Self-organized growth of ZnTe nanoscale islands on (001)GaAs

The Stransky-Krastanow metalorganic vapor phase epitaxy growth of self-organized ZnTe islands on homoepitaxial ~001!GaAs is demonstrated. The 27.4% lattice mismatch of the ZnTe/GaAs heterostructure leads to a strain-driven distribution of nanoscale ZnTe islands on top of a two-dimensionally ~2D! grown wetting layer. Atomic force microscopy and Rutherford backscattering spectrometry are used to determine the island dimensions and the thickness of the wetting layer. The density of the islands, their average diameter, and aspect ratio turn out to be about 520 mm22, 13.6 nm, and 0.20, respectively, for a 1.2 ML thick 2D layer. Furthermore, the average aspect ratio of the islands decreases by increasing the thickness of the wetting layer, as expected by the progressive extinction of the strain-driven island nucleation.