. By lowering the growth temperature the QDs average size and i ts standard deviation decreased and the density increased due to the slower surface migration. With the application of the scaling theory, it was reve aled that the normalized size distributions were uniquely determined by the nucleation process although the apparent standard deviations of the QD siz es were dependent on the growth temperature. The influence of surface rough ness of the underneath layer on the formation of the relations of the dot h eight and diameter was also examined. It was shown that the fluctuation of the surface potential contributes significantly to the apparent standard de viations of ZnSe self-organized QDs sizes.