Anisotropic and inhomogeneous Coulomb screening in the Thomas-Fermi approximation: Application to quantum dot-wetting layer system and Auger relaxation

A model for anisotropic Coulomb screening by 2D and 3D carriers simultaneously, is proposed in the Thomas-Fermi approximation. Analytical expressions for the screened interaction potentials and scattering matrix elements are obtained. This model is applied to the Auger relaxation of carriers in an InAs/InP quantum dot (QD) – wetting layer (WL) system. The influences of the QD morphology and carriers densities on screening and Auger effects are studied. 2D-2D scattering is found to be the most important process, depending especially on QD morphology. A smearing effect is associated to the wetting layer wavefunction extension along the growth axis. The screened potential is similar to a potential screened by 3D carriers. P.A.C.S. 73.21.La, 71.15.Qe, 71.15.-m, 73.22.Dj