The role of 2D islands in the epitaxial growth of (001) CdTe

We present an extensive study of the homoepitaxial growth of (001) CdTe with a particular emphasis on the variation of the lattice parameter and on the determination of the surface stoichiometry during the growth as well as the related evolution of the growth rate. An oscillatory behavior of the in plane lattice parameter during the 2D homoepitaxial growth of (001) CdTe is demonstrated. It is associated to a deformation, induced by the surface reconstructions, at the free edges of the small islands formed during the growth by molecular beam epitaxy (MBE) or atomic layer epitaxy. During the MBE growth, the presence on top of the CdTe growing surface of both chemisorbed dimerized tellurium atoms and weakly bonded Te atoms adsorbed on top of this Te layer is evidenced. The influence of the stoichiometry on the evolution of the growth rate is demonstrated. Moreover, an influence of strain on the growth mechanisms of CdTe has been observed.