Structural Properties Of Pbte/Cdte Interfaces From First Principles

The structural and energetic properties of the PbTe/CdTe(100), (110), and (111) interfaces are investigated using an ab initio pseudopotential method within a slab approximation. A scheme is proposed to calculate interface energies for polar faces with a resulting dipole moment. The atomic relaxation gives rise to similar effects as those observed for free surfaces. At (110) interfaces the rebonding leads to pronounced additional lateral displacements. The PbTe/CdTe(111) interface is the most energetically stable interface studied. The interface energies are used to predict the equilibrium crystal shape of a PbTe quantum dot embedded in a CdTe host matrix by means of a Wulff construction.