Effect of an electric field on the formation of a stressed heterointerface under molecular beam epitaxy

Abstract

PACS 62.20.-x, 68.35.GyThe electron-deformation interaction is investigated in PbS/ZnSe heterostructures obtained by MBE growth of thin PbS films on monocrystalline ZnSe substrates with lattice parameter mismatch more than 4%. Within the framework of an electron-deformation model it is shown that lead sulfide films undergo the lattice compression strain or lattice tensile strain depending on direction of applied electric field.

Stress Analysis of Strained Superlattices.

“…To estimate the contribution of the electron-deformation potential in the electric behavior of the investigated structures [5] we should solve the one-dimensional time-independent Schrödinger equation (8) ), , ( L, b, n) is the periodical potential of the superlattice dependent on the thickness L of the narrow-gap PbS thin film, thickness of the substrate b and the carriers concentration n in the narrow-gap material:…”

“…The second term takes care for the change of the potential energy of the charge carriers due to mechanical distortions of the lattice appeared at the interface because of the lattice parameters mismatch, and the third term stands for the change in the potential energy of the carriers due to the local redistribution of the electron density in the vicinity of the mechanically stressed heterointerface [4 and Ref. The numerical procedure (see for details [4][5] The numerical simulation of the experimental data performed taking into account the contribution of the electron-deformation effects in the electric characteristics of the investigated The numerical procedure (see for details [4][5] The numerical simulation of the experimental data performed taking into account the contribution of the electron-deformation effects in the electric characteristics of the investigated…”

“…Due to the sufficient lattice mismatch of the components we should take into consideration the in-plane lattice constant of the structure a || depending on the elastic properties (see Tables 1, 2): As we consider the case of the thin PbS epitaxial overlayer on the thick (up to 3 mm) monocrystalline substrate ZnSe (ZnTe), this fixes a || = 5.65 Å for PbS/ZnSe and a || = 6.08 Å for PbS/ZnTe structures. So, the epitaxial lead sulfide film is under the tensile (compress) stress and the experimental electric field-induced characteristics of our superlattices should be treated with accounting the electron-deformation phenomenon contributed in the energy spectrum of the structure [4][5]. Thus, the values of the strain are -0.049 and +0.023 for the lead sulfide film in the PbS/ZnSe and PbS/ZnTe structures, respectively.…”