A model for anisotropic Coulomb screening : application to Auger relaxation by 2D and 3D charge carriers in a quantum dot – wetting layer system

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 J. EVEN et al. 1 ha l-0 04 92 29 7, v er si on 1 28 J un 2 01 0 Author manuscript, published in "Physica Status Solidi B 244, 9 (2007) 3105" DOI : 10.1002/pssb.200642334